JP2013115924A - Charger - Google Patents

Abstract

[PROBLEMS] There is a problem that a charging battery in which a battery voltage gradually rises such that a battery voltage drop cannot be detected rarely exists among charging batteries, so that charging cannot be completed in an intended time.
A control unit for controlling power supply to a rechargeable battery, a rechargeable battery mounting unit for mounting a rechargeable battery, a voltage detecting unit for detecting a charging voltage of the rechargeable battery, and also detecting the temperature of the rechargeable battery And a display unit for detecting a voltage drop at the end of charging of the rechargeable battery by the voltage detecting unit and displaying the full charge after the detection, a predetermined timing is provided by the voltage detecting unit. The charger provided with the determination part which detects the amount of change of the voltage of the charging battery per unit time detected by (1) and determines completion of charging or continuation of charging based on a preset threshold value.
[Selection] Figure 1

Description

  The present invention relates to a charger that detects the voltage and temperature of a charging battery when charging a plurality of charging batteries individually, and can complete charging in a substantially appropriate time even for a charging battery that is difficult to complete charging. It is.

  In recent years, from the viewpoint of environment and ecology, the use of nickel metal hydride batteries that can be reused when charged in the same form as single- to single-size dry batteries is increasing. Many chargers for charging the rechargeable battery are also provided.

  For charging control of these chargers, generally, a method of detecting a drop in battery voltage at the end of charging by a microcomputer or IC (hereinafter referred to as a -ΔV method), or a method of completing charging after the charging time has elapsed by a charging timer. In many cases, charging control is performed by the following method (hereinafter referred to as a timer method). (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 9-261884

  In the case of the -ΔV method in which the battery voltage drop at the end of charging is detected by a microcomputer-controlled charger as in Patent Document 1, the voltage drop from the peak voltage and the peak voltage of the charging battery do not appear remarkably. It is difficult to determine when charging should be stopped for a rechargeable battery whose voltage gradually increases or a rechargeable battery that needs to be charged with a low charging current. Since such a rechargeable battery exists, there is a problem that charging is continued without completing charging in an appropriate charging time, and the battery is overcharged to promote deterioration of the rechargeable battery.

  In the present invention, it is necessary to perform charging with a charging battery in which the voltage gradually rises without causing a voltage drop from the peak voltage or the peak voltage of the charging battery to appear remarkably, or with a low charging current. An object of the present invention is to provide a charger that solves the problem that charging of a rechargeable battery or the like does not stop and that prevents overcharging of the rechargeable battery.

  In order to achieve the above object, the present invention connects a current control unit connected to an external power supply unit to a plurality of rechargeable batteries via a voltage input switching unit, and a temperature detection unit and a voltage detection unit of the rechargeable battery. And a charger including a determination unit that determines detection data of the voltage drop detection unit from the peak voltage and a control unit that controls the current control unit and the voltage input switching unit based on a determination result of the determination unit. As a unit, the control is performed as a charge completion by the detection signal of the voltage drop detection unit from the peak voltage, and by setting a threshold value for the voltage increase width per unit time, charging is continued in a sudden voltage increase and a gentle voltage The battery charger is characterized in that charging is completed in the case of ascending.

  By adopting the configuration of the present invention, a proper time is required for a rechargeable battery in which a voltage drop or a peak voltage from the peak voltage of the charge voltage is not detected and the voltage gradually increases. Can complete charging.

The block diagram of the charger which shows one embodiment of this invention Explanatory drawing which shows schematic structure of the charger of one embodiment of this invention Charging voltage waveform diagram that can detect the voltage drop from the general peak voltage Charging voltage waveform diagram that can be handled by the present invention Waveform diagram showing voltage rise per unit time Outline flowchart of voltage determination processing to which the present invention corresponds

  According to a first aspect of the present invention, a current control unit connected to an external power supply unit is connected to a plurality of rechargeable batteries via a voltage input switching unit, and a temperature detection unit, a voltage detection unit, and a peak voltage of the rechargeable battery In a battery charger including a determination unit that determines detection data of the voltage drop detection unit from the battery and a control unit that controls the current control unit and the voltage input switching unit based on the determination result of the determination unit, a peak is used as the control unit. In the case of a gradual voltage rise by controlling the completion of charging with the detection signal of the voltage drop detector from the voltage and setting a threshold value for the voltage rise width per unit time to continue charging when sudden voltage rises In this case, charging is completed in an appropriate amount of time for a rechargeable battery that does not detect -ΔV or peak voltage of the charging voltage and gradually increases. It can be.

  In the first aspect of the present invention, charging is performed in a sudden voltage rise by changing and setting the threshold value of the voltage rise width per unit time according to the temperature of the rechargeable battery input by the temperature detector. In the case of a gradual voltage increase, charging is completed, and it is finer and more accurate to control by detecting the temperature together than when controlling only by detecting the voltage. Charge control is possible.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of a charger according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a configuration in which a plurality of rechargeable batteries according to an embodiment of the present invention are connected to the charger.

  In FIG. 2, reference numeral 1 denotes a charger main body for a rechargeable battery. The rechargeable battery 3 is charged by attaching the rechargeable battery 3 to the rechargeable battery attachment portion 6 of the charger main body 1. At this time, the charge control circuit 2 determines the number of the rechargeable batteries 3 to be attached, and if attached, performs charge control on the rechargeable batteries 3 that are attached.

  Moreover, the charging state of the mounted rechargeable battery 3 is indicated by a combination of lighting, blinking, extinguishing, etc. of the display unit 4 made of LED.

  The charging method of the connected rechargeable battery 3 in the first embodiment will be described in detail with reference to FIG. The charger main body 1 has a space for mounting the rechargeable battery 3, the rechargeable battery 3 is mounted, and the outlet plug 5 provided in the charger main body 1 is connected to a household outlet.

  As a result, the charge control circuit 2 operates, and charging control is performed on the mounted rechargeable battery 3 by detecting in which space the rechargeable battery 3 is mounted and determining the voltage and temperature of the battery.

  FIG. 1 is a block diagram of a charger including the charging control circuit 2 in FIG. In FIG. 1, reference numeral 7 denotes a power supply unit, which comprises a circuit including an outlet plug 5 that receives power supplied from an outlet.

  The power source unit 7 is connected to an output control unit 9 including a plurality of switching elements via a current control unit 8, and the rechargeable battery 3 is connected to the output side of the output control unit 9.

  A plurality of temperature detection elements 10 constituting a temperature detection unit such as a thermistor are arranged in the vicinity of the rechargeable battery 3, and the temperature detection elements 10 are connected to the temperature detection unit 11. A determination unit 15 that determines temperature information detected by the rechargeable battery 3 is connected to the temperature detection unit 11.

  Further, a voltage input switching unit 12 is connected to the rechargeable battery 3, and this voltage input switching unit 12 is connected to a voltage detection unit 13 and a ΔV detection unit 14 for detecting detailed vertical fluctuations of the battery voltage. 13 and ΔV detector 14 detect the voltage of each rechargeable battery 3 at a fixed timing.

  Information on the voltage of the rechargeable battery 3 detected by the voltage detection unit 13 is configured to be sent to the determination unit 15. The detected battery voltage and temperature information is stored in the storage unit 18, and the stored various information is used as necessary for comparison and calculation.

  When the individual temperature and voltage of the rechargeable battery 3 reach a predetermined value or when the time count unit 17 connected to the control unit 16 counts up for a predetermined time, the control unit 16 receives a signal and the charge battery 3 is fully charged. Perform charge detection.

  Here, the control unit 16 is configured to operate the display unit 4 in a charging state such as charging or full charging.

  The temperature detection unit 11, voltage detection unit 13, ΔV detection unit 14, determination unit 15, control unit 16, time count unit 17, and storage unit 18 are configured by a single microcomputer 19.

  A simple operation of FIG. 1 will be described. When the outlet plug 5 arranged in the charger main body 1 is connected to a household outlet, the power is turned on and charging is started.

  When the power is turned on, the mounted charging control microcomputer 19 operates. The control unit 16 provided inside the microcomputer 19 determines whether or not the rechargeable battery 3 is attached to the rechargeable battery attachment unit 6 and performs a series of charge control when the rechargeable battery 3 is attached.

  First, a battery voltage is input to determine the presence or absence of a battery. The voltage detection unit 13 controls the voltage of each charging battery 3 while sequentially switching each charging battery 3 by controlling the voltage input switching unit 12. Make input. It is determined whether or not the rechargeable battery 3 is attached based on the input voltage. This battery voltage is input periodically to monitor battery attachment / detachment. When it is determined that the appropriate rechargeable battery 3 is attached by the battery voltage input, the rechargeable battery connected by controlling the current control unit 8 and the output control unit 9 from the control unit 16 in the microcomputer 19 3 is charged.

  When charging the rechargeable battery 3 is started, the voltage detector 13 periodically monitors the voltage of the rechargeable battery 3 and the temperature detecting element 10 monitors the temperature of the rechargeable battery 3. In some cases, the charger does not have the temperature monitoring function. Similarly, the voltage detector 13 and the ΔV detector 14 monitor the battery voltage and the presence or absence of a voltage drop at the end of charging.

  While the rechargeable battery 3 is being charged, the time counting unit 17 counts how long the rechargeable battery 3 is being charged. If this count exceeds the maximum charging time, the control unit 16 ends the charging for safety.

  A series of charging control is performed in which the state of charging as described above is displayed by turning on, blinking, and turning off the LED of the display unit 4.

  In this way, by performing charging control that combines the detection of the battery voltage drop -ΔV at the end of charging and the time count monitoring, the charging battery 3 is prevented from being insufficiently charged or overcharged. Charging becomes possible. In the normal state, for example, when the charging battery 3 is normally charged as shown in the charging voltage waveform of FIG. 3, the control is performed by setting the standard time of charging determined by the charging battery 3, and around that time. The charging control is such that the charging is completed by detecting the battery voltage drop -ΔV at the end of the battery charging that appears.

  Depending on the usage environment of the rechargeable battery and the like, there is a rechargeable battery having the charge voltage waveform shown in FIG. In such a case, the battery voltage drop -ΔV at the end of charging shown above cannot be detected, and charging is not completed in an appropriate charging time, resulting in an overcharged state and poor battery life and safety issues. May need to be avoided.

  In the present invention, when charging a plurality of individual rechargeable batteries 3, overcharge is suppressed and substantially appropriate even for rechargeable batteries having a charge voltage waveform having no peak as shown in FIG. 4. Safe charging control is performed so that charging is completed in a short time.

  A schematic flowchart and operation of the voltage waveforms in FIGS. 4 and 5 and the voltage determination process in FIG. 6 will be described. The charging waveform shown in FIG. 4 does not show the peak voltage and the voltage drop (−ΔV) from the peak voltage shown in FIG. 3 even after the standard charging time derived from the battery capacity has passed. It is a charging voltage waveform of a charging battery in which the voltage gradually rises without being completed. This state is an overcharged state and will accelerate deterioration of the rechargeable battery, and should be avoided.

  Next, in FIG. 5, the standard charging time derived from the battery capacity of a certain rechargeable battery 3 is A, the point where the unit time is divided therefrom is B, and further C, and the voltage increase width of the rechargeable battery 3 per unit time is detected. . The battery voltage at the start of detection is stored in the storage unit 18 in the microcomputer 19, and the battery voltage at the start of detection stored in the storage unit 18 when the unit time has elapsed is compared with the current battery voltage. FIG. 5 shows that the voltage increase is large in the unit time between AB and the voltage increase is small in the unit time between BC.

  Thus, by detecting the voltage rise width of the rechargeable battery 3 per unit time, the inclination of the charge voltage waveform of the rechargeable battery 3 can be detected.

  Here, the rechargeable battery 3 has various kinds of capacities, and there are a battery having a small capacity such as a AAA charge battery and a battery having a large battery capacity such as a AAA charge battery. When charging these various types of rechargeable batteries with a single charger, there are rechargeable batteries with similar charging waveforms despite the different battery capacities. With a rechargeable battery with a large battery capacity, the battery voltage rises earlier with a rechargeable battery with a small battery capacity. For example, in FIG. 5, a charging voltage waveform a indicated by a thick solid line is a charging battery having a small battery capacity, and a charging voltage waveform b indicated by a thick broken line is a charging battery waveform having a large battery capacity.

  Here, a schematic flowchart of the voltage determination process in FIG. 6 will be described. This is a process for detecting and determining the voltage rise width. First, it is determined whether the battery has been charged up to a preset standard time. If the standard time is not reached, this process does not function. It functions when the standard time is exceeded, for example, determines unit time such as an interval of 20 minutes, and compares the voltage data previously held for comparison with the latest input voltage data after the unit time has passed to confirm the range of inclination. . If the battery voltage is greater than the set threshold within the battery voltage gradient range, the charging is completed, and if not, the charging is continued.

  In this way, in order to distinguish the above-mentioned similar charging waveform, the threshold voltage is set after the standard charging time derived from the battery capacity, and the voltage rise width per unit time and the voltage higher than the set threshold voltage The process flow determines whether charging is to be completed or continued depending on whether the voltage is low or low.

  Further, when the ambient environmental temperature changes, for example, the charging voltage waveform a and the charging voltage waveform b shown in FIG. 5 are likely to increase when the temperature of the charging battery 3 is low, and the voltage does not increase when the temperature is high. More detailed control is possible by raising and lowering the threshold voltage setting according to the detected temperature information.

  As described above, by setting the voltage threshold after the standard charging time, it is possible to suppress overcharging and complete charging in an almost appropriate time to perform safe charging control.

  When charging a plurality of rechargeable batteries, the charger according to the present invention monitors the number of connected rechargeable batteries and the number of recharged batteries, and the voltage drop from the peak voltage or the peak voltage of the rechargeable battery appears remarkably. The battery continues to charge up to the limit of the safety timer, such as a rechargeable battery whose voltage gradually increases without charging, or a rechargeable battery that needs to be charged with a low charging current. By adopting the control of the invention, overcharge can be suppressed and charging can be completed properly in such a rechargeable battery in a set time.

DESCRIPTION OF SYMBOLS 1 Charger main body 2 Charge control circuit 3 Rechargeable battery 4 Display part 5 Outlet plug 6 Rechargeable battery mounting part 7 Power supply part 8 Current control part 9 Output control part 10 Temperature detection element 11 Temperature detection part 12 Voltage input switching part 13 Voltage detection part 14 ΔV detection unit 15 determination unit 16 control unit 17 time count unit 18 storage unit 19 microcomputer

Claims (2)

  The current control unit connected to the external power supply unit is connected to a plurality of rechargeable batteries via the voltage input switching unit, and the temperature detection unit, the voltage detection unit, and the detection data of the drop voltage detection unit from the peak voltage of this charging battery In a battery charger including a determination unit for determining the voltage and a control unit for controlling the current control unit and the voltage input switching unit based on the determination result of the determination unit, detection of a drop voltage detection unit from a peak voltage as the control unit By controlling the signal to complete charging and setting a threshold value for the voltage rise per unit time, charging is continued for sudden voltage rises, and charging is completed for moderate voltage rises. A charger characterized by that.   In the case of a gradual voltage rise, charging is continued in a sudden voltage rise by changing and setting the threshold value of the voltage rise width per unit time according to the temperature of the rechargeable battery input by the temperature detection unit. The charger according to claim 1, wherein the charging is completed.

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