KR100480664B1 - Overcharge prevention device of battery charger - Google Patents

Abstract

The present invention is installed so that the air membrane made of an elastic body is connected to the rechargeable battery, and when the battery is charged for a predetermined time and fully charged, the air membrane made of the elastic body is expanded by the increase of the battery temperature to detect a fully charged state of the battery. It relates to a battery overcharge protection device, which is connected to the battery to be charged and is installed at the bottom of the storage member and the storage member for receiving the air membrane made of an elastic body, the elastic body is expanded as the temperature increases according to the charging time of the battery Under the control of the overcharge detection switch and the microcomputer on / off by the air film consisting of a, the overcharge detection switch "on" is composed of a power cut off to cut off the supply power, by the battery temperature without having to implement a complex overcharge protection circuit Power off by detecting overcharge There eliminating wasted power and leverage, and the performance of the battery up to the effect that you can extend the battery time and life.

Description

Overcharge prevention device of battery charger

The present invention relates to an overcharge preventing device of a battery charger, and more particularly, to install an air membrane made of an elastic body to be connected to a charging battery, and when the battery is charged for a predetermined time and is fully charged, the elastic body is formed by an increase in battery temperature. The present invention relates to an overcharge preventing device for a battery charger that detects a full charge state of a battery using an expansion of an air film.

There have been a number of conventional battery charging methods.

The first method is a voltage control method that checks the voltage of the battery to charge and cuts off the charging current when the set voltage is reached. The second method is a time control method that sets a predetermined charging time and cuts off the charging current applied to the battery to charge after the predetermined time elapses. The third method is a temperature control method that detects the surface temperature of the battery to be charged and detects the start of overcharging when the predetermined temperature is detected. The fourth method is the -ΔV method in which the control circuit is operated by the set element when the voltage of the charge battery increases in proportion to the set element value by the element in which the control value is set.

Since the above methods are well known techniques, a detailed description of each method is omitted for clarity of the present specification, and a battery charging method using the -ΔV method will be briefly described with reference to FIG. 1.

As shown in FIG. 1, a block diagram showing a circuit configuration of a conventional battery charger, a switching unit for switching the output of the DC power supply unit 1 and the DC power supply unit 2 for charging and circuit operation power supply (2), a rectifying / smoothing unit 3 for rectifying and smoothing the switched power and outputting the switching power source, a switching control unit 4 for controlling the switching unit 2 to perform stabilizing power output, and the rectifying and smoothing operation. A voltage / current detection control unit 5 for detecting the supplied power supply voltage and current, an optical coupler PT1 for supplying the detection control signal of the voltage / current detection control unit 5 to the switching control unit 4, and a battery for charging And (6), a switch (7) for detecting the mounting of the battery (6), a -ΔV detector (8) for detecting the full charge stage of the charging current when the switch (7) is turned on, and the switch is turned on Of the voltage stabilizer 9 and -ΔV detector 8 for supplying the operating power of the timer when Therefore, the timer 10 performs the end of charge and charge state display driving control, the switch 11 and the current limiting resistor R1 that are turned on / off under the control of the timer 10 to control the battery charging current; , LED (L2) indicating the charging state under the control of the timer 10, and LED (L1) indicating the rectified and smooth power supply, D1 is a diode, R0, R1, R2, R3 Resistance.

The operation of the conventional charging device configured as described above is as follows.

DC power output from the DC power supply unit 1 is supplied to the switching unit 2, the switching unit 2 receives the PWM switching drive control from the switching control unit 4 to switch the input power to output the AC, this output The power is rectified and stabilized by direct current at the rectifying and smoothing section.

The voltage and current of the output power are detected by the voltage / current detection control section 5, and the detection result is fed back to the switching control section 4 through the optical coupler PT1. PWM control of the switching part according to the fed back voltage / current ensures a stabilized power output.

On the other hand, since the LED (L1) is turned on by the power output from the rectifying / smoothing unit 3 as described above, the power output state is displayed.

On the other hand, when the battery 6 is mounted in the charger for charging, the switch 7 for detecting this is turned on. When the switch 7 is turned on, power is supplied to the voltage stabilizer 9 so that the timer 10 is powered. The timer 10 starts to operate as it is supplied.

The timer 10 is set in advance as a timer time as a time determined as an overcharge state while charging is continued after a predetermined time has elapsed from the start of charging. Therefore, the timer 10 outputs a high signal until the set time, and outputs a low signal when the set time comes.

When the high signal is output, the LED (L2) is turned on to indicate that it is being charged, and since the switch 11 which uses this high signal as a control signal is turned on, the charging current is output (V +) of the rectifying / smoothing unit 3, Battery charging is performed by flowing through the switch 11, the diode D1, the battery 6, the resistor R0, and the output terminal V-.

At this time, the charging voltage applied to the battery 6 gradually increases with time, but gradually decreases when the battery is fully charged. Since a direct current is applied through the switch, rapid charging by a large current is performed initially. do. When the charge is continued and the full charge time is reached, the voltage level decreases thereafter. The decrease of the voltage level is detected by the -ΔV detector 8, and the detection signal is input to the timer 10.

The timer outputs a low signal when-DELTA V is detected before the set time elapses. When the low signal is output in this manner, the LED L2 is turned off and the switch 11 is also turned off.

Therefore, from this point of time, the charging current of the micro level with the limited current level is flowed to the battery by the resistor R1, and when the -ΔV detector 8 fails to operate due to a circuit malfunction, as described above when the set timer time is reached. By outputting a low signal, the LED L2 is turned off and the switch 11 is turned off to prevent damage to the battery 6 due to overcharging.

However, the conventional method for preventing overcharging in a battery charger has a problem in that the charging circuit is cut off only when a predetermined time is reached by counting the time, so that the battery continues to be charged for a predetermined time even when the battery has a remaining amount.

In addition, a problem arises that an increase in power consumption due to overcharge and an increase in cost due to the complexity of the overcharge prevention circuit occur.

Accordingly, the present invention has been made to solve such a problem, the object of the present invention is to prevent the overcharge of the battery charger to prevent the battery from being overcharged by using the property of increasing the temperature of the battery being charged according to the charging time To provide a device.

Another object of the present invention is to install an air membrane made of an elastic body that can expand as the battery temperature increases with charging time, and when the battery is overcharged and the air membrane made of an elastic member is expanded, the overcharge detection switch is used to overcharge. The present invention provides an overcharge preventing device for a battery charger for detecting and blocking a charging circuit.

The present invention for achieving the above object is applied from the constant voltage circuit unit and the constant voltage circuit unit for regulating the AC power supply unit for supplying the AC current and the AC current supplied from the AC power supply unit to convert the DC current and maintain a constant voltage A battery charging device comprising a microcomputer for controlling a DC current to be supplied to a battery side and a charging display unit indicating that the battery is being charged, the battery charging device comprising: a storage member connected to the battery to be charged, and a storage member for accommodating an air film made of an elastomer; It is installed, and under the control of the overcharge detection switch and the microcomputer on / off by the air membrane made of an elastic membrane that expands as the temperature increases according to the charging time of the battery, when the overcharge detection switch is "on" to cut off the power supply Characterized in that the power cut off It shall be.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a graph of temperature change of a battery according to a charging time. As shown in FIG. 2, as the battery is charged, the battery temperature gradually increases, and rapidly increases from the time when the charging time elapses and the overcharging occurs.

Figure 3 is a schematic cross-sectional view for showing the external configuration of the overcharge protection of the battery charger according to the present invention.

Reference numeral 20 is a main body for protecting the internal components of the overcharge preventing device of the battery charger according to the present invention, 21 is a rechargeable battery.

Reference numeral 22 denotes a charging chamber capable of receiving and charging a rechargeable battery, and reference numeral 22a denotes a protective cover for protecting the charging chamber.

Reference numeral 23 is a temperature sensing means made of an elastic body so that air expands as the temperature is increased, and 24 is an elastic body through the opening when the temperature of the battery rises as the charging time elapses. It is a storage member configured to allow the air membrane made to flow out.

Reference numeral 25 is an overcharge detection switch connected to the microcomputer and configured to be “on” when the air membrane made of the elastic body expands as it is overcharged and “off” when the air membrane made of the elastic body contracts.

Reference numeral 26 denotes a case surrounding the battery charging chamber 22.

Figure 4 is a block diagram showing the internal configuration of the overcharge protection of the battery charger according to the present invention.

Reference numeral 30 denotes a microcomputer that is programmed to receive signals from arithmetic units, input / output units, storage units, and to extract and decode commands, to control inputs and outputs, and to supply the converted DC current to the battery side. Connect the plug of the charger to the AC cord, AC power supply for supplying AC power and AC power to convert the AC current into DC current and the constant voltage circuit to maintain the rated voltage to charge the microcomputer ( 30 is a charging circuit including a power cut-off unit which cuts off the supply power under the control of 30), and reference numeral 50 denotes a charging display unit using a light emitting diode (LED), for example, indicating a charging state to the outside.

Hereinafter, the operation of the overcharge preventing device of the battery charger according to the present invention having the above configuration will be described in detail.

When the user connects the plug of the charger to the electric cord for charging, AC current flows into the charger through the plug, and the current flows into the constant voltage circuit part and is rectified by the bridge diode. Maintain the rated voltage so that it can be converted and charged to a constant voltage.

The microcomputer 30 instructs charging by flowing the rated voltage to the battery 21, and starts charging to the battery 21 and simultaneously turns on the LED of the charge display unit 50 to indicate that the battery is being charged. To control.

As the charging time elapses, the charging amount of the battery 21 increases, and as the charging amount increases, the temperature of the battery 21 gradually increases. When the temperature of the battery 21 rises, the air in the temperature sensing means (for example, silicon) 23 made of an elastic body connected to the battery 21 is increased in kinetic energy by Brownian movement, and thus the temperature sensing means 23 gradually increases. Will expand. The expanded temperature sensing means 23 moves to the opening 24a of the storage member 24, and as the temperature of the battery 21 increases, the amount of the temperature sensing means 23 moving to the opening 24a increases. When the battery 21 is overcharged, the overcharge detection switch 25 located at the bottom of the storage member 24 is pressed.

When the overcharge detection switch 25 is "on", the microcomputer 50 determines that the battery 21 is in the overcharge state and operates to cut off the AC current flowing into the AC power source by driving the power cutoff unit.

As described above, according to the overcharge preventing device of the battery charger according to the present invention, when the battery reaches an overcharge state, the temperature of the battery is rapidly increased by using the property of connecting the air membrane made of an elastomer to contact the battery and the temperature is increased. By pushing the overcharge detection switch to expand the air film, it can detect the overcharge state by battery temperature and cut off the power without having to implement the complicated overcharge protection circuit, eliminating power waste and maximizing the performance of the battery. There is an effect that can extend the use time and life.

1 is a block diagram showing a circuit configuration of a conventional battery charger.

2 is a graph showing a temperature change of a battery according to a charging time.

Figure 3 is a schematic cross-sectional view for showing the external configuration of the overcharge protection of the battery charger according to the present invention.

Figure 4 is a block diagram showing the internal configuration of the overcharge preventing device of the battery charger according to the present invention.

<Explanation of symbols for the main parts of the drawings>

23: temperature sensing means 24: storage member

25: overcharge detection switch 30: microcomputer

40: charging circuit 50: charging display

Claims (3)

In the battery charging device comprising a microcomputer 30 and a charging circuit 40 for supplying a charging current to the battery 21 by the control signal from the microcomputer and a charging display unit 50 indicating that the battery 21 is charging. , Temperature sensing means (23) installed in the battery case (26) in contact with the surface of the battery and changing in volume depending on temperature; An overcharge detection switch 25 located in the expansion direction of the temperature sensing means 23 and switched by a physical change; And a microcomputer 30 for controlling a current supplied from the charging circuit 40 to the battery based on a signal applied by the switching operation of the sensing switch 25. Device. 2. The overcharge preventing device of a battery charger according to claim 1, wherein the temperature sensing means (23) comprises a fluid expanded according to a temperature and a storage membrane for storing the fluid. 3. The hollow storage according to claim 2, wherein the temperature sensing means (23) extends from the case (26) and is opposite to the case (26) and has an opening toward the overcharge detection switch (25). An overcharge preventing device of a battery charger, characterized in that formed inside the case.

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