CN205960725U - Take overcharge protection's charging indication circuit - Google Patents

Abstract

This utility model discloses a charging indicator circuit with overcharge protection, including a charging interface, a rechargeable battery, and a first unidirectional diode. An overcharge protection circuit and a charging indicator circuit are further provided between the first unidirectional diode and the rechargeable battery. The charging indicator circuit includes a fifth resistor, a second unidirectional diode, a second transistor, a sixth resistor, a seventh resistor, a first capacitor, and an indicator LED. The emitter of the second transistor is connected to the output terminal of the overcharge protection circuit, the collector is connected to the negative terminal of the rechargeable battery through a series circuit of the seventh resistor and the indicator LED, and the base is connected to the positive terminal of the rechargeable battery through the sixth resistor. The first capacitor is connected between the positive and negative terminals of the rechargeable battery. This utility model has a simple structure, is easy to operate, and can effectively reflect whether the battery is charging normally through the on/off state of the indicator light. It has good stability, strong applicability, and good practicality.

Description

Charging indication circuit with overcharge protection

technical field

The utility model belongs to the technical field of charging circuits, in particular to a charging indicating circuit with overcharging protection.

Background technique

Portable lighting equipment has been widely used in people's daily life, and generally has a built-in or external rechargeable battery, which is applied to various types of charging circuits, and generally has a charging indicator light. However, most of the charging indicator lights just let the user know that the charging circuit is working, but it is generally difficult to know whether the battery is in a normal charging state; challenge.

Contents of the invention

The purpose of this utility model is to provide a charging indicator circuit with overcharge protection with simple structure, good stability and strong applicability, aiming to solve the problem that the indicator light in the charging circuit of the traditional technology cannot reflect whether the battery is in a normal charging state insufficient.

The technical solution to achieve the purpose of the utility model is a charging indication circuit with overcharge protection, including a charging interface, a rechargeable battery and a first one-way diode connected between the positive pole of the charging interface and the positive pole of the rechargeable battery. An overcharge protection circuit and a charging indication circuit are also provided between a one-way diode and the rechargeable battery, and the charging indication circuit includes a fifth resistor, a second one-way diode, a second triode, a sixth resistor, and a seventh resistor , the first capacitor and the indicator LED light, the emitter of the second triode is connected to the output terminal of the overcharge protection circuit, the collector is connected to the negative pole of the rechargeable battery, the base after the series circuit of the indicator LED light through the seventh resistor The pole is connected to the positive pole of the rechargeable battery through the sixth resistor, the first capacitor is connected between the positive pole and the negative pole of the rechargeable battery, the fifth resistor is connected in series with the second unidirectional diode, and the other end of the fifth resistor It is connected to the emitter of the second triode, and the negative pole of the second one-way diode is connected to the positive pole of the rechargeable battery.

The overcharge protection circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an eighth resistor, a first triode and a controllable precision voltage regulator, and the collector of the first triode After passing through the parallel circuit of the first resistor and the second resistor, it is connected to the cathode of the first unidirectional diode, the emitter of the first triode is connected with the emitter of the second triode, and the first The base of the triode is connected to the negative pole of the controllable precision voltage regulator, the positive pole of the controllable precision voltage regulator is connected to the negative pole of the rechargeable battery, and the third resistor is connected to the collector of the first transistor and the negative pole of the rechargeable battery. Between the bases, the fourth resistor is connected in series with the eighth resistor, and the other end of the fourth resistor is connected to the emitter of the first triode, and the other end of the eighth resistor is connected to the negative pole of the rechargeable battery, so The control terminal of the controllable precision voltage stabilizing source is connected to the connection point of the fourth resistor and the eighth resistor.

The first transistor is an NPN transistor.

The second transistor is a PNP transistor.

The utility model has positive effects: The utility model has simple structure and convenient operation, and is provided with an overcharge protection circuit and a charging indication circuit, and the charging indication circuit adopts a triode with a fifth resistor connected in series with a second unidirectional diode. The built-in circuit can effectively reflect the function of whether the battery is in normal charging through the on and off of the indicator light. It has good stability in use, strong applicability and good practicability.

Description of drawings

In order to make the content of the utility model easier to understand clearly, the utility model will be further described in detail according to specific embodiments below in conjunction with the accompanying drawings, wherein:

Fig. 1 is the structural representation of the utility model.

detailed description

(Example 1)

Fig. 1 shows a specific embodiment of the utility model, wherein Fig. 1 is a structural schematic diagram of the utility model.

As shown in Fig. 1, a charging indication circuit with overcharge protection includes a charging interface 1, a rechargeable battery 2 and a first unidirectional diode D1 connected between the positive pole of the charging interface 1 and the positive pole of the rechargeable battery 2. An overcharge protection circuit 3 and a charging indication circuit 4 are also provided between a one-way diode D1 and the rechargeable battery 2, and the charging indication circuit 4 includes a fifth resistor R5, a second one-way diode D2, and a second triode Q2 , the sixth resistor R6, the seventh resistor R7, the first capacitor C1 and the indicator LED light, the emitter of the second triode Q2 is connected to the output terminal of the overcharge protection circuit 3, and the collector passes through the seventh resistor R7, Indicating LED lights are connected in series to the negative pole of the rechargeable battery 2, and the base is connected to the positive pole of the rechargeable battery 2 through the sixth resistor R6. The first capacitor C1 is connected between the positive pole and the negative pole of the rechargeable battery 2. The first Five resistors R5 are connected in series with the second one-way diode D2, and the other end of the fifth resistor R5 is connected to the emitter of the second triode Q2, and the negative pole of the second one-way diode D2 is connected to the positive pole of the rechargeable battery 2 .

The overcharge protection circuit 3 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, an eighth resistor R8, a first triode Q1 and a controllable precision voltage regulator U1. The collector of the first triode Q1 is connected to the cathode of the first unidirectional diode D1 through the parallel circuit of the first resistor R1 and the second resistor R2, and the emitter of the first triode Q1 is connected to the second The emitters of the triode Q2 are connected, the base of the first triode Q1 is connected to the negative pole of the controllable precision voltage regulator U1, and the positive pole of the controllable precision voltage regulator U1 is connected to the rechargeable battery 2 Negative electrode, the third resistor R3 is connected between the collector and the base of the first triode Q1, the fourth resistor R4 is connected in series with the eighth resistor R8 and the other end of the fourth resistor R4 is connected to the first The emitter of a triode Q1, the other end of the eighth resistor R8 is connected to the negative pole of the rechargeable battery 2, the control end of the controllable precision voltage regulator U1 is connected to the connection between the fourth resistor R4 and the eighth resistor R8 Point.

The first transistor is an NPN transistor.

The second transistor is a PNP transistor.

The charging circuit is connected through the charging interface, and the voltage is provided for charging the battery through the diode D1; the resistors R1, R2, R3, R4, R8, Q1 and the three-terminal regulator U1 form a constant voltage circuit to achieve the overcharge protection function; the circuit diagram The voltage at point A is constant, and the battery is charged through the resistor R5 and diode D2; when the battery is in a normal charging state, R5 and D2 have a current passing through to form a bias voltage to make the triode Q2 conduct, and the charging indicator LED lights up; When it cannot be charged normally or is in an open circuit state, Q2 will stop due to no bias voltage, and the indicator LED will go out; in this way, the function of reflecting whether the battery is in normal charging through the on and off of the indicator light can be achieved; adjusting resistors R4 and R8 can Adjust the voltage at point A to achieve the effect of adjusting the overcharge protection voltage.

The utility model has simple structure and convenient operation, and is provided with an overcharge protection circuit and a charging indication circuit, and the charging indication circuit adopts a bias circuit formed by connecting a triode with a fifth resistor and a second unidirectional diode in series, which can effectively pass the indication The on and off of the light reflect whether the battery is in the normal charging function. It has good stability in use, strong applicability and good practicability.

Apparently, the above-mentioned embodiments of the present utility model are only examples for clearly illustrating the present utility model, rather than limiting the implementation manner of the present utility model. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. And these obvious changes or changes derived from the essential spirit of the present utility model still belong to the protection scope of the present utility model.

Claims (4)

1. a kind of band overcharges the charging indication of protection, including charging inlet, rechargeable battery be just connected to charging inlet The first unilateral diode between pole and rechargeable battery positive pole it is characterised in that：In described first unilateral diode and the electricity that charges It is additionally provided with overcharge protection circuit and charging indication, described charging indication includes the 5th resistance, second unidirectional between pond Diode, the second audion, the 6th resistance, the 7th resistance, the first electric capacity and indication LED lamp, the transmitting of described second audion Pole is connected to the outfan of overcharge protection circuit, colelctor electrode is connected to charging after the 7th resistance, indication LED lamp series circuit The negative pole of battery, base stage are connected to the positive pole of rechargeable battery by the 6th resistance, and described first capacitance connection is in rechargeable battery Between positive pole and negative pole, after described 5th resistance is connected with the second unilateral diode and the other end of described 5th resistance is connected to The emitter stage of the second audion, the negative pole of the second unilateral diode are connected on the positive pole of rechargeable battery.

2. band according to claim 1 overcharge protection charging indication it is characterised in that：Described overcharge protection circuit Including first resistor, second resistance, 3rd resistor, the 4th resistance, the 8th resistance, the first audion and controllable accurate source of stable pressure, The colelctor electrode of described first audion is connected to the negative of the first unilateral diode after first resistor, second resistance parallel circuit Extremely go up, the emitter stage of described first audion is connected with the emitter stage of described second audion, the base of described first audion Pole is connected to the negative pole of controllable accurate source of stable pressure, and the positive pole of described controllable accurate source of stable pressure is connected to the negative pole of rechargeable battery, institute State between colelctor electrode and the base stage that 3rd resistor is connected to the first audion, described 4th resistance and described 8th resistant series and The other end of the 4th resistance is connected on the emitter stage of the first audion, the other end of the 8th resistance is connected to the negative of rechargeable battery Pole, the control end of described controllable accurate source of stable pressure is connected on the 4th resistance and the junction point of the 8th resistance.

3. band according to claim 2 overcharge protection charging indication it is characterised in that：Described first audion is NPN type triode.

4. band according to claim 3 overcharge protection charging indication it is characterised in that：Described second audion is PNP type triode.