Charger control circuit

Abstract

The utility model relates to the technical field of charger circuits, and discloses a charger control circuit with relatively high reliability, which comprises a secondary rectification circuit (110) for receiving voltage signals input by a pre-stage circuit, a switching circuit (120), a battery pack interface circuit (130), a main control circuit (140) and an auxiliary power supply circuit (150), and is characterized in that the secondary rectification circuit (110) comprises a secondary protection circuit (111); when the battery pack is charged abnormally, a trigger level signal output by the battery pack interface circuit (130) is a high level, the trigger level signal controls the secondary protection circuit (111) to be switched on, the voltage output by the secondary rectification circuit (110) is pulled to a 0V level, and the auxiliary power supply circuit (150) outputs no voltage signal.

Description

A charger control circuit Technical Field

[0001] This utility model relates to the field of charger circuit technology, and more specifically, to a charger control circuit. Background Technology

[0002] To ensure the safety of battery charging circuits, overvoltage and overcurrent protection measures must be implemented. For example, by incorporating logic control circuits and trigger capacitors, a protection mechanism can be triggered immediately upon charger connection to prevent damage to the battery due to excessive voltage. Furthermore, the use of Zener diodes ensures that the charging process automatically stops when the battery voltage reaches a predetermined value, avoiding damage caused by overcharging or over-discharging. In particular, charging anomaly protection functions are typically found in lithium-ion battery packs to protect the battery from charging system malfunctions.

[0003] However, current charging circuits lack secondary protection mechanisms when batteries encounter abnormal conditions (such as over-temperature protection, over-current protection, and short-circuit protection). Once a single fault occurs in the battery pack, it may significantly increase the risk of dangerous events such as explosions and fires. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a charger control circuit with higher reliability, which addresses the shortcomings of existing charging circuits in the prior art that fail to provide secondary protection when the battery malfunctions (such as over-temperature protection, over-current protection, and short-circuit protection).

[0005] The technical solution adopted by this utility model to solve its technical problem is: to construct a charger control circuit, which includes:

[0006] The secondary rectifier circuit, configured within the control circuit, receives the voltage signal input from the preceding circuit.

[0007] The secondary rectifier circuit includes a secondary protection circuit, the first terminal of which is connected to the power supply terminal.

[0008] The third terminal of the secondary protection circuit is connected to the common terminal;

[0009] A switching circuit, the input terminal of which is connected to the output terminal of the secondary rectifier circuit, is used to receive the voltage signal;

[0010] A battery pack interface circuit, whose input terminal is connected to the output terminal of the switching circuit, is used to receive the voltage signal to provide charging voltage to the battery pack connected to the battery pack interface circuit.

[0011] One signal output terminal of the battery pack interface circuit is connected to the second terminal of the secondary protection circuit for receiving a trigger level signal;

[0012] An auxiliary power supply circuit, whose input terminal is connected to the output terminal of the secondary rectifier circuit, is used to receive voltage signals.

[0013] The main control circuit has its power input terminal connected to the output terminal of the auxiliary power supply circuit, and is used to receive the voltage signal.

[0014] One output terminal of the main control circuit is connected to the signal input terminal of the switching circuit;

[0015] When the battery pack experiences a charging abnormality, the trigger level signal output by the battery pack interface circuit is at a high level. The trigger level signal controls the secondary protection circuit to turn on, pulling the voltage output by the secondary rectifier circuit to 0V. The auxiliary power supply circuit then has no voltage signal output.

[0016] In some embodiments, the secondary protection circuit includes a second MOSFET and a fifth resistor.

[0017] One end of the fifth resistor is connected to one end of the secondary winding of the transformer.

[0018] The other end of the fifth resistor is connected to the drain of the second MOS transistor.

[0019] The gate of the second MOSFET is connected to a signal output terminal of the battery pack interface circuit to receive the trigger level signal.

[0020] The source of the second MOSFET is connected to the common terminal.

[0021] In some embodiments, the secondary rectifier circuit further includes a voltage controller and a first MOSFET.

[0022] The drain of the first MOSFET is connected to the other end of the secondary winding of the transformer.

[0023] The control terminal of the voltage controller is connected to the gate of the first MOS transistor.

[0024] The source of the first MOSFET is connected to the common terminal.

[0025] In some embodiments, the battery pack interface circuit includes at least a connection module, an optocoupler, and a fifth MOSFET.

[0026] One end of the optocoupler is connected to the output of the switching circuit via an eleventh resistor.

[0027] The other end of the optocoupler is connected to the drain of the fifth MOS transistor.

[0028] The gate of the fifth MOS transistor is connected to the fourth terminal of the connection module through the thirteenth resistor.

[0029] The second end of the connection module is connected to the input end of the switching circuit for receiving the voltage signal.

[0030] The source of the fifth MOS transistor is connected to the common terminal.

[0031] The fourth terminal of the connection module is connected to the gate of the second MOS transistor through the thirteenth resistor.

[0032] In some embodiments, the second MOS transistor and the fifth MOS transistor are selected as N-channel enhancement-mode MOS transistors.

[0033] In some embodiments, the main control circuit includes at least a main controller and a sixth MOS transistor.

[0034] The power input terminal of the main controller is connected to the output terminal of the auxiliary power supply circuit to receive the voltage signal.

[0035] One output terminal of the main controller is connected to the gate of the sixth MOS transistor.

[0036] The drain of the sixth MOS transistor is connected to the signal input terminal of the switching circuit.

[0037] The source of the sixth MOS transistor is connected to the common terminal.

[0038] In some embodiments, the switching circuit includes at least a third MOSFET and a fourth MOSFET.

[0039] The drain of the third MOS transistor is connected to the output terminal of the secondary rectifier circuit.

[0040] The source of the fourth MOS transistor is connected to the drain of the third MOS transistor.

[0041] The drain of the fourth MOS transistor is connected to the second terminal of the connection module.

[0042] The gates of the third MOS transistor and the fourth MOS transistor are respectively connected to the drain of the sixth MOS transistor.

[0043] When the sixth MOS transistor is turned on, it pulls the gate levels of the third and fourth MOS transistors to a low level to control the third and fourth MOS transistors to turn on.

[0044] In some embodiments, the auxiliary power supply circuit includes at least a voltage regulator.

[0045] The power input terminal of the voltage regulator is connected to the output terminal of the secondary rectifier circuit through the thirtieth resistor.

[0046] The power output terminal of the voltage regulator is connected to the power input terminal of the main controller through the thirty-first resistor.

[0047] The charger control circuit of this invention includes a secondary rectifier circuit for receiving voltage signals from the preceding circuit, a switching circuit, a battery pack interface circuit, an auxiliary power supply circuit, and a main control circuit. The secondary rectifier circuit includes a secondary protection circuit. When a charging abnormality occurs in the battery pack, the trigger level signal output by the battery pack interface circuit is high, controlling the secondary protection circuit to conduct and pulling the voltage output by the secondary rectifier circuit to 0V. The auxiliary power supply circuit then outputs no voltage signal. Compared to existing technologies, when a charging abnormality occurs in the battery pack, the secondary protection circuit is triggered, pulling the voltage output by the secondary rectifier circuit to 0V and cutting off the charging circuit of the battery pack, ensuring the safety of battery pack charging. In addition to over-temperature, over-current, and short-circuit protection functions, the added secondary protection function effectively avoids losses caused by charger and battery malfunctions. Attached Figure Description

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0049] Figure 1 is a circuit diagram of an embodiment of the charger control circuit provided by this utility model. Detailed Implementation

[0050] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0051] As shown in Figure 1, in the first embodiment of the charger control circuit of this utility model, the charger control circuit includes a primary power supply circuit (not shown), a secondary rectifier circuit 110, a switching circuit 120, a battery pack interface circuit 130, a main control circuit 140, and an auxiliary power supply circuit 150.

[0052] The primary circuit of the power supply (not shown) includes AC input, EMI section, rectification and filtering, transformer T1 and absorption section, transformer T1, main MOSFET section, and PWM control section.

[0053] Pin 2 of the PWM wave controller is the RT pin, which is the over-temperature protection pin. When the level of pin 2 of the PWM wave controller is lower than 1.25V, the PWM wave controller will be in protection mode.

[0054] The secondary rectifier circuit 110 has the functions of filtering, switching and secondary protection;

[0055] Switching circuit 120 functions as a switch;

[0056] The main control circuit 140 has the functions of calculation, signal reception / processing, and control signal output;

[0057] The auxiliary power supply circuit 150 has the function of step-down / voltage regulation and is used to output a +3.3V voltage;

[0058] The secondary rectifier circuit 110 includes a secondary protection circuit 111, which is used to provide secondary protection when the battery pack (not shown) experiences a charging abnormality.

[0059] Specifically, the secondary rectifier circuit 110 is configured within the control circuit to receive the voltage signal input from the preceding circuit (corresponding to the primary power supply circuit) and to filter the input voltage signal.

[0060] The secondary rectifier circuit 110 includes a secondary protection circuit 111.

[0061] The first terminal of the secondary protection circuit 111 is connected to the power supply terminal (corresponding to the output terminal of the primary power supply circuit).

[0062] The third terminal of the secondary protection circuit 111 is connected to the common terminal;

[0063] Furthermore, the input terminal of the switching circuit 120 is connected to the output terminal of the secondary rectifier circuit 110 to receive voltage signals;

[0064] The input terminal of the battery pack interface circuit 130 is connected to the output terminal of the switching circuit 120 to receive voltage signals, thereby providing charging voltage to the battery pack connected to the battery pack interface circuit 130.

[0065] One signal output terminal of the battery pack interface circuit 130 is connected to the second terminal of the secondary protection circuit 111 to receive a trigger level signal.

[0066] The input terminal of the auxiliary power supply circuit 150 is connected to the output terminal (corresponding to the V+ terminal) of the secondary rectifier circuit 110. It is used to receive the voltage signal output by the secondary rectifier circuit 110 and perform voltage step-down / voltage regulation on the voltage signal to output a +3.3V voltage.

[0067] The power input terminal of the main control circuit 140 is connected to the output terminal of the auxiliary power supply circuit 150 to receive voltage signals (corresponding to +3.3V voltage).

[0068] One output terminal of the main control circuit 140 is connected to the signal input terminal of the switching circuit 120, and is used to output a control signal to control the on / off state of the switching circuit 120.

[0069] When the switching circuit 120 is turned on, the voltage signal output by the secondary rectifier circuit 110 is input to the connection module CN101 of the battery pack interface circuit 130 via the switching circuit 120 to charge the battery pack connected to the connection module CN101.

[0070] During the charging process, when a charging abnormality occurs in the battery pack, the trigger level signal output by the battery pack interface circuit 130 is high. The trigger level signal controls the secondary protection circuit 111 to conduct, pulling the voltage output by the secondary rectifier circuit 110 to 0V. This results in no voltage at the power input terminal of the auxiliary power supply circuit 150, and no voltage signal output from the auxiliary power supply circuit 150. The main control circuit 140 loses its operating voltage and stops outputting control signals. At this time, the switch circuit 120 changes from conducting to turning off, and the battery pack has no charging circuit, thus ensuring the safety and reliability of the battery pack charging process.

[0071] Using this technical solution, when the battery pack experiences a charging abnormality, the secondary protection circuit 111 is triggered, pulling the voltage output of the secondary rectifier circuit to 0V and cutting off the charging circuit of the battery pack to ensure the safety of battery pack charging. In addition to over-temperature, over-current and short-circuit protection functions, a secondary protection function is added, which can effectively avoid losses caused by charger and battery abnormalities.

[0072] In some implementations, to ensure the stability of the output voltage signal, a voltage controller U101 and a first MOSFET Q101 can be provided in the secondary rectifier circuit 110. The voltage controller U101 functions as a switch and a signal transmitter.

[0073] The first MOSFET Q101 functions as a switch and is selected as an N-channel enhancement-mode MOSFET.

[0074] Specifically, the drain of the first MOSFET Q101 is connected to one end of the secondary winding of the transformer T1 through the third resistor R103.

[0075] The control terminal of the voltage controller U101 is connected to the gate of the first MOSFET Q101.

[0076] The source of the first MOSFET Q101 is connected to the common terminal.

[0077] When the first MOSFET Q101 is turned on, the voltage signal output from the secondary winding of the transformer T1 can be input to the connection module CN101 of the battery pack interface circuit 130 via the secondary rectifier circuit 110 and the switching circuit 120 to charge the battery pack connected to the connection module CN101.

[0078] In some implementations, in order to improve the safety of the battery pack charging process, a second MOSFET Q102 and a fifth resistor R105 can be provided in the secondary protection circuit 111. The second MOSFET Q102 has the function of a switch and is selected as an N-channel enhancement-type MOSFET.

[0079] Specifically, one end of the fifth resistor R105 is connected to the other end of the secondary winding of transformer T1.

[0080] The other end of the fifth resistor R105 is connected to the drain of the second MOSFET Q102.

[0081] The gate of the second MOSFET Q102 is connected to a signal output terminal (corresponding to pin 4) of the battery pack interface circuit 130 to receive the trigger level signal.

[0082] The source of the second MOSFET Q102 is connected to the common terminal.

[0083] In some implementations, to improve the safety of the battery pack charging process, the battery pack interface circuit 130 may include at least a connection module CN101, an optocoupler PC1A, and a fifth MOSFET Q301.

[0084] The connection module CN101 is used to connect to the battery pack for charging.

[0085] The optocoupler PC1A serves both signal transmission and isolation purposes.

[0086] The fifth MOSFET, Q301, functions as a switch and is selected as an N-channel enhancement-mode MOSFET.

[0087] Specifically, one end of the optocoupler PC1A is connected to the output of the switching circuit 120 through the eleventh resistor R301.

[0088] The other end of optocoupler PC1A is connected to the drain of the fifth MOSFET Q301.

[0089] The gate of the fifth MOSFET Q301 is connected to the fourth terminal (pin 4) of the connection module CN101 through the thirteenth resistor R303.

[0090] The second terminal (corresponding to pin 2) of the connection module CN101 is connected to the output terminal of the switching circuit 120 for receiving voltage signals.

[0091] The source of the fifth MOSFET Q301 is connected to the common terminal.

[0092] The fourth terminal (corresponding to pin 4) of the connection module CN101 is connected to the gate of the second MOSFET Q102 through the thirteenth resistor R303.

[0093] During the charging process, when the battery pack experiences a charging abnormality, the trigger level signal of the fourth terminal (corresponding to pin 4) of the connection module CN101 is at a high level. The trigger level signal controls the second MOSFET Q102 and the fifth MOSFET Q301 to conduct. The optocoupler PC1A feeds back the abnormal signal (such as over-temperature) to the primary circuit of the power supply to cut off the output voltage.

[0094] To prevent some PWM controllers from still outputting voltage under over-temperature / over-temperature protection conditions, causing oscillation and weak voltage output, which would result in the auxiliary power supply circuit 150 experiencing voltage fluctuations of 1.6-2.5V and leading to a restart of the main control circuit 140,

[0095] The controlled-on second MOSFET Q102 can pull the voltage output of the secondary rectifier circuit 110 to 0V, so that there is no voltage at the power input terminal of the auxiliary power supply circuit 150, the auxiliary power supply circuit 150 has no voltage signal output, the main control circuit 140 loses its working voltage and stops outputting control signals. At this time, the switching circuit 120 changes from on to off, and the battery pack has no charging circuit to ensure the safety and reliability of the battery pack charging process.

[0096] In some implementations, to ensure the reliability of the circuit operation, a main controller U401 and a sixth MOSFET Q401 can be provided in the main control circuit 140.

[0097] The main controller U401 is responsible for logic operations, signal reception / processing, and outputting control signals.

[0098] The sixth MOSFET, Q401, functions as a switch and is selected as an N-channel enhancement-mode MOSFET.

[0099] Specifically, the power input terminal (corresponding to pin 5) of the main controller U401 is connected to the output terminal (corresponding to pin 1) of the auxiliary power supply circuit 150 to receive voltage signals (corresponding to +3.3V voltage).

[0100] One output terminal (corresponding to pin 7) of the main controller U401 is connected to the gate of the sixth MOSFET Q401 through the fifteenth resistor R402.

[0101] The drain of the sixth MOSFET Q401 is connected to the signal input terminal of the switching circuit 120.

[0102] The source of the sixth MOSFET Q401 is connected to the common terminal.

[0103] In some embodiments, the switching circuit 120 includes at least a third MOSFET Q201 and a fourth MOSFET Q202, wherein the MOSFETs are all P-channel MOSFETs and have the function of switching;

[0104] Specifically, the drain of the third MOSFET Q201 is connected to the output terminal of the secondary rectifier circuit 110 to receive the voltage signal output by the secondary rectifier circuit 110.

[0105] The source of the fourth MOSFET Q202 is connected to the drain of the third MOSFET Q201.

[0106] The drain of the fourth MOSFET Q202 is connected to the second terminal (pin 2) of the connection module CN101.

[0107] The gate of the third MOSFET Q201 is connected to the drain of the sixth MOSFET Q401 through the ninth resistor R203.

[0108] The gate of the fourth MOSFET Q202 is connected to the drain of the sixth MOSFET Q401 through a series connection of the seventh resistor R201, the eighth resistor R202, and an optocoupler PC2A.

[0109] Among them, the connection terminals of the seventh resistor R201 and the eighth resistor R202 are connected to the gate of the fourth MOSFET Q202.

[0110] When the sixth MOSFET Q401 is turned on, it pulls the gate level of the third MOSFET Q201 to a low level. The seventh resistor R201, the eighth resistor R202, and the optocoupler PC2A then pull the gate level of the fourth MOSFET Q202 to a low level, thereby controlling the third MOSFET Q201 and the fourth MOSFET Q202 to turn on.

[0111] When the third MOSFET Q201 and the fourth MOSFET Q202 are controlled to be turned on, the voltage signal output from the secondary winding of the transformer T1 is input to the connection module CN101 of the battery pack interface circuit 130 through the secondary rectifier circuit 110, the third MOSFET Q201 and the fourth MOSFET Q202, so as to charge the battery pack connected to the connection module CN101.

[0112] In some embodiments, the auxiliary power supply circuit 150 includes at least a voltage regulator U501, which has the function of voltage regulation / buck reduction.

[0113] The power input terminal (pin 3) of the voltage regulator U501 is connected to the output terminal (V+) of the secondary rectifier circuit 110 through the 30th resistor R501.

[0114] The power output terminal (corresponding to pin 1) of the voltage regulator U501 is connected to the power input terminal (corresponding to pin 5) of the main controller U401 through the thirty-first resistor R502, providing the main controller U401 with a +3.3V operating power.

[0115] Specifically, when the battery pack is charging normally, the ID pin in the battery pack is connected to a resistor directly to ground. Therefore, the eleventh resistor R303 is directly to ground, so the network "DP" is at a low level, that is, the gate of the fifth MOSFET Q301 is at a 0V level. The fifth MOSFET Q301 does not work, and the DS of the fifth MOSFET Q301 is not conducting. No current flows through the optocoupler PC1A. Therefore, the resistance of the optocoupler PC1B in the same body is infinite, which has no effect on the PWM wave controller and also has no effect on the charging of the whole machine.

[0116] The main controller U401 is working normally, as are LED101 and LED102. Power is drawn from "V+" through R21, and a stable 3.3V voltage is obtained through the twelfth resistor C501, the voltage regulator U501, and the thirteenth resistor C502 to power the main controller U401. The normal operating voltage of the main controller U401 is 1.8-3.3V.

[0117] When the operating voltage of the main controller U401 is lower than 1.8V, a startup phenomenon will occur;

[0118] When the battery pack is abnormally charged (overvoltage / overtemperature), the ID pin in the battery pack becomes open-circuited with the resistor to ground, resulting in high impedance. At this time, the network "DP" is at a high level.

[0119] The gate of the fifth MOSFET Q301 is turned on by the "B+" voltage through the tenth resistor R302. Therefore, the current of the optocoupler PC1A flows from "B+" through the eleventh resistor R301, the optocoupler PC1A, and the drain-source (DS) of the fifth MOSFET Q301 to ground. In other words, there is current flowing through the optocoupler PC1A. The photosensitive effect within the same component makes the resistance of the optocoupler PC1B very small, causing pin 2 of the PWM controller to be almost short-circuited to ground. Therefore, there is no output at pin 6 of the PWM controller. In order to prevent some PWM controllers from still outputting during over-temperature protection, causing oscillation and a weak voltage output, the voltage regulator U501 fluctuates between 1.6-2.5V, causing the main controller U401 to restart.

[0120] When the battery pack malfunctions, the network "DP" is high, turning on the second MOSFET Q202. "V+" is short-circuited to ground through the fifth resistor R105 and the drain-sink of the second MOSFET Q202, releasing the voltage across the third capacitor C103 and the fourth capacitor C104. This causes the "V+" voltage to become 0V. The voltage regulator U501 has no input and therefore no output. The main controller U401 does not operate, and the LED does not misfire.

[0121] The fifth resistor R105 and the second MOSFET Q202 only participate in the discharge operation when the battery pack malfunctions. They do not participate in the operation when the battery pack is not in operation, thus effectively playing a secondary protection role and preventing the LED lights from malfunctioning.

[0122] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A charger control circuit, characterized in that, It comprises: a secondary rectifier circuit configured within a control circuit for receiving a voltage signal input from a preceding circuit, wherein the secondary rectifier circuit includes a secondary protection circuit, a first terminal of which is connected to a power supply terminal, and a third terminal of which is connected to a common terminal; a switching circuit, the input terminal of which is connected to the output terminal of the secondary rectifier circuit for receiving the voltage signal; and a battery pack interface circuit, the input terminal of which is connected to the output terminal of the switching circuit for receiving the voltage signal to provide a charging voltage to the battery pack connected to the battery pack interface circuit, wherein a signal output terminal of the battery pack interface circuit is connected to the secondary protection circuit. The second terminal of the circuit is connected to receive a trigger level signal; the auxiliary power supply circuit, whose input terminal is connected to the output terminal of the secondary rectifier circuit, is used to receive a voltage signal; the main control circuit, whose power input terminal is connected to the output terminal of the auxiliary power supply circuit, is used to receive the voltage signal; one output terminal of the main control circuit is connected to the signal input terminal of the switching circuit; when the battery pack experiences a charging abnormality, the trigger level signal output by the battery pack interface circuit is high, and the trigger level signal controls the secondary protection circuit to conduct, pulling the voltage output by the secondary rectifier circuit to 0V, and the auxiliary power supply circuit has no voltage signal output.

2. The charger control circuit according to claim 1, characterized in that, The secondary protection circuit includes a second MOSFET and a fifth resistor. One end of the fifth resistor is connected to one end of the secondary winding of the transformer, and the other end of the fifth resistor is connected to the drain of the second MOSFET. The gate of the second MOSFET is connected to a signal output terminal of the battery pack interface circuit to receive the trigger level signal. The source of the second MOSFET is connected to a common terminal.

3. The charger control circuit according to claim 2, characterized in that, The secondary rectifier circuit further includes a voltage controller and a first MOSFET. The drain of the first MOSFET is connected to the other end of the secondary winding of the transformer. The control terminal of the voltage controller is connected to the gate of the first MOSFET, and the source of the first MOSFET is connected to the common terminal.

4. The charger control circuit according to claim 3, characterized in that, The battery pack interface circuit includes at least a connection module, an optocoupler, and a fifth MOSFET. One end of the optocoupler is connected to the output terminal of the switching circuit through an eleventh resistor, and the other end of the optocoupler is connected to the drain of the fifth MOSFET. The gate of the fifth MOSFET is connected to the fourth terminal of the connection module through a thirteenth resistor. The second terminal of the connection module is connected to the input terminal of the switching circuit for receiving the voltage signal. The source of the fifth MOSFET is connected to the common terminal, and the fourth terminal of the connection module is connected to the gate of the second MOSFET through the thirteenth resistor.

5. The charger control circuit according to claim 4, characterized in that, The second MOSFET and the fifth MOSFET are selected as N-channel enhancement-mode MOSFETs.

6. The charger control circuit according to claim 4, characterized in that, The main control circuit includes at least a main controller and a sixth MOS transistor. The power input terminal of the main controller is connected to the output terminal of the auxiliary power supply circuit to receive the voltage signal. One output terminal of the main controller is connected to the gate of the sixth MOS transistor. The drain of the sixth MOS transistor is connected to the signal input terminal of the switching circuit. The source of the sixth MOS transistor is connected to the common terminal.

7. The charger control circuit according to claim 6, characterized in that, The switching circuit includes at least a third MOSFET and a fourth MOSFET. The drain of the third MOSFET is connected to the output terminal of the secondary rectifier circuit. The source of the fourth MOSFET is connected to the drain of the third MOSFET. The drain of the fourth MOSFET is connected to the second terminal of the connection module. The gates of the third MOSFET and the fourth MOSFET are respectively connected to the drain of the sixth MOSFET. When the sixth MOSFET is turned on, it pulls the gate levels of the third MOSFET and the fourth MOSFET to a low level to control the third MOSFET and the fourth MOSFET to turn on.

8. The charger control circuit according to claim 7, characterized in that, The auxiliary power supply circuit includes at least a voltage regulator. The power input terminal of the voltage regulator is connected to the output terminal of the secondary rectifier circuit through a thirtieth resistor, and the power output terminal of the voltage regulator is connected to the power input terminal of the main controller through a thirty-first resistor.

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