CN209250229U - 380VAC protection circuit and charger - Google Patents

Abstract

The utility model relates to power electronics fields; specifically a kind of reliable operation, highly-safe, 380VAC protection circuit and charger of reasonable cost; it is characterized in that, being equipped with input lightning protection circuit, input power supply interlock circuit, input filter rectification circuit, high pressure auxiliary power circuit, high tension voltage sample circuit；Wherein input lightning protection circuit is set to the front end of input power supply interlock circuit, the rear end of input power supply interlock circuit connects input rectifying filter circuit, the electrical signal of high pressure auxiliary power circuit connects between input lightning protection circuit and input power supply interlock circuit, the sampled signal input of high tension voltage sample circuit connects in the front end of input power supply interlock circuit, pass through the implementation of this programme, expand the scope of application of product, trouble free service performance of the product under complex working condition is improved, product market can be effectively reduced and return the rate of moving back.

Description

380VAC protection circuit and charger

Technical field:

The utility model relates to the technical field of power electronics, in particular to a 380VAC protection circuit and a charger with reliable operation, high safety and reasonable cost.

Background technique:

At present, small and medium power switching power supply products are basically powered by single-phase 220VAC. In terms of device application, the withstand voltage of the device on the AC side of the input stage is selected according to 300VAC; in terms of protection design, a fuse is generally connected in series on the live or neutral line of the input stage. This kind of circuit design has a low probability of failure in normal use, but in some special industrial application scenarios, there are both single-phase and three-phase power supply lines on site, and it is very easy for site users to connect three-phase power to the charger. The product, which causes the failure and damage of the charger product.

Invention content:

The utility model proposes a 380VAC protection circuit, a charger and its application when the 380VAC power supply is connected to the shortcomings and deficiencies in the prior art.

The utility model can be achieved through the following technical solutions:

A 380VAC protection circuit, characterized in that it is provided with an input lightning protection circuit, an input power supply interlock circuit, an input filter rectifier circuit, a high-voltage auxiliary power supply circuit, and a high-voltage voltage sampling circuit; wherein the input lightning protection circuit is set in the input power supply interlock circuit The front end of the input power supply interlock circuit is connected to the input rectifier filter circuit, the electrical signal output terminal of the high-voltage auxiliary power supply circuit is connected between the input lightning protection circuit and the input power supply interlock circuit, and the sampling signal input terminal of the high-voltage voltage sampling circuit Connected to the front end of the input power supply interlock circuit,

The input lightning protection circuit is provided with a first piezoresistor MOV1, a second piezoresistor MOV2 and a third piezoresistor MOV3, wherein the first piezoresistor MOV1 is connected between the zero line and the live line of the input power supply, and the second piezoresistor The sensitive resistor MOV2 is connected between the input power supply live wire and the ground wire, and the third varistor MOV3 is connected between the input power supply neutral wire and the ground wire;

The input power supply interlock circuit is provided with a first relay K1, a second relay K2, a first thermal NTC resistor RT1 and a second thermal NTC resistor RT2, wherein the normally open contact of the first relay K1 is connected in series with the power supply input fire wire Above; the soft start component is connected in series with the normally open contact of the second relay K2 after the first thermal NTC resistor RT1 and the second thermal NTC resistor RT2 are connected in series; the soft start component is connected in parallel with the first relay K1;

The input filter rectifier circuit is located after the input power supply interlock circuit; the input filter rectifier circuit includes a first X capacitor C1, a first Y capacitor C2, a second Y capacitor C3, an input common mode inductor and an input rectifier bridge; the first X capacitor C1 is connected between the LN lines, the first Y capacitor C2 and the second Y capacitor C3 are respectively located behind the first X capacitor C1, and the first Y capacitor C2 is connected between the live wire and the ground wire, and the second Y capacitor C3 is connected Between the neutral line and the ground line, the front end of the input common mode inductor is connected behind the first Y capacitor C2 and the second Y capacitor C3, and the rear end of the input common mode inductor is connected to the input rectifier bridge;

The high-voltage auxiliary power supply circuit is provided with a cross power supply assembly, a balanced filter assembly and an auxiliary power supply power conversion assembly; the cross power supply assembly includes a first filter inductor L1, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, where one end of the first filter inductor L1 is connected to the node between the second thermistor NTC resistor RT2 and the second relay K2 in the input power supply interlock circuit, and the other end of the first filter inductor L1 is connected to the anode of the diode D1 , the cathode of the diode D1 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the anode of the diode 3, the cathode of the diode D3 is connected to the anode of the diode D4, and the cathode of the third diode D3 is connected to the anode of the fourth diode D4; The anode of the fifth diode D5 is connected to the positive bus bar of the PFC booster circuit, the cathode of the fifth diode D5 is connected to the anode of the sixth diode D6, and the cathode of the fourth diode D4 is connected to the anode of the sixth diode D4. The cathodes of D6 are connected, and both are connected to the input end of the equalization filter component;

The balanced filter component includes a voltage equalizing resistor R1, a voltage equalizing resistor R2, a voltage equalizing resistor R3, a voltage equalizing resistor R4, a first filter electrolytic capacitor C1, a second filter electrolytic capacitor C2 and a first filter ceramic capacitor C3, the first One end of the voltage equalizing resistor R1, the positive electrode of the first filter electrolytic capacitor C1 and one end of the first filter ceramic capacitor C3 are connected as the input end of the equalizing filter component, the voltage equalizing resistor R1, the voltage equalizing resistor R2, the voltage equalizing resistor R3, The equalizing resistor R4 is connected in series, the other end of the equalizing resistor R4, the negative pole of the second filter electrolytic capacitor C2 and the other end of the first ceramic capacitor C3 are connected, and then connected to the negative busbar of the PFC step-up circuit, the equalizing resistor R2 The connection point with the equalizing resistor R3 is connected to the negative pole of the first filter electrolytic capacitor C1 and the negative pole of the second filter electrolytic capacitor C2.

The power conversion component of the auxiliary power supply described in the utility model is a multi-winding output flyback switching power supply. The power supply is designed according to the AC input 530Vac design to meet the normal operation of the power supply under high voltage conditions.

The high-voltage voltage sampling circuit described in the utility model includes an AC rectification component, a step-down average value component, and an isolation sampling component; the AC rectification component includes a rectifier diode D7, a rectifier diode D8, a rectifier diode D9, and a rectifier diode D10, wherein the rectifier diode D9 The anode of the rectifier diode D9 is connected to the input N line, the cathode of the rectifier diode D9 is connected to the anode of the rectifier diode D10, the anode of the rectifier diode D7 is connected to the anode connection point of the first filter inductor L1 and the diode D1, and the cathode of the rectifier diode D7 is connected to the rectifier diode The anode of D8, the cathode of the rectifier diode D10 are connected to the cathode of the rectifier diode D8, and then connected to the input terminal of the step-down average value component;

The step-down average component includes six drop-down resistors R9, R10, R11, R12, R13, R14, four equipotential resistors R5, R6, R7, R8, the first average value capacitor C4, six drop-down resistors sequentially connected in series,

The other end of the drop-down resistor R9 is connected to the connection between the cathode of the diode D10 and the cathode of the diode D8, and the other end of the drop-down resistor R14 is grounded; the four equipotential resistors are connected in series in sequence, and the front end of the resistor R5 and the front end of the drop-down resistor R9 are simultaneously connected to the The connection point of the cathode of the diode D10 and the cathode of the diode D8, the rear end of the resistor R8 is connected to the negative ground wire of the PFC bus; the first average value capacitor C4 is connected in parallel to both ends of the drop-down resistor R14;

The isolated sampling assembly includes a triangular wave generating circuit, a voltage comparison circuit, an optocoupler isolation transmission circuit and an MCU sampling circuit, wherein the output end of the triangular wave generating circuit is connected to one input end of the voltage comparison circuit, and the output end of the step-down averaging component is connected to the input end of the voltage comparison circuit. The other input terminal of the voltage comparison circuit is connected, the output terminal of the voltage comparison circuit is connected with the input terminal of the optocoupler isolation transmission circuit, the output terminal of the optocoupler isolation transmission circuit is connected with the MCU sampling circuit, and the MCU sampling circuit is connected with the control unit.

It can be seen from the above scheme that the scheme described in this case can effectively electrically isolate the voltage of the AC input port and at the same time accurately sample the voltage value.

A charger, characterized in that it is provided with the above-mentioned 380VAC protection circuit, AC-DC conversion circuit and control unit, wherein the rear end of the input rectification filter circuit in the 380VAC protection circuit is connected to the AC-DC conversion circuit, and the control unit is connected with the AC-DC conversion circuit respectively. The conversion circuit is connected with the high-voltage auxiliary power supply circuit and the high-voltage voltage sampling circuit in the 380VAC protection circuit.

The 380VAC protection circuit described in the utility model is the circuit in the above scheme or its modified circuit.

The AC-DC conversion circuit described in the utility model includes: a PFC active power factor conversion circuit, which is used to convert the external AC mains power into a high-voltage bus DC power, and at the same time improve the power factor of the whole machine; a DC/DC conversion circuit, which is used for Realize the conversion of DC voltage, and convert the DC power of the high-voltage bus into the level voltage required for battery charging.

The control unit of the utility model includes: a main control MCU unit, which is used to realize the control algorithm of the whole machine, and respond to the control and protection action of the work sequence logic of the whole machine; an internal indicator light driving circuit, which is used to receive the main control MCU unit The output control signal is used to drive and display the indicator light on the charger body; the external indicator light drive circuit is used to receive the control signal output by the main control MCU unit to drive and display the indicator light outside the charger;

The first temperature sampling circuit is used for sampling the internal temperature of the charger product;

The second temperature sampling circuit is used for sampling the external ambient temperature of the charger product;

A first drive circuit, used for driving the first relay in the input power supply interlock circuit;

The second drive circuit is used for driving the second relay in the input power supply interlock circuit;

The third drive circuit is used for driving the output relay in the AC-DC conversion circuit.

It can be seen from the above scheme that when the input power supply voltage is within the normal working voltage range of the charger product, the 380VAC protection circuit does not perform any action, and the AC power supply provided by the grid is converted into the DC power supply required for power battery charging through the AC-DC conversion circuit. . When the wrong power supply system is connected and the system voltage is too high, the 380VAC protection circuit will take protective action to isolate the high-voltage grid power supply and protect the AC-DC conversion circuit.

When the charger described in the utility model is in use, the control unit collects the internal ambient temperature of the charger and the external ambient temperature of the charger product through the first temperature sampling circuit and the second temperature sampling circuit; Calibration of the charging curve; the calibration algorithm is: based on 20°C, for every increase/decrease in the ambient temperature by 1°C, the output voltage of the charger is normalized to a single battery decrease or increase by 4mV or 3mV; the control unit is calibrated according to The charging curve controls the DC output of the AC-DC conversion circuit to reach the voltage and current points required by the charged battery.

It can be seen from the above scheme that the sampling accuracy and linearity of the AC power supply voltage are improved through the implementation of the method used in this scheme and the implementation of the linear fitting control algorithm. By controlling the action of the two relays in the input interlock circuit according to the state of the input power supply voltage, the control unit can effectively realize the physical isolation between the input power supply voltage and the electrical circuit of the AC/DC conversion circuit, and achieve a definite protection effect. At the same time, the high-voltage auxiliary power supply circuit can safely supply power to the control unit, ensuring that the control unit circuit can be supplied with power under any voltage state. Through the implementation of the method for using the charger described in this solution, the charging curve can be guaranteed to meet the charging requirements of the battery at any temperature, and the occurrence of overcharging and undercharging can be avoided.

Through the implementation of this scheme, the scope of application of the product has been expanded, the safe working performance of the product under complex working conditions has been improved, and the market return rate of the product can be effectively reduced.

Description of drawings:

Accompanying drawing 1 is a block diagram of the utility model.

Accompanying drawing 2 is the circuit schematic diagram of the utility model 380VAC protection circuit.

Reference signs: 1 input lightning protection circuit; 2 input power supply interlock circuit; 3 high-voltage auxiliary power supply circuit; 4 high-voltage voltage sampling circuit; 5 input filter rectification circuit.

Detailed ways:

Referring to Fig. 2, the 380VAC protection circuit proposed by the utility model includes: input lightning protection circuit 1, input power supply interlock circuit 2, high-voltage auxiliary power supply circuit 3, high-voltage voltage sampling circuit 4 and input filter rectifier circuit 5; input lightning protection circuit 1 Placed in parallel on the input power port, the input power supply interlock circuit 2 is connected in series with the power supply L line; the input of the high-voltage auxiliary circuit circuit 3 is connected with the power supply L line and the DC bus after PFC boost; the high-voltage voltage sampling circuit 4 is connected with the input LN line Connect to the ground wire of the DC bus after PFC boost.

In the input lightning protection circuit 1, the first varistor MOV1 is connected in parallel between the input power supply LN lines, the second varistor MOV2 is connected in parallel between the input power supply L line and the Earth line, and the third varistor MOV3 is connected in parallel with the input power supply N line and the Earth line.

The normally open contact of the first relay K1 in the power supply interlock circuit 2 is connected in series on the input L line; the first thermistor NTC resistor RT1, the second thermistor NTC resistor RT2 are connected in series and the normally open contact of the second relay K2 is connected in series, A soft start component is formed; the soft start component is connected in parallel with the first relay K1.

The input filter and rectifier circuit 5 is located after the input power supply interlock circuit; the first X capacitor C1 is connected in parallel between the LN lines; the first Y capacitor C1 and the second Y capacitor C2 are connected in series before the LN line, and the first Y capacitor C1 and the second Y capacitor C2 are connected in parallel before the LN line. The node connected in series with the second Y capacitor C2 is connected to the ground point Earth.

The cross power supply component of the high-voltage auxiliary power supply 3 includes a first filter inductor L1 and first to sixth diodes D1-D6. One end of the first filter inductor L1 is connected to the node connected in series with the second thermistor NTC resistor RT2 and the second relay K2 in the input power supply interlock circuit, and the other end of the first filter inductor L1 is connected to the anode of the first diode D1 , the cathode of the first diode D1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to the anode of the second diode D3 The anode of the fourth diode D4; the anode of the fifth diode D5 is connected to the positive bus of the PFC booster circuit, the cathode of the fifth diode D5 is connected to the anode of the sixth diode D6; the fourth diode D4 The cathode of the sixth diode D6 is connected to the cathode of the sixth diode D6, and is connected to the input end of the equalization filter component.

The equalizing filter components of the high-voltage auxiliary power supply 3 include first to fourth equalizing resistors R1-R4, a first filter electrolytic capacitor C1, a second filter electrolytic capacitor C2 and a first filter ceramic capacitor C3. One end R1 of the first equalizing resistor, the positive pole of the first filter electrolytic capacitor C1 and one end of the first filter ceramic capacitor C3 are connected to serve as the input end of the equalizing filter component. One end of the fourth voltage equalizing resistor R4, the negative pole of the second filter electrolytic capacitor C2 and one end of the first ceramic capacitor C3 are connected, and then connected to the negative busbar of the PFC boost circuit. The connection point of the second voltage equalizing resistor R2 and the third voltage equalizing resistor R3 is connected to the negative pole of the first filter electrolytic capacitor C1 and the negative pole of the second filter electrolytic capacitor C2.

The auxiliary power conversion component of the high-voltage auxiliary power supply 3 is a multi-winding output flyback switching power supply. This power supply is designed according to the AC input 530Vac design to meet the high voltage conditions, and the power supply can work normally.

The AC rectification component of the high voltage sampling circuit 4 includes seventh to tenth rectification diodes D7-D10. The anode of the seventh rectifying diode D7 is connected to the input N line, and the cathode of the seventh rectifying diode D7 is connected to the anode of the eighth rectifying diode D8. The anode of the ninth rectifier diode D9 is connected to the connection point between the first filter inductor L1 and the anode of the first diode D1, the cathode of the ninth rectifier diode D9 is connected to the anode of the tenth rectifier diode D10, and the cathode of the tenth rectifier diode D10 is connected to the eighth rectifier diode The cathode of diode D8 is then connected to the input of the buck averaging component.

The step-down average component of the high voltage sampling circuit 4 includes first to sixth drop resistors R9-R14, a first average capacitor C4 and first to fourth equipotential resistors (R5-R8). The first drop resistor to the sixth drop resistor (R9-R14) are connected in series in sequence, wherein one end of the first drop resistor R9 is connected to the node where the cathode of the tenth rectifier diode D10 is connected to the cathode of the eighth rectifier diode D8, and the sixth drop resistor One end of the drop resistor R14 is connected to the negative ground of the PFC bus; the first average value capacitor C4 is connected in parallel to the sixth drop resistor R14. The first to fourth equipotential resistors (R5-R8) are connected in sequence, wherein one end of the first equipotential resistor R5 is connected to the node where the cathode of the tenth rectifier diode D10 is connected to the cathode of the eighth rectifier diode D8, and the fourth equipotential resistor One end of R8 is connected to the negative ground of the PFC bus.

The isolated sampling component of the high voltage sampling circuit 4 includes a triangular wave generating circuit, a voltage comparison circuit, an optocoupler isolated transmission circuit and an MCU sampling circuit.

It can be seen from the circuits of the above embodiments that the control unit controls the actions of the two relays in the input interlock circuit according to the state of the input power supply voltage, so that the physical isolation between the input power supply voltage and the electrical circuit of the AC-DC conversion circuit can be effectively realized, achieving definite protective effect. At the same time, the high-voltage auxiliary power supply circuit can safely supply power to the control unit, ensuring that the control unit circuit can be supplied with power under any voltage state.

Claims (6)

1. a kind of 380VAC protects circuit, which is characterized in that be equipped with input lightning protection circuit, input power supply interlock circuit, input filter Wave rectification circuit, high pressure auxiliary power circuit, high tension voltage sample circuit；Wherein it is mutual to be set to input power supply for input lightning protection circuit The rear end of the front end of lock circuit, input power supply interlock circuit connects input rectifying filter circuit, the electricity of high pressure auxiliary power circuit Signal output end connects between input lightning protection circuit and input power supply interlock circuit, and the sampled signal of high tension voltage sample circuit is defeated Enter to terminate at the front end of input power supply interlock circuit, the input lightning protection circuit is equipped with the first varistor MOV1, second pressure-sensitive Resistance MOV2 and third varistor MOV3, wherein between the first varistor MOV1 access input power supply zero curve and firewire, the Between two varistor MOV2 access input power supply firewire and ground wire, third varistor MOV3 access input power supply zero curve and ground Between line；

Input power supply interlock circuit is equipped with the first relay K1, the second relay K2, the first temperature-sensitive NTC resistance RT1 and the Two temperature-sensitive NTC resistance RT2, wherein the normally opened contact of the first relay K1 is series on supply input firewire；Soft start component by It connects after first temperature-sensitive NTC resistance RT1, the second temperature-sensitive NTC resistance RT2 series connection with the normally opened contact of the second relay K2；It is soft to open Dynamic component is in parallel with the first relay K1；

The input filter rectification circuit is located at after input power supply interlock circuit；Input filter rectification circuit includes the first X electricity Hold C1, the first Y capacitance C2, the second Y capacitance C3, input common mode inductance and input rectifying bridge；First X capacitor C1 be connected to LN line it Between, the first Y capacitance C2 and the second Y capacitance C3 are located at after the first X capacitor C1, and the first Y capacitance C2 access firewire and ground Between line, the second Y capacitance C3 is accessed between zero curve and ground wire, is terminated at the first Y capacitance C2, the 2nd Y electricity before inputting common mode inductance After holding C3, input rectifying bridge is terminated after inputting common mode inductance；

The high pressure auxiliary power circuit is equipped with crossfeed component, equalization filtering component and accessory power supply power conversion component； The crossfeed component includes the first filter inductance L1, diode D1, diode D2, diode D3, diode D4, diode D5, diode D6, wherein one end of the first filter inductance L1 is connected to the second temperature-sensitive NTC resistance in input power supply interlock circuit On node between RT2 and the second relay K2, the other end of the first filter inductance L1 is connected to the anode of diode D1, two poles The anode of the cathode connection diode D2 of pipe D1, the anode of the cathode connection diode 3 of diode D2, the cathode of diode D3 connect The anode of diode D4 is connect, the cathode of third diode D3 is connected to the anode of the 4th diode D4；The sun of 5th diode D5 Pole is connected to PFC boost circuit anode bus, and the cathode of the 5th diode D5 is connected to the anode of the 6th diode D6, and the four or two The cathode of pole pipe D4 is connected with the cathode of the 6th diode D6, and is connected on equalization filtering component inputs；

The equalization filtering component includes equalizing resistance R1, equalizing resistance R2, equalizing resistance R3, equalizing resistance R4, the first filtering Electrolytic capacitor C1, the second electrolytic capacitor filter C2 and the first filtering ceramic disc capacitor C3, one end of the first equalizing resistance R1, the first filter The anode of wave electrolytic capacitor C1 is connected with one end of the first filtering ceramic disc capacitor C3, as the input terminal of equalization filtering component, Piezoresistance R1, equalizing resistance R2, equalizing resistance R3, equalizing resistance R4 series connection, the other end of equalizing resistance R4, the second filtering electrolysis The other end of the cathode of capacitor C2 and the first ceramic disc capacitor C3 are connected, and are then attached to PFC boost circuit negative electrode bus, described equal The cathode and the second electrolytic capacitor filter C2 of the tie point of piezoresistance R2 and equalizing resistance R3 and the first electrolytic capacitor filter C1 Cathode is connected.

2. a kind of 380VAC according to claim 1 protects circuit, which is characterized in that the accessory power supply power conversion group Part is that Multiple coil exports inverse-excitation type switch power-supply, and the design of this power supply meets under high-pressure situations according to exchange input 530Vac design, The normal work of this power supply.

3. a kind of 380VAC according to claim 1 protects circuit, which is characterized in that the high tension voltage sample circuit packet Include AC rectification component, decompression average value component and isolation sampling component；The AC rectification component include rectifier diode D7, Rectifier diode D8, rectifier diode D9, rectifier diode D10, wherein the anode of rectifier diode D9 is connected to input N line On, the cathode of rectifier diode D9 is connected to the anode of rectifier diode D10, and the anode of rectifier diode D7 is connected to the first filter The anode tie point of wave inductance L1 and diode D1, rectifier diode D7 cathode are connected to rectifier diode D8 anode, rectification two Pole pipe D10 cathode is connected to rectifier diode D8 cathode, is then attached to decompression average value component inputs；

The decompression average value component includes six dropping resistor R9, R10, R11, R12, R13, R14, four equipotential resistance R5, R6, R7, R8, the first average value capacitor C4, six dropping resistors are sequentially connected in series, and the other end of dropping resistor R9 connects two poles The junction of pipe D10 cathode and diode D8 cathode, the other end ground connection of dropping resistor R14；Four equipotential resistance are successively gone here and there Connection, the front end of resistance R5 and the front end of dropping resistor R9 are connected to the tie point of diode D10 cathode and diode D8 cathode simultaneously, It is terminated at after resistance R8 on the cathode ground wire of PFC bus；First average value capacitor C4 is parallel to the both ends dropping resistor R14；Institute Stating isolation sampling component includes triangle wave generating circuit, voltage comparator circuit, light-coupled isolation transmission circuit and MCU sample circuit, Wherein the output end of triangle wave generating circuit is connected with the input terminal all the way of voltage comparator circuit, is depressured the output of average component End is connected with the another way input terminal of voltage comparator circuit, and the output end of voltage comparator circuit is defeated with light-coupled isolation transmission circuit Enter end to be connected, the output end of light-coupled isolation transmission circuit is connected with MCU sample circuit, and MCU sample circuit is connected with control unit It connects.

4. a kind of charger, which is characterized in that equipped with as described in any one of claim 1-3 380VAC protection circuit, Ac-dc conversion circuit and control unit, wherein 380VAC protects the rear end connection of the input rectifying filter circuit in circuit to hand over straight Translation circuit is flowed, control unit is electric with the high pressure accessory power supply in ac-dc conversion circuit and 380VAC protection circuit respectively Road, high tension voltage sample circuit are connected.

5. a kind of charger according to claim 4, it is characterised in that the ac-dc conversion circuit includes: PFC active Power factor translation circuit, the electric main for providing outside is transformed to high voltage bus direct current, while improving complete machine Power factor；High voltage bus DC power conversion is battery charging for realizing the transformation of DC voltage by DC/DC translation circuit Required level voltage.

6. a kind of charger according to claim 4, it is characterised in that described control unit includes: main control MCU unit, is used In the realization of complete machine control algolithm, the response of control and protection act to complete machine working sequence logic；Interior lamp driving Circuit carries out driving to indicator light on charger ontology and shows for receiving the control signal of main control MCU unit output；It is external Drive circuit of indicator drives the indicator light outside charger for receiving the control signal of main control MCU unit output Display；

First temperature sampling circuit, the sampling for charger product internal temperature；

Second temperature sample circuit, the sampling for charger product ambient temperature；

First driving circuit, the driving for the first relay in the input power supply interlock circuit；

Second driving circuit, the driving for the second relay in the input power supply interlock circuit；

Third driving circuit, the driving for output relay in the ac-dc conversion circuit.