CN212343405U

CN212343405U - Control circuit and power supply product for realizing bidirectional charging and discharging through single interface

Info

Publication number: CN212343405U
Application number: CN202021939676.4U
Authority: CN
Inventors: 吴玉锋
Original assignee: Poweroad Xiamen Renewable Energy Technology Co ltd
Current assignee: Fujian Liangdao New Energy Development Co ltd
Priority date: 2020-09-08
Filing date: 2020-09-08
Publication date: 2021-01-12
Anticipated expiration: 2030-09-08

Abstract

The utility model discloses a control circuit and a power supply product for realizing bidirectional charge and discharge by a single interface, the control circuit for realizing bidirectional charge and discharge by the single interface comprises a first switch circuit, a second switch circuit and a main control circuit, the control ends of the first switch circuit and the second switch circuit are respectively connected with the control output end of the main control circuit, the first switch circuit and the second switch circuit form a bidirectional conduction switch circuit, the bidirectional conduction switch circuit is connected between the input/output end of the rechargeable power supply and the external interface in series, the output ends of the discharging insertion detection circuit and the charging insertion detection circuit are respectively connected with the input end of the main control circuit, the discharging insertion detection circuit is used for detecting whether the external interface has discharging insertion, and the charging insertion detection circuit is used for detecting whether the external interface has charging insertion. The utility model discloses realize that single interface both can connect the charger to charge and can connect the discharged function of consumer, it is with low costs, the circuit is small.

Description

Control circuit and power supply product for realizing bidirectional charging and discharging through single interface

Technical Field

The utility model belongs to charge-discharge control circuit field specifically relates to a control circuit and power supply product that two-way charge-discharge was realized to single interface.

Background

In mobile power products or energy storage products, there are design requirements for external output discharge and internal input to charge rechargeable batteries (mainly lithium batteries), and many products in the market at present use two different interfaces and two sets of circuits for battery charging input and external discharge output.

Disclosure of Invention

An object of the utility model is to provide a control circuit and power product that two-way charge-discharge was realized to single interface are used for solving the technical problem that above-mentioned exists.

In order to achieve the above object, the utility model adopts the following technical scheme: the utility model provides a control circuit that two-way charge-discharge was realized to single interface, including first switch circuit, the second switch circuit, main control circuit, discharge and insert detection circuitry, charge and insert detection circuitry and external interface, the control end of first switch circuit and second switch circuit is connected with main control circuit's control output respectively, first switch circuit and second switch circuit constitute two-way switch circuit that switches on, two-way switch circuit that switches on concatenates between chargeable source's input/output end and external interface, the output that discharge inserted detection circuitry and charge and insert detection circuitry connects the input of main control circuit respectively, discharge and insert detection circuitry and be used for detecting whether external interface has the discharge to insert, charge and insert detection circuitry and be used for detecting whether external interface has the charge to insert.

Furthermore, the first switch circuit is composed of a PMOS transistor Q1, the second switch circuit is composed of a PMOS transistor Q2, a source electrode of the PMOS transistor Q1 is connected with a source electrode of the PMOS transistor Q2, a drain electrode of the PMOS transistor Q1 is connected with an anode of the rechargeable power supply, and a drain electrode of the PMOS transistor Q2 is connected with an anode of the external interface.

Furthermore, the device also comprises a current sampling circuit, a first comparison circuit and a second comparison circuit, wherein the current sampling circuit is used for collecting the current of a loop where PMOS tubes Q1 and Q2 are located, the discharging current sampling output end of the current sampling circuit is respectively connected with the input ends of the main control circuit and the first comparison circuit, the charging current sampling output end of the current sampling circuit is respectively connected with the input ends of the main control circuit and the second comparison circuit, and the output ends of the first comparison circuit and the second comparison circuit are respectively connected with the control ends of the first switch circuit and the second switch circuit.

Furthermore, the device also comprises a first amplifying circuit and a second amplifying circuit, wherein the discharging current sampling output end of the current sampling circuit is respectively connected with the input ends of the main control circuit and the first comparing circuit through the first amplifying circuit, and the charging current sampling output end of the current sampling circuit is respectively connected with the input ends of the main control circuit and the second comparing circuit through the second amplifying circuit.

The short-circuit judging circuit is connected with the output end of the discharge current sampling circuit, the output end of the short-circuit judging circuit is respectively connected with the control end of the third switching circuit and the input end of the main control circuit, and the third switching circuit is configured to control the second switching circuit to be switched off when the short-circuit judging circuit judges that the output circuit is short-circuited.

Further, the short circuit judgment circuit is implemented by using a comparator.

And the external interface reverse connection detection circuit is used for outputting a signal to control the second switch circuit to be disconnected and outputting the signal to the main control circuit when the external interface is detected to be charged and inserted into the reverse connection.

Further, the discharging insertion detection circuit comprises a resistor R1 and a diode D1, a first end of a resistor R1 is connected with a power supply, a second end of the resistor R1 is connected with a positive end of a diode D1, a negative end of a diode D1 is connected with a positive electrode of an external interface, a second end of a resistor R1 is an output end of the discharging insertion detection circuit, the charging insertion detection circuit comprises a voltage regulator tube Z1, a diode D9, a resistor R5 and a resistor R15, a negative end of the voltage regulator tube Z1 is connected with a positive electrode of the external interface, a positive end of the voltage regulator tube Z1 is sequentially connected with the diode D9, the resistor R5 and the resistor R15 in series and is connected with a negative electrode of the external interface, and a node between the resistors R5 and R15 is an output end of the.

Furthermore, the positive end of the voltage regulator tube Z1 is connected to the control input end of the start-up circuit of the main control circuit, and is used for providing an input power supply for the start-up circuit of the main control circuit when the external interface is plugged in, so as to realize automatic start-up power supply when the external interface is plugged in.

The utility model also provides a power supply product is equipped with foretell single interface and realizes the control circuit of two-way charge-discharge.

The utility model has the advantages of:

the utility model discloses realize single interface both can connect the charger to charge and can connect the discharged function of consumer to save product design cost, the circuit is small, solves the problem that the product volume requires higher or interface position is limited.

The utility model discloses still have overcurrent protection, short-circuit protection, external interface charge and insert protect function such as reversal connection protection, security and reliability height.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a circuit diagram of an embodiment of the present invention.

Detailed Description

To further illustrate the embodiments, the present invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references, one of ordinary skill in the art will appreciate other possible embodiments and advantages of the present invention. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The present invention will now be further described with reference to the accompanying drawings and detailed description.

As shown in fig. 1, a control circuit for realizing bidirectional charging and discharging with a single interface includes a first switch circuit, a second switch circuit, a main control circuit, a discharging insertion detection circuit, a charging insertion detection circuit and an external interface X1, wherein control terminals of the first switch circuit and the second switch circuit are respectively connected with a control output terminal of the main control circuit, the first switch circuit and the second switch circuit form a bidirectional conducting switch circuit, the bidirectional conducting switch circuit is connected in series between an input/output terminal of a rechargeable power supply and the external interface X1, the rechargeable power supply is a lithium battery, the anode BAT + (input/output end) of the lithium battery is connected with the anode 1 of the external interface X1 through a bidirectional conduction switch circuit, the cathode 2 of the external interface X1 is grounded GND, the cathode of the lithium battery is grounded GND, but is not limited thereto and in other embodiments the power source may be other rechargeable batteries.

The output ends of the discharging insertion detection circuit and the charging insertion detection circuit are respectively connected with the input end of the main control circuit, the discharging insertion detection circuit is used for detecting whether the external interface has discharging insertion (electric equipment access), and the charging insertion detection circuit is used for detecting whether the external interface has charging insertion (namely charging equipment, such as charger access).

In this embodiment, the main control circuit is implemented by using the MCU processor U3, and the detailed circuit structure is shown in fig. 1, which is not described in detail, but in other embodiments, the main control circuit may also be implemented by using other processors.

In this embodiment, the first switch circuit is composed of a PMOS transistor Q1, the second switch circuit is composed of a PMOS transistor Q2, a source of the PMOS transistor Q1 is connected to a source of the PMOS transistor Q2, a drain of the PMOS transistor Q1 is connected to an anode BAT + of the lithium battery, and a drain of the PMOS transistor Q2 is connected to an anode 1 of the external interface X1, and more specifically, the circuit connection is shown in fig. 1, which is not described in detail. The first switch circuit and the second switch circuit are both implemented by PMOS transistors, and the circuit structure is simple, easy to implement, low in loss and low in cost, but not limited thereto.

Preferably, in this embodiment, the first switch circuit further includes an NPN transistor Q3, a collector series resistor R9 of the NPN transistor Q3 is connected to the gate of the PMOS transistor Q1, an emitter of the NPN transistor Q3 is connected to the negative electrode 2 of the external interface X1, a base series diode D3 and a resistor R11 of the NPN transistor Q3 are connected to the 9 th pin (control output end) of the MCU processor U3, and a base series resistor R19 of the NPN transistor Q3 is connected to the emitter of the NPN transistor Q3.

Preferably, in this embodiment, the second switch circuit further includes an NPN transistor Q4, a collector series resistor R10 of the NPN transistor Q4 is connected to the gate of the PMOS transistor Q2, an emitter of the NPN transistor Q4 is connected to the negative electrode 2 of the external interface X1, a base series diode D4 and a resistor R12 of the NPN transistor Q4 are connected to the 8 th pin (control output end) of the MCU processor U3, and a base series resistor R20 of the NPN transistor Q4 is connected to the emitter of the NPN transistor Q4.

In this embodiment, the discharging insertion detection circuit includes a resistor R1 and a diode D1, a first end of the resistor R1 is connected to a power supply, which is +5V in this embodiment and is provided by a power supply circuit of a product, but not limited thereto, a second end of the resistor R1 is connected to a positive end of the diode D1, a negative end of the diode D1 is connected to the positive electrode 1 of the external interface X1, and a second end of the resistor R1 is an output end of the discharging insertion detection circuit and is connected to a 12 th pin (input end) of the MCU processor U3.

In this embodiment, the charging insertion detection circuit includes a voltage regulator tube Z1, a diode D9, resistors R5 and R15, a negative terminal of the voltage regulator tube Z1 is connected to an anode 1 of an external interface X1, a positive terminal of the voltage regulator tube Z1 is sequentially connected in series to the diode D9, the resistors R5 and R15 are connected to a negative terminal 2 of the external interface X1, and a node between the resistors R5 and R15 is an output terminal of the charging insertion detection circuit and is connected to a 13 th pin (input terminal) of the MCU processor U3.

Further, in this embodiment, a positive terminal of the voltage regulator tube Z1 is connected to a control input terminal of a power-on circuit of the MCU processor U3, and is configured to provide an input power source for the MCU processor U3 when the external interface X1 is charged and plugged when the product is powered off, so that the MCU processor U3 operates. The starting circuit of the MCU processor U3 may adopt various existing power supply circuits, and reference may be made to the prior art, which is not described in detail.

Furthermore, the device also comprises a current sampling circuit, a first comparison circuit and a second comparison circuit, wherein the current sampling circuit is used for collecting the current of a loop where PMOS tubes Q1 and Q2 are located, the output end of the discharging current sampling of the current sampling circuit is respectively connected with the input ends of the main control circuit and the first comparison circuit, the output end of the charging current sampling of the current sampling circuit is respectively connected with the input ends of the main control circuit and the second comparison circuit, and the output ends of the first comparison circuit and the second comparison circuit are respectively connected with the control ends of the first switch circuit and the second switch circuit.

In this embodiment, the device further includes a first amplifying circuit and a second amplifying circuit, wherein the output terminal of the discharging current sampling of the current sampling circuit is connected to the input terminals of the main control circuit and the first comparing circuit through the first amplifying circuit, and the output terminal of the charging current sampling of the current sampling circuit is connected to the input terminals of the main control circuit and the second comparing circuit through the second amplifying circuit. The first amplifying circuit and the second amplifying circuit are used for amplifying the sampling current, so that stability and accuracy are improved.

In this embodiment, the current sampling circuit is implemented by using the current sampling resistor RS1, and has a simple structure and low cost, but not limited thereto. Specifically, the first end of the current sampling resistor RS1 is grounded, and the second end of the current sampling resistor RS1 is connected to the negative electrode 2 of the external interface X1.

In this embodiment, the first comparison circuit is implemented by a comparator U4 of the model LMV331, a pin 4 (output end) of the comparator U4 is sequentially connected in series with a resistor R17 and a diode D7 to a base of an NPN transistor Q3, and a pin 1 (input end) of the comparator U4 is connected to an output end of the first amplification circuit, and a more specific circuit structure is shown in fig. 1 and will not be described in detail. Of course, in other embodiments, the first comparison circuit may be implemented by using other existing comparison circuits.

Preferably, in this embodiment, the second amplifying circuit and the second comparing circuit are implemented by using an operational amplifier U5 with a model LM258, so that the circuit structure is simpler and the devices are fewer. Specifically, the pin 5 of the operational amplifier U5 is the input terminal of the second amplifying circuit and the output terminal GND of the charging current sampling circuit, the pin 7 of the operational amplifier U5 is the output terminal of the second amplifying circuit and the series resistor R26 is connected to the pin 7 (input terminal) of the MCU processor U3 and the pin 3 (input terminal of the second comparing circuit) of the operational amplifier U5, and the pin 1 of the operational amplifier U5 is the output terminal of the second comparing circuit and the series resistor R18 and the diode D8 are connected to the base of the NPN triode Q4. Of course, in other embodiments, the second amplifying circuit may also be implemented by using other existing amplifying circuits, and the second comparing circuit may also be implemented by using other existing comparing circuits.

Further, in this embodiment, the short circuit detection circuit further includes a short circuit determination circuit and a third switch circuit, an input end of the short circuit determination circuit is connected to the output end CH "of the discharge current sampling of the current sampling circuit, an output end of the short circuit determination circuit is connected to a control end of the third switch circuit and an input end of the main control circuit, respectively, and the third switch circuit is configured to control the second switch circuit to be turned off when the short circuit determination circuit determines that the output circuit is short-circuited.

Preferably, in this embodiment, the first amplifying circuit and the short circuit determining circuit are implemented by using an operational amplifier U2 with a model number LM258, so that the circuit structure is simpler, and the number of devices is less, but not limited thereto, and the third switching circuit is implemented by using an NPN triode Q5, which is simple in circuit structure and low in cost, but not limited thereto.

Specifically, a pin 5 of the operational amplifier U2 is an output terminal CH of the first amplifying circuit, which is connected to the discharge current sampling terminal of the current sampling circuit, a pin 7 of the operational amplifier U2 is an output terminal series resistor R6 of the first amplifying circuit, and then, the first pin 6 (an input terminal) of the MCU processor U3 is connected to the second pin 1 of the comparator U4, a pin 3 of the operational amplifier U2 is an input terminal of the short-circuit judging circuit, which is connected to the discharge current sampling terminal CH of the current sampling circuit, a pin 1 of the operational amplifier U2 is an output terminal of the short-circuit judging circuit, a pin D2 of the MCU processor U3 is connected to the first pin, and the second pin is connected to the base of the NPN triode Q5, the emitter of the NPN triode Q5 is grounded, and the collector of the NPN triode Q5 is connected to the base of the NPN triode Q4, and more specifically, the circuit structure is not detailed in fig. 1.

Further, in this embodiment, the device further includes an external interface reverse connection detection circuit, where the external interface reverse connection detection circuit is configured to output a signal to control the second switch circuit to be turned off when detecting that the external interface X1 is inserted into the external interface in a reverse connection during charging, and output the signal to the MCU processor U3.

In this embodiment, the external interface reverse connection detection circuit is realized by adopting the optocoupler U1, the circuit structure is simple, and the external interface reverse connection detection circuit has an isolation effect, avoids interference, improves stability and reliability, but is not limited thereto.

Specifically, the optocoupler U1 adopts a phototriode type optocoupler, a positive end series resistor R2 of a light emitting diode of the optocoupler U1 is connected with a negative end of a diode D6, a positive end of the diode D6 is connected with a negative electrode 2 of an external interface X1, a negative end of a light emitting diode of the optocoupler U1 is connected with a positive electrode 1 of the external interface X1, an emitter of a phototriode of the optocoupler U1 is grounded, and a collector of a phototriode of the optocoupler U1 is connected with a base of an NPN triode Q4 and a 10 th pin (input end) of the MCU processor U3.

In this embodiment, the alarm circuit is connected to the MCU processor U3 and configured to perform an abnormal alarm, and specifically, the alarm circuit is composed of a buzzer B1 and an NPN triode Q6, and the specific circuit is shown in fig. 1 and will not be described in detail.

The working process is as follows:

after the product is started, the system is normally powered on and self-tested, when the external interface X1 is not connected with a charger or an electric device, pins 8, 9 and 10 of the MCU processor U3 are in a high-impedance state, and the pin 4 of the comparator U4 and the pin 1 of the operational amplifier U5 are in a low level due to no charging and discharging current output, so that the NPN triode Q3, the NPN triode Q4, the PMOS tube Q1 and the PMOS tube Q2 are all in a closed state.

Output discharge function: when the external interface X1 is connected with an electric device, which is equivalent to a resistor R connected in parallel with the output end, because the internal resistance of the electric device is small, the voltage of the 12 th pin of the MCU processor U3 is instantly pulled down through the diode D1, the MCU processor U3 detects the pulled-down signal and then considers that a discharge device is inserted, the 8 th pin outputs high level at the moment, the NPN triode Q4 and the PMOS tube Q2 are conducted through the resistor R12 and the diode D4, the positive pole current of the lithium battery returns to the negative pole of the lithium battery through the diode in the PMOS tube Q1, the PMOS tube Q2, the electric device and the current sampling resistor RS1 to supply power to the electric device, the current sampling resistor RS1 samples current to generate voltage, the voltage is input through the 5 th pin of the operational amplifier U2, the amplified current is output through the 7 th pin, one path of the current is input to the 1 st pin of the comparator U4 and compared with the voltage of the 3 rd pin of the comparator U4 and exceeds the reference of the 3 rd, the 4 th pin outputs high level, and an NPN triode Q3 and a PMOS tube Q1 are started through a resistor R17 and a diode D7, so that the voltage of a lithium battery is completely applied to electric equipment, the equipment works normally, and the diode inside the PMOS tube Q1 is prevented from being damaged due to overheating (the reference voltage of the 3 pins can be adjusted, and the PMOS tube Q1 is started after a certain discharge current is set, so that the interference is prevented, the misoperation is prevented, and the safety and the reliability are improved); the other path is output to a 6 th pin of the MCU processor U3, and the MCU processor U3 carries out corresponding processing operation.

Overload (overcurrent) protection: when the power of externally connected equipment exceeds the set power of the external interface X1, the MCU processor U3 judges that the voltage output by the 7 th pin of the operational amplifier U2 exceeds a set value, the 8 th pin of the MCU processor U3 outputs a low level, so that the NPN triode Q4 and the PMOS tube Q2 are closed, the output is turned off, the overload (over-current) protection is realized, and at the moment, the MCU processor U3 buzzes and alarms through the buzzer B1.

Short-circuit protection: when an externally connected device is in fault short circuit, the current is sampled through the current sampling resistor RS1 to generate voltage and the voltage is output to the 3 rd pin of the operational amplifier U2, the operational amplifier U2 compares the voltage with the 2 nd pin short circuit reference and outputs high level through the 1 st pin, one path of the high level directly turns on the NPN triode Q5 through the resistor R24, and the NPN triode Q4 and the PMOS tube Q2 are forcibly turned off to turn off the output, so that the reliability is improved; in addition, the operational amplifier U2 is self-locked through diodes D2, D5 and D10 and informs the MCU processor U3, the MCU processor U3 closes the 8 th pin high level after recognizing a short-circuit signal, short-circuit protection is achieved, and at the moment, the MCU processor U3 buzzes and alarms through a buzzer B1.

Inputting a charging function: when the external interface X1 is connected to a charger, because the input voltage of the charger is higher (all the voltages are higher than the voltage of the lithium battery), at this time, the zener diode Z1 is conducted, the voltage is divided by the diode D9, the resistor R5 and the resistor R15 and is added to the 13 th pin of the MCU processor U3, when the first pin 13 of the MCU processor U3 detects that the input signal is within the set value, it is determined that the charger is inserted, at this time, the 9 th pin outputs a high level, the triode Q3 and the PMOS Q1 are conducted by the resistor R11 and the diode D3, the positive electrode current of the charger returns to the negative electrode of the charger through the diode inside the PMOS Q2, the PMOS Q1, the lithium battery and the current sampling resistor RS1, and charges the lithium battery, the current sampling resistor RS1 samples the current to generate a voltage, the voltage is input through the 5 th pin 5 of the operational amplifier U5, after amplification, the 7 th pin outputs a path to the 3 rd pin of the operational amplifier U5, after the reference of the No. 2 pin is exceeded, the No. 1 pin outputs high level, an NPN triode Q4 and a PMOS tube Q2 are started through a resistor R18 and a diode D8, so that the voltage of a charger is completely applied to a lithium battery, the lithium battery is normally charged, and the diode inside the PMOS tube Q2 is prevented from being damaged due to overheating (the reference voltage of the No. 2 pin can be adjusted, and the PMOS tube Q2 is started after certain charging current is set, so that interference is prevented, malfunction is caused, and safety and reliability are improved); the other path is output to a 7 th pin of the MCU processor U3, and the MCU processor U3 carries out corresponding processing operation.

Fully charging and shutting down: when the lithium battery enters a constant voltage state during charging, the charging current gradually decreases, and after the charging current is decreased to a set value, the MCU processor U3 sets the pin 9 to be at a low level, so that the NPN triode Q3 and the PMOS tube Q1 are closed, and charging is turned off (at this time, the NPN triode Q4 and the PMOS tube Q2 are also automatically closed due to the fact that the charging current disappears).

Protection of charging overcurrent: when the 7 th pin of the MCU processor U3 detects that the charging current exceeds the specified value, the 9 th pin is set to be low level, so that the NPN triode Q3 and the PMOS tube Q1 are closed, the charging is turned off, and the MCU processor U3 buzzes and alarms through the buzzer B1.

In a shutdown state, the product can be charged as well, when a matched charger is inserted into an external interface X1, a voltage stabilizing diode Z1 is conducted, one path of the voltage stabilizing diode is added to a control input end of a startup circuit of the MCU processor U3 to execute power supply startup, the other path of the voltage stabilizing diode is added to a 13 th pin of the MCU processor U3 through voltage division of a diode D9, a resistor R5 and a resistor R15, when a 13 th pin of the MCU processor U3 detects a charging input signal, the insertion of the matched charger is confirmed, and the subsequent process is the same as the description of the input charging function.

When the charger is pulled out, the NPN triode Q4 and the PMOS tube Q2 are closed due to the fact that charging current disappears, meanwhile, the 7 th pin of the MCU processor U3 detects no charging current, the 9 th pin is set to be at a low level, the NPN triode Q3 and the PMOS tube Q1 are closed, the PMOS tube Q1 and the PMOS tube Q2 are closed simultaneously, the output end does not have voltage, and the MCU processor U3 supplies power and disappears and shuts down.

Reverse connection protection of the charger: when the external interface X1 is inserted into the charger and the positive and negative polarities are reversed, at the moment, the reverse voltage makes the optocoupler U1 work and output low level through the diode D6 and the resistor R2, the NPN triode Q4 and the PMOS tube Q1 are forcibly closed, a loop is cut off, and meanwhile the MCU processor U3 is informed that a power supply is reversely connected, so that the problems of large-current short circuit and runaway caused by a lithium battery and an external power supply are alarmed and avoided.

The utility model also provides a power supply product is equipped with foretell single interface and realizes the control circuit of two-way charge-discharge. The power supply product may be a mobile power supply or the like.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides a control circuit that two-way charge-discharge was realized to single interface which characterized in that: the charging plug-in detection circuit is used for detecting whether the external interface has the discharging plug-in or not, and the charging plug-in detection circuit is used for detecting whether the external interface has the charging plug-in or not.

2. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 1, wherein: the first switch circuit is composed of a PMOS tube Q1, the second switch circuit is composed of a PMOS tube Q2, the source electrode of the PMOS tube Q1 is connected with the source electrode of the PMOS tube Q2, the drain electrode of the PMOS tube Q1 is connected with the anode of the rechargeable power supply, and the drain electrode of the PMOS tube Q2 is connected with the anode of the external interface.

3. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 2, wherein: the current sampling circuit is used for collecting the current of a loop where PMOS tubes Q1 and Q2 are located, the discharging current sampling output end of the current sampling circuit is connected with the input ends of the main control circuit and the first comparison circuit respectively, the charging current sampling output end of the current sampling circuit is connected with the input ends of the main control circuit and the second comparison circuit respectively, and the output ends of the first comparison circuit and the second comparison circuit are connected with the control ends of the first switch circuit and the second switch circuit respectively.

4. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 3, wherein: the output end of the discharge current sampling of the current sampling circuit is respectively connected with the input ends of the main control circuit and the first comparison circuit through the first amplification circuit, and the output end of the charge current sampling of the current sampling circuit is respectively connected with the input ends of the main control circuit and the second comparison circuit through the second amplification circuit.

5. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 3, wherein: the short-circuit judging circuit is connected with the discharging current sampling output end of the current sampling circuit, the short-circuit judging circuit is connected with the control end of the third switching circuit and the input end of the main control circuit respectively, and the third switching circuit is configured to control the second switching circuit to be switched off when the short-circuit judging circuit judges that the output circuit is short-circuited.

6. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 5, wherein: the short circuit judgment circuit is realized by adopting a comparator.

7. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 2, wherein: the external interface reverse connection detection circuit is used for outputting a signal to control the second switch circuit to be disconnected and outputting the signal to the main control circuit when the external interface is detected to be charged and inserted into the reverse connection.

8. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 1, wherein: the discharging insertion detection circuit comprises a resistor R1 and a diode D1, a first end of a resistor R1 is connected with a power supply, a second end of the resistor R1 is connected with a positive end of a diode D1, a negative end of a diode D1 is connected with a positive electrode of an external interface, a second end of a resistor R1 is an output end of the discharging insertion detection circuit, the charging insertion detection circuit comprises a voltage regulator tube Z1, a diode D9, a resistor R5 and a resistor R15, a negative end of the voltage regulator tube Z1 is connected with a positive electrode of the external interface, a positive end of the voltage regulator tube Z1 is sequentially connected with the diode D9, the resistor R5 and the resistor R15 in series to be connected with a negative electrode of the external interface, and a node between the resistors R5 and R15 is an output end.

9. The control circuit for realizing bidirectional charge and discharge of the single interface according to claim 8, wherein: the positive end of the voltage regulator tube Z1 is connected with the control input end of the starting circuit of the main control circuit and used for providing an input power supply for the starting circuit of the main control circuit when the external interface is charged, and automatic starting power supply is realized when the external interface is charged.

10. A power supply product characterized by: the control circuit for realizing bidirectional charging and discharging is provided with the single interface of any one of claims 1 to 9.