JPH08106923A - Battery - Google Patents

Abstract

PURPOSE: To enhance reverse voltage resistance in an electronic switching circuit of an overcharge preventing circuit and reduce production cost of a battery. CONSTITUTION: Bipolar transistors Tr10 , Tr12 are used in an electronic switching circuit of an overcharge preventing circuit 4 and an electronic switching circuit of an overdischarge preventing circuit 5, and a circuit Tr11 in which a collector and a base are shorted is connected to the electronic switching circuit of the overcharge preventing circuit 4. Production cost of a battery 1 is reduced, and reverse voltage resistance of the switching circuit of the overcharge preventing circuit 4 is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery, and is suitable for application to, for example, a camera-integrated VTr.

[0002]

2. Description of the Related Art Conventionally, a battery having an overdischarge and overcharge prevention function has a power field effect transistor as a charge switch transistor and a discharge switch transistor as shown in FIG. is there. In this battery, at the time of charging, the transistor Tr ₁ is turned on, and the current flows from the ground GND ₁ through the transistor Tr ₁ to the diode D ₁ and then to the battery B through the charger C. Further, at the time of discharging, the transistor Tr ₂ is turned on, and the current flows from the battery B through the transistor Tr ₂ through the load L such as a camera-integrated video, and then to the ground GND ₁ through the diode D ₂ .

There is also a bipolar transistor which is used as a transistor for a charge switch and a discharge switch of a battery having an over-discharge and over-charge preventing function and which is connected in parallel. In this case, a power bipolar transistor having a high reverse breakdown voltage is used as the charging switch transistor, or a combination of a power switch transistor and a power diode is used.

[0004]

However, since the power field effect transistor, the power bipolar transistor and the power diode are expensive, the use of these transistors as a charge switch and a discharge switch transistor results in an increase in battery manufacturing cost. There was a problem that it became expensive in itself.

The present invention has been made in consideration of the above points, and an object of the present invention is to propose a battery in which the manufacturing cost of the battery is reduced and the reverse breakdown voltage of the charging switch circuit is increased.

[0006]

In order to solve such a problem, the present invention provides an overcharge prevention circuit (4) for preventing overcharge and an overdischarge prevention circuit (5) for preventing overdischarge, Bipolar transistors ((Tr ₁₀ ), (Tr ₁₂ )) are used in the electronic switch circuit of the overcharge prevention circuit (4) and the electronic switch circuit of the overdischarge prevention circuit (5).

[0007]

In the electronic switch circuit of the overcharge prevention circuit (4) and the electronic switch circuit of the overdischarge prevention circuit (5), bipolar transistors ((Tr ₁₀ ), (Tr ₁₂ )) are used. Thereby, the manufacturing cost of the battery (1) can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 1 generally indicates a battery with an over-discharge and over-charge preventing function according to an embodiment of the present invention. In this battery, bipolar transistors are used as transistors for charging and discharging, and diode-connected bipolar transistors are connected to the transistors for charging and switching to increase the reverse breakdown voltage.

A switch 2 is provided in a battery 1 made up of a housing. For example, when the battery 1 is attached to a load such as a camera-integrated VTr, the switch 2 is turned on to turn on the power and remove the load. The power is turned off. As a result, the dark current of the circuit when no load is attached to the battery 1 can be reduced. Further, the battery 1 is provided with external terminals (+) and (-) 3.

FIG. 2 shows the circuit configurations of the overcharge prevention circuit 4 and the overdischarge prevention circuit 5 provided in the battery 1. In the overcharge prevention circuit 4, the bipolar transistor Tr ₁₀ is a transistor for charging switch, and the bipolar transistor Tr ₁₁ is a transistor in which the collector and the base are short-circuited. Therefore, the base and the emitter of the transistor Tr ₁₁ are used as a diode to increase the reverse breakdown voltage of the transistor Tr ₁₀ . In the overdischarge prevention circuit 5, the bipolar transistor Tr ₁₂ is a transistor for discharging switch, and the bipolar transistor Tr ₁₃ is the transistor Tr for discharging switch when the load is shorted.
_This is a transistor that sets the operation of the comparator to the “L” level in order to turn off ₁₂ .

The emitter of the transistor Tr ₁₀ is connected to the transistor Tr ₁₁ which shorts the collector and the base and uses the base and the emitter as a diode. The collector of the transistor Tr ₁₀ is connected to the ground, and the base is connected to the output terminal of the comparator C ₁ . The output terminal of the comparator C ₁ is a resistor R ₁
And R ₂ and is connected to the non-inverting input terminal and one end of the resistor R ₃ . The other end of the resistor R ₃ is a diode D ₁₀
, And D ₁₁ are connected to the anode side, and the anode sides of these diodes D ₁₀ and D ₁₁ are connected to the ground. Here, the diodes D ₁₀ and D ₁₁ are for preventing an abnormal temperature rise during charging.

The anode side of the Zener diode ZD ₁ is connected between the resistors R ₁ and R _2, and the anode side is connected to the comparator C ₁ . The cathode side of the Zener diode ZD ₁ is connected to one end of the resistor R ₄ . The other end of the resistor R ₄ is connected to ground
Connected to ₅ . The inverting input terminal of the comparator C ₁ is connected between the resistors R ₄ and R ₅ .

In the overdischarge prevention circuit section 5, the collector of the transistor Tr ₁₂ is connected to the emitter of the transistor Tr ₁₁ , and the emitter of the transistor Tr ₁₂ is connected to the ground. Therefore, the transistor Tr ₁₀ for charging switch and the transistor Tr ₁₂ for discharging switch are
They are connected in parallel so that the current flows in opposite directions. Also connected the base of the transistor Tr ₁₂ is connected to one end of resistor R _6, the other end of the resistor R ₆ is connected to one end of resistor R _7. The other end of the resistor R ₇ is connected to the anode side of the Zener diode ZD ₂ .

[0015] Here and emitter of the bipolar transistor Tr ₁₄ between the base and the resistor R ₆ of the transistor Tr ₁₂ is connected, the collector of the transistor Tr ₁₄ between the resistor R ₆ and the resistor R ₇ is connected. Transistor T
The base of r ₁₄ is connected to the emitter of the bipolar transistor Tr ₁₅ .

The collector of the transistor Tr ₁₅ is connected to the battery 1, and the base is connected to the output terminal of the comparator C ₂ via the resistor R ₈ . Further, between the collector of the transistor Tr ₁₅ and the battery ₁ , the cathode of the Zener diode ZD ₁ and the bipolar transistor T.
The collector of r ₁₃ is connected. Transistor Tr ₁₃
Is connected between the emitter of the transistor Tr ₁₁ and the collector of the transistor Tr ₁₂ , and is also connected to the non-inverting input terminal of the comparator C ₂ via the resistor R ₉ . A resistor R ₁₀ connected to ground is connected between the resistor R ₉ and the non-inverting input terminal of the comparator C ₂ .

The emitter of the transistor Tr ₁₃ is connected to the inverting input terminal of the comparator C ₂ and is also connected between the resistor R ₁₁ and the resistor R ₁₂ connected to the ground. The other end of the resistor R ₁₁ is connected to one end of the resistor R ₄ of the overcharge prevention circuit unit 4, and the resistor R ₁₃ is connected between the resistor R ₁₁ and the resistor ₄ . The other end of the resistor R ₁₃ is connected to the comparator C ₂ .

One end of the load or charger has an external terminal (-)
3. Emitter of transistor Tr ₁₁ and transistor T
connected to the collector of r ₁₂ . The other end of the load or charger is connected to the external terminal (+) 3 and battery 1. Here, the switch 2 is connected between the external terminal (+) 3 and the load or the charger. When the switch 2 is turned on, the resistor R ₄ and the resistor R ₁₁ are connected and the power is turned on.

In the above structure, when the battery 1 is attached to the charger, the switch 2 is turned on and the operation of the comparator C ₁ becomes "H" level. As a result, the transistor Tr ₁₀ is turned on, a current flows from the ground GND ₁₀ to the charger via the transistors Tr ₁₀ and Tr ₁₁ , and the charging current is supplied to the battery 1 from the charger.

Next, when the battery 1 is attached to the load, the switch 2 is turned on and the operation of the comparator C ₂ becomes "H" level, and the transistor Tr ₁₅ is turned on by the output from the comparator C _2. To be done. When the transistor Tr ₁₅ is turned on, the transistor Tr ₁₄ is turned on,
Thus current from Batsuteri 1 via a Zener diode ZD ₂ and the resistor R _7, transistor Tr ₁₂ is turned on to flow the emitter from the collector of the transistor Tr ₁₄ to the base of the through connexion transistor Tr _12. As a result, a current is supplied from the battery 1 to the load, and a current flows from the load to the ground via the collector of the transistor Tr ₁₂ and the emitter.

When the load is shorted, the transistor Tr ₁₃ is turned on, so that the operation of the comparator C ₂ becomes "L" level and the transistor Tr ₁₅ is turned off. When the transistor Tr ₁₅ is turned off, the transistor Tr ₁₄ is also turned off. As a result, the current flowing from the battery 1 to the transistor Tr ₁₂ becomes small, so that the transistor Tr ₁₂ is turned off. As a result, the current supplied from the battery 1 to the load is stopped.

According to the above structure, the bipolar transistors Tr ₁₀ and Tr ₁₂ are used as the charging switch circuit and the discharging switch circuit, so that the manufacturing cost of the battery 1 can be reduced. Also by connecting the transistor Tr ₁₁ which is Shiyoto between collector and base to the transistor Tr ₁₀ for charging switch, it is possible to reduce the manufacturing cost of Batsuteri 1 it is possible to increase the reverse breakdown voltage of the charging switch circuit.

Further, according to the above configuration, since the switch 2 is provided in the battery 1, the dark current of the circuit when the battery 1 is not attached to the load can be reduced. Further, according to the above-mentioned configuration, the power supply can be mechanically turned on / off by the switch 2 and the output from the terminal is stopped when the voltage has dropped to a predetermined voltage. Can be reduced.

In the above embodiment, the battery 1
I described the case of using a camera-integrated VTr.
The present invention is not limited to this, and the same effect can be obtained when used in other devices.

As described above, according to the present invention, the bipolar transistor is used in the electronic switch circuit of the overcharge prevention circuit and the electronic switch circuit of the overdischarge prevention circuit, so that the manufacturing cost of the battery can be reduced. it can.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a configuration of a battery with an overcharge and overdischarge prevention function according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a circuit configuration of an overcharge stop circuit and an overcharge stop circuit according to an embodiment.

FIG. 3 is a connection diagram for explaining a conventional battery with overcharge and overdischarge prevention functions.

[Explanation of symbols]

1 …… Battery with overcharge and overdischarge prevention function 2 ……
Switch, 3 ... External terminals (+) (-), 4 ... Overcharge prevention circuit, 5 ... Overdischarge prevention circuit section.

Claims (3)

[Claims] 1. An electronic switch circuit for the overcharge protection circuit and an electronic switch circuit for the overdischarge protection circuit, comprising an overcharge protection circuit for preventing overcharge and an overdischarge protection circuit for preventing overdischarge. Batteries characterized by using a transistor. 2. The electronic switch circuit of the overcharge prevention circuit and the electronic switch circuit of the overdischarge prevention circuit are connected in parallel so that the currents flow in opposite directions. The battery according to claim 1. 3. The battery according to claim 1, wherein the electronic switch circuit of the overcharge prevention circuit is connected to a circuit in which a collector and a base are short-circuited.