MXPA98007335A - Electric series circuit - Google Patents

Abstract

Un circuito eléctrico en serie con cargas plurales tales como focos conectados en serie y una pluralidad de dispositivos de interrupción de estado sólido, con cada dispositivo de interrupción conectado en paralelo con una de las cargas. Cada dispositivo de interrupción conduce corriente cuando la carga con la que estáconectada en paralelo no conduce corriente porque la carga se funde. Los medios de interrupción de estado sólido pueden ser cualquier dispositivo con un voltaje de ruptura que es suficientemente alto que no conduce cuando todas las cargas conducen corriente de manera normal. Cuando una de las cargas se funde, esa carga no conduce corriente y toda la línea de voltaje aparece a través de los medios de interrupción en paralelo con la carga fundida. Los medios de interrupción se abren. Por consiguiente, el medio de interrupción conduce corriente y la corriente fluye a las cargas restantes. Por consiguiente, los focos restantes en una cadena de focos continúa iluminando. Los medios de interrupción pueden ser un"sidac". Alternativamente, una combinación de un rectificador controlado por silicio y un diodo zener que controla la compuerta del rectificador controlado por silicio también se divulgan como los medios de interrupción. Un diodo puede reemplazar al diodo zener.

Description

^ ?? SERIAL ELECTRIC CIRCUIT FIELD OF THE INVENTION This invention relates to an electric circuit with plural loads connected in series, and more particularly, the invention relates to a series circuit that allows to identify a molten charge in a series for replacement . BACKGROUND OF THE INVENTION Serial electric circuits such as a series circuit * Low-voltage bulbs are known. The low voltage loads such as bulbs can be connected in series to conform a normal line voltage. This is the usual scheme of the "Christmas Tree" light chain. However, if a focus melts, the entire chain will shut down. For Christmas tree lights, this is not a big problem, because the strings of lights are not expensive and can be easily discarded and replaced. There are some types of these chains of lights that are intended to continue lit even if some bulbs have been extinguished. They use a spring as one of the terminals that connect to the filament of the focus. The spring keeps the filament in tension. When the filament is melts, the spring travels and makes contact with the other terminal for the filament, shorting said focus. There is no provision to prevent the voltage through the remaining bulbs from increasing. This increase in voltage could cause other sources to burn prematurely. At least one displacement Partially it might be possible to start with a minimum operating voltage of ^ 5 so that a small number of bulbs can be tolerated. In the decades of the 20s and 30s, municipalities used series circuits for street lights with the purpose of saving 5 in the cost of copper. To prevent the entire series circuit from opening if one of the spotlights was blown, the lamps in a high-voltage series circuit had bypass shields connected in parallel with them. If one of the lamps melted, then all the voltage of the series circuit goes to the deviation guard, which then becomes conductive and allows the rest of the circuit to continue in operation. In other lighting applications, the bypass shield was a thin paper disk placed between a pair of contacts in parallel with a focus for each focus connected in a circuit in series. The thin paper acted as insulation between the contacts and the current flowed through each bulb to ignite it. Only about one hundred volts passed through each bulb, which was not enough to burn the thin paper. However, if a focus melted, 5-10K volts passed through the contacts and burned the thin paper so that the contacts made connection. As a result, the current flowed in a path parallel to the molten focus and the remaining bulbs went on. A current regulator ensured that the remaining bulbs operated at their previous voltage. The above-mentioned series electric circuits do not provide an adequate solution to the problem of a complete chain of charges connected in series and therefore, the bulbs extinguished when a charge is melted for most applications. In many lighting applications, it is not possible to bear the cost of discarding the chain of bulbs connected in series. It is not desirable for the life of the remaining foci to be significantly diminished. Additionally, current regulators are expensive and bulky for low voltage lighting applications. Additionally, insulated film bypass protectors are not suitable for low voltage lighting. In addition, inserting thin paper discs into electrical circuits is not practical or efficient to meet modern standards for low voltage electrical lighting. Therefore, there is a need for a series electrical circuit for low voltage loads such as bulbs in which current flows through the plural charges of bulbs connected in series even if one or more of the charges is melted., to identify the load or charges fused to replace them. Additionally, a series electrical circuit is required that is practical for use in modern lighting applications. An electrical circuit in series is required that allows the current to flow through the loads of the foci that do not melt and that does not significantly reduce the life of the remaining bulbs. Additionally, a series electric circuit is required which has a simple and inexpensive construction and which allows the current to flow through f ^ a chain of loads connected in series such as foci, when one or more loads have gone off. A serial electrical circuit is required to ensure current flow to a string of series-connected loads such as bulbs when a bulb is fused and 5 does not require a current regulator. An electric circuit in series is required that allows the current to flow to a chain of loads connected in series when a load stops conducting current for low voltage loads. A low voltage series electrical circuit without a transformer is required. OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION A purpose of the invention is to provide an electrical circuit in series for serially connected plugs that ensure current flow to all remaining loads, even when a load does not drive. current. Another object of the invention is to provide an electrical circuit in series for plural charges connected in series that ensures the < 5 flow of current to a chain of charges, even when one or more loads does not conduct current and has a simple and inexpensive construction. Still another object of the invention is to provide an electrical circuit in series for plural loads connected in series that is practical to use and meets modern electrical standards for lighting applications and which ensures current flow to the remaining charges in the series when a or more loads do not drive current.

It is a further object of the invention to provide an electrical circuit in series for plural loads connected in series which ensures the flow of current to the remaining charges when one or more loads does not conduct current, which is practical to use and which does not require a regulator. expensive and bulky current, and that can be used for low voltage loads. Another additional object of the invention is to provide an electrical circuit in series for a chain of bulbs connected in * series that allows the remaining bulbs to be illuminated at a level reduced when a bulb is melted, so that the molten bulb can be identified and replaced immediately. Still another object of the invention is to provide illumination even if one or more bulbs are fused in an electrical circuit in series so that the area to which the bulbs serve no longer remains in complete darkness. These and other objects of the invention are achieved by providing an electrical circuit comprising plural charges connected in series, and a plurality of solid state interrupting means, each interrupting means being connected in parallel with one of the loads, wherein each interruption means conducts current when the load that is connected in parallel does not conduct current. In another embodiment of the invention, a method for energizing plural low voltage loads connected in series, even if one or More loads stops conducting current comprises connecting the solid-state interrupting means in parallel with each low-voltage load, and conducting current through one of the interrupting means to pass current to the remaining loads when a load in parallel with the interrupting means stops 5 from driving current. The objects, aspects, characteristics and advantages mentioned above and others of the invention will be readily apparent from the description of the preferred embodiments, taken in conjunction with the accompanying drawings and the claims annexes. BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which similar numbers denote similar and corresponding parts in which: Figure 1 is an electrical diagram schematic of the electric circuit with plural charges connected in series according to the present invention; Figure 2 is a schematic electrical diagram of an electrical circuit with plural loads connected in series employing "sidacs" for interrupting means in accordance with an embodiment of the present invention; Figure 3 is a schematic electrical diagram of an electric circuit with plural charges connected in series with a The combination of zener diode and silicon-controlled rectifier for interruption means according to a second embodiment of the present invention; Figure 4 is a curve of the current-voltage characteristics of the zener diode used in the electrical circuit illustrated in Figure 3; Figure 5 is a curve of the current-voltage characteristics of the "AIDS" used in the electrical circuit illustrated in Figure 2; Figure 6 is a schematic electrical diagram of a electrical circuit with plural charges connected in series using "sidacs" in series with diodes for interruption means in accordance with another embodiment of the present invention; Figure 7 is a schematic electrical diagram of an electric circuit with plural charges connected in series with a combination of diodes in series and zener diode, silicon-controlled rectifier for interruption means in accordance with another embodiment of the present invention; Figure 8A illustrates the "sidac" versus time voltage for the circuit of Figure 2; Figure 8B illustrates the lamp voltage versus time for the circuit of Figure 2; Figure 9A illustrates the voltage of the combination of diode and "sidac" versus time for the circuit of Figure 6; Figure 9B illustrates the lamp voltage versus time for the circuit of Figure 6; '# Figure 10 is a graph of the voltage across individual receptacles that contain foci compared to the voltage through individual receptacles that do not have foci, based on the number of 24 volt bulbs removed from the circuit in series of the present invention. Figure 11 is a schematic representation of 10-12 volt bulb modules in series. Figure 12 is an electrical diagram of another embodiment of a module using a rectifier interrupting means controlled by silicon and zener diode. Figure 13 is a graph of the voltage across individual receptacles containing foci compared to the voltage across individual receptacles without foci based on the number of 12-volt foci removed from the series circuit of the present invention. Figure 14 is a graph that lists the maximum current and voltage of focus for 12 volts and 24 volts. Figure 15A is a graph of the voltage measured across the five 24-volt modules with one focus off and two bulbs 20 off. Figure 15B is a graph of the voltage measured across the ten 12-volt modules with one, two, three and four off bulbs. Figure 16 is a schematic electrical diagram of a 12-volt module employing a silicon-controlled rectifier, zener diode and diode as the interrupting means and a transient voltage overvoltage eliminator. Figure 17 is a schematic electrical diagram of a 12 volt module that can be placed in series with the module of Figure 16. Figure 18 is an electrical representation of the modules of Figure 17 connected in series with a surge voltage eliminating device transient through the lines of -é power supply. Figure 19 is a schematic representation of the bulbs of 24-volt modules connected in series with a transient voltage overvoltage eliminator device across the power supply lines. Description of preferred embodiments With reference to Figure 1, an electrical circuit with plural charges connected in series is shown. The electrical circuit according to the invention, as shown in Figure 1, comprises plural charges 12, 14, 16, 18 and 20 connected in series through a voltage source 22 of voltage + A, which can be 120 volts, for example. The actual voltage may be in the range of 10% less than the nominal (120 volts) to 10% above the nominal. The load 20 is represented by interrupted lines to indicate that no current is flowing due to a molten filament, for example. The charges 12, 14, 16, 18 and 20 are represent as resistors. Loads can be foci such as low voltage bulbs that have a low impedance. For example, five 12 volt bulbs can be used through a 120 volt source 22 if a serial diode is connected in series with each bulb. If serial diodes are not used, loads of 5 12-volt bulbs each are used for a source 22 of 120 volts. Alternatively, as illustrated in Figure 1, five 24 volt bulbs are employed through a 120 volt source 22. The charge focus 20 melts as illustrated in Figure 1 * through interrupted lines. Therefore, all the voltage of 120 volt supply from source 22 appears through the terminals for charging head 20. A voltage of 120 volts appears through nodes E and F. Also illustrated in Figure 1, interrupting means are shown 24 , 26, 28, 30 and 32. When 120 volts appear through the nodes E and F because the focus of load 20 has melted, the interruption means 32 starts to conduct current. Accordingly, the molten state of the charging head 20 does not open the circuit and the current anyway flows through the charging bulbs 12, 14, 16 and 18. Consequently, the remaining charging bulbs 12, 14, 16 and 18 remain on a reduced level, which allows the molten charge focus 20 to be immediately identified for replacement. Therefore, the invention allows the series electrical circuit to operate with a molten focus. More than one load center could melt and the circuit will still operate, however, extra effort is exerted on the remaining charging lights.

The number of foci to use N in a chain of foci is equal to: N = total line voltage / focus voltage N = 120 volts / 24 volts = 5 for the circuit of Figure 1. Where the focus voltage of each focus is the same. Interrupt means 24, 26, 28, 30 and 32 are solid state devices that do not conduct current when a low voltage such as 12-24 volts is applied across the terminals of the device. However, when a high voltage such as a line voltage (120 volts) appears through the terminals of the solid state devices, they conduct current. Thus, the interrupting means 24, 26, 28, 30 and 32 with ideally solid-state switching devices having current-voltage characteristics including a breaking voltage Vt where current conducts. When the charging head (such as charging head 20) stops conducting current (because it burns), all the supply voltage of the source 22 appears through the terminals of the solid-state interrupting medium 32. The voltage The rupture medium of the interruption means 32 is reached and the interruption means 32 conducts current. The electrical circuit of the present invention employing solid state devices as interrupting means is ideal for low voltage lighting applications. Candelabrum circuits are an application of this type. Other applications include cabinet lighting, emergency lighting, ß lights for the hallways of theaters such as cinemas, and lights for use on exit signs, for example. In low-voltage lighting, a series circuit of charge bulbs through a voltage supply eliminates the need for a step-down transformer, which is 5 bulky, or the use of high-frequency illumination, which generates interference and noise On the line. Instead, a series of low-voltage charging bulbs is connected in series for use in lighting fixtures and other combinations. Low voltage is appropriate for the use of solid state devices. Figure 2 illustrates the electrical circuit with plural charges connected in accordance with a first embodiment of the present invention. In Figure 2, the interruption means are solid state devices known as "sidacs". Each "sidac" 24 ', 26', 28 ', 30' and 32 'is illustrated within the interrupted lines.

The "sidacs" employed in the first embodiment illustrated in Figure 2 have current-voltage characteristics as illustrated in Figure 5. A "sidac" is a solid state device that is bidirectional as illustrated in Figure 5 The current-voltage characteristics of a "sidac" are symmetrical. When a However, as the current increases there is a sudden decrease in voltage of the breakdown voltage Vt in the forward and reverse directions. The breaking voltage Vt is reached through the terminals of an interrupting device such as a "sidac" 32 'when the focus of load 20 melts and all supply voltage from voltage source 22 appears through nodes E and F and through "sidac" 32 '. When the breaking voltage Vt is reached, the "sidac" 32 'conducts current so that the remaining charging bulbs 12, 14, 16, and 18 remain on. As strated by the current-voltage curve of Figure 5, after "sidac" 32 'reaches the breaking voltage Vt, the voltage across the "sidac" 32' substantially decreased. As the current increases, a small voltage of 2-3 volts appears through the "sidac" 32 'while conducting current. In this way, most of the voltage of the source of supply voltage 22 appears through the four remaining charging bulbs 12, 14, 16 and 18. The "sidacs" 24 ', 26', 28 ', 30' and 32 'can be components manufactured by Teccor. The "sidac" in the TO-92 configuration is a device for 95- 170 volt applications. The "AIDS" are connected to the receptacle of each load focus on the chain in series.

Figure 3 illustrates a second embodiment of the electric circuit with plural charges connected in series of the present invention. In Figure 3, the interruption means are illustrated as combinations of zener diode and rectifier controlled by silicon. As illustrated in Figure 3, each interruption means 24", 26", 28", 30" and 32"includes a silicon-controlled rectifier 34, a zener diode 36 and the resistor 38. The silicon-controlled rectifier 34 The anode of the silicon-controlled rectifier 34 is at a higher voltage than the cathode of rectifier controlled by silicon. Then, for example, silicon-controlled rectifier 34 of the interrupting means 24"has an anode connected to the + A terminal of the voltage source 22 and a cathode connected to the node B. The zener diode 36 is connected between the rectifier gate controlled by silicon 34 and the 5 anode of the silicon-controlled rectifier 34. The cathode of the zener diode 36 is connected to the gate of the silicon-controlled rectifier 34, through a current limiting resistor 38. The zener diode 36 , has a voltage of 1 00 volts, Figure ß 4 illustrates the current-voltage characteristics of the zener diode 36.

The Vt in Figure 4 is 100 volts. The use of a unidirectional device such as the silicon-controlled rectifier 34 is preferred over the use of a bidirectional device, such as the "sidacs" 24 ', 26', 28 ', 30' and 32 'because when it is melted any focus, the remaining bulbs receive voltage and half-wave current and the RMS voltage falls below the nominal operating voltage of the bulbs. This ensures that the life of the remaining lit bulbs is not reduced during the time they are turned on before a good replacement bulb is found. 20 In operation, when none of the loading bulbs 12, 14, 16, 18 and 20 are melted (all the bulbs are on), the 120 volts of the voltage supply 22 are distributed through the series circuit. Therefore, approximately 24 volts appear through each interruption medium 24", 26", 28", 30" and 32". is not sufficient for the breaking of the zener diode 36. Additionably, the silicon-controlled rectifier 34 does not conduct until a current appears in its door. However, there is no current in the gate of the silicon-controlled rectifier 34 until the zener diode 36 opens and conducts. When the charging head 20 is blown, all 120 volts of the voltage supply 22 appear through the nodes E and F. Therefore, more than 1000 volts appear through the zener diode 36. Therefore, the diode zener 36 opens and conducts in the reverse direction generating a current in the gate of the silicon controlled rectifier 34. The silicon-controlled rectifier 34 begins to conduct allowing current to flow through the remaining charge bulbs 12, 14, 16, and 18 so that they remain lit. The silicon-controlled rectifier 34 can be component number 2N5064. The zener diode 36 may be the number 1 component N5378 with a breakdown voltage of 100 volts. The charging bulbs 12, 14, 16, 18 and 20 are represented as resistors. The resistance of the charging bulbs can be 48 ohm. In a prototype of Figure 3, the silicon-controlled rectifier 34 is a 0.8-ampere sensing gate element such as Part No. OX-3691 1 -89-00-00 of Leviton Man ufacturing Co., I nc. the assignee of the present invention. The resistor 38 is a resistor of 1000 k ohms, VA wat and the zener diode 36 is a 62 volt, 250 MW (minimum) element.

The "sidacs" 24 ', 26', 28 ', 30' and 32 'lead in both directions. Even when the "sidac" does not start to drive until the voltage across it exceeded its breakdown voltage, thus reducing the voltage through the remaining lamps. The 5 experiments have shown that the "true RMS voltage" through each of the remaining lamps was at the upper end of the maximum measured lamp voltage. One solution is to include a diode in series with each "sidac", so that the combination drives • SR only in one direction. This is not necessary in the circuit of Figure 3, since the silicon-controlled rectifier 34 conducts in only one direction. When the zener diode 36 conducts in the reverse direction because the charging source 20 is blown, the voltage across the remaining charging bulbs 12, 14, 16 and 18 is less than 24 volts. 15 Therefore, the remaining bulbs still light at a reduced level. The molten charge focus 20 can be immediately identified for replacement. Continuous operation with molten focus is allowed. ii-smá = Isc max- where lBmá? is the maximum current of focus and 20 cRmá is the maximum rectifier current controlled by silicon. VTz > VPb, where VTz is the breakdown voltage of the zener and VPb is the peak voltage across any focus before it melts. As discussed above, the "sidacs" 24 ', 26', 28 ', 30' and 32 'of Figure 2 have the current-voltage characteristics as illustrated in Figure 5. After the voltage # of break Vt is reached in the "sidacs". The voltage drops significantly as the current increases. This differs from the operation of the zener diodes 36 of Figure 3, which have the current-voltage characteristics as illustrated in Figure 4. 5 Other circuits and / or solid-state components can be employed for the state-interrupting means solid 24, 26, 28, 30 and 32 of Figure 1. A half-wave "sidac" could be sent. Said component * Reduce the RMS voltage when one or more bulbs melt, resulting in the voltage remaining within the limits of the values for the remaining bulbs. Alternatively, a diode 39 could be placed in series with the "sidac", as illustrated in Figure 6. In another alternative, a diode 40 could be placed in the rectifier gate controlled by silicon in series with the zener diode as illustrated in Figure 7. The diode 40 prevents the gate cathode function of the silicon-controlled rectifier from opening when the anode voltage polarity is negative. The diodes reduce the RMS voltage and avoid excess voltage through the remaining bulbs to increase the life of the spotlights. In Figure 3, the zener diodes 36 could be replaced with the diodes. The sum of the voltages of the bulbs must be equal to the total line voltage, 120 volts here. The circuit requires that the current through each focus be the same, since the current must be constant in a series circuit. The line voltage could ^ be 1 10, 220 or 240 volts, provided that the sum of the voltages of the bulbs is equal to the line voltage. One or more visual or audible indicators may be used in the circuit when one or more bulbs are melted, so that the user knows that he has to look for the bulb (s) to replace them. Each replacement of molten bulbs increases the life of the remaining bulbs. Preferably, the indicator does not signal until two or more bulbs melt so that it is not a nuisance when only one bulb is melted. The lighting is already affected if two or more bulbs are melted, so an additional discomfort through an indicator informing that it is time to change bulbs may be appropriate. The indicator can be a visual indicator such as a lamp, a light-emitting diode, a neon lamp, a crystal Liquid, or an audible indicator such as a vibrator or annunciator.

T lPt. For example, the indicator may be a piezoelectric transducer. A visual or audible indicator may be of a variety that includes flashing circuits included that turn the indicator on and off intermittently. The indicator can be placed in series with the interruption means as illustrated in reference number 41 in Figure 6. Alternatively, a separate indicator may be placed in series with or through each interruption means as illustrated by reference number 42 in Figure 6. The appropriate circuits for the indicator accompany each indicator of compliance with known techniques.

Figure 8A illustrates the voltage waveform for a "sidac" in series with a diode against time for the circuit of Figure 6. Figure 8B illustrates the waveform of the positive voltage of the focus against time for the circuit of Figure 2. Figures 5 9A and 9B are waveforms for the circuit of Figure 6 without the optional indicators 41 and 42. Figure 9A illustrates the waveform of the voltage across the "sidac" and the diode against time for the circuit of Figure 6. Figure 9B illustrates the waveform of the -fc positive voltage of the focus against time for the circuit of Figure 6.

A circuit of five 24-volt bulbs was constructed in accordance with Figure 3 for a source of 120 volts, 60 Hertz. Each or both lights can be fused and the remaining lights work, providing the user with information about which lights have been fused and not turning off the remaining lights.

All the bulbs in the circuit had the same current value, power value, and lighting power value. Any replacement bulb is identical to the remaining bulbs. The type of spotlights that will be used are lighting spotlights 2860X-2 TH HC or its equivalent. All measurements were made with a real RMS meter. The Figure 10 is a graph showing the voltages when one and two foci are removed (simulating melting). Figure 1 1 illustrates a circuit of ten 12-volt bulbs similar to the circuit in Figure 3 but with more bulbs in series and low-voltage bulbs. Each module is as illustrated in Figure 12. In In the case of the circuit of Figure 11, one, two, three or four bulbs can be melted and the rest will still work. All the bulbs in the built circuit had the same current value, energy value and lighting energy value as before. The type of spotlights that will be used are lighting bulbs 1250X-2-TH HC or its equivalent 5. Any replacement bulb is identical to the remaining bulbs. All measurements were made with a real RMS meter. Figure 13 is a graph showing the voltages when one, two, three and four bulbs are removed (simulating that they are fused). The silicon-controlled rectifier is Part No. OX-10 3691 1 -89-00-00 of Leviton Manufacturing Co., I nc. , the owner of the present invention. The resistor is a resistor of 10 Kohm,% wat and the zener diode is a 60 volt zener. Figure 14, provides the maximum values of current / power of focus for the circuits of five foci of 24 volts and 10 bulbs of 12 volts built. Figure 15A is a graph showing the voltage values across the five 24 volt bulbs of the circuit of Figure 3 with one and two bulbs turned off. Figure 15B is a graph that shares the voltage readings through the 10 foci of 12 volts of the circuit of Figure 1 1 with one, two, three and four fused spotlights. The different charging sources, for example, foci 12, 14, 16, 18 and 20, may be in separate locations between them or may be concentrated in a single device such as a candelabra containing all the bulbs, each ß connected in series with the remaining bulbs. To provide transient voltage protection, a metal oxide varistor 50 is placed through the poles of the power supply 52, 54 of the current source 22 of 120 volts to the 5 modules 56, as shown in Figure 16. The mod u 56 is similar to the module of Figure 7, except that there is a current limiting resistor R-¡for the zener diode Zi co located at the anode of the silicon-controlled rectifier. Also a resistor R2 is flt coupled between the gate and the cathode of the controlled rectifier per silicon to provide a path for the leakage current from the anode to the door to be diverted to ground, preventing the silicon-controlled rectifier from turning on at a high temperature. Only one metal oxide varistor is required to protect the entire chain from the charging bulbs. The rest of the chain is formed of the modules 58 (see Figure 1 7) designated "modules Y" containing all the elements of the module 56, with the exception of the metal oxide varistor 50. Alternatively, all the modules used may be the Y modules 58, connected in series 60 with a single metal oxide varistor 50 connected through the start of the module chain at the tip 52 of the power source 22 to the end of said chain 60 of ten 12 volt charge lamps at the tip 54 of the source 22 as shown in Figure 1 8. This allows a medium simple and method to protect a number of modules located at a common point. 25 The parts and values of common components for the mod u lo ß 56 were a 60 volt zener diode for Zi; a resistor of 1 Kohm VA of wat for Ri and R2; the rectifier controlled by silicon was a TECCOR, PART # S401 E, the diode D1 is part number 1 N4004 and the metal oxide varistor is 150 volts, part 5 Leviton # X39676-89-00-00. The components for the module 58 are the same as those of the module 56, with the exception of the absence of the metal oxide varistor. Modules 56 and 58 for a strip of five charging lamps < ^ ß-L of 24 volts 62, would be the same as modules 56 and 58, respectively, of the strip of the 12-volt charging lamp, except that the zener diode Z1 would have a value of 120 volts instead of the value 60 volts of the devices 16 and 17. The metal oxide varistor 50 is connected from the first input to the first module Y to the output of the last module Y in the chain 62.

As is well known, metal oxide varistors are generally at high impedance when subjected to normal operating voltages and conduct low current. At higher voltages, the impedance of the metal oxide varistor decreases significantly allowing the current to bypass the chains of the charging bulbs 60 and 62. The invention also contemplates the method of energizing, plural low voltage charges connected in series even when one or more loads stop conducting current. The solid-state interruption means are connected in parallel with each load of low voltage. The current is conducted through a means of interruption to pass current to the remaining charges when a load in parallel with the interrupting means stops conducting current. Where each load is a low voltage source, current flows through the circuit to illuminate the remaining bulbs when one or more bulbs are melted because the interrupting means in parallel with the molten spot (s) conducts current to the rest of the bulbs . Although the invention has been described with reference to 9L preferred embodiments, will be apparent to those skilled in the art that variations and modifications are contemplated within the spirit and scope of the invention. The drawings and description of the preferred embodiments are made by way of example rather than to limit the scope of the invention, and it is intended that said changes and modifications be covered within the spirit and scope of the invention. nvention. * twenty

Claims (54)

1. ß CLAIMS 1. An electrical circuit comprising: a) plural charges connected in series; and b) solid state plural interruption means, each of said interruption means connected in parallel with one of said loads; c) wherein each such interrupting means conducts current when the load that is connected in parallel & t that does not conduct current.
2. 2. The electrical circuit of claim 1, wherein each solid-state interruption means comprises a "sidac".
3. 3. The electrical circuit of claim 1, wherein each solid-state interruption means comprises a device that is bidirectional, and has current-voltage characteristics that are symmetrical, and includes a breakdown voltage where the current B drives and there is a sudden reduction in voltage of the breakdown voltage as the current increases in the forward and reverse directions.
4. 4. The electrical circuit of claim 3, wherein each solid state interruption means comprises a "sidac".
5. The electrical circuit of claim 3, wherein each solid-state interruption means comprises a "sidac" and a diode is connected in series with the sidac.
6. The electrical circuit of claim 1, wherein each solid-state interruption means comprises: ß a) a silicon-controlled rectifier connected through the load in parallel with the load; b) an anode of said rectifier controlled by silicon at a voltage greater than a cathode of said rectifier 5 controlled by silicon; and c) a zener diode connected between a gate and said anode of such a silicon controlled rectifier.
7. 7. The electrical circuit of claim 6, wherein a cathode of said zener diode is connected to each said anode of said The rectifier controlled by silicon and an anode of said zener diode is operatively connected to such a gate of said silicon-controlled rectifier.
8. The electrical circuit of claim 7, wherein the anode of said zener diode is connected to the gate of such a silicon-controlled rectifier via a resistor.
9. 9. The electrical circuit of Claim 1, wherein each solid-state interruption means comprises: a) a silicon-controlled rectifier connected through the load in parallel with the load; B) an anode of said rectifier controlled by itself at a voltage greater than a cathode of said silicon-controlled rectifier; and c) a diode connected between a gate and said anode of such a silicon controlled rectifier.
10. 10. The electric circuit of claim 1, wherein each solid-state interruption means has current-voltage characteristics that include a breaking voltage where the current conducts.
11. The electrical circuit of claim 3, wherein said breaking voltage is reached when said load stops conducting current.
12. The electrical circuit of claim 10, wherein said breaking voltage is reached when said load stops conducting current.
13. 13. The electrical circuit of claim 1, wherein each of said loads is a low voltage load.
14. 14. The electrical circuit of claim 1, wherein each of said loads is a focus.
15. The electric circuit of claim 1, wherein the current flows through said circuit to illuminate the charge of remaining bulbs even when one or more charging bulbs are melted since the interrupting means in parallel with such molten focus lead current to the rest of the charging lights.
16. 16. A method of energizing plural low voltage loads connected in series even if a load stops conducting current, comprising: a) connecting such solid state interrupting means in parallel with each of said low voltage load; and b) driving current through one of said interruption means to pass current to the remaining loads when a load in parallel with such interrupting means stops conducting current.
17. 17. The method of claim 16, wherein each of the interruption means is a "sidac".
18. The method of claim 16, wherein each of the interrupting means comprises a device that is bidirectional, and has current-voltage characteristics that are symmetrical, and include a breakdown voltage where the current conducts and a decrease sudden voltage in the breakdown voltage as the current increases in the forward and reverse directions.
19. 19. The circuit of the method of claim 18, wherein each of said interruption means comprises a "sidac".
20. 20. The circuit of the method of claim 18, wherein each of said interruption means comprises a "sidac" and a diode is connected in series with such "sidac".
21. The method of claim 16, wherein each of said interrupting means comprises: a) a silicon-controlled rectifier connected through the load in parallel with the load; b) an anode of said silicon-controlled rectifier at a voltage greater than a cathode of said silicon-controlled rectifier; and c) a zener diode connected between a gate and said * anode of such a silicon-controlled rectifier.
22. 22. The method of claim 21, wherein a cathode of said zener diode is connected to said anode of said silicon-controlled rectifier and an anode of said zener diode is connected to said anode. 5 operatively to such door of said silicon-controlled rectifier.
23. 23. The method of claim 16, wherein each of said interrupting means comprises: ß a) a silicon-controlled rectifier connected through the load in parallel with the load; b) an anode of said rectifier controlled by silicon at a higher voltage than a cathode of said silicon-controlled rectifier; and c) a diode connected between a gate and said anode of said silicon controlled rectifier. ß
24. 24. The method of claim 16, wherein each solid state interruption means has current-voltage characteristics that include a breakdown voltage where the current conducts.
25. 25. The method of claim 1, wherein said breaking voltage is reached when said load stops conducting current.
26. 26. The method of claim 24, wherein said breaking voltage is reached when said load stops conducting current.
27. 27. The method of claim 16, wherein each of said loads is a focus.
28. 28. The method of claim 1, wherein the current flows through said circuit to illuminate the remaining focus charges even when a focus charge melts since the interrupting means in parallel with such molten focus charge conducts current to the remainder of the focus areas.
29. 29. A solid-state interruption circuit coupled in parallel with a low-voltage load and through a source of two AC power lines so that the current flows through such a circuit. interruption when the current can not flow through such a load comprising: a) a silicon-controlled rectifier having an anode terminal, a cathode terminal and a gate terminal; b) first means for coupling said anode terminal to one side of a load and to one line of said AC power source; c) second means for coupling said cathode terminal to the second side of a load and to the second line of said AC power source; and d) a conduction control circuit connected between said gate terminal and said anode terminal.
30. 30. A solid state interrupting circuit, as defined in claim 29, wherein said conduction control circuit comprises a zener diode.
31. 31 A solid-state interrupting circuit, as defined in claim 29, wherein said driving control circuit comprises: a) a zener diode; and b) a diode.
32. 32. A solid state interrupting circuit, as defined in claim 29, wherein said conduction control circuit comprises: a) a zener diode having an anode and a cathode; b) a diode having a diode anode and a diode cathode; c) d or diode cathode coupled to such gate term; d) said diode anode coupled to said anode terminal; and e) said zener diode anode coupled to such a diode anode.
33. 33. A solid state interruption circuit, as defined in claim 32, further comprising a resistor between said zener diode cathode and said anode terminal.
34. 34. A solid-state interrupting circuit, as defined in claim 29, further comprising: a) a transient voltage overvoltage eliminator coupled through said two lines of such an AC power source.
35. 35. A solid state interrupting circuit, as defined in claim 33, further comprising a transient voltage overvoltage eliminator coupled through the two aforementioned lines of said AC power source.
36. 36. A system for maintaining the flow of current through * a series connection of a plurality of low voltage cables when at least one of the low voltage loads is non-conductive comprising: a) a plurality of circuits of solid state interruption, 5 one for each of several plurality of low voltage loads, each of such solid state interrupting circuits coupled in parallel with one of the aforementioned low voltage loads so that current flows to through ß such an interruption circuit when the current can not fl ow through an associated low-voltage load; b) a source of two AC power conductors; c) each or both of the aforementioned solid state interruption comprising a silicon-controlled rectifier having an anode terminal, a cathode terminal and 15 a term of the door; d) first means for coupling said anode terminal of each of said silicon controlled rectifiers to one side of an associated load and to a conditor of said AC power source; 20 e) sec means for coupling said cathode terminal of each of said silicon-controlled rectifiers to the other side of an associated load and to the second conductor of said AC power source; and f) a driving control circuit connected between each 25 one of the anode terminals and gate of the silicon-controlled rectifier.
37. 37. A system, as defined in claim 36, wherein each of said driving control circuits comprises a zener diode.
38. 38. A system, as defined in claim 36, wherein each of said conduction control circuits comprises: a) a zener diode; and ß b) a diode.
39. 39. A system, as defined in claim 36, wherein each of said control control circuits comprises: a) a zener diode having an anode and a cathode; b) a diode having a diode anode and a diode cathode; 15 c) each of said diode cathodes coupled to an associated gate terminal of the controlled rectifier t ^ j - * by silicon; d) each of said diode anodes coupled to an associated gate terminal of the controlled rectifier 20 for silicon; and e) each of said zener diode anodes coupled to said diode anode.
40. 40. A system, as defined in claim 39, additionally comprising: a) a plurality of resistors, each coupled between said ß-associated zener diode cathode and a therm of said associated anode.
41. 41 A system, as defined in claim 36, further comprising: a) U n the transient voltage overvoltage inductor coupled through said two conductors of said AC power source.
42. 42. A system, as defined in claim 40, comprising additionally:
43. 43. A solid-state interrupting circuit coupled in parallel with a low-voltage load so that current flows through said circuit. interruption circuit when the current can not flow through such a load comprising: a) a silicon-controlled rectifier having an anode terminal; ß b) first means for coupling said anode terminal to one side of a load; c) second means for coupling said cathode terminal to the second side of said load; and 20 d) a conduction control circuit connected between said gate terminal and said anode terminal.
44. 44. A solid state interruption circuit, as defined in claim 43, wherein said conduction control circuit comprises a zener diode.
45. 45. A solid-state interruption circuit, as defined in claim 43, wherein said conduction control circuit comprises: a) a zener diode; and b) a diode.
46. 46. A solid state interruption circuit, as defined in claim 43, wherein said conduction control circuit comprises: a) a zener diode having an anode and a cathode; b) a diode that has a diode anode and a diode cathode; c) said diode cathode coupled to such a gate thermistor; d) said diode anode coupled to said anode terminal; and e) said zener diode anode coupled to such a diode anode.
47. 47. A solid-state interrupting circuit, as defined in claim 46, further comprising: a) a resistor between said zener diode cathode and said anode terminal.
48. 48. A system for maintaining the flow of current through a series connection of a plurality of low voltage loads when at least one of the low voltage loads is non-conductive comprising: a) a plurality of circuits of solid-state interruption, one for each of said plurality of low-voltage loads, each of said solid-state interruption circuits coupled in parallel with one of said low-voltage loads so that the current flows through of said interruption circuit when the current can not flow through an associated low voltage load; b) each of said solid state interruption circuits has an input terminal and an output terminal; c) means for connecting said output terminals of said solid-state interrupting circuits to said adjacent solid-state interruption circuit input terminals to place said solid-state interruption circuits in an open-ended string; d) each of said solid-state interruption circuits comprising a silicon-controlled rectifier having an anode terminal, a cathode terminal and a gate terminal; e) first means for coupling said anode terminal of each of said silicon controlled rectifiers to one side of an associated load; f) second means for coupling said cathode terminal of each of said silicon controlled rectifiers to the other side of an associated load; and g) a plurality of conduction control circuits, one for each of said solid-state interruption circuits, each connected between said anode terminals and silicon-controlled rectifier gate.
49. 49. A system as defined in claim 48, wherein each of said driving control circuits 5 comprises a zener diode.
50. 50. A system as defined in claim 48, wherein each of said driving control circuits comprises: ß a) a zener diode; and 10 b) a diode.
51. 51 A system as defined in claim 48, wherein each of said conduction control circuits comprises: a) a zener diode having an anode and a cathode; 15 b) a diode having a diode anode and a diode cathode; c) each of said diode cathodes coupled to an associated gate terminal of the silicon controlled rectifier; d) each of said diode anodes coupled to an associated gate terminal of the silicon controlled rectifier; and e) each of said zener diode anodes coupled to said diode anode.
52. 52. A system as defined in claim 51, 25 further comprising: a) a plurality of resistors, each coupled between a zener diode cathode and a terminal of said associated anode.
53. 53. A system, as defined in claim 48, wherein: a) said input terminal of a first such solid state interrupting circuit is coupled to a conductor of an AC power source; and b) said output terminal of the last such solid state interruption circuit in said chain is coupled to the other conductor of said AC power source.
54. 54. A system, as defined in claim 53, further comprising a transient voltage overvoltage eliminator coupled between said two conductors of said AC power source. RESU MEN An electrical circuit in series with plural loads such as bulbs connected in series and a plurality of solid-state interrupting devices, with each interrupting device connected in parallel with one of the loads. Each interrupting device carries current when the load with which it is connected in parallel does not conduct current because the load melts. The solid state interrupting means can be any device with a breaking voltage that is high enough that it does not conduct when all loads conduct current in a normal manner. When one of the charges melts, that charge does not conduct current and the entire voltage line appears through the interrupting means in parallel with the molten charge. The means of interruption open. Accordingly, the interrupting means conducts current and the current flows to the remaining loads. Consequently, the remaining bulbs in a chain of spotlights continue to illuminate. The means of interruption can be a "sidac". Alternatively, a combination of a silicon-controlled rectifier and a zener diode that controls the gate of the silicon-controlled rectifier are also disclosed as the means of interruption. A diode can replace the zener diode.