CN201726176U - Charge control circuit with bidirectional reverse connection protection for storage batteries - Google Patents

Abstract

The utility model relates to a charge control circuit with bidirectional reverse connection protection for storage batteries, consisting of a terminal 1, an input terminal 2, a terminal 3, a p-channel field-effect transistor 4, a resistor 5, a p-channel field-effect transistor 6, a diode 7, a resistor 8, a resistor 9, a diode 10, a capacitor 11, a resistor 12, a photocoupler 13, a resistor 14, a photocoupler 15, a resistor 16, a capacitor 17, an NPN crystal triode 18, a resistor 19, a capacitor 20, a resistor 21, a terminal 22 and a terminal 23. The charge control circuit with bidirectional reverse connection protection for the storage batteries adopts the design of complete symmetrical circuits, and can also carry out programmable charging on the storage batteries while realizing the bidirectional reverse connection protection of a charging power and the storage batteries. The charge control circuit with bidirectional reverse connection protection for the storage batteries can be effectively applied to electromobiles, other electric vehicles and various high-power charging devices, and can be widely applied to and effectively protect various direct current power supply systems, therefore, the reliability of the system can be improved and windfall loss caused by misuse can be reduced. The charge control circuit with bidirectional reverse connection protection for the storage batteries is especially applicable to solar and wind power supply systems to carry out programmable charging and bidirectional reverse connection protection on the storage batteries, thereby greatly improving the working performance and the reliability of the solar and wind power supply systems.

Description

Battery charging control circuit with bidirectional reverse polarity protection

technical field

The utility model relates to battery charging protection technology, in particular to a battery charging control circuit adopting bidirectional reverse connection protection.

Background technique

At present, the adoption of new energy has become an urgent issue facing mankind. When using new energy for power and lighting, it is often necessary to configure a battery power supply system. When using a battery-powered system, no matter whether the charging power supply or the battery is reversed, it will bring serious consequences. In the prior art, fuses, relays, diodes, thyristors, transistors and diodes are generally used in series with field effect transistors to protect the reverse connection of the charging power supply or the reverse connection of the battery. The above methods all have the following disadvantages:

Although it is simple to use a fuse for one-time protection, it is very inconvenient to manually replace a new fuse after the fuse is blown;

Relay protection is used, the contacts are easy to burn out when working with high current, and the number of contact on and off is limited; diodes, thyristors, transistors, and diodes and field effect transistors are used for series protection, and the on-resistance is large, and the power loss is large when working at high currents. etc.

Utility model content

The purpose of the utility model is to overcome the above-mentioned shortcomings of the prior art and provide a battery charging control circuit using bidirectional reverse connection protection.

The technical scheme of the utility model is: a storage battery charging control circuit adopting bidirectional reverse connection protection, which is composed of terminal 1, input terminal 2, terminal 3, P-channel field effect tube 4, resistor 5, P-channel field effect tube 6, Diode 7, resistor 8, resistor 9, diode 10, capacitor 11, resistor 12, photocoupler 13, resistor 14, photocoupler 15, resistor 16, capacitor 17, NPN transistor 18, resistor 19, capacitor 20, resistor 21 , Terminal 22, and terminal 23.

Terminal 1 is respectively connected with the anode of diode 7, the source (S) of P channel field effect transistor 4, and resistor 8, and the other end of resistor 8 is respectively connected with the grid (G) of P channel field effect transistor 4, resistor 14, P channel The grid (G) of the Doff 6 is connected to the resistor 9, and the other end of the resistance 9 is connected to the source (S) of the P-channel FET 6, the positive pole of the diode 10, and the terminal 22 respectively, and one end of the resistor 5 is connected to the P-channel The drain (D) of the Doff FET 4 is connected, the other end of the resistor 5 is connected with the drain (D) of the P channel FET 6, the negative pole of the diode 7 is connected with the resistor 12 and the capacitor 11 respectively, and the other end of the resistor 12 is connected with the The positive pole of the light-emitting diode in the photocoupler 13 is connected, the other end of the capacitor 11 is grounded, the negative pole of the light-emitting diode in the photocoupler 13 is grounded, the collector of the phototransistor in the photocoupler 13 and the emitter of the phototransistor in the photocoupler 15 Connect, the phototransistor emitter in the photocoupler 13 is connected with the collector of the NPN transistor 18, the emitter of the NPN transistor 18 is grounded, the base of the NPN transistor 18 is connected with the resistor 19 and the resistor 21 respectively, and the resistor 21 The other end is grounded, the other end of the resistor 19 is connected to the capacitor 20 and connected to the input terminal 2, the other end of the capacitor 20 is grounded, the collector of the phototransistor in the photocoupler 15 is connected to the other end of the resistor 14, and the negative pole of the diode 10 is connected to the other end of the resistor 14 respectively. Resistor 16 and capacitor 17 are connected, the other end of capacitor 17 is grounded, the other end of resistor 16 is connected to the anode of the light-emitting diode in the photocoupler 15, the cathode of the light-emitting diode in the photocoupler 15 is grounded, and terminal 3 and terminal 23 are grounded.

The further technical solution of the utility model is: the P-channel field effect transistor 4 and the P-channel field effect transistor 6 can be replaced by PNP transistors. At this time, the positions connected to the gate (G), drain (D) and source (S) of the P-channel field effect transistor are respectively replaced by the base (B), collector (C) and emitter (E) of the PNP transistor. ) are replaced one by one. There is no freewheeling diode integrated inside the PNP transistor. When replacing it, a diode needs to be connected between the collector (C) and emitter (E) of each PNP transistor, and its anode is connected to the collector of the PNP transistor ( C), the negative pole is connected to the emitter (E) of the PNP transistor.

A further technical solution of the utility model is: the P-channel FET 4 and the P-channel FET 6 can be replaced by the N-channel FET. At this time, the polarities of the charging power supply 24 and the storage battery 25 should be reversed when they are working normally, that is, the negative pole of the charging power supply 24 is connected to the terminal 1, and the positive pole of the charging power supply 24 is grounded; the negative pole of the storage battery 25 is connected to the terminal 22, and the positive pole of the storage battery 25 is grounded.

The further technical scheme of the utility model is: the N channel field effect transistor can be replaced with the NPN type transistor, at this moment, be connected to the N channel field effect transistor grid (G), drain (D) and source (S) The positions are replaced one by one by the NPN transistor base (B), collector (C) and emitter (E). There is no freewheeling diode integrated inside the NPN transistor. When replacing it, a diode needs to be connected between the collector (C) and emitter (E) of each NPN transistor, and its anode is connected to the emitter of the NPN transistor ( E), the negative pole is connected to the NPN transistor collector (C).

The working principle of the storage battery charging control circuit with bidirectional reverse connection protection provided by the utility model is as follows: under normal circumstances, the positive pole of the charging power supply 24 is connected to terminal 1, the negative pole of the charging power supply 24 is grounded, the positive pole of the storage battery 25 is connected to the terminal 22, and the negative pole of the storage battery 25 grounded. When the anode voltage of the charging power supply 24 is loaded on the anode of the diode 7, the diode 7 is turned on, and the current passes through the diode 7, the resistor 12, the anode of the light-emitting diode in the photocoupler 13, and the cathode of the light-emitting diode in the photocoupler 13 are grounded to form a loop, and the photocoupler 13 The middle light-emitting diode works, and the phototransistor in the photocoupler 13 is turned on. When the anode voltage of the storage battery 25 is loaded on the anode of the diode 10, the diode 10 is turned on, and the current passes through the diode 10, the resistor 16, the anode of the light-emitting diode in the photocoupler 15, and the cathode of the light-emitting diode in the photocoupler 15 are grounded to form a loop. The light-emitting diode works, and the phototransistor in the photocoupler 15 is turned on. Because the grid (G) of the P channel field effect transistor 4 and the grid (G) of the P channel field effect transistor 6 all pass through the photosensitive transistor in the resistor 14, the photocoupler 13, the photosensitive transistor in the photocoupler 15, and the NPN transistor. 18 is grounded, so when the phototransistor in the photocoupler 15, the phototransistor in the photocoupler 15, and the NPN transistor 18 are all in the conduction state, the P channel field effect transistor 4 and the P channel field effect transistor 6 will also be in the conduction state at the same time. pass status. At this time, the positive pole of the charging power supply 24 is connected to the positive pole of the battery 25 through the P-channel field effect transistor 4 , the resistor 5 and the P-channel field effect transistor 6 , and the charging power supply 24 charges the battery 25 normally. The circuit of the utility model can work in a simple protection state, and can also work in a programmable state: when the circuit works in a simple protection state, the input terminal 2 should always be at a high level; Input programming signals such as pulse width modulation (PWM) signals. The resistor 5 is connected between the drain (D) of the P-channel field effect transistor 4 and the drain (D) of the P-channel field effect transistor 6, and its function is to limit the current; The starting voltage of reverse polarity protection.

Due to the advancement of modern field effect transistor manufacturing technology, the on-resistance of field effect transistors can be very small (as low as several milliohms). Therefore, by selecting the field effect transistor 4 and the field effect transistor 6, the power consumption of the present invention can be made very small, and it can work well under the state of high current. In the circuit, the phototransistor in the photocoupler 13, the phototransistor in the photocoupler 15, and the NPN transistor 18 form a three-input AND gate circuit. When the phototransistor in the photocoupler 13 and the phototransistor in the photocoupler 15 are simultaneously turned on , controlling the NPN transistor 18 through the input terminal 2 can realize various required functions: ① programmable charging function: input pulse width modulation (PWM) and other programming signals to control the charging process; ② switch function: input high level or low level The charging circuit can be turned on or off; ③Protection function: the circuit can be turned off when the circuit is over-current or over-voltage.

If there is a wrong connection of the charging power supply or battery, the circuit may have three connection states:

1. Reverse connection of charging power supply:

When the charging power supply 24 is reversely connected, the negative pole of the power supply is mistakenly connected to terminal 1, and the positive pole of the power supply is grounded; the battery 25 is connected normally, that is, the positive pole of the battery 25 is connected to terminal 22, and the negative pole of the battery 25 is grounded. At this time, the negative pole voltage of the charging power supply 24 is loaded on the positive pole of the diode 7. In this case, the diode 7 will not conduct, and no current will flow through the positive pole of the light-emitting diode in the resistor 12, the photocoupler 13, and the light-emitting diode in the photocoupler 13. The loop formed by the negative electrode being grounded, the light-emitting diode in the photocoupler 13 does not work, and the phototransistor in the photocoupler 13 is turned off. Because the grid (G) of the P channel field effect transistor 4 and the grid (G) of the P channel field effect transistor 6 pass through the resistor 14 and are formed by the photosensitive transistor in the photocoupler 13, the photosensitive transistor in the photocoupler 15, and the NPN transistor. The three-input terminal AND gate formed by 18 is grounded, so when any device in the phototransistor in the photocoupler 15, the phototransistor in the photocoupler 15 and the NPN transistor 18 is turned off, the P channel field effect transistor 4 and the NPN transistor 18 will be turned off at the same time. The P-channel field effect transistor 6 disconnects the electrical connection between the negative pole of the charging power supply 24 and the positive pole of the storage battery 25, effectively protecting the charging power supply 24 and the storage battery 25.

2. Reverse battery connection:

When the battery 25 is reversely connected, the negative pole of the battery 25 is mistakenly connected to the terminal 22, and the positive pole of the battery 25 is connected to the ground; the charging power supply 24 is connected normally, that is, the positive pole of the charging power supply 24 is connected to the terminal 1, and the negative pole of the power supply is grounded. At this time, the negative pole voltage of the storage battery 25 is loaded on the positive pole of the diode 10. In this case, the diode 10 will not conduct, and no current will flow through the resistor 16, the positive pole of the light-emitting diode in the photocoupler 15, and the negative pole of the light-emitting diode in the photocoupler 15. In the loop formed by grounding, the light-emitting diode in the photocoupler 15 does not work, and the phototransistor in the photocoupler 15 is turned off. Because the grid (G) of the P channel field effect transistor 4 and the grid (G) of the P channel field effect transistor 6 pass through the resistor 14 and are formed by the photosensitive transistor in the photocoupler 13, the photosensitive transistor in the photocoupler 15, and the transistor 18 The formed three-input terminal AND gate is grounded, so when any device in the phototransistor in the photocoupler 15, the phototransistor in the photocoupler 15, and the transistor 18 is turned off, the P-channel field effect transistor 4 and the P-channel field effect transistor 4 will be turned off at the same time. Dojo FET 6 disconnects the electrical connection between the positive pole of the charging power supply 24 and the negative pole of the storage battery 25, effectively protecting the charging power supply 24 and the storage battery 25.

3. Both the charging power supply and the battery are reversely connected:

Can draw from above-mentioned 1, the principle of two kinds of circuit connection states of 2, when charging power source 24 and storage battery 25 all reverse connection, photocoupler 13, photodiode in photocoupler 15 all do not work, photosensitive diode in photocoupler 15 In the triode and the photocoupler 15, the phototransistor is turned off, and the P channel field effect transistor 4 and the P channel field effect transistor 6 are turned off simultaneously, thereby disconnecting the electrical connection between the negative pole of the charging power source 24 and the negative pole of the storage battery 25, effectively The charging power source 24 and the storage battery 25 are protected.

Since the utility model adopts a fully symmetrical circuit design, in actual use, the terminal 1 can be interchangeably connected with the terminal 22, and the terminal 3 can be interchangeably connected with the terminal 23, which greatly improves the reliability of the circuit.

Compared with the prior art, the utility model has the following characteristics:

1. The utility model adopts a fully symmetrical circuit design. In actual use, the input terminal can be used interchangeably with the output terminal, which greatly improves the reliability of the circuit operation.

2. When the utility model adopts a high-power MOS field effect transistor as a protection device, its on-resistance is very small (the lowest can reach several milliohms), and the power loss during use is far lower than that of other components such as diodes or thyristors. circuit, so it can work well under high current conditions.

3. The utility model realizes the bidirectional reverse connection protection of the charging power source and the storage battery, and can also carry out programmable charging on the storage battery. It is applied to various high-power storage battery power supply systems such as electric vehicles and other electric vehicles, and will greatly improve the power supply of the system. performance and reliability.

4. The utility model is especially suitable for programmable charging and bidirectional reverse connection protection for storage batteries in a solar-wind energy power supply system, which improves the working performance and reliability of the solar-wind energy power supply system.

5. The utility model can also be widely used in various DC power supply systems, so that it can be effectively protected, improve the reliability of the system, and reduce accidental losses caused by improper use.

The detailed structure of the present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Accompanying drawing 1 is the circuit schematic diagram that the utility model adopts P channel field effect transistor;

Accompanying drawing 2 is the circuit diagram that the utility model adopts PNP transistor;

Accompanying drawing 3 is the circuit schematic diagram that the utility model adopts N channel FET;

Accompanying drawing 4 is the circuit schematic diagram that the utility model adopts NPN transistor.

Detailed ways

Embodiment 1, as shown in Figure 1: a battery charging control circuit using bidirectional reverse connection protection, which is composed of terminal 1, input terminal 2, terminal 3, P-channel field effect transistor 4, resistor 5, P-channel field effect Tube 6, diode 7, resistor 8, resistor 9, diode 10, capacitor 11, resistor 12, photocoupler 13, resistor 14, photocoupler 15, resistor 16, capacitor 17, NPN transistor 18, resistor 19, capacitor 20 , Resistor 21, terminal 22, terminal 23.

Terminal 1 is respectively connected with the anode of diode 7, the source (S) of P channel field effect transistor 4, and resistor 8, and the other end of resistor 8 is respectively connected with the grid (G) of P channel field effect transistor 4, resistor 14, P channel The grid (G) of the Doff 6 is connected to the resistor 9, and the other end of the resistance 9 is connected to the source (S) of the P-channel FET 6, the positive pole of the diode 10, and the terminal 22 respectively, and one end of the resistor 5 is connected to the P-channel The drain (D) of the Doff FET 4 is connected, the other end of the resistor 5 is connected with the drain (D) of the P channel FET 6, the negative pole of the diode 7 is connected with the resistor 12 and the capacitor 11 respectively, and the other end of the resistor 12 is connected with the The positive pole of the light-emitting diode in the photocoupler 13 is connected, the other end of the capacitor 11 is grounded, the negative pole of the light-emitting diode in the photocoupler 13 is grounded, the collector of the phototransistor in the photocoupler 13 and the emitter of the phototransistor in the photocoupler 15 Connect, the phototransistor emitter in the photocoupler 13 is connected with the collector of the NPN transistor 18, the emitter of the NPN transistor 18 is grounded, the base of the NPN transistor 18 is connected with the resistor 19 and the resistor 21 respectively, and the resistor 21 1. The other end of the resistor 19 is connected to the capacitor 20 and connected to the input terminal 2. The other end of the capacitor 20 is connected to the ground. The collector of the photosensitive transistor in the photocoupler 15 is connected to the other end of the resistor 14. Connect with resistor 16 and capacitor 17, the other end of capacitor 17 is grounded, the other end of resistor 16 is connected with the anode of the light-emitting diode in the photocoupler 15, the cathode of the light-emitting diode in the photocoupler 15 is grounded, and terminal 3 and terminal 23 are grounded.

Embodiment 2, as shown in Figure 2: a battery charging control circuit using bidirectional reverse connection protection, which is composed of a terminal 1, an input terminal 2, a terminal 3, a PNP transistor 4, a resistor 5, a PNP transistor 6, a diode 7, Resistor 8, resistor 9, diode 10, capacitor 11, resistor 12, photocoupler 13, resistor 14, photocoupler 15, resistor 16, capacitor 17, NPN transistor 18, resistor 19, capacitor 20, resistor 21, terminal 22 , Terminal 23, diode 26, and diode 27.

Terminal 1 is respectively connected with the emitter (E) of diode 7 anodes, PNP transistor 4, resistor 8, diode 26 cathodes, and the other end of resistor 8 is connected with the base (B) of PNP transistor 4, resistor 14, PNP transistor 6 respectively. The base (B) is connected to the resistor 9, and the other end of the resistor 9 is connected to the emitter (E) of the PNP transistor 6, the negative pole of the diode 27, the positive pole of the diode 10, and the terminal 22 respectively, and one end of the resistor 5 is connected to the collector of the PNP transistor 4 (C), diode 26 positive poles are connected, the other end of resistance 5 is connected with collector (C) of PNP transistor 6, diode 27 positive poles, diode 7 negative poles are connected with resistance 12, electric capacity 11 respectively, the other end of resistance 12 is coupled with photoelectricity The positive pole of the light-emitting diode in the device 13 is connected, the other end of the capacitor 11 is grounded, the negative pole of the light-emitting diode in the photocoupler 13 is grounded, and the collector of the phototransistor in the photocoupler 13 is connected with the emitter of the phototransistor in the photocoupler 15. The phototransistor emitter in the optocoupler 13 is connected with the collector of the NPN transistor 18, the emitter of the NPN transistor 18 is grounded, the base of the NPN transistor 18 is connected with the resistor 19 and the resistor 21 respectively, and 1 of the resistor 21 One end is grounded, the other end of the resistor 19 is connected to the capacitor 20 and connected to the input terminal 2, the other end of the capacitor 20 is grounded, the collector of the phototransistor in the photocoupler 15 is connected to the other end of the resistor 14, and the cathode of the diode 10 is respectively connected to the resistor 16. The capacitor 17 is connected, the other end of the capacitor 17 is grounded, the other end of the resistor 16 is connected to the anode of the light-emitting diode in the photocoupler 15, the cathode of the light-emitting diode in the photocoupler 15 is grounded, and the terminal 3 and terminal 23 are grounded.

Embodiment 3, as shown in Figure 3: a battery charging control circuit using bidirectional reverse connection protection, which is composed of terminal 1, input terminal 2, terminal 3, N-channel FET 4, resistor 5, N-channel FET Tube 6, diode 7, resistor 8, resistor 9, diode 10, capacitor 11, resistor 12, photocoupler 13, resistor 14, photocoupler 15, resistor 16, capacitor 17, PNP transistor 18, resistor 19, capacitor 20 , Resistor 21, terminal 22, terminal 23.

Terminal 1 is respectively connected with the cathode of diode 7, the source (S) of N-channel field effect transistor 4, and resistor 8, and the other end of resistor 8 is respectively connected with the grid (G) of N-channel field effect transistor 4, resistor 14, and N-channel field effect transistor 4. The grid (G) of the Doffet 6 is connected to the resistor 9, and the other end of the resistor 9 is connected to the source (S) of the N-channel Doffet 6, the cathode of the diode 10, and the terminal 22 respectively, and one end of the resistor 5 is connected to the N-channel The drain (D) of the FET 4 is connected, the other end of the resistor 5 is connected with the drain (D) of the N-channel FET 6, the positive pole of the diode 7 is connected with the resistor 12 and the capacitor 11 respectively, and the other end of the resistor 12 is connected with the capacitor 11. The negative pole of the light-emitting diode in the photocoupler 13 is connected, the other end of the capacitor 11 is grounded, the positive pole of the light-emitting diode in the photocoupler 13 is grounded, the emitter of the phototransistor in the photocoupler 13 and the collector of the phototransistor in the photocoupler 15 Connect, the collector of the phototransistor in the photocoupler 13 is connected with the collector of the PNP transistor 18, the emitter of the PNP transistor 18 is grounded, the base of the PNP transistor 18 is connected with the resistor 19 and the resistor 21 respectively, and the resistor 21 1. The other end of the resistor 19 is connected to the capacitor 20 and connected to the input terminal 2. The other end of the capacitor 20 is connected to the ground. Connect with resistor 16 and capacitor 17, the other end of capacitor 17 is grounded, the other end of resistor 16 is connected with the cathode of the light-emitting diode in the optocoupler 15, the anode of the light-emitting diode in the optocoupler 15 is grounded, and terminal 3 and terminal 23 are grounded.

Embodiment 4, as shown in Figure 4: a battery charging control circuit using bidirectional reverse connection protection, which is composed of a terminal 1, an input terminal 2, a terminal 3, an NPN transistor 4, a resistor 5, an NPN transistor 6, a diode 7, Resistor 8, resistor 9, diode 10, capacitor 11, resistor 12, photocoupler 13, resistor 14, photocoupler 15, resistor 16, capacitor 17, PNP transistor 18, resistor 19, capacitor 20, resistor 21, terminal 22 , Terminal 23, diode 26, and diode 27.

Terminal 1 is respectively connected with the emitter (E) of diode 7 cathodes, NPN transistor 4, resistor 8, diode 26 anodes, and the other end of resistor 8 is connected with the base (B) of NPN transistor 4, resistor 14, NPN transistor 6 respectively. The base (B) is connected to the resistor 9, and the other end of the resistor 9 is connected to the emitter (E) of the NPN transistor 6, the cathode of the diode 10, the anode of the diode 27, and the terminal 22 respectively, and one end of the resistor 5 is connected to the collector of the NPN transistor 4 (C), diode 26 negative poles are connected, the other end of resistance 5 is connected with collector (C) of NPN transistor 6, diode 27 negative poles, diode 7 positive poles are connected with resistance 12, electric capacity 11 respectively, the other end of resistance 12 is coupled with photoelectricity The negative pole of the light-emitting diode in the device 13 is connected, the other end of the capacitor 11 is grounded, the positive pole of the light-emitting diode in the photocoupler 13 is grounded, and the emitter of the phototransistor in the photocoupler 13 is connected with the collector of the phototransistor in the photocoupler 15. The collector of the phototransistor in the photocoupler 13 is connected with the collector of the PNP transistor 18, the emitter of the PNP transistor 18 is grounded, and the base of the PNP transistor 18 is connected with the resistor 19 and the resistor 21 respectively. One end is grounded, the other end of the resistor 19 is connected to the capacitor 20 and connected to the input terminal 2, the other end of the capacitor 20 is grounded, the emitter of the phototransistor in the photocoupler 15 is connected to the other end of the resistor 14, and the anode of the diode 10 is respectively connected to the resistor 16. The capacitor 17 is connected, the other end of the capacitor 17 is grounded, the other end of the resistor 16 is connected to the cathode of the light-emitting diode in the photocoupler 15, the anode of the light-emitting diode in the photocoupler 15 is grounded, and the terminals 3 and 23 are grounded.

The specific embodiments described herein are only a specific illustration of the concept of the present utility model, and those skilled in the art to which the utility model belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods Replacement, but will not deviate from the spirit of the utility model or go beyond the scope defined by the appended claims.

Claims (4)

1. A storage battery charging control circuit adopting bidirectional reverse connection protection, characterized in that: terminal 1, input terminal 2, terminal 3, P channel field effect transistor 4, resistor 5, P channel field effect transistor 6, diode 7, Resistor 8, resistor 9, diode 10, capacitor 11, resistor 12, photocoupler 13, resistor 14, photocoupler 15, resistor 16, capacitor 17, NPN transistor 18, resistor 19, capacitor 20, resistor 21, terminal 22 , terminal 23; Terminal 1 is respectively connected with the anode of diode 7, the source (S) of P channel field effect transistor 4, and resistor 8, and the other end of resistor 8 is respectively connected with the grid (G) of P channel field effect transistor 4, resistor 14, P channel The grid (G) of the Doff 6 is connected to the resistor 9, and the other end of the resistance 9 is connected to the source (S) of the P-channel FET 6, the positive pole of the diode 10, and the terminal 22 respectively, and one end of the resistor 5 is connected to the P-channel The drain (D) of the Doff FET 4 is connected, the other end of the resistor 5 is connected with the drain (D) of the P channel FET 6, the negative pole of the diode 7 is connected with the resistor 12 and the capacitor 11 respectively, and the other end of the resistor 12 is connected with the The positive pole of the light-emitting diode in the photocoupler 13 is connected, the other end of the capacitor 11 is grounded, the negative pole of the light-emitting diode in the photocoupler 13 is grounded, the collector of the phototransistor in the photocoupler 13 and the emitter of the phototransistor in the photocoupler 15 Connect, the phototransistor emitter in the photocoupler 13 is connected with the collector of the NPN transistor 18, the emitter of the NPN transistor 18 is grounded, the base of the NPN transistor 18 is connected with the resistor 19 and the resistor 21 respectively, and the resistor 21 The other end is grounded, the other end of the resistor 19 is connected to the capacitor 20 and connected to the input terminal 2, the other end of the capacitor 20 is grounded, the collector of the phototransistor in the photocoupler 15 is connected to the other end of the resistor 14, and the negative pole of the diode 10 is connected to the other end of the resistor 14 respectively. Resistor 16 and capacitor 17 are connected, the other end of capacitor 17 is grounded, the other end of resistor 16 is connected to the anode of the light-emitting diode in the photocoupler 15, the cathode of the light-emitting diode in the photocoupler 15 is grounded, and terminal 3 and terminal 23 are grounded. 2. A storage battery charging control circuit using bidirectional reverse connection protection according to claim 1, characterized in that: the P-channel field effect transistor 4 and the P-channel field effect transistor 6 can be replaced by PNP transistors, at this time connected to The positions of the gate (G), drain (D) and source (S) of the P-channel field effect transistor are respectively corresponding to the base (B), collector (C) and emitter (E) of the PNP transistor. Replacement, if there is no freewheeling diode integrated inside the PNP transistor, when replacing it, a diode needs to be connected between the collector (C) and emitter (E) of each PNP transistor, and its anode is connected to the PNP transistor set The electrode (C), the cathode is connected to the emitter (E) of the PNP transistor. 3. A battery charging control circuit using bidirectional reverse connection protection according to claim 1, characterized in that: N-channel FETs can be used to replace P-channel FETs 4 and P-channel FETs 6, at this time The normal working polarity of the charging power supply 24 and the battery 25 should be reversed, that is, the negative pole of the charging power supply 24 is connected to the terminal 1, the positive pole of the charging power supply 24 is grounded, the negative pole of the battery 25 is connected to the terminal 22, and the positive pole of the battery 25 is grounded. 4. A kind of accumulator charging control circuit adopting bidirectional reverse connection protection according to claim 3 is characterized in that: the N channel field effect transistor can be replaced by an NPN type transistor, and at this moment it is connected to the N channel field effect transistor grid ( The positions of G), drain (D) and source (S) are replaced by the NPN transistor base (B), collector (C) and emitter (E) in one-to-one correspondence, and there is no inside the NPN transistor For integrated freewheeling diodes, when replacing them, a diode needs to be connected between the collector (C) and emitter (E) of each NPN transistor, the anode of which is connected to the emitter (E) of the NPN transistor, and the cathode is connected to the NPN type transistor collector (C).

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