WO2014163659A1 - Energy collection technique - Google Patents

Abstract

In one embodiment, a system provides energy from an oscillating-voltage, power generation subsystem to an energy collection subsystem. The system includes a DC-DC conversion subsystem connected between the oscillating-voltage, power generation subsystem and the energy collection subsystem. The energy collection subsystem has an energy-collection acceptance voltage. The oscillating-voltage, power generation subsystem is configured to generate an oscillating-voltage output having low-voltage portions lower than the acceptance voltage and high- voltage portions higher than the acceptance voltage. The DC-DC conversion subsystem is configured to raise at least some low-voltage portions in the oscillating-voltage output to a voltage at least as high as the acceptance voltage, thereby allowing the energy collection subsystem to collect energy from the at least some low-voltage portions in the oscillating-voltage output.

Description

ENERGY COLLECTION TECHNIQUE

Cross-Reference to Related Applications

[ 0001 ] This application claims the benefit of the filing dates of U.S. provisional application no. 61/808,274, filed on 04/04/13 as attorney docket no. LWTN-1003USP; U.S. provisional application no. 61/828,759, filed on 05/30/13 as attorney docket no. LWTN- 1003USP2; and U.S. provisional application no. 61/847,702, filed on 07/18/13 as attorney docket no. SEAS-1003USP3, the teachings of all of which are incorporated herein by reference in their entirety.

BACKGROUND

[ 0002 ] The present disclosure relates generally to electronics and, more particularly but not necessarily exclusively, to electronic systems for harvesting potential energy from power sources.

[ 0003 ] Many power sources are capable of producing potential energy at a voltage that is below the acceptance voltage of a power collection system, such as a power grid or a power storage system such as a battery. That lower-than-acceptance-voltage potential energy is untapped. For example, rectified alternator output to charge a battery is known in the art. In such systems, when the peak-to-peak AC voltage from the alternator is rectified to DC using a full-wave bridge rectifier, a DC voltage is generated. When this DC voltage exceeds the battery acceptance voltage, current flows from the rectifier to the battery, thereby charging the battery. When the DC voltage generated through the rectifier is below the battery acceptance voltage, there is no current and the battery is not charged.

[ 0004 ] In a particular example of a wind-driven alternator, conventional battery-charging systems are not able to capture potential energy for charging the battery during low wind or moderate wind conditions. For example, a conventional wind-driven alternator in low wind conditions generates low voltage AC, which is rectified to low voltage DC. However, when the DC voltage is less than the battery acceptance voltage, no current flows from the alternator to the battery. The energy remains untapped potential energy, and the wind-driven alternator simply pin- wheels. [ 0005 ] Even in mid-wind conditions, some energy potential is not harvested by the energy collection system. In mid-wind conditions, the AC voltage is higher and the rectified AC-to-DC voltage is higher, but the DC voltage has significant ripple. Some of the rippled DC voltage is higher than the battery acceptance voltage at the peaks in the voltage ripple. During such periods, current flows to the battery, and therefore the potential energy is harvested as useful stored energy. However, when the valleys of the rippled DC voltage are below the acceptance voltage of a battery storage system, no current flows from the alternator to the battery, and the energy remains untapped potential energy.

[ 0006 ] When the potential energy of a wind-driven alternator is untapped, the blades of the wind-generator pinwheel or rotate at a fast enough speed that noise is created. The tips of the blades are moving quickly enough during the rotation to generate such noise. This may happen less in low-wind conditions, but, in mid-wind conditions, the noise is more noticeable.

[ 0007 ] The acceptance voltage of an energy storage or usage system, such as a battery bank or a power grid, may vary over time. For example, as a battery is charged, the voltage increases, and therefore the battery acceptance voltage increases. Or, for example, during peak power periods, a power grid may experience low voltage or brownouts. During such periods, the grid acceptance voltage is lower. A lower grid acceptance voltage makes it easier for low-voltage energy collection systems to release the potential energy into the grid. But a higher battery acceptance voltage makes it more difficult for low- voltage energy collection systems to provide the potential energy into the battery.

[ 0008 ] It is within the nature of conventional designs that some power generating systems generate AC output or rippled DC output, which is an oscillating output. Many magneto- electric systems such as alternators, oscillating linear generators, induction generators, and the like are examples. The driving forces (such as wind, waves, engines, etc.) that drive these AC output or rippled DC output power generator systems, may have their own inherent oscillations, but the AC output or rippled DC output power generating systems impose a designed-in oscillation that creates the AC output or the DC voltage output. And some of this designed-in oscillation voltage output potential is too low to be captured by power collection systems that have a higher acceptance voltage. [ 0009 ] "Improving Alternator Efficiency Measurably Reduces Energy Costs" by Mike Bradfield (Remy Inc., 2008), the teachings of which are incorporated herein by reference, describes the efficiency losses associated with alternators. As indicated by Figure 23 of that report, all losses in an alternator are a function of alternator RPM. The higher the RPM, the greater the losses.

[ 0010 ] FIG. 1 shows an example prior-art battery-charging system 100 implemented with a driven alternator 120, a full-bridge diode rectifier 130, and a battery 160.

[ 0011 ] FIG. 2 graphically shows signals associated with the conventional battery- charging system 100 of FIG. 1. In FIG. 2, the X-axis represents time (sec), and the Y-axis represents voltage or amperage. The dotted curve at the top of FIG. 2 is a representation of the DC voltage of the battery 160 as measured between connections DC+ and DC-. The oscillating curve represents a single AC phase, for example, LI relative to battery ground DC-, peak-to-peak voltage (multiplied by two). When the AC voltage is multiplied by two, it approximates the amplitude of the rectified AC or DC voltage that charges a battery.

[ 0012 ] As the alternator 120 begins rotation, the frequency and amplitude of the AC voltage increases. Once the rectified AC voltage exceeds the battery's acceptance voltage (which, in this example, is the sum of (i) -13.5 V DC and (ii) the rectifier's diode drop of approximately 0.6 V), rectified DC current (A Total), shown as the dark curve at the center of FIG. 2, is transferred to the battery 160. The amperage measurements were made using a Hantek CC-65 AC/DC Current Clamp (QuingDao, China) with ImV / 10mA sensitivity and connected to a Fluke 190 oscilloscope. When the rectifier AC voltage is lower than the battery 160 voltage, no energy is extracted from the alternator 120. When the rectified AC voltage exceeds the sum of the rectifier 130 diode drop voltage and the battery 160

acceptance voltage, power is extracted from the alternator 120. See, e.g., "Owner's Manual Freedom Combi^™ Inverter/Chargers (Heart Interface Corporation, 1997), the teachings of which are incorporated herein by reference in their entirety.

[ 0013 ] Therefore, during acceleration of the wind-driven alternator 120 and at wind speeds that drive the alternator 120 to produce rectified AC voltages below the battery 160 acceptance voltage, the alternator 120 turns but produces no useful power. Furthermore, during low-wind conditions, the wind generator turns but produces no energy. For example, in low-wind anchorages, or protected anchorages, on a marine vessel, the wind generator turns but produces no energy. The energy is available but it is untapped potential power.

SUMMARY

[ 0014 ] This disclosure teaches means and apparatus to harvest the hitherto untapped potential energy from AC and rippled DC oscillating- voltage, power generator systems. When the rectified AC or rippled DC voltage, generated by such systems, is lower than the acceptance voltage of a power collection or storage system, a DC-DC converter is used to boost that voltage to at least the acceptance voltage of the power collection system. As such, when the valleys of rectified AC or rippled DC voltage are below the acceptance voltage, that valley voltage is boosted to above the acceptance voltage allowing harvesting of the valley energy. Likewise, when the entire rectified AC or rippled DC voltage is below the acceptance voltage of a power collection or storage system, more of that voltage is boosted to above the acceptance voltage allowing harvest of that previously untapped potential energy.

[ 0015 ] Certain embodiments of this disclosure yield many advantages in terms of efficiency, reduced mechanical wear, lower weight, lower noise, and lower fuel usage. For example, when a wind-driven alternator generates rectified AC voltage that is low or has portions of DC ripple voltage that are low, the boosting by a DC-DC converter to a voltage that is above the power collection acceptance voltage, and therefore the work of harvesting that potential energy, slows down the wind-driven alternator such that it has silent operation. More power is harvested from the alternator at low- and mid-wind speeds, even though the alternator rotates more slowly. The ability to collect more power from a wind-driven alternator at slower rotation, not only makes the wind-driven alternator operation quieter, it reduces all the efficiency losses that arise as a result of increased RPM operation of the alternator as well as blade-related RPM losses.

[ 0016 ] This disclosure teaches means to collect more energy from an engine-driven alternator at lower RPM as well. The rectified AC voltage, produced from an idling engine- driven alternator, is boosted by a DC-DC converter to a higher voltage, which is at least above the acceptance voltage of an energy collection system, such as a battery or a power grid, and therefore more potential energy is harvested. Even at mid-RPM, engine-driven alternator potential energy can be harvested. When the rectified AC of an alternator is producing rippled DC voltage having peaks below the energy collection acceptance voltage, the valley voltage is boosted by a DC-DC converter to a voltage that is at least as high as the energy collection acceptance voltage, thereby harvesting the low voltage valley potential energy from a rippled DC voltage source.

[ 0017 ] Often, the potential energy from an engine-driven alternator during high RPM operation is wasted or regulated because the energy-collection system cannot absorb or use the excess energy. Certain embodiments of this disclosure allow harvesting of potential energy from an engine-driven alternator at lower RPMs. As such, the rotation speeds of the alternator at engine idle can be reduced and, for example, the pulley drive ratios that cause the alternator to rotate at speeds greater than engine RPM can be reduced. Such reduction in pulley drive ratio reduces the rotation speed of the alternator at high engine speeds. The lower RPM operation of the alternator reduces the RPM-related efficiency losses. It allows the alternator manufacturer to design an alternator for efficiency rather than rotation-proof strength. At high engine RPM operation, an engine-driven alternator, driven with a lower engine-to-alternator pulley ratio, has less potential energy waste and less regulation. The alternator potential energy is distributed more uniformly over the RPM range of operation. More potential energy is collected when the engine is at idle, and less potential energy is wasted at higher engine RPM.

[ 0018 ] Some engine-driven alternator systems require that the engine be operated at a relatively high speed that allows the alternator to generate enough current to charge, for example, a battery bank quickly. Certain embodiments of this disclosure cause the alternator to produce more current at lower engine RPM, thereby saving fuel and reducing engine wear, alternator wear, and engine noise.

[ 0019 ] Therefore this disclosure details an energy collection technique comprising an energy drive system that drives an energy generation system, said energy generation system having a rectified AC or rippled DC oscillating-voltage potential output, and an energy collection system having an acceptance voltage, wherein said oscillating-voltage is lower than said acceptance voltage, and a DC-DC converter is adapted to raise said rectified AC or rippled DC voltage to a voltage that is at least as high as said acceptance voltage, thereby harvesting at least some of said potential output. [ 0020 ] Said energy drive system may be blades adapted to convert fluid energy such as wind or water energy to rotational energy. Alternatively, said energy drive system may be waves adapted to raise and lower a lever or other device to convert wave energy to linear motion. Furthermore, said energy drive system may be an engine or regenerative braking system adapted to produce rotational energy.

[ 0021 ] Said generation systems may be generators, alternators, or linear generators adapted to generate AC voltages that can be rectified to rectified AC or rippled DC voltage oscillating-voltage output. Said AC voltage may be rectified using a diode bridge adapted to convert said AC to DC voltage. Said AC voltage may be rectified using an active rectifier system comprising gate-driven FETs wherein said FETs are selectively gated to convert AC to rectified AC or DC voltage. Said AC voltage may be rectified using selectively gate-driven FETs that route positive portions of the AC cycle to one portion of a circuit and negative portions of the AC cycle to another portion of a circuit. Said rectified AC voltage or rippled DC voltage may be completely below said acceptance voltage. Alternatively, said rectified AC voltage or rippled DC voltage may comprise valley portions of voltage that are below said acceptance voltage. Said AC voltage may be DC biased to a predominately rippled DC voltage. As such, the energy output can be fed directly to a DC-DC converter without the need for a rectifier. Said AC voltage may be DC biased to a high oscillating-voltage level which the DC-DC converter buck converts, or lowers, to a voltage at least as high as the acceptance voltage.

[ 0022 ] Said energy collection systems may be power grid systems, battery systems, or other potential energy storage systems, such as water pumped to a height or energy stored in a flywheel, or any combination of said systems. Such energy collection systems have an acceptance voltage wherein energy with voltages generated from said generation systems that are higher than said acceptance voltage, can be collected, and wherein energy from said generation systems having voltages that are lower than said acceptance voltage remains as unused and uncollected potential energy.

[ 0023 ] Said DC-DC converter systems may be adapted to convert a selectively routed AC positive portion of the cycle, a selectively routed AC negative portion of the cycle, or rippled DC oscillating-voltage energy generated from said energy generation systems to an energy having a voltage that is at least as high as said acceptance voltage of said energy collection system. Said DC-DC converter may convert all the energy from said energy generation system to an energy having a voltage at least as high as said acceptance voltage, or said DC- DC converter may convert only a portion of said energy to energy with a voltage that is at least as high as said acceptance voltage.

[ 0024 ] Some DC-DC converters may convert the positive portion of an AC cycle to a voltage at least as high as said acceptance voltage. Some DC-DC converters may convert the negative portion of an AC cycle to a positive voltage that is at least as high as said acceptance voltage. In such cases, the DC-DC converters act as a part of the rectification system to produce rectified AC that is at least as high as the energy collection system acceptance voltage.

[ 0025 ] Said energy generation system may have internal rectification and as such only supply rippled DC oscillating-voltage energy. When all or a portion of said rippled DC oscillating-voltage energy has a voltage that is lower than said energy collection acceptance voltage, said DC-DC converter raises at least some portions of said lower voltage rippled DC oscillating-voltage potential energy to a voltage that is at least as high as said acceptance voltage thereby collecting said potential energy.

[ 0026 ] Furthermore this disclosure discloses an energy collection technique comprising a driven alternator system having a rectified AC or rippled DC oscillating-voltage energy output, and a energy collection system having an acceptance voltage, wherein at least a portion of said energy is potential energy having a voltage below said acceptance voltage and wherein said low voltage potential energy is converted to an energy with a voltage at least as high as said acceptance voltage using a DC-DC converter, thereby allowing collection of said potential energy. Said driven alternator system may be a wind-driven alternator system using rotating blades, having a rotation speed and having a noise, wherein collection of said potential energy slows the rotation speed of said blades and reduces the noise. Said driven alternator system may be an engine-driven alternator system having an engine rotational speed, said engine rotation speed is transmitted to said alternator by means of a belt-and- pulley ratio thereby imparting a rotation speed to said alternator, and wherein said potential energy is collected at lower engine speeds, and/or wherein said potential energy is collected using a lower pulley ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[ 0027 ] Embodiments of the present disclosure are illustrated by way of example and are not limited by the accompanying figures, in which like references indicate similar elements.

[ 0028 ] FIG. 1 shows a block diagram of a prior-art battery-charging system;

[ 0029 ] FIG. 2 graphically shows signals associated with the conventional battery- charging system of FIG. 1 ;

[ 0030 ] FIG. 3 shows a block diagram of a battery-charging system according to an exemplary embodiment of the disclosure;

[ 0031 ] FIGs. 4(a)-4(c) graphically show signals associated with the exemplary battery- charging system of FIG. 3;

[ 0032 ] FIGs. 5 and 6 show block diagrams of battery-charging systems according to other exemplary embodiments of the disclosure;

[ 0033 ] FIG. 7 presents data associated with the prior art output of a Delco Remy lOsi alternator;

[ 0034 ] FIGs. 8(a)-8(h) graphically show signals associated with the exemplary battery- charging system of FIG. 6;

[ 0035 ] FIGs. 9 and 10 show block diagrams of battery-charging systems according to yet other exemplary embodiments of the disclosure;

[ 0036 ] FIG. 10(a) shows a block diagram of one possible implementation of the battery- charging system of FIG. 10, in which the rectifier is internal to the alternator;

[ 0037 ] FIGs. 1 l(a)-l 1(d) graphically show signals associated with the exemplary battery- charging system of FIG. 10;

[ 0038 ] FIG. 12 shows a block diagram of a battery-charging system according to yet another exemplary embodiment of the disclosure; [ 0039 ] FIGs. 13(a) and 13(b) graphically show signals associated with the exemplary battery-charging system of FIG. 12; and

[ 0040 ] FIGs. 14-17 show block diagrams of battery-charging systems according to yet other exemplary embodiments of the disclosure.

DETAILED DESCRIPTION

[ 0041 ] Detailed illustrative embodiments of the present disclosure are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments of the present disclosure. Embodiments of the present disclosure may be embodied in many alternative forms and should not be construed as limited to only the embodiments set forth herein. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the disclosure.

[ 0042 ] As used herein, the singular forms "a," "an," and "the," are intended to include the plural forms as well, unless the context clearly indicates otherwise. It further will be understood that the terms "comprises," "comprising," "has," "having," "includes," and/or "including" specify the presence of stated features, steps, or components, but do not preclude the presence or addition of one or more other features, steps, or components. It also should be noted that, in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

[ 0043 ] FIG. 3 shows a block diagram of a battery-charging system 300 according to an exemplary embodiment of the disclosure. In the figure, an alternator 320 has a three-phase AC output consisting of phased signals (aka phases) LI, L2, and L3, wherein the phases are spaced approximately 120 apart. The three phases LI, L2, and L3 are connected to a first full- bridge three-phase rectifier 330 at its AC terminals. The three phases LI, L2, and L3 are also connected to a second full-bridge three-phase rectifier 340 at its AC terminals.

[ 0044 ] The positive DC terminal of the first rectifier 330 is connected by connection (e.g., wire) R1DC+ to a fuse Fl, and then through fuse Fl to the positive DC terminal of battery 360 by connection DC+. The fuse Fl is optional. The negative DC terminal of the first rectifier 330 is connected to the negative terminal of battery 360 by connection DC-. The positive DC terminal of the second rectifier 340 is connected to the positive input terminal +In of DC-DC converter 350 by connection R2DC+. The negative DC terminal of the second rectifier 340 is connected to the negative input terminal -In of DC-DC converter 350 by connection RDC-. Optionally, a capacitor CI is connected between the positive and negative DC terminals of the second rectifier 340.

[ 0045 ] As known in the art, a DC-DC converter converts an incoming DC voltage into an outgoing DC voltage, which is usually more regulated and fixed at a desired value. In some implementations, a DC-DC converter is a component that contains a control module and a number of FETs (LTM4607, DC1601, DO 198). In other implementations, the control module and FETs are discrete elements (e.g., an LTC 3789 or LT3791 converter control module) that has a gate-drive output for external power FETs.

[ 0046 ] DC-DC converter 350 has (i) a positive output +Out, which is connected by connection BDC+ to connecting wire R1DC+ and then via fuse Fl to the positive DC terminal of battery 360 by connection DC+, and (ii) a negative output -Out, which is connected by connection BDC- to the negative DC terminal of battery 360. The output voltage of DC-DC converter 350 can optionally be trimmed to tailor the maximum output voltage of the converter 350 using resistor Rl connected between the converter's two trim inputs.

[ 0047 ] Optionally, the converter 350 can be turned off by pulling the converter's On/Off input down to the -Vin voltage level of the negative input terminal -In of the converter 350. For this optional purpose, resistors R2 and R3 are shown forming a voltage divider between connections R2DC+ and RDC-. The divisor node between R2 and R3 is connected to the base of an NPN transistor Tl. The collector of transistor Tl is connected to the On/OFF input of the converter 350. The emitter of transistor Tl is connected to RDC- and therefore to the negative input terminal -In of the converter 350.

Example 1

[ 0048 ] Referring to FIG. 3, in Example 1, the alternator 320 is a Kiss Energy Systems (Tarpon Springs, FL) High Output Wind Generator designed for a nominal 12-volt battery system. The three AC phase outputs LI, L2, and L2 of the wind generator alternator 320 are connected to the three AC terminals of the first rectifier 330 by a #10 three-conductor boat wire. The connection order is arbitrary. The three AC phase outputs LI, L2, and L3 are also jumpered from the three AC terminals of the first rectifier 330 to the three AC terminals of the second rectifier 340 by a #12 three-conductor boat wire or any wire suitably sized for the current and distance involved. The order of connection is arbitrary.

[ 0049 ] The first and second rectifiers 330 and 340 are Delco Remy 5000 full-wave bridge rectifiers (Pendleton, Indiana) or any equivalent 30-amp full-wave bridge diode rectifier usable with alternator 320. Connections DC+, DC-, and R1DC+ are #10 boat wire or any wire size appropriate for the peak current (-30 amps) and distance from the first rectifier 330 and fuse Fl to the battery 360.

[ 0050 ] The battery 360 consists of four Full River DC 224-6 (distributed through Royal Battery Distributors, Inc., Kissimmee, Florida) 6V golf-cart batteries, paired in series for nominal 12V DC and then in parallel for capacity purposes. DC-DC converter 350 is a Cincon CHB75-12S15 DC-DC converter (Mouser Electronics, Mansfield, TX) with the manufacturer-supplied cooling fins. The nominal DC output of the CHB75-12S15 DC-DC converter between the output terminals +Out and -Out is, by design, 15V DC. However, the CHB75-12S15 DC-DC converter can be trimmed down by connecting a resistor Rl between the +Sense pin 8 and Trim pin 7 to provide a reduced constant voltage, though transient voltages may vary. In Example 1, resistor Rl is a 10-kohm resistor, and the trimmed output voltage from the CHB75-12S15 DC-DC converter is 13.8V DC.

[ 0051 ] The CHB75-12S15 DC-DC converter will begin producing a 13.8-volt output between its output terminals +Out and -Out when the converter senses at least 8.8-9 volts between its input terminals +In and -In. Once powered up, the converter 350 will continue producing the boost voltage until the converter 350 senses input voltages less than approximately 8 volts, at which point the output will shut down. The remaining wires BDC+/-, R2DC+, and RDC- are #14 boat wire but can be any size appropriate for the current and the distance between component terminals. [ 0052 ] The addition of the second rectifier 340 and DC-DC converter 350, as depicted in FIG. 3 according to the instant disclosure, allows capture of previously uncaptured potential energy during wind generator acceleration and during low- wind conditions.

[ 0053 ] FIG. 4(a) graphically shows signals associated with the exemplary battery- charging system 300 of FIG. 3. In FIG. 4(a), the X-axis represents time (sec) and the Y-axis represents voltage or amperage. In FIG. 4(a), the oscillating curve is the peak-to-peak AC voltage. As the wind generator accelerates, the alternator 320 produces three-phase AC voltage LI, L2, and L3. The oscillating curve is obtained by using an oscilloscope probe measuring the voltage on a single AC phase, for example, LI, relative to battery ground DC-. The dot-dashed curve depicts the voltage measured between the positive and negative DC terminals of the second rectifier 340. As can be seen in FIG. 4(a), this voltage (V DC-DC In) increases as the AC voltage from the phase LI increases.

[ 0054 ] Once the voltage between the +In and -In terminals of the converter 350 reaches 8.8-9 volts, there is a drop in the voltages of both the alternator phase LI and the voltage measured between the terminals +In and -In of converter 350. This occurs at time -9.6 to -8.8 seconds. At this point, the converter 350 begins generating voltage between output terminals +Out and -Out that is as high as 13.8 volts but actually at a charge acceptance voltage of battery 360, since the battery 360 pulls down the output voltage of the converter 350. The converter output is set for 13.8 V, but the battery voltage is lower. The converter cannot instantaneously charge the battery to 13.8V. Therefore, the actual voltage out of the converter is at the battery charge acceptance voltage. If the battery has a higher voltage than the 13.8V converter setting, the converter would not generate voltage at those higher voltages.

[ 0055 ] The solid-line curve (A Converter) in FIG. 4(a) represents the current measured in connecting line BDC+ using the current clamp. Between times -9.6 to -8.8 seconds, the current clamp probe measured current going to the battery 360 from the converter 350. This current, at battery 360 voltage, is energy extracted from the alternator 320 during wind generator acceleration. This potential energy would not have been collected from the prior-art configuration of FIG. 1.

[ 0056 ] Such potential energy would also be extracted when the wind generator, driving the alternator 320, is rotating at the speeds that occurred during time -9.6 to -8.8 seconds in FIG. 4(a). When the wind generator starts rotating the alternator 320 at faster speeds, the AC voltage in the phases LI, L2, and L3 rectified by the first rectifier 330 reaches the battery 360 acceptance voltage, and power is extracted from that portion of the circuit. During this period, as shown in FIG. 4(a), time -8.8 to -8 seconds, the current generated by the converter 350 in wire BDC+/- falls to zero. This means that, for the Example 1 configuration, the amperage limitations of the converter 350 can be lower than the usual and maximum output from the wind generator. That is, the converter 350 boosts the voltage at low wind speeds when there is low current.

[ 0057 ] At high wind speeds, the first rectifier 330 portion of the circuit extracts the high current energy, eliminating high current operation through the DC-DC converter 350. Further evidence of high wind speed alternator 320 energy being transferred through the first rectifier 330 to the battery 360, and not via the second rectifier 340 and the converter 350 to the battery 360, is that the first rectifier 330 gets very hot, and the second rectifier 340 stays relatively cool.

[ 0058 ] Current generation, by the converter only, is exhibited in FIG. 4(b). In FIG. 4(b), the grey background is the AC voltage oscillation from one phase LI of the alternator 320 (multiplied by 2 to aid understanding). The current (A Converter) from DC-DC converter 350 to the battery 360 measured using a current clamp on connection BDC+ only, is the lower dark line curve. During low-speed wind generator periods (-36 to -29 seconds, -13 to -3.5 seconds, and 2 to 10 seconds), the converter 350 amperage exists, and energy is extracted from the alternator 320. During higher wind generator speed periods (-29 to -13 seconds and - 3.5 to 2 seconds), no current is measured between the converter 350 and the battery 360 through connection BDC+.

[ 0059 ] In FIG. 4(b), the dashed curve in the middle of the Y axis range is the voltage measured between the converter 350 +In and -In terminals. The relatively uniform dotted curve at approximately 13 volts is the battery 360 voltage. As can be seen, the contribution of current from the DC-DC converter 350 at the battery 360 voltage provides a significant boost to energy capture from the wind generator that would not be harvested by the prior art during low- wind conditions. [ 0060 ] In the configuration of FIG. 3 using the trim resistor Rl and optional capacitor CI as described below, the Cincon converter 350 current as measured in line BDC+ rises above zero approximately when the voltage between terminals +In and -In on the converter 350 drops below the battery 360 voltage. The converter 350 current drops back to zero when the voltage between terminals +In and -In on the converter 350 rises above the battery 360 voltage. The Cincon converter 350 has an over-voltage protection trip and a current limit but there is no evidence that either of these circuit limits were reached.

[ 0061 ] Nevertheless, it is possible to optionally utilize the Positive Logic Remote On/Off feature of the Cincon converter 350 to start and stop the operation of the converter 350 as required. For example, if the On/Off terminal is pulled down below 0.8 V with reference to the -In terminal of the converter 350, then the Cincon converter 350 will turn off and no longer boost or buck the voltage out. Such a signal could be designed using, for example, a resistive voltage divider between terminals +In and -In with an NPN transistor Tl having the base connected to the divider node of resistors R2 and R3, the On/Off terminal connected to the collector, and the emitter connected to terminal -In. For example, during low wind drive power periods, the converter 350 might extract too much energy from the wind driven alternator 320 and slow it or stop the blade rotation. Under such conditions, the voltage between R2DC+ and RDC- would be low, causing the converter 350 to turn off, thereby reducing the energy extraction during low drive power periods.

[ 0062 ] The resistors in the divider circuit would be selected to actuate the base of the transistor, thereby pulling down or disconnecting the On/Off terminal of the converter 350. Alternatively, a logic signal or simple switch between the On/Off and -In terminals on the converter 350 could be used to switch the converter 350 on or off.

[ 0063 ] Although the instant Example 1 employs a wind generator, other mechanical-to- electrical generation devices can be used wherein the device generates a rectified AC or rippled DC voltage that is or contains periods of voltage lower than a battery acceptance voltage or grid voltage. For example, a car alternator or water generator could be the generation device, or any of the other known generators such as a dynamo, induction generator, oscillating linear generator, etc. Furthermore, instead of using a diode-based rectifier, rectifier 330 and/or rectifier 340 may be implemented using an active rectifier system providing greater efficiency. Such driven generation systems may generate low voltage DC, for which an AC rectifier is not needed. Such systems may generate at least one AC phase or a plurality of AC phases and may require rectification of those phase(s). A DC- DC converter 350 may be adapted to efficiently handle all the power from a given energy source. As such, the rectifier 330 and its associated connection wiring may be eliminated.

[ 0064 ] During operation of the wind generator, having all of the circuit features detailed in FIG. 3 except for the capacitor CI and the On/Off electronics, significant humming of the wind generator during the acceleration and low-speed operation periods could be heard and felt. The addition of a capacitor CI substantially reduced the humming. The capacitor CI used in testing was 3300μΡ, but, according to the vendor data, as high as 4000μΡ capacitance CI can be employed to further reduce the humming. Although a polarized capacitor CI is depicted in FIG. 3, any capacitor CI having adequate capacitance and voltage rating may be used.

[ 0065 ] FIG. 4(c) shows the total current going to the battery 360 during low-wind periods and during a wind gust. The grey region represents the AC oscillating voltage in one phase (LI, L2, or L3) relative to battery negative. The relatively uniform dotted curve near the top at -13.8V represents the battery 360 voltage. The middle dash-dot curve represents the +In to -In voltage between the second rectifier 340 and the Cincon converter 350. The bottom curve with the peaks in the middle portion of the graph is the measured current in line DC+ feeding the battery 360.

[ 0066 ] From -37 seconds to -36 seconds, the rectified peak-to-peak AC phase voltage is below the battery 360 voltage and is also below the converter 350 low- voltage limit of 8.8 volts. Therefore, no current is generated by the wind generator system. From -36 to -27 seconds, the second rectifier 340, fed by the slowly spinning wind generator alternator 320, sporadically produces voltage that exceeds the 8.8 voltage limit of the converter 350, which in turn boosts the voltage across terminals +Out to -Out to a value above the battery 360 voltage and produces a current. The current peaks are relatively large which may be a result of initially uncontrolled converter 350 output in addition to, for example, suddenly released inductor surge voltage from the alternator 320. As such, turning off the converter 350 sporadically provides an inductance voltage boost from the AC side of the circuit and further enhances energy harvesting performance. [ 0067 ] In Figure 4(c), from approximately -27 seconds to -12 seconds, a gust of wind occurred. During this period, when the rectified peak-to-peak AC voltage exceeded the battery 360 voltage, the current is substantially generated via the first rectifier 330 to the battery 360. (In FIG. 4(b), during a similar period of -29 to -13 seconds, when the rectified peak-to-peak AC voltage exceeded the battery voltage, the converter 350 produced no current.)

[ 0068 ] In FIG. 4(c), during the periods of -12 seconds to -8 seconds and -5 to -3 seconds, the rectified peak-to-peak AC voltage is generally below the battery 360 voltage but still above the converter 350 8V shut-down limit. As such, no current will pass through the first rectifier 330, and all current is generated via the second rectifier 340 and the converter 350 leading to the battery 360.

[ 0069 ] Further improvements are made when a DC-DC converter 350 is adapted to convert a lower voltage input (+In to -In) for an equivalent voltage output (+Out to -Out) that is above a battery or grid-acceptance voltage. For example, a Linear Technology DC-DC converter 350 LTM® 4607EV Buck-Boost Power Supply (Milpitas, California, USA) is capable of handling down to 4.5V DC, +In to -In, while producing a useful +Out to -Out voltage. As such, when the LTM® 4607 converter 350 is substituted for the Cincon CHB75- 12S15 DC-DC converter 350, extracting useful energy from an alternator 320 producing 4.5V or greater rectified AC peak-to-peak is achieved. Current can be extracted from the wind generator alternator 320 starting at rectified 4.5V DC and above rather than at 8.8V DC and above. Thus, use of the 4607 converter 350 allows energy harvest in, for example, periods from -37 seconds to -36 seconds in FIG. 4(c) when the +In to -In voltage is above 4.5V but below the 8.8V DC that the Cincon converter 350 was designed to capture.

[ 0070 ] Use of paralleled DC-DC converters 350 brings the possibility of extracting higher amperage output from the alternator. Such paralleled DC-DC converters 350 can be combined using a Linear Technology LTM®1601(B-A) converter for 10-amp boost capacity, an LTM®1601(B-B) converter for 15-amp boost capacity, or an LTM®1601(B-C) converter for 20-amp boost capacity. Furthermore, the 4607 converter 350 can be adapted to provide a "soft-start" which would reduce or eliminate the need for capacitor CI and would further reduce or eliminate noise generated during converter 350 energy harvest periods. [ 0071 ] Indeed the use of paralleled DC-DC converters, or a converter control module coupled with external high-power FETs, allows all the power to be harvested solely through the converter 350 and converter-related circuitry. For example, a converter control module such as a LTC3791 can be adapted for use with higher power capacity FETs, such as for example a BUK7905-40AIE for power output.

[ 0072 ] FIG. 5 shows a block diagram of a battery-charging system 500 according to another exemplary embodiment of the disclosure. In FIG. 5, a single full-bridge rectifier 540 rectifies all the harvested power from the alternator 520. From there, DC-DC converter 550 or a DC-DC control module with related circuitry is used to charge a battery 560. All the components described in FIG. 3 are the same, except that first rectifier 330 and wire R1DC+ have been eliminated. DC-DC converter 550 may be a paralleled converter to handle the low and the high power from the alternator 520 or it can be a DC-DC converter control module with high-powered FETs to handle the alternator 520 harvested energy.

[ 0073 ] FIG. 6 shows a block diagram of a battery-charging system 600 according to yet another exemplary embodiment of the disclosure. FIG. 6 shows a depiction of a test apparatus adapted to harvest more energy from a car alternator. The alternator 620 is a remanufactured Delco Remy lOSi alternator (available from Pep Boys, U.S., as P/N 7127109), which has 14 poles and a Generator Factor (GF) of 8.57, according to Delco, and a nominal 12-volt and 63- amp output. The shaft pulley and fan were removed from the alternator 620. As such, the alternator RPM can be calculated to be 8.57 times the frequency of a single output phase LI, L2, or L3. The alternator 620 was bolted, shaft pointing up, to the bottom side of the drill- press 610 platen (not shown).

[ 0074 ] The alternator 620 is direct driven via an ~79-mm (5/16-inch) hex shaft 615 clinched by a drill-press 610 chuck (not shown). The drill-press 610 is driven by a ¾-hp, 60- cycle, 115-Vac, 1750-RPM, Craftsman capacitor motor (not shown). The motor has a 4-step- size pulley (not shown) attached to its shaft. In the Example 2 test described below, the next- to-smallest pulley on the motor, which is -6.4 cm (2.5 inches) in diameter, is connected by a drive belt (not shown) to the next-to-largest size pulley on the drill chuck, which is -8.9 cm (3.5 inches). As such the drill-press 610 motor would be expected to turn -1.4 times faster than the alternator 620. If the drill-press 610 motor actually ran at 1750 RPM, it would be expected that the alternator 620 would be driven at -1250 RPM. According to actual measurements of alternator 620 AC output, described below, the actual rotation speed of the alternator 620 in steady state varies in the range of -1200 to -1400 RPM. This is described as medium speed operation of the alternator 620.

[ 0075 ] The alternator 620 comes with a full bridge rectifier (not shown), which is not used in these examples. The alternator 620 also comes with a trio (not shown), which may contribute operating current to the field coil (not shown) of the alternator 620 when the alternator 620 is generating sufficient power to the trio. However, battery 660 voltage and current were supplied to the alternator 620 regulator (not shown) and ignition connection (not shown) on the alternator 620 during the testing. As such, the battery 660 was used to power the field coil of the alternator 620 during the tests and was used to provide a sense voltage to the regulator. The regulator turned the field current, whether supplied by the trio or the battery 660, on or off as required to limit the charging voltage to the battery 660.

[ 0076 ] The three AC output phases LI, L2, and L3 of the alternator 620 were connected using #12 gauge stove wire (Tempco P/N LDWR-1023, available from Grainger, USA) to a first full-bridge rectifier 630 and a second full-bridge rectifier 640, via a screw terminal strip (not shown), at the AC legs of the rectifiers. The rectifiers 630 and 640 are manufactured by IXYS and have the P/N FUS 45-0045B (Mouser Electronics, USA). The rectifiers 630 and 640 were mounted to a heat sink (not shown, Crydom 558-HS351, Mouser, USA) such that the pins were pointed toward each other, and the AC pins 3, 4, and 5 were soldered together and to the AC alternator 620 phases LI, L2, and L3.

[ 0077 ] The ground pins of the rectifiers 630 and 640 were soldered and connected together via jumper connection JP-. These ground pins of the rectifiers 630 and 640 were then connected (i) to the negative terminal of the battery 660 via wire DC- and (ii) to the -In terminal of DC-DC converter 650 via connection RDC-. The positive pin of the first rectifier 630 was connected to the positive terminal of the battery 660 via wire R1DC+ and via connection DC+. The positive pin of the second rectifier 640 was connected to the +In terminal of DC-DC converter 650 via wire R2DC+. Alternatively, power-FET-based, active, full-bridge rectifiers may be substituted for even lower resistance and forward voltage.

[ 0078 ] DC-DC converter 650 is a DC1601B-A converter (Linear Technology, Milpitas, CA) capable of handling an average of 10 amps of current in boost mode. The converter 650 was adapted for use as follows. Resistor R22 on the bottom side of the converter 650 board was removed and replaced with variable potentiometer RV22, which is a 15-turn, lOkohm variable potentiometer (271-343 Radio Shack, USA) connected as a variable resistor. This allows adjustment of the converter 650 to a desired range of output voltage or, in the case of these examples, to 13.7V dc.

[ 0079 ] Heat sinks (not shown) were adhered to the surface of the LTM4607V converter 650 modules (not shown). The heat sinks were P/N 375424B00034G manufactured by Aavid Thermalloy (Digikey, USA).

[ 0080 ] Optionally, a wire was connected to the COMP connection to the LTM4607V converter 650 on the chip Ul side of capacitor C3 (refer to schematic diagram, rev. 1, sheet 1 of 3, on page 9 of Demo Manual DC 160 IB for LTM4607EV High Efficiency PolyPhase Buck-Boost Power Supply (Copyrighted 2004 and 2012, Linear Technology Corporation, Milpitas, California, the teachings of which are incorporated herein by reference in their entirety.). This wire was connected to the divider node of resistors RCl (1M ohm, Radio Shack, USA) and RVC1 (Bourns Trimmer Resistor P/N RJR24FP104R 15-turn, lOOkohm potentiometer connected as a variable resistor, Mouser, USA). The other pin of variable resistor RVC1 was soldered to the converter 650 ground connector. The other pin of resistor RCl was connected to wire R1DC+.

[ 0081 ] Modification of the COMP voltage on the converter 650 leads to modified control of the output current from the converter 650. The magnitude of the resistance of resistor RCl controls the sensitivity of the converter 650 current as a function of battery 660 voltage. The larger the resistance of RCl, the less the controlled sensitivity to the battery 660 voltage. The magnitude of the resistance of variable resistor RVC1 controls the converter 650 current as a function of the battery 660 voltage and the internal circuitry of the converter 650 chips designed by the manufacturer.

[ 0082 ] If variable resistor RVC1 is set to a low value, then the maximum current generated by the converter 650 will be lower even though the In voltage to the converter 650 is high. The current generated by the converter 650 will also be much lower when the In voltage to the converter 650 is low. In such a case, for example, the converter 650 current generation onset voltage may rise from, for example, 4.5V to 6V, and the maximum current may drop from 10 amps to 5 amps. Such control of the COMP voltage is important to limit the output current of the converter 650 to its average current rate limit, as will be seen in the following examples. Also, such control of the COMP voltage is very important to limit the energy draw from, for example, a wind generator alternator 620.

[ 0083 ] If the energy draw from a wind generator, operating in light winds, is too severe, then the wind generator will be stalled and will not even begin rotation. Lowering the resistance of RVC1 reduces the energy draw from a wind generator in low winds, while still allowing higher energy harvesting in higher winds. It is recognized that wind energy potential usually varies as the cube of wind speed. Therefore, rather than a relatively linear RVC1 voltage control of the COMP voltage, the COMP voltage control can be improved upon by utilizing a non-linear voltage control. This would better tailor the energy draw of the converter 650 to the output capability of a wind generator. Such non-linear control is accomplished using an op- amp circuit in place of resistor RVC1.

[ 0084 ] Modification of the COMP pin is optional and may be unnecessary in situations where the drive power of the alternator 620 is unaffected by the alternator load, for example, in a car where the horsepower of the engine is large compared to the horsepower demand of the alternator 620. In such cases, the RVC1 and RC1 divider circuit is not used.

[ 0085 ] In the examples that follow, an initial COMP voltage was calibrated to a value using the following procedure. The adjustment was made with all components connected as shown in FIG. 6. The alternator 620 was not being driven by the drill-press 610. A DC power supply (not shown) was connected to the battery with a 10-amp rectifier diode (Radio Shack, USA) between the power supply and the positive terminal of the battery 660. The DC power supply was adjusted to provide a steady 13V charge as measured at the battery 660. The variable resistor RVC1 was adjusted to provide a voltage between the COMP connection at the divider node and the negative terminal on the battery 660. Such voltages are described as, for example, a COMP 0.6V or, for example, a COMP 0.2V setting.

[ 0086 ] The -Out terminal of DC-DC converter 650 is connected to the battery 660 negative terminal. The +Out terminal of DC-DC converter 650 is first connected to output rectifier diode RD1, and then connected to connection R1DC+, where, via wire DC+, it connects to the positive terminal of the battery 660. The output rectifier diode RD1 may be optional for some converters but is preferred for use with the DC1601B-A converter 650 when used in circuits of the instant examples. The output rectifier diode RD1 is a

SBR1045SD1 (Diodes Incorporated available from Mouser, USA), and is preferred due to low forward voltage. Though more complex, a power FET circuit may be substituted to allow even lower resistance and forward voltage, while preventing or reducing reverse current back to the converter 650.

[ 0087 ] The battery 660 is a used and weak Deka model #5UL1 12V battery (Tri-State Batteries, DE). Although the battery 660 can hold a charge for a day, it has low capacity. As such, it provides a useful test battery 660 for the examples to follow.

[ 0088 ] FIG. 7 presents the prior art (Electrical-Specifications— Selection-Guide.pdf, Delco Remy, metadata revision date 5/2/2008, pg. 16/146) output of a Delco Remy lOsi alternator, which is equivalent to the remanufactured 63 -amp-rated alternator 620 used in the instant test apparatus. It should be noted that there is essentially no amperage output below 900 RPM in FIG. 7. The Delco Remy testing is depicted as being performed at 12 volts. Although the testing to follow was performed using a battery 660 with an ~12-volt starting voltage, the voltage in the battery 660 rose as charging by the apparatus of FIG. 6 allowed. As such, any amperage measurements made using the test apparatus of FIG. 6 would be expected to be less than or equal to the amperage readings in the FIG. 7 chart and table published by Delco Remy.

Example 2

[ 0089 ] In Example 2, the apparatus of FIG. 6 was used to collect measurements of voltage and current. A Fluke 4-channel oscilloscope was used to collect and store the data. The battery 660 voltage was measured with one oscilloscope probe. The alternator 620 AC phase LI, L2, or L3 was measured with a second oscilloscope probe. A Hantek current clamp was used to measure the current from the first rectifier 630 in wire R1DC+ just after the first rectifier 630. In addition, the Hantek current clamp was used to measure (i) the current from the DC-DC converter 650 terminal +Out in wire BDC+ and (ii) the total current in wire DC+.

[ 0090 ] During each test cycle, in order to make the measurements, the battery 660 was first charged to approximately 13 volts using a DC power supply (not shown). Then the DC power supply was turned down to 12.1 volts. With the rectifier diode between the DC power supply and the remainder of the apparatus, the DC power supply no longer affected any readings. Next, the regulator sense and field coil connections of the alternator 620 were connected to the battery 660. The voltage of the battery 660 was monitored using a Fluke 289 multimeter.

[ 0091 ] When the current to the field coil (3-5 amp draw) drained the battery voltage down to just above 12V, (i) the oscilloscope was set to begin recording; (ii) the drill-press 610 was turned on for several seconds, then turned off; and finally (iii) the oscilloscope recording was stopped. Different test cycles were used to measure the readings for the converter 650 and the first rectifier 630 current. In these test cycles, only (i) the current clamp location was changed and (ii) the turn-on to turn-off times were varied.

[ 0092 ] In Example 2, the COMP voltage was set to 0.6V using the procedure described above. The pulleys on the drill-press 610 were set such that the drill-press 610 motor would rotate 1.4 times the RPM of the alternator 620. As such, the expected rotation speed of the alternator would be around 1250 RPM or medium speed.

[ 0093 ] FIG. 8(a) shows the results of oscilloscope measurements when the current clamp was measuring the first rectifier 630 current in Example 2. The upper "dotted" line is the battery voltage. The grey region is the measured AC phase voltage. The dark grey line that starts at zero and increases to nearly 15 is the amperage coming from the first rectifier 630. The turn-off time of the drill-press 610 can be identified as the point where the battery 660 voltage begins to drop after being charged by the alternator 620. This is also the time, around 1.3 seconds, when the amperage drops sharply.

[ 0094 ] FIG. 8(b) shows another view of the same data collection cycle as that of FIG. 8(a). In FIG. 8(b), there is little or no amperage obtained from the alternator 620 through the first rectifier 630 below 900 RPM. This is a close match to the Delco Remy result shown in the chart in FIG. 7. Also, in FIG. 8(b), it can be observed that most of the current was generated from the alternator 620 through the first rectifier 630 between -1200 to 1400 RPM. The peak amperage generated is around 13 amps.

[ 0095 ] In FIG. 8(c), another data collection cycle was obtained, where the only changes were that (i) the Hantek current clamp was moved from the wire R1DC+ to the wire BDC+ and (ii) the drill-press 610 had different turn-on and turn-off times. Note that current is measured in connection BDC+ shortly after the AC phase LI, L2, or L3 voltage begins to rise. When compared to FIG. 8(a), there is no current measured at this time. Also, it can be seen that the converter 650 generates a significant amount of current after the drill-press 610 has been turned off, at approximately 1.8 seconds. This current greatly exceeds the current obtained from the first rectifier 630 after the drill-press 610 is turned off.

[ 0096 ] FIG. 8(d) shows the amperage harvested from the converter 650 at different RPMs. The data is the same data as that collected in FIG. 8(c). The converter 650 is collecting energy from the alternator 620 at rotation speeds as low as 300 RPM. The use of the second rectifier 640 and the DC-DC converter 650 significantly increases the RPM energy collection range of the alternator 620 over the prior art.

[ 0097 ] The DC1601B-A DC-DC converter 650 can be turned off by moving the JP1 RUN jumper (op. cit. LT Demo Manual DC1601B.pdf, pg. 9/12, schematic pg. 1/3) to OFF. Doing so and then measuring the total current in wire DC+ yields the data shown in FIGs. 8(e) and 8(f). Comparing FIG. 8(e) and FIG. 8(a), it becomes clear that the converter 650, when running, significantly takes away from the energy harvesting capability of the first rectifier 630 during some periods.

[ 0098 ] With the converter 650 off, it appears that the apparatus of FIG. 6 has superior performance to that of the advertised Delco Remy lOsi. While the prior art alternator of FIG. 7 did not produce current until 900 RPM, the alternator 620 in the apparatus of FIG. 6 starts producing power around 800 RPM. It also appears that the current produced by the apparatus of FIG. 6 is greater than the prior art apparatus of FIG. 7 in the range of 1200 to 1400 RPM. The forward voltage of the first and second full-bridge rectifiers 630 and 640 is lower than the forward voltage of earlier rectifiers and is contributing to the performance improvement over the prior art.

[ 0099 ] FIG. 8(g) shows the total current in wire DC+ when the converter 650 is turned on. While the converter 650 may, under certain conditions, compete in harvesting energy with the alternator 620 and the first rectifier 630 portion of the circuit, when comparing FIG. 8(e) with FIG. 8(g), the two energy harvesting paths act synergistically to produce a significantly greater increase in energy production. The converter 650 takes over in collecting energy at low RPMs, which is when the alternator 620 and the first rectifier 630 portion of the circuit has lower energy harvest capacity. The alternator 620 and the first rectifier 630 portion of the circuit takes over collecting energy at higher RPMs, when the converter 650 has amperage limitations.

[ 00100 ] FIG. 8(h) exhibits this synergism. With the converter 650 turned on, the apparatus of FIG. 6 begins producing power as low as 300 RPM, and the peak amperage produced from the total system increases as well.

[ 00101 ] The DC1601B-A converter 650, with an average amperage capacity of 10 amps, can be substituted with a DC1601B-B converter (15 amps) or a DC1601B-C converter (20 amps) unit to allow even greater energy harvest than shown in FIGs. 8(g) and 8(h). In addition, several converter boards can be installed in parallel to further increase energy capture. The Linear Technology LTM 4607 chips have power FETs within. This limits the power-handling capability of the chip architecture. Higher power handling can also be achieved utilizing converter modules that act to mainly control boost or buck with external power FETs adapted to handle the higher current loads.

[ 00102 ] Converter control modules, such as, for example, the LTC 3789 (Linear

Technology, USA) modules, could be used to achieve the control coupled with, for example, power FETs, such as an NXP BUK7905-40AIE power FET (Mouser.com) having 155-amp switching capability. A DC-DC control module with associated high-power FETs can be used to implement the DC-DC converter 650.

[ 00103 ] As in Example 1, the use of paralleled DC-DC converters or a converter control module with converter-related circuitry, such as, for example, external high-power FETs, allows all the power to be harvested solely through the converter and converter-related circuitry.

[ 00104 ] FIG. 9 shows a block diagram of a battery-charging system RA according to yet another exemplary embodiment of the disclosure. In FIG. 9, all the harvested power from the alternator 920 is rectified by full-bridge rectifier 940. From there, DC-DC converter 950 (or a DC-DC control module with related circuitry) is used to charge a battery 660. All the components are the same as those in FIG. 6, except that the first rectifier 630, the wire JP-, and the wire R1DC+ have been eliminated. DC-DC converter 950 may be a paralleled converter to handle the low power and the high power from the alternator 920 or it can be a DC-DC converter control module with high-powered FETs to handle the alternator 920 harvested energy.

[ 00105 ] The advantages of adding the lower RPM capability, using the apparatus design of FIG. 6, compound when considering other design aspects of alternators and drive systems. For example, consider a modern car in a city. With the prior art alternator system, the alternator pulley drive system was designed to be a multiple of the engine RPM. For example, if the engine idled at 800 RPM, then the alternator needed a pulley ratio of, for example, two times in order to produce adequate power while at idle.

[ 00106] Consider when (i) a car in a city is at a stoplight, (ii) the brake lights are on, (iii) the stereo boom box is blaring and consuming many amps, (iv) the field coil of the alternator is consuming amperage, (v) the air conditioner and fan are running, (vi) the instrument lights are running, (vii) the engine control systems are consuming power, (viii) the cell phone is being charged, (ix) the GPS is being powered, etc. During this period, the amperage capability of the idling vehicle alternator current production is exceeded, and the battery is being discharged. This robs acceleration power from the engine when the light turns green, since some of the horsepower of the engine is consumed just recharging the battery at the moment the alternator RPM increases.

[ 00107 ] Furthermore, the double ratio of alternator RPM means that the alternator is spinning at 10,000 RPM when the engine is run at 5,000 RPM. At these high RPMs, the centripetal forces on the alternator rotor are enormous. The alternator should be built to withstand the forces. The windings should be higher gauge, reducing the winding density of the alternator. As such, the efficiency of the alternator is reduced just due to the need to be able to spin at high RPM. However, if a lower engine-to-alternator RPM ratio can be used, then the alternator structure can be built for energy efficiency rather than strength. With greater energy efficiency, the alternator power capacity increases throughout its RPM range. This, in turn, allows more energy harvesting potential by the DC-DC converter 950.

[ 00108 ] While a drill-press 910 drive means was utilized in the instant examples, any suitable drive mechanism to cause alternator rotation can be substituted.

Example 3 [ 00109] FIG. 10 shows a block diagram of a battery-charging system 1000 according to yet another exemplary embodiment of the disclosure. In FIG. 10, a drill-press 1010 motor drives alternator 1020 via hex key 1015 as described in detail for FIG. 6. The rectifier 1030 is a full-bridge, three-phase rectifier. In this embodiment, there is no second rectifier.

[ 00110 ] DC-DC converter 1050 is a DC1601B-A board manufactured by Linear

Technology and modified as described in Example 2. The R22 resistor has been replaced with a 10k, 15-turn potentiometer (Radio Shack, USA) wired as a variable resistor.

Optionally, the COMP terminal of the DC-DC converter 1050 is connected to the voltage divider node of resistor RC1 and variable resistor RVC1. The non-divider-node side of variable resistor RVC1 is connected to ground. The non-divider-node side of resistor RC1 is connected to the battery 1060 + terminal. Note that, in general, such controllable voltage dividers can also be implemented with the resistor and variable resistor swapped with one another or with two variable resistors.

[ 00111 ] For the Example 3 tests, when the battery 1060 is at 13 volts and with the alternator 1020 not rotating, the COMP voltage is adjusted, using variable resistor RVC1, to approximately 0.2 volts. The - terminal of the rectifier 1030 is connected to the -In terminal of the DC-DC converter 1050 via wire RDC- and also connected to the battery 1060 - terminal via wire DC-. The -Out terminal of the DC-DC converter 1050 is connected to the - terminal of the battery 1060 via wire BDC-. The +Out terminal of the DC-DC converter 1050 is connected to the anode of rectifier diode RD1, and the cathode of diode RD1 is connected to the + terminal of the battery 1060 via wire BDC+. The rectifier diode RD1 is a Diodes Inc. SBR1045SD1-T diode (www.mouser.com).

[ 00112 ] Prior to starting the measurement of Example 3, the DC-DC converter 1050 +In terminal was connected to a DC power supply (not shown) and set to 12-volt output. Variable resistor RV22 was adjusted until the battery 1060 was charged to approximately 13.7 V. After the adjustment of the resistor RV22, the power supply was removed. The DC-DC converter 1050 has a RUN jumper pin JP1 (refer to schematic diagram, rev. 1, sheet 1 of 3, on page 9 of Demo Manual DC1601B for LTM4607EV High Efficiency PolyPhase Buck- Boost Power Supply (Copyrighted 2004 and 2012, Linear Technology Corporation, Milpitas, California, the teachings of which are incorporated herein by reference in their entirety), which, when removed or tied to OFF or ground, turns off the converter 1050. [ 00113 ] When the RUN jumper JP1 is placed in the ON position, the converter 1050 can operate. In Example 3, Converter OFF will refer to the position of the RUN jumper JP1 being in the OFF position. Converter ON will refer to position of the RUN jumper JP1 being in the ON position. Medium Drive Speed refers to the belt and pulley position of the drill-press 1010 and is approximately 1250 RPM as detailed in Example 2.

[ 00114 ] In Example 3, measurements were taken using a Fluke 190 four-channel scope. One channel measured the battery 1060 voltage across the + and - terminals and is labeled Battery V. A second channel measured the +In to -In voltage of the DC-DC converter 1050 and is labeled Converter In V. A third channel measured the current fed to the battery 1060 using a Hantek CC-65 current clamp encircling wire DC+. This measurement is labeled Alternator A, since it measures the amperage fed to the battery 1060 from the alternator 1020 only. A fourth channel measures only the current in wire BDC+. It is labeled Converter A, since it depicts the amperage generated by just the DC-DC converter 1050. The current clamp used for this measurement was a Fluke i30 AC/DC Current Clamp (StockwiseAuto.com). The battery 1060 voltage was also measured using a Fluke 289 multimeter and was used for timing purposes.

[ 00115 ] During each test, the field coil (not shown but described in FIG. 2) and sense (not shown) of alternator 1020 was connected to the + terminal of the battery 1060 through two paralleled 3A/each rectifier diodes Model #276-1141 (not shown, Radio Shack, USA). The current energizing the field coil drained the battery 1060 down to approximately 12 V. At that time, the Fluke 190 oscilloscope was set to record, and then the drill-press 1010 was switched on. After a few seconds, the drill-press 1010 was switched off, and the recording by the Fluke oscilloscope was stopped.

[ 00116] In FIG. 11(a), the DC-DC converter 1050 was turned off using the RUN jumper JP1. The pulley ratios on the drill-press 1010 were set for medium drive speed operation. The upper curve, depicted as a dash-dot line, is the measured battery 1060 voltage. The larger ridge curve, depicted by a dotted line, is the measured converter 1050 In voltage. The smaller raised curve, starting at zero, represented by the solid line, is the alternator 1020 amperage measured by the Hantek current clamp. The line at zero, depicted as a dashed line, represents the amperage generated by the DC-DC converter 1050. This amperage is zero as might be expected when the converter 1050 is in the OFF JP1 jumper position. [ 00117 ] The drill-press 1010 was turned on at approximately 0.3 seconds, and the drill- press 1010 was turned off at approximately 2.0 seconds. Current flows to the battery 1060 only when the Converter In V (which is the full bridge rectifier 1030 output voltage from the alternator 1020) exceeds the battery 1060 voltage.

[ 00118 ] In FIG. 11(b), the DC-DC converter 1050 was turned on using the RUN jumper JPl. Again, the drill-press 1010 was set for medium drive speed. In this example, the converter 1050 produces most of the amperage to the battery 1060 as can be seen in the dashed Converter A curve. The converter 1050 produces amperage even when the Converter In V is less than battery 1060 voltage. The alternator 1020 produces less than one amp, as measured in wire DC+ and as shown in the solid curve Alternator A.

[ 00119] In FIG. 11(b), during the period when the drill-press 1010 was turned on at approximately 0.6 seconds until it was turned off at approximately 2.0 seconds, the total current (the sum of the Converter A current and the Alternator A current) averaged 6.5 amps. In FIG. 11(a), during a similar drill-press 1010 on period, the total current averaged about 6.13 amps. Therefore, in the configuration shown in FIG. 10, the DC-DC converter 1050, when on, harvests an additional 5.5% of current. Since the average battery 1060 voltage was 13 volts in both FIGs. 11(a) and 11(b), the DC-DC converter 1050 increased the power harvested from the alternator 1020 by approximately 5.5%.

[ 00120 ] In FIG. 11(c), the converter 1050 RUN jumper JPl is in the off position turning the converter 1050 off. The drill-press 1010 pulley ratio is set for slow drive speed. The diameter of the pulley on the motor is approximately 5 cm (2 inches), and the diameter of the pulley on the shaft of the drill-press 1010 is approximately 11.5 cm (4.5 inches). At slow drive speed, the alternator 1020 is rotated at around 630 RPM. At this speed, the rectifier 1030 generates approximately 8 volts DC as can be seen in the curve labeled Converter In V. Since this voltage is below the battery 1060 voltage, the alternator 1020 does not generate current that charges the battery 1060. The Alternator A curve is at zero.

[ 00121 ] In FIG. 11(d), the JPl jumper is put in the RUN position and the converter 1050 is turned on. The drill-press 1010 is set for slow drive speed or approximately 630 RPM. At this speed, the DC-DC converter 1050 boosts the 4.5-volt output (see Converter In V), from the rectifier 1030, to above the battery 1060 voltage, and approximately 3 amps is fed to the battery 1060. This represents an ability to harvest power from the alternator 1020 at a slow drive speed when no such ability previously existed.

[ 00122 ] FIG. 10(a) shows a block diagram of one possible implementation of the battery- charging system 1000 of FIG. 10, in which the rectifier 1030 is internal to the alternator 1020, such that the phases LI, L2, and L3 (not shown in FIG. 10(a)) of the alternator 1020 are connected by the manufacturer to the AC inputs (not shown in FIG. 10(a)) of the internal rectifier 1025. The + terminal of the internal rectifier 1025 is connected to the battery (BAT) terminal of the alternator 1020. The - terminal on the internal rectifier 1025 is connected to the ground (GND) terminal of the alternator 1020.

[ 00123 ] If a higher-powered, paralleled DC-DC converter 1050 or a DC-DC control module with external FETs is employed, then all the power can be harvested by the converter circuitry. If not, optionally, the + terminal of the intenal rectifier 1025 (or BAT terminal on the alternator 1020) is connected to optional rectifier diode RD2 via connecting wire R1DC+. If used, rectifier diode RD2 can be an NTE 5980 rectifier diode (parts-express.com). If used, the cathode of rectifier diode RD2 is connected to the positive terminal of the battery 1060 via wire DC+. If used, rectifier diode RD2 may be substituted with an active rectifying component adapted to prevent reverse current and backfeed to the +In terminal of DC-DC converter 1050 via wire R2DC+.

Example 4

[ 00124 ] FIG. 12 shows a block diagram of a battery-charging system 1200 according to yet another exemplary embodiment of the disclosure. FIG. 12 depicts the apparatus of Example 4. The alternator 1220 is a Kiss wind generator as in Example 1. The alternator 1220 is rotated by blades (not shown). The three AC output phases LI, L2, and L3 of the alternator 1220 were connected using #12 gauge stove wire (Tempco P/N LDWR-1023, available from Grainger, USA) to a first full-bridge rectifier 1230 and a second full-bridge rectifier 1240, via a screw terminal strip (not shown), at the AC legs of the rectifiers. The rectifiers 1230 and 1240 are manufactured by IXYS, P/N FUS 45-0045B (Mouser

Electronics, USA). The rectifiers were mounted to a heat sink (not shown, Crydom 558- HS351, Mouser, USA) such that the pins were pointed toward each other, and the AC pins were soldered together and connected to the LI, L2, and L3 AC alternator 1220 phases.

[ 00125 ] The ground pins of the rectifiers were soldered and connected together via jumper JP-. These pins of the rectifiers were then connected to the negative terminal of the battery 1260 via wire DC- and to the -In terminal of a DC-DC converter 1250. The positive pin of the first rectifier 1230 was connected to the positive terminal of the battery 1260 via connecting wire R1DC+ and via connecting wire DC+. The positive pin of the second rectifier 1240 was connected to the +In terminal of the DC-DC converter 1250 via wire R2DC+. Alternatively, power-MOSFET-based, active, full-bridge rectifiers may be substituted for even lower resistance and forward voltage.

[ 00126] The DC-DC converter 1250 is a DC1198B-B converter (Linear Technology, Milpitas, CA) capable of handling an average of 5 amps of current in boost mode. The converter 1250 was adapted for use as follows. Resistor R5 on the bottom side of the converter 1250 board was removed and replaced with variable potentiometer RV5, which is a 15-turn, 10-kohm variable potentiometer (271-343 Radio Shack, USA) connected as a variable resistor. This allows adjustment of the converter 1250 to a desired range of output voltage or, in the case of these examples, to 14.4V dc.

[ 00127 ] A heat sink (not shown) was adhered to the surface of the LTM4607EV converter 1250 module (not shown). The heat sink was P/N 375424B00034G manufactured by Aavid Thermalloy (Digikey, USA).

[ 00128 ] Optionally, a wire was connected to the COMP connection to the LTM4607EV converter 1250 on the chip Ul side of capacitor C2 (refer to schematic diagram, rev. 1, sheet 1 of 1, on page 5 of Demo Manual DC1198B-A LTM 4605 20V, 5A High efficiency Buck- Boost μModule Regulator (Copyrighted 2004 and 2011, Linear Technology Corporation, Milpitas, California, the teachings of which are incorporated herein by reference in their entirety). This wire was connected to the divider node of resistors RC1 (300k ohm, Radio Shack, USA) and RVCl (Vishay-Spectol M43P204KB40, 15-turn, 200-kohm potentiometer connected as a variable resistor, Mouser, USA). The other pin of variable resistor RVCl was soldered to the converter 1250 ground connector. The other pin of resistor RC1 was connected to wire R1DC+. [ 00129] Modification of the COMP voltage on the converter 1250 leads to modified control of the output current from the converter. The magnitude of the resistance of resistor RC1 controls the sensitivity of the converter 650 current as a function of battery 1260 voltage. The larger the resistance of resistor RC1, the less the controlled sensitivity to the battery 1260 voltage. The magnitude of the resistance of variable resistor RVCl controls the converter 1250 current as a function of the battery 1260 voltage and the internal circuitry of the converter 1250 chip designed by the manufacturer.

[ 00130 ] If variable resistor RVCl is set to a low value, then the maximum current generated by the converter 1250 will be slightly lower, even though the In voltage to the converter 1250 is high. And the current generated by the converter 1250 will also be much lower when the In voltage to the converter 1250 is low. In such a case, for example, the converter 1250 current generation onset voltage may rise from, for example, 4.5V to 6V, and the maximum current may drop.

[ 00131 ] Such control of the COMP voltage is very important to limit the energy draw from, for example, a wind generator 1220. If the energy draw from a wind generator 1220, operating in light winds, is too severe, then the wind generator will be stalled and will not even begin rotation. Lowering the resistance of resistor RVCl reduces the energy draw from a wind generator in low winds, while still allowing higher energy harvesting in higher winds. It is recognized that wind energy potential usually varies as the cube of wind speed.

Therefore, rather than a relatively linear RVCl voltage control of the COMP voltage, the COMP voltage control can be improved upon by utilizing a non-linear voltage control. This would better tailor the energy draw of the converter 1250 to the output capability of a wind generator. Such non-linear control is accomplished using an op-amp circuit in place of resistor RVCl.

[ 00132 ] In Example 4, the COMP voltage was set to 1.2V. For this measurement, alternator 1220 phases LI , L2, and L3 were connected together, stopping the wind generator rotation. The batteries 1260 had a charge of 13V. The DC1198B-B converter 1250 board was modified as follows. Coil LI was replaced by a Sumida CDEP147NP-3R1MC-125

(Mouser.com) coil. Sense resistor RS2 was removed and replaced by new sense resistor Panasonic RS2 ERJ-8BWJR043V (Digikey.com). Sense resistor RS3 was added. It was also a Panasonic RS2 ERJ-8BWJR043V (Digikey.com). [ 00133 ] The -Out terminal of the DC-DC converter 1250 is connected to the battery 1260 negative terminal. The +Out terminal of the DC-DC converter 1250 is first connected to output rectifier diode RD1, and then connected to R1DC+, where, via wire DC+, it connects to the positive terminal of the battery 1260. The output rectifier diode RD1 may be optional for some converters but is preferred for use with the DC1198B-B converter when used in circuits of Example 4. The output rectifier diode RD1 is a SBR1045SD1 (Diodes

Incorporated available from Mouser, USA) and is preferred due to low forward voltage. Though more complex, a power FET circuit may be substituted to allow even lower resistance and forward voltage, while preventing or reducing reverse current back to the converter 1250.

[ 00134 ] The battery 1260 consisted of four Full River DC224-6 (distributed through Royal Battery Distributors, Inc., Kissimmee, Florida) 6V golf cart batteries, paired in series for nominal 12V DC and then in parallel for capacity purposes.

[ 00135 ] Measurements for FIG. 13(a) were taken using the apparatus of FIG. 12 when the Kiss wind generator alternator 1220 was subjected to a period of wind gusts. A Fluke 190 oscilloscope was used to capture the data in Trend Mode. One channel measured the battery 1260 voltage and is labeled Battery V. A second channel measured the peak-to-peak AC voltage between one of the phases LI, L2, or L3 and the battery 1260 negative. This is labeled AC p-p V. A third channel is used with a Fluke 130 current clamp encircling wire BDC+, thereby measuring the current from the converter 1250 to the battery 1260. It is labeled Converter A. A fourth channel is used with a Hantek CC-65 current clamp encircling wire DC+, thereby measuring the current from the first rectifier 1230 and the converter 1250. This is the total current produced by the apparatus of FIG. 12 and is labeled Total A.

[ 00136] The Hantek CC-65 current clamp was prone to significant drift during measurements, and data adjustments were later made to correct the drift. In general, below approximately 4.5 amps, the Total A (total current) should be equal to or greater than the Converter A (converter 1250 current). However, the data was not always corrected to show this.

[ 00137 ] Surprisingly, the data indicates that the converter 1250 may be producing current even when the peak-to-peak AC voltage is less than 2V. The converter 1250, in the modified configuration of FIG. 12, appears to have a maximum current output of 4.5 amps.

Surprisingly, below this 4.5 amp output, the Kiss wind generator rotates at a much lower speed than normal and is silent in operation. When the alternator 1220 output exceeds the 4.5-amp output, the blade noise increases, but, in general, since the converter 1250 still maintains the 4.5-amp output, the rotation speed of the wind generator is lower than when the converter 1250 is not used.

[ 00138 ] FIG. 12 exhibits the performance of a wind generator modified as in the apparatus of FIG. 12. The battery 1260 voltage is the curve at approximately 12.8 volts. The converter 1250 amperage output is shown as the grey curve. The Total Amps, i.e., the total of the first rectifier 1230 and the converter 1250, is in white. The Peak-to-Peak AC V curve is the grey to black background. In general, the faster the speed of the wind generator; the higher the AC frequency; the darker the curve region; and the greater the noise from the wind generator. A converter 1250 with greater energy extraction capability, or higher average amperage output capability, would lead to equivalent energy harvesting with much lower noise potential.

[ 00139] Indeed, as in Examples 1, 2, and 3, the use of paralleled DC-DC converters or a converter control module with converter-related circuitry, such as for example external high- power FETs, allows all the power to be harvested solely through the converter and the converter-related circuitry.

[ 00140 ] FIG. 14 shows a block diagram of a battery-charging system 1400 according to yet another exemplary embodiment of the disclosure. In FIG. 14, all the harvested power from the alternator 1420 is rectified by the full-bridge rectifier 1440. From there, the DC-DC converter 1450 or a DC-DC control module with related high-power FET circuitry is used to charge a battery 1460. All the components described in FIG. 12 are the same except that the first rectifier 1230, wire JP-, and wire R1DC+ have been eliminated. The DC-DC converter 1450 may be a paralleled converter to handle the low and the high power from the alternator 1420 or it can be a DC-DC converter control module with high-powered FETs to handle the alternator 1420 harvested energy.

[ 00141 ] The use of boost circuitry in wind generators opens the possibility to design the system for low rotation speed operation. For example, it would be possible to design the wind generator blades for low rotation speed but high torque operation. The low rotation speed would decrease blade tip noise and also significantly reduce structural vibrations in the wind generator and support structures.

[ 00142 ] Referring, for example, to the embodiment of FIG. 3, higher or lower output voltage +Out to -Out can be generated by the DC-DC converter 350. The 13.8V output voltage (+Out to -Out) of the trimmed Cincon DC-DC converter is somewhat ideal since it matches the recommended float voltage for the AGM (absorbed glass mat) battery 360 made by Full River and used in the tropics. As such, for example, during storage, the battery 360 could be safely float charged by a wind generator where the output of the first rectifier 330 is disconnected from that battery and connected to a resistor bank. As such, the output of the second rectifier 340 and the DC-DC converter 350 circuit would be used to provide a regulated maximum charge of 13.8V on the battery. The converter 350 would provide the float charge, and any excess wind-generated energy would be wasted in resistance heat, thereby preventing the wind generator from free-spinning. Use of the 4607 converter 350, which can be trimmed to lower output voltages, would allow even lower float-charge voltages for the stored battery 360.

[ 00143 ] FIG. 15 shows a block diagram of a battery-charging system 1500 according to yet another exemplary embodiment of the disclosure. In FIG. 15, a driven alternator 1520 outputs a single AC phase LI, which is connected to the AC terminal of a rectifier 1530. The rectifier 1530 is a full-bridge rectifier having a positive terminal connected to the positive terminal of battery 1560 by wire R1DC+. The negative terminal of the rectifier 1530 is connected to the negative terminal of battery 1560 by wire DC-. AC phase LI is also connected to FETs 1591 and 1592. Comparator 1570 monitors the AC voltage of phase LI and provides (i) a signal +S to gate driver 1581 when the voltage of AC phase LI is positive and (ii) a signal -S to gate driver 1582 when the voltage of AC phase LI is negative. The signal +S toggles gate driver 1581 from off to on, thereby energizing the gate of FET 1591. When FET 1591 is on, the positive cycle of AC phase LI is routed to DC-DC converter 1531 as L1+. The signal -S toggles gate driver 1582 from off to on, thereby energizing the gate of FET 1592. When FET 1592 is on, the negative cycle of AC phase LI is routed to DC-DC converter 1532 as L1-. As such, the comparator 1570, the gate drivers 1581 and 1582, and the FETs 1591 and 1592 act as positive and negative power routers of AC phase LI. The positive cycle portion L1+ is connected to the +Vin terminal of DC-DC controller 1531. The negative cycle portion LI- is connected to the -Vin terminal of DC-DC controller 1532. Battery 1560 ground is connected to the -Vin terminal of DC-DC controller 1531 through wire BDC-. Battery 1560 ground is connected to the +Vin terminal of DC-DC controller 1532 through wire BDC-. In this way, the DC-DC controller 1532 low input -Vin floats with the voltage of L1-, and the high input +Vin of DC-DC controller 1532 has a relatively positive voltage with respect to -Vin. DC-DC controllers 1531 and 1532 both boost the input voltages to a voltage at terminal +Vout that is at least as high as the sum of the battery 1560 acceptance voltage and the diode drop voltage of rectifier diode RDl. The +Vout terminal of DC-DC controller 1532 is connected to the +Vout of DC-DC controller 1531 via wire IDC+. The +Vout of both controllers 1531 and 1532 are connected to the wire R1DC+ after passing through wire BDC+ and rectifier diode RDl. In this embodiment, the comparator 1570, the gate drivers 1581 and 1582, the FETs oscillating-voltage and 1592, and the DC-DC converters 1531 and 1532 form a second rectification system. In some embodiments, the DC- DC converter subsystem may be a single DC-DC converter (not shown) that combines the functions of DC-DC converters 1531 and 1532.

[ 00144 ] As in the previous embodiments, rectifier 1530 may be adapted to charge battery 1560 whenever the rectified AC or rippled DC voltage is above the battery 1560 acceptance voltage. Or the DC-DC converters 1531 and 1532 charging paths (the second rectification system) may be configured to convert all the energy from alternator 1520 to a voltage that is at least as high as the acceptance voltage of battery 1560.

[ 00145 ] FIG. 16 shows a block diagram of a battery-charging system 1600 according to yet another exemplary embodiment of the disclosure. In FIG. 16, a driven alternator 1620 outputs a single AC phase LI. The alternator 1620 ground terminal GND is biased by battery 1660 positive voltage via wire DCBias+, which is connected to the battery 1660 positive terminal via wire DC+. Because alternator 1620 ground is biased by the battery 1660 voltage, the AC phase LI is DC biased by the battery 1660 voltage. This biasing is reflected as LI + DCBias+ in FIG. 16. The LI + DCBias+ signal is connected to the +Vin terminal of DC-DC converter 1650. The -Vin terminal of DC-DC converter 1650 is connected to the battery 1660 negative terminal via wire DC-. The +Vout terminal of DC-DC converter 1650 is connected to the battery 1660 via wire BDC+, through rectifier diode RDl, and via wire DC+. In some embodiments, the AC phase LI is biased by a voltage higher than the battery 1660 voltage by, for example, a DC-DC converter (not shown) adapted to provide the higher bias voltage or a second battery (not shown) in series with the battery 1660.

[ 00146] In operation, all or most of the AC phase LI is raised to a voltage that can be boosted or bucked by DC-DC converter 1650, which has a voltage output that is at least as high as the acceptance voltage of the battery 1660 after passing through the rectifier diode RD1. As such, the battery 1660 is charged by alternator 1620 without AC rectification. The signal LI + DCbias+ is rippled DC voltage.

Example 5

[ 00147 ] FIG. 17 shows a block diagram of a battery-charging system 1700 according to yet another exemplary embodiment of the disclosure. FIG. 17 shows a depiction of a test apparatus adapted to harvest more energy from a car alternator. The alternator 1720 is a remanufactured Delco Remy lOSi, previously described. The shaft pulley and fan were removed from the alternator 1720. The alternator RPM can be calculated to be 8.57 times the frequency of a single output phase LI, L2, or L3. The alternator 1720 was bolted, shaft pointing up, to the bottom side of the drill-press 1710 platen (not shown).

[ 00148 ] The alternator 1720 is direct driven via an ~79-mm (5/16-inch) hex shaft 1715 clinched by a drill-press 1710 chuck (not shown). The drill-press 1710 is driven by a ¾-hp motor (not shown) previously described. The motor has a 4-step-size pulley (not shown) attached to its shaft. In the Example 5 test described below, the next-to-smallest pulley on the motor, which is -6.4 cm (2.5 inches) in diameter, is connected by a drive belt (not shown) to the next-to-largest size pulley on the drill chuck, which is -8.9 cm (3.5 inches). As such, the drill-press 1710 motor would be expected to turn -1.4 times faster than the alternator 1720. If the drill-press 1710 motor actually ran at 1750 RPM, then it would be expected that the alternator 1720 would be driven at -1250 RPM. According to actual measurements of alternator 1720 AC output, described below, the actual rotation speed of the alternator 1720 in steady state varies in the range of -1250 to -1330 RPM. This is described as medium speed operation of the alternator 1720.

[ 00149] The alternator 1720 comes with an internal full-bridge rectifier 1725. The positive terminal of rectifier 1725 is internally connected to the BAT terminal of the alternator 1720. During the testing, wire RADC+ is sometimes connected to the BAT terminal of the alternator 1720. Other times, the wire RADC+ is disconnected from the BAT terminal during the testing. The negative terminal of the internal rectifier 1725 is connected to the ground terminal of the alternator 1720. The GND terminal of the alternator 1720 is connected to the battery 1760 negative terminal via wire DC-.

[ 00150 ] The alternator 1720 also comes with a trio (not shown), which may contribute operating current to the field coil (not shown) of the alternator 1720 when the alternator 1720 is generating sufficient power to the trio. However, battery 1760 voltage and current were supplied to the alternator 1720 regulator (not shown) and ignition connection (not shown) on the alternator 1720 during the testing. As such, the battery 1760 was used to power the field coil of the alternator 1720 during the tests and was used to provide a sense voltage to the regulator. The regulator turned the field current, whether supplied by the trio or the battery 1760, on or off as required to limit the charging voltage to the battery 1760.

[ 00151 ] The three AC phases LI, L2, and L3 of the alternator 1720 were connected to the internal rectifier 1725 by the remanufacturer. The three AC output phases LI, L2, and L3 were piggy-backed to the internal rectifier 1725 terminals (not shown), using #12 gauge stove wire (Tempco P/N LDWR-1023, available from Grainger, USA) to a first external full-bridge rectifier 1730 and a second external full-bridge rectifier 1740, via a screw terminal strip (not shown), at the AC legs of the rectifiers. The rectifiers 1730 and 1740 are manufactured by IXYS and have the P/N FUS 45-0045B (Mouser Electronics, USA). The rectifiers 1730 and 1740 were mounted to a heat sink (not shown, Econobox CU-477, Bud Industries US) such that the pins were pointed toward each other, and the AC pins 3, 4, and 5 were soldered together and to the AC alternator 1720 phases LI, L2, and L3.

[ 00152 ] The ground pins of the rectifiers 1730 and 1740 were soldered and connected together via jumper connection JP-. These ground pins of the rectifiers 1730 and 1740 were then connected (i) to the negative terminal of the battery 1760 via wire DC- and (ii) to the -In terminal of DC-DC converter 1750 via connection RDC-. The positive pin of the first rectifier 1730 was connected to the positive terminal of the battery 1760 via wire RlDC+.The positive pin of the second rectifier 1740 was connected to the +In terminal of DC-DC converter 1750 via wire R2DC+. On the path to the battery, both positive output wires of the alternator rectifier 1725 and the first rectifier 1730 are connected to wire RADC+ + R1DC+. The +Out terminal of the DC-DC converter 1750 is connected to the anode of rectifier diode RD1 via wire BDC+. Then the cathode output of diode RD1 is connected to wire RADC+ + R1DC+. The positive outputs of both rectifiers 1725 and 1730 and the positive output of DC- DC controller 1750 are therefore carried to the battery 1760 via wire DC+.

[ 00153 ] DC-DC converter 1750 is a DC1601B-A converter (Linear Technology, Milpitas, CA) capable of handling an average of 10 amps of current in boost mode. The converter 1750 was adapted for use as follows. Resistor R22 on the bottom side of the converter 1750 board was removed and replaced with variable potentiometer RV22, which is a 15-turn, 10-kohm variable potentiometer (271-343 Radio Shack, USA) connected as a variable resistor. This allows adjustment of the converter 1750 to a desired range of output voltage or, in the case of these examples, to 14.5V dc.

[ 00154 ] Heat sinks (not shown) were adhered to the surface of the LTM4607V converter 1750 modules (not shown). The heat sinks were P/N 375424B00034G manufactured by Aavid Thermalloy (Digikey, USA).

[ 00155 ] Table 1 details the results of measurements taken with the system of FIG. 17. In the tests, a Fluke 190 oscilloscope was used to record the data. The oscilloscope probes also measured the battery 1760 voltage and the AC voltage from one of the phases LI, 12, or L3. The voltage of the battery 1760 "Starting V" was also measured using a Fluke 289 Volt Ohmmeter. In tests 28-33, 35-37, and 41, the output amperage A of the DC-DC controller 1750 was measured using a Fluke i30 current clamp encircling wire BDC+. This measured amperage is reported in column "DC-DC A". In tests 38 and 39, the amperage in wire R1DC+ was measured using the Fluke i30 current clamp. In these tests, the measured amperage is reported in column "Rectifier #1 A". In tests 28-33 and 37, a Fluke 80i-l 10s current clamp was used to measure the amperage in wire DC+. This measured amperage is reported in column "Total A". In tests, 35, 36, and 38, the Fluke 80i-l 10s current clamp measured the current in wire RADC+. This measured amperage is reported in column "Alternator A". The data is left blank in tests where the positions of the current clamps do not allow one to distinguish the source of the amperage.

[ 00156] In the tests, the DC-DC controller 1750 was turned on or off utilizing the RUN jumper on the DC 1601 circuit board. The first rectifier 1730 was turned on or off by connecting or disconnecting wire R1DC+. The alternator 1720 rectifier 1725 was turned on or off by connecting or disconnecting wire RADC+.

[ 00157 ] The initial starting voltage of 12.6V was established by connecting a DC power supply (not shown, Mastech HY3020E, San Jose, CA) to the battery 1760 with the positive output of the supply isolated by a rectifier diode (not shown). The power supply was adjusted such that the battery voltage was 12.6V as measured by the voltmeter. During alternator 1720 operation, the power supply no longer provided voltage influence or current due to the isolation diode. That is, the battery 1760 voltage exceeded the power supply voltage when the alternator 1720 was running. The power supply was not used in tests 35-41.

[ 00158 ] The drill-press 1710 was turned on for a few seconds and then turned off. The oscilloscope was set to make a recording of the measured values every 8 milliseconds. A local average of 41 measurements was calculated and a peak of the local average is reported.

Table 1

Test DC-DC Controller Rectifier #1 Alternator Rectifier Starting V DC-DC A Rectifier #1 A Alternator A Total Amps

28 Off Off On 12.6 0 0 10.1 10.1

29 On Off On 12.6 11.9 0 0.2 12.1

30 On On On 12.6 12.2 12.4

31 Off On On 12.6 0 13.3

32 Off On Off 12.6 0 13.1 0 13.1

33 On On Off 12.6 12.2 0.4 0 12.6

Test DC-DC Controller Rectifier #1 Alternator Rectifier Starting V DC-DC A Rectifier #1 A Alternator A Total Amps

35 Off Off On 12.1 0 0 11.6 11.6

36 On Off On 12.1 14.5 0 0 14.5

37 On On On 12.1 14.5 15.1

38 Off On On 12.1 0 13.4 0.5 13.9

39 Off On Off 12.1 0 13.4 0 13.4

41 On On Off 12.1 15.3 0 0 15.3

[ 00159] In general, the disclosure may be said to relate to a system for providing energy from an oscillating-voltage, power generation subsystem (e.g., 320, 520, 620, 920, 1020, 1220, 1420, 1520, 1620, 1720) to an energy collection subsystem (e.g., 360, 560, 660, 960, 1060, 1260, 1460, 1560, 1660, 1760), such as a battery or a collection of batteries or for supplying energy to a grid. Depending on the particular embodiment, the oscillating-voltage output generated by the power generation subsystem may be, for example, an AC output, a DC-biased AC output, a rectified AC output, or a rippled DC output. Note that, for some embodiments, the oscillating-voltage output may be characterized as simultaneously being a DC-biased AC output, a rectified AC output, and/or a rippled DC output. [ 00160 ] The system comprises a DC-DC conversion subsystem (e.g., 350, 550, 650, 950, 1050, 1250, 1450, 1550, 1650, 1750) connected between the oscillating-voltage, power generation subsystem and the energy collection subsystem. The energy collection subsystem has an energy-collection acceptance voltage. The oscillating-voltage, power generation subsystem is configured to generate an oscillating-voltage output (e.g., LI, L2, L3) having low-voltage portions lower than the acceptance voltage and high-voltage portions higher than the acceptance voltage. The DC-DC conversion subsystem is configured to raise at least some low- voltage portions in the oscillating-voltage output to a voltage (e.g., BDC+) at least as high as the acceptance voltage, thereby allowing the energy collection subsystem to collect energy from the at least some low-voltage portions in the oscillating-voltage output.

[ 00161 ] In the embodiments shown in FIGs. 3, 5, 6, 9, 10, 12, 14, and 17, the oscillating- voltage output from the oscillating voltage, power generation subsystem is an AC output having the low-voltage portions and the high-voltage portions. The system further comprises a rectifier subsystem (e.g., 330/340, 540, 630/640, 940, 1030, 1230/1240, 1440, 1730/1740) configured to receive the AC output from the oscillating-voltage, power generation subsystem and provide a first rectified AC output (e.g., R2DC+) to the DC-DC conversion subsystem. Note that, for some implementations, a rectified AC output generated by the rectifier subsystem may also be characterized as a rippled DC output and/or a DC-biased AC output. The DC-DC conversion subsystem is configured to raise at least some low-voltage portions in the first rectified AC output to the voltage at least as high as the acceptance voltage, thereby allowing the energy collection subsystem to collect energy from the at least some low- voltage portions in the rectified AC output.

[ 00162 ] In some embodiments, the rectifier subsystem is configured to provide energy (e.g., R1DC+) from at least some high-voltage portions in the AC output to the energy collection subsystem independent of a DC-DC conversion function of the DC-DC conversion subsystem. In some embodiments, the rectifier subsystem is configured to provide energy (e.g., R1DC+) from at least some mid-voltage portions of the AC output to the energy collection subsystem in conjunction with the DC-DC conversion function of the DC-DC conversion subsystem providing energy to the energy collection subsystem. In some embodiments, the rectifier subsystem is further configured to provide a second rectified AC output (e.g., R1DC+) to the energy collection subsystem bypassing the DC-DC conversion subsystem. Note that, as used in this specification, the terms "low- voltage," "mid- voltage," and "high-voltage" refer to relative magnitudes of signals independent of their positive or negative signs.

[ 00163 ] In the embodiments shown in FIGs. 3, 6, 12, and 17, the rectifier subsystem comprises (i) a first rectifier (e.g., 330, 630, 1230, 1730) connected to receive the AC output from the oscillating- voltage, power generation subsystem and configured to provide a second rectified AC output (e.g., R1DC+) to the energy collection subsystem bypassing the DC-DC conversion subsystem and (ii) a second rectifier (e.g., 340, 640, 1240, 1740) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide the first rectified AC output (e.g., R2DC+) to the DC-DC conversion subsystem.

[ 00164 ] In the embodiment shown in FIG. 17, the oscillating-voltage, power generation subsystem comprises a third rectifier (e.g., 1725) configured to provide a third rectified AC output (e.g., RADC+) to the energy collection subsystem bypassing the DC-DC conversion subsystem.

[ 00165 ] In the embodiment shown in FIG. 10, the rectifier subsystem comprises a first rectifier (e.g., 1030) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide the first rectified AC output both (i) to the DC-DC conversion subsystem (e.g., R2DC+) and (ii) to the energy collection subsystem bypassing the DC-DC conversion subsystem (e.g., R1DC+).

[ 00166] In the embodiment shown in FIGs. 5, 9, and 14, the rectifier subsystem comprises a first rectifier (e.g., 540, 940, 1440) connected to receive the AC output from the oscillating- voltage, power generation subsystem and configured to provide the first rectified AC output (i) to the DC-DC conversion subsystem (e.g., R2DC+) and (ii) not to an energy collection subsystem bypassing the DC-DC conversion subsystem.

[ 00167 ] In the embodiment shown in FIG. 15, the oscillating-voltage output from the oscillating-voltage, power generation subsystem (e.g., 1520) is an AC output (e.g., LI) having positive-voltage portions and negative-voltage portions. The system further comprises a first rectifier (e.g., 1530) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide a first rectified AC output (e.g., R1DC+) to the energy collection subsystem (e.g., 1560) bypassing the DC- DC conversion subsystem. The DC-DC conversion subsystem comprises (i) a first DC-DC converter (e.g., 1531) configured to provide energy from at least some positive- voltage portions of the AC output to the energy collection subsystem and (ii) a second DC-DC converter (e.g., 1532) configured to provide energy from at least some negative-voltage portions of the AC output to the energy collection subsystem. The DC-DC conversion subsystem further comprises (i) a comparator (e.g., 1570) configured to detect the positive- voltage portions and the negative-voltage portions in the AC output, (ii) a first gate-driver and FET subsystem (e.g., 1581 and 1591) configured to route at least some detected positive- voltage portions of the AC output to the first DC-DC converter, and (iii) a second gate-driver and FET subsystem (e.g., 1582 and 1592) configured to route at least some detected negative- voltage portions of the AC output to the second DC-DC converter.

[ 00168 ] In the embodiment shown in FIG. 16, the oscillating-voltage output from the oscillating-voltage, power generation subsystem (e.g., 1620) is a DC-biased AC output (e.g., Ll+DCBias+) having the low-voltage portions and the high-voltage portions. In some implementations, the DC-DC conversion subsystem (e.g., 1650) is configured to reduce at least some high-voltage portions in the DC-biased AC output to a voltage (e.g., BDC+) closer to the acceptance voltage, thereby allowing the energy collection subsystem (e.g., 1660) to collect energy from the at least some high- voltage portions. In some implementations, the DC-DC conversion subsystem is configured to raise at least some low-voltage portions in the DC-biased AC output to a voltage (e.g., BDC+) at least as high as the acceptance voltage, thereby allowing the energy collection subsystem (e.g., 1660) to collect energy from the at least some low-voltage portions. The energy collection subsystem is connected to provide a DC bias (e.g., DCBias+) to the oscillating-voltage, power generation subsystem, and the oscillating-voltage, power generation subsystem is configured to generate the DC-biased AC output based on the DC bias from the energy collection subsystem.

[ 00169] In some embodiments, the DC-DC conversion subsystem is configured to limit energy applied to the energy collection subsystem.

[ 00170 ] In some embodiments, the system further comprises the oscillating-voltage, power generation subsystem. In some embodiments, the system comprises the energy collection subsystem. [ 00171 ] In some embodiments, the oscillating-voltage, power generation subsystem is configured to operate during low-power periods and high-power periods, and the DC-DC conversion subsystem is configured (e.g., R2, R3, Tl, ON/Off or RC1, RVC1, COMP) to reduce the energy collected by the energy collection subsystem during the low-power periods.

[ 00172 ] In some embodiments, the oscillating-voltage, power generation system is a wind generator comprising (i) blades configured to be rotated by wind power at a speed that causes noise generation and (ii) an alternator driven by the blades. The system is configured such that the collection of energy from the low-voltage portions by the DC-DC conversion subsystem slows the speed of blade rotation and thereby reduces blade noise.

[ 00173 ] In some embodiments, the oscillating-voltage, power generation subsystem comprises an engine-driven alternator having a rotation speed and having belt and pulley ratios. The system is configured such that the collection of energy from the low-voltage portions by the DC-DC conversion subsystem allows the same amount of energy to be collected at lower rotation speed. The collection of energy from the low-voltage portions by the DC-DC conversion subsystem allows the ratio of alternator rotation speed with respect to engine rotation speed to be reduced.

[ 00174 ] Although the disclosure is described herein with reference to specific

embodiments, various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.

[ 00175 ] Although the present disclosure has been described in the context of particular embodiments implemented using specifically identified components, those skilled in the art will understand that other suitable components can be used in alternative implementations.

[ 00176] Although the present disclosure has been described in the context of figures showing alternators that generate three AC phases and rectifiers that receive three AC phases, in general, embodiments can be implemented with alternators that generate one or more AC phases and rectifiers that rectify one or more of those AC phases.

[ 00177 ] It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the invention.

[ 00178 ] Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.

[ 00179 ] Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term "implementation."

[ 00180 ] Embodiments of the disclosure may be implemented as (analog, digital, or a hybrid of both analog and digital) circuit based processes, including possible implementation as a single integrated circuit (such as an ASIC or an FPGA), a multi chip module, a single card, or a multi card circuit pack.

[ 00181 ] Also for purposes of this description, the terms "couple," "coupling," "coupled," "connect," "connecting," or "connected" refer to any manner known in the art or later developed in which energy is allowed to be transferred between two or more elements, and the interposition of one or more additional elements is contemplated, although not required. Conversely, the terms "directly coupled," "directly connected," etc., imply the absence of such additional elements.

[ 00182 ] Also, for purposes of this disclosure, it is understood that all gates are powered from a fixed voltage power domain (or domains) and ground unless shown otherwise. Accordingly, all digital signals generally have voltages that range from approximately ground potential to that of one of the power domains and transition (slew) quickly. However and unless stated otherwise, ground may be considered a power source having a voltage of approximately zero volts, and a power source having any desired voltage may be substituted for ground. Therefore, all gates may be powered by at least two power sources, with the attendant digital signals therefrom having voltages that range between the approximate voltages of the power sources.

[ 00183 ] Signals and corresponding nodes or ports may be referred to by the same name and are interchangeable for purposes here.

[ 00184 ] It should be appreciated by those of ordinary skill in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the invention. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

[ 00185 ] Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word "about" or "approximately" preceded the value of the value or range.

[ 00186] It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain embodiments of this invention may be made by those skilled in the art without departing from embodiments of the invention encompassed by the following claims.

[ 00187 ] The use of figure numbers and/or figure reference labels in the claims is intended to identify one or more possible embodiments of the claimed subject matter in order to facilitate the interpretation of the claims. Such use is not to be construed as necessarily limiting the scope of those claims to the embodiments shown in the corresponding figures.

[ 00188 ] It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the invention.

[ 00189] Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.

[ 00190 ] Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term "implementation."

[ 00191 ] The embodiments covered by the claims in this application are limited to embodiments that (1) are enabled by this specification and (2) correspond to statutory subject matter. Non enabled embodiments and embodiments that correspond to non statutory subject matter are explicitly disclaimed even if they fall within the scope of the claims.

Claims

1. A system for providing energy from an oscillating-voltage, power generation subsystem (e.g., 320, 520, 620, 920, 1020, 1220, 1420, 1520, 1620, 1720) to an energy collection subsystem (e.g., 360, 560, 660, 960, 1060, 1260, 1460, 1560, 1660, 1760), the system comprising a DC-DC conversion subsystem (e.g., 350, 550, 650, 950, 1050, 1250, 1450, 1550, 1650, 1750) connected between the oscillating-voltage, power generation subsystem and the energy collection subsystem, wherein:

the energy collection subsystem has an energy-collection acceptance voltage;

the oscillating-voltage, power generation subsystem is configured to generate an oscillating-voltage output (e.g., LI, L2, L3) having low-voltage portions lower than the acceptance voltage and high- voltage portions higher than the acceptance voltage; and

the DC-DC conversion subsystem is configured to raise at least some low-voltage portions in the oscillating-voltage output to a voltage (e.g., BDC+) at least as high as the acceptance voltage, thereby allowing the energy collection subsystem to collect energy from the at least some low-voltage portions in the oscillating-voltage output.

2. The invention of claim 1, wherein:

the oscillating-voltage output from the oscillating-voltage, power generation subsystem is an AC output having the low- voltage portions and the high-voltage portions; the system further comprises a rectifier subsystem (e.g., 330/340, 540, 630/640, 940, 1030, 1230/1240, 1440, 1730/1740) configured to receive the AC output from the oscillating- voltage, power generation subsystem and provide a first rectified AC output (e.g., R2DC+) to the DC-DC conversion subsystem; and

the DC-DC conversion subsystem is configured to raise at least some low-voltage portions in the first rectified AC output to the voltage at least as high as the acceptance voltage, thereby allowing the energy collection subsystem to collect energy from the at least some low- voltage portions in the rectified AC output.

3. The invention of claim 2, wherein the rectifier subsystem is configured to provide energy (e.g., R1DC+) from at least some high-voltage portions in the AC output to the energy collection subsystem independent of a DC-DC conversion function of the DC-DC conversion subsystem.

4. The invention of claim 3, wherein the rectifier subsystem is configured to provide energy (e.g., R1DC+) from at least some mid-voltage portions of the AC output to the energy collection subsystem in conjunction with the DC-DC conversion function of the DC-DC conversion subsystem providing energy to the energy collection subsystem.

5. The invention of claim 2, wherein the rectifier subsystem is further configured to provide a second rectified AC output (e.g., R1DC+) to the energy collection subsystem bypassing the DC-DC conversion subsystem.

6. The invention of any of claims 2-5, wherein the rectifier subsystem comprises: a first rectifier (e.g., 330, 630, 1230, 1730) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide a second rectified AC output (e.g., R1DC+) to the energy collection subsystem bypassing the DC-DC conversion subsystem; and

a second rectifier (e.g., 340, 640, 1240, 1740) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide the first rectified AC output (e.g., R2DC+) to the DC-DC conversion subsystem.

7. The invention of claim 6, wherein the oscillating-voltage, power generation subsystem comprises a third rectifier (e.g., 1725) configured to provide a third rectified AC output (e.g., RADC+) to the energy collection subsystem bypassing the DC-DC conversion subsystem.

8. The invention of any of claims 2-5, wherein the rectifier subsystem comprises a first rectifier (e.g., 1030) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide the first rectified AC output both (i) to the DC-DC conversion subsystem (e.g., R2DC+) and (ii) to the energy collection subsystem bypassing the DC-DC conversion subsystem (e.g., R1DC+).

9. The invention of claim 2, wherein the rectifier subsystem comprises a first rectifier (e.g., 540, 940, 1440) connected to receive the AC output from the oscillating- voltage, power generation subsystem and configured to provide the first rectified AC output (i) to the DC-DC conversion subsystem (e.g., R2DC+) and (ii) not to the energy collection subsystem bypassing the DC-DC conversion subsystem.

10. The invention of claim 1, wherein:

the oscillating-voltage output from the oscillating-voltage, power generation subsystem (e.g., 1520) is an AC output (e.g., LI) having positive-voltage portions and negative-voltage portions;

the system further comprises a first rectifier (e.g., 1530) connected to receive the AC output from the oscillating-voltage, power generation subsystem and configured to provide a first rectified AC output (e.g., R1DC+) to the energy collection subsystem (e.g., 1560) bypassing the DC-DC conversion subsystem; and

the DC-DC conversion subsystem comprises:

a first DC-DC converter (e.g., 1531) configured to provide energy from at least some positive-voltage portions of the AC output to the energy collection subsystem; and a second DC-DC converter (e.g., 1532) configured to provide energy from at least some negative-voltage portions of the AC output to the energy collection subsystem.

11. The invention of claim 10, wherein the DC-DC conversion subsystem further comprises:

a comparator (e.g., 1570) configured to detect the positive-voltage portions and the negative-voltage portions in the AC output;

a first gate-driver and FET subsystem (e.g., 1581 and 1591) configured to route at least some detected positive-voltage portions of the AC output to the first DC-DC converter; and

a second gate-driver and FET subsystem (e.g., 1582 and 1592) configured to route at least some detected negative- voltage portions of the AC output to the second DC-DC converter.

12. The invention of claim 1, wherein: the oscillating-voltage output from the oscillating-voltage, power generation subsystem (e.g., 1620) is a DC-biased AC output (e.g., Ll+DCBias+) having the low-voltage portions and the high- voltage portions; and

the DC-DC conversion subsystem (e.g., 1650) is configured to reduce at least some high-voltage portions in the DC-biased AC output to a voltage (e.g., BDC+) closer to the acceptance voltage, thereby allowing the energy collection subsystem (e.g., 1660) to collect energy from the at least some high- voltage portions.

13. The invention of claim 1, wherein:

the oscillating-voltage output from the oscillating-voltage, power generation subsystem (e.g., 1620) is a DC-biased AC output (e.g., Ll+DCBias+) having the low-voltage portions and the high- voltage portions; and

the DC-DC conversion subsystem (e.g., 1650) is configured to raise at least some low-voltage portions in the DC-biased AC output to a voltage (e.g., BDC+) at least as high as the acceptance voltage, thereby allowing the energy collection subsystem (e.g., 1660) to collect energy from the at least some low- voltage portions.

14. The invention of claim 13, wherein:

the energy collection subsystem is connected to provide a DC bias (e.g., DCBias+) to the oscillating-voltage, power generation subsystem; and

the oscillating-voltage, power generation subsystem is configured to generate the DC- biased AC output based on the DC bias from the energy collection subsystem.

15. The invention of any of claims 1-14, wherein the DC-DC conversion subsystem is configured to limit energy applied to the energy collection subsystem.

16. The invention of any of claims 1-15, wherein the system further comprises the oscillating-voltage, power generation subsystem.

17. The invention of claim 16, wherein the system further comprises the energy collection subsystem.

18. The invention of any of claims 1-15, wherein the system further comprises the energy collection subsystem.

19. The invention of any of claims 1-18, wherein:

the oscillating-voltage, power generation subsystem is configured to operate during low-power periods and high-power periods; and

the DC-DC conversion subsystem is configured (e.g., R2, R3, Tl, ON/Off or RC1, RVCl, COMP) to reduce the energy collected by the energy collection subsystem during the low-power periods.

20. The invention of any of claims 1-19, wherein the oscillating-voltage, power generation system is a wind generator comprising:

blades configured to be rotated by wind power at a speed that causes noise generation; and

an alternator driven by the blades.

21. The invention of claim 20, wherein the system is configured such that the collection of energy from the low- voltage portions by the DC-DC conversion subsystem slows the speed of blade rotation and thereby reduces blade noise.

22. The invention of any of claims 1-19, wherein the oscillating-voltage, power generation subsystem comprises an engine-driven alternator having a rotation speed and having belt and pulley ratios.

23. The invention of claim 22, wherein the system is configured such that the collection of energy from the low- voltage portions by the DC-DC conversion subsystem allows the same amount of energy to be collected at lower rotation speed.

24. The invention of claim 23, wherein the collection of energy from the low- voltage portions by the DC-DC conversion subsystem allows the ratio of alternator rotation speed with respect to engine rotation speed to be reduced.

25. A method for providing energy from an oscillating-voltage, power generation subsystem (e.g., 320, 520, 620, 920, 1020, 1220, 1420, 1520, 1620, 1720) to an energy collection subsystem (e.g., 360, 560, 660, 960, 1060, 1260, 1460, 1560, 1660, 1760), wherein:

the energy collection subsystem has an energy-collection acceptance voltage; and the oscillating-voltage, power generation subsystem is configured to generate an oscillating-voltage output (e.g., LI, L2, L3) having low-voltage portions lower than the acceptance voltage and high-voltage portions higher than the acceptance voltage, the method comprising:

(a) receiving the oscillating-voltage output from the oscillating-voltage, power generation subsystem;

(b) converting at least some low- voltage portions in the oscillating-voltage output into converted portions having a voltage (e.g., BDC+) at least as high as the acceptance voltage; and

(c) providing the converted portions to the energy collection subsystem, thereby allowing the energy collection subsystem to collect energy from the at least some low-voltage portions in the oscillating-voltage output.

26. The invention of claim 25, wherein:

the oscillating-voltage output from the oscillating-voltage, power generation subsystem is an AC output having the low- voltage portions and the high-voltage portions; and

step (b) comprises:

(bl) converting the AC output received from the oscillating-voltage, power generation subsystem into a first rectified AC output (e.g., R2DC+); and

(b2) converting at least some low-voltage portions in the first rectified AC output into the converted portions having the voltage at least as high as the acceptance voltage, thereby allowing the energy collection subsystem to collect energy from the at least some low- voltage portions in the rectified AC output.