CN106058335A - Battery discharge device and battery discharge method - Google Patents

Abstract

The present invention specifically relates to a battery discharge device and method, the device comprising: a PTC resistance temperature detection circuit, a current sensor, a processor, a fan unit, a switch drive circuit, a PTC resistance switch circuit and a voltage stabilizing circuit, wherein the voltage stabilizing circuit, Its input terminal is connected with the battery to be discharged, and the output terminal is connected with the power supply input terminal of the PTC resistance switch circuit; the current sensor is arranged on the circuit where the voltage stabilizing circuit and the battery to be discharged are located, and the output terminal of the current sensor is connected with the processor The first input end of the processor is connected; the second input end of the processor is connected with the PTC resistance temperature detection circuit, and the output end of the processor is connected with the fan unit and the switch drive circuit respectively, and the output end of the switch drive circuit is connected with the PTC resistance The switch control terminal of the switch circuit is connected. The technical solution of the present invention utilizes the PTC resistor to realize constant current discharge, which can solve the problems in the prior art that the magnitude of the constant resistance discharge current is uncontrollable and the structure of the constant current discharge circuit is complicated, and the volume and weight are large.

Description

A battery discharge device and method

technical field

The invention relates to the technical field of batteries, in particular to a battery discharge device and method.

Background technique

During the maintenance of the battery, it is necessary to discharge, and the methods currently used include constant resistance discharge and constant current discharge.

Constant resistance discharge is to use a constant resistance load to discharge the battery. When discharging, the discharge current depends on the load resistance and the battery voltage. During the discharge process, the battery discharge voltage and current change with time. Constant resistance discharge is the simplest discharge method. The cost of constant resistance discharge is low, but the equipment is heavy, large in size, long in time, and the discharge process is uncontrollable.

Constant current discharge uses an adjustable electronic load to discharge the battery. When discharging, the discharge current can be set through the electronic load. During the discharge process, the battery discharge voltage changes with time. Constant current discharge is the most complicated discharge method. Constant current discharge has high cost, heavy equipment, large size, controllable time and controllable discharge process.

PTC (Positive Temperature Coefficient, positive temperature coefficient) resistance is a thermistor, which is a typical temperature-sensitive semiconductor resistance. When it exceeds a certain temperature (Curie temperature), its resistance value increases with temperature. The height increases stepwise.

Resistance and temperature characteristics of PTC resistors: When the temperature of PTC thermistor rises above the switch temperature Tsw, its resistance will increase rapidly by more than 1000 times.

The current and temperature characteristics of PTC resistance: the temperature of PTC rises, and the current reaches the maximum current; then, the resistance of PTC increases, and the current decreases, and finally drops to a stable value.

Heat dissipation conditions and power characteristics of PTC resistors: For the same PTC heating element, its stable power varies with heat dissipation conditions. The higher the switching temperature of the PTC heating element, the greater the stable power.

In addition, PTC resistors also have the characteristics of low cost, light weight, and small size. Since the working state of PTC resistors has a great relationship with temperature, it is generally applied to resistive discharge loads that do not require precise control. However, in the prior art, there is still a lack of a technical solution for using the PTC resistance to discharge the storage battery.

Contents of the invention

In view of this, the purpose of the present invention is to overcome the deficiencies of the prior art, to provide a battery discharge device and method, using PTC resistance to achieve constant current discharge, to solve the uncontrollable constant resistance discharge current and constant current discharge circuit in the prior art The problem of complex structure, large volume and weight.

To achieve the above object, the present invention adopts the following technical solutions:

A battery discharge device, comprising: a PTC resistance temperature detection circuit, a current sensor, a processor, a fan unit, a switch drive circuit, a PTC resistance switch circuit and a voltage stabilizing circuit, wherein the fan unit includes a plurality of extensions, and the PTC The resistive switch circuit contains multiple PTC resistors,

In the voltage stabilizing circuit, its input terminal is connected to the battery to be discharged, and the output terminal is connected to the power supply input terminal of the PTC resistance switch circuit; the current sensor is arranged in the circuit where the voltage stabilizing circuit and the battery to be discharged are located Above, the output end of the current sensor is connected to the first input end of the processor; the second input end of the processor is connected to the PTC resistance temperature detection circuit, and the output end of the processor is respectively connected to the The fan unit is connected to the switch drive circuit, and the output terminal of the switch drive circuit is connected to the switch control terminal of the PTC resistance switch circuit.

Preferably, the voltage stabilizing circuit includes inductors L1, L2, diodes V1, V2, N-channel depletion type field effect transistors V5, V6, and a load resistor R21, wherein,

The anode of the battery to be discharged is connected to the anode of the diode V1 through the inductor L1, and connected to the anode of the diode V2 through the inductor L2. After the cathode of the diode V2 and V1 is connected, the positive power supply input terminal of the PTC resistance switch circuit is externally connected; to be discharged The negative pole of the battery is externally connected to the negative power supply input terminal of the PTC resistance switch circuit through the load resistor R21;

The gate of the N-channel depletion type field effect transistor V5 is empty, the drain is connected between the inductor L2 and the anode of the diode V2, and the source is connected between the load resistor R21 and the negative power supply input terminal of the PTC resistor switch circuit ; The gate of the N-channel depletion type field effect transistor V6 is vacant, the drain is connected between the anode of the inductor L1 and the diode V1, and the source is connected to the negative power supply input end of the load resistor R21 and the PTC resistance switch circuit; Wherein, a reverse-connected diode is respectively connected between the drains and the gates of the N-channel depletion field effect transistors V5 and V6.

Preferably, the voltage stabilizing circuit further includes filter capacitors C2 and C3, wherein,

The positive pole of the filter capacitor C2 is connected between the positive pole of the battery to be discharged and the inductor L1, and the negative pole is connected between the negative pole of the battery to be discharged and the load resistor R21; the positive pole of the filter capacitor C3 is connected between the diode V2 and the load resistor R21. Between the cathode of V1 and the positive power supply input terminal of the PTC resistance switch circuit, its negative pole is connected between the load resistor R21 and the negative power supply input terminal of the PTC resistance switch circuit.

Preferably, the current sensor is arranged between the positive pole of the filter capacitor C2 and the inductors L1 and L2.

Preferably, the PTC resistance switch circuit includes N-channel enhancement type field effect transistors V7, V8, V9, V10 and RTC resistors R22, R23, R24, R25, wherein,

The gate of the N-channel enhanced field effect transistor V7 is connected to the first output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R22, and its source is connected to the negative power supply input terminal ; The N-channel enhanced field effect transistor V8 is connected to the second output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R23, and its source is connected to the negative power supply input terminal connection; the gate of the N-channel enhanced field effect transistor V9 is connected to the third output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R24, and its source is connected to the negative power supply input terminal terminal connection; the N-channel enhanced field effect transistor V10, its gate is connected to the fourth output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R25, and its source is connected to the negative power supply The input terminals are connected; wherein, the drains and gates of the N-channel enhanced field effect transistors V7, V8, V9, and V10 are respectively connected with a reversed connection diode.

Preferably, the switch driving circuit includes an amplifier U1, an amplifier U2, an amplifier U3 and an amplifier U4, wherein,

Described amplifier U1, its non-inverting input end is connected with 5V DC power supply through resistance R7, its inverting input end is connected with the first output end of processor through resistance R8, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of the enhanced field effect transistor V10;

Described amplifier U2, its non-inverting input end is connected with 5V DC power supply through resistance R9, its inverting input end is connected with the second output end of processor through resistance R10, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of the enhanced field effect transistor V9;

Described amplifier U3, its non-inverting input end is connected with 5V DC power supply through resistance R17, its inverting input end is connected with the third output end of processor through resistance R18, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of the enhanced field effect transistor V8;

Described amplifier U4, its non-inverting input end is connected with 5V DC power supply through resistance R19, and its inverting input end is connected with the fourth output end of processor through resistance R20, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of enhancement mode field effect transistor V7.

Preferably, the PTC resistance temperature detection circuit includes a resistor R1 and a thermistor R2, wherein one end of the thermistor R2 is connected to the second input end of the processor, and connected in series with the resistor R1 to a 5V DC power supply , the other end of the thermistor R2 is grounded.

Preferably, the processor is a single-chip microcomputer U5, and the fan group includes a first fan, a second fan, a third fan and a fourth fan,

The fifth output end of the single-chip microcomputer U5 is connected to the first blower fan, the sixth output end of the single-chip microcomputer U5 is connected to the second blower fan, the seventh output end of the single-chip microcomputer U5 is connected to the third blower fan, and the eighth output end of the single-chip microcomputer U5 is connected to the fourth blower fan;

The single-chip microcomputer U5 controls the air volume transmitted to the RTC resistance by the first fan, the second fan, the third fan and the fourth fan according to the output signal of the PTC resistance temperature detection circuit and the current sensor until the output of the current sensor is discharged. The current value reaches the preset current value.

Preferably, the battery discharge device further includes a PWM drive circuit; the input end of the PWM drive circuit is connected to the processor, and the output end is connected to the fan unit.

A battery discharge method, applied to the above-mentioned battery discharge device, comprising:

The voltage stabilizing circuit stabilizes the discharge voltage of the battery to be discharged at a preset voltage value, and outputs it to the PTC resistance switch circuit;

The processor calculates the difference between the RTC resistance operating temperature value and the preset temperature value according to the RTC resistance operating temperature value detected by the PTC resistance temperature detection circuit, and controls each fan in the fan unit to transmit to the RTC resistance value according to the difference value. At the same time, the processor controls the on-off of the branches of the RTC resistors in the PTC resistor switch circuit through the switch drive circuit until the discharge current value output by the current sensor reaches the preset current value.

The present invention adopts the above technical solutions, and at least has the following beneficial effects:

It can be seen from the above technical solution that the battery discharge device and method provided by the present invention stabilize the discharge voltage of the battery to be discharged at a preset value through a voltage stabilizing circuit; The temperature and the discharge current in the discharge circuit are detected to control the air volume transmitted by the fan to the PTC resistor, thereby controlling the working temperature of the PTC resistor and obtaining a stable discharge current. At the same time, the processor can also control whether each PTC resistor in the switch circuit of the PTC resistor is connected to the battery discharge circuit through the switch drive circuit, so as to obtain different discharge currents. Compared with the prior art, the battery discharge device and method provided by the present invention can realize constant current discharge using PTC resistors, can solve the problem of uncontrollable constant resistance discharge current in the prior art, and can be applied to discharges that require precise control of discharge. current in the battery discharge product.

In addition, since the PTC resistor has the characteristics of low cost, light weight, and small size, the battery discharge device composed of the PTC resistor can solve the problems of complex structure, large volume and heavy weight of the constant current discharge circuit in the prior art.

Description of drawings

Fig. 1 is a schematic block diagram of a battery discharge device provided by an embodiment of the present invention;

2 is a schematic diagram of a voltage stabilizing circuit in a battery discharge device provided by an embodiment of the present invention;

3 is a schematic diagram of a PTC resistance switch circuit in a battery discharge device provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a switch drive circuit in a battery discharge device according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of circuit connection between a PTC resistance temperature detection circuit and a processor in a battery discharge device provided by an embodiment of the present invention.

detailed description

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Referring to Fig. 1, a battery discharge device provided by an embodiment of the present invention includes: a PTC resistance temperature detection circuit 1, a current sensor 2, a processor 3, a fan unit 4, a switch drive circuit 5, a PTC resistance switch circuit 6 and a stabilizer Pressure circuit 7, wherein, the fan unit 4 includes a plurality of extensions, and the PTC resistor switch circuit 6 includes a plurality of PTC resistors,

Described voltage stabilizing circuit 7, its input end is connected with the battery to be discharged, and output end is connected with the power supply input end of described PTC resistance switch circuit 6; On the circuit where the battery is located, the output terminal of the current sensor 2 is connected to the first input terminal of the processor 3; the second input terminal of the processor 3 is connected to the PTC resistance temperature detection circuit 1, and the The output terminal of the processor 3 is respectively connected with the fan unit 4 and the switch drive circuit 5 , and the output terminal of the switch drive circuit 5 is connected with the switch control terminal of the PTC resistance switch circuit 6 .

It is not difficult to understand that since the resistance value of the PTC resistor changes with temperature, the current of the loop where the PTC resistor is located also changes with temperature. According to the power calculation formula P=UI, where P is power, U is voltage, and I is current. If you want the PTC resistor to obtain a stable power output, the voltage at both ends of the PTC resistor and the current of the loop where the PTC resistor is located need to be stable. If the voltage is stabilized, as long as the PTC resistor is controlled to work stably at the maximum current state, stable power output can be obtained.

In addition, according to the heat dissipation conditions and power characteristics, current and temperature characteristics of the PTC resistor, it can be seen that the working state of the PTC resistor has a great relationship with the temperature, so that the PTC resistor can maintain good heat dissipation, so that the heat generation and heat dissipation can be balanced, so that the The PTC resistor works stably to obtain a stable discharge current.

It can be seen from the above technical solution that the battery discharge device provided by the present invention stabilizes the discharge voltage of the battery to be discharged at a preset value through a voltage stabilizing circuit; The discharge current in the discharge circuit is detected to control the air volume transmitted by the fan to the PTC resistor, thereby controlling the working temperature of the PTC resistor and obtaining a stable discharge current. At the same time, the processor can also control whether each PTC resistor in the switch circuit of the PTC resistor is connected to the battery discharge circuit through the switch drive circuit, so as to obtain different discharge currents. Compared with the prior art, the battery discharge device provided by the present invention can realize constant current discharge by using the PTC resistance, can solve the problem of uncontrollable constant resistance discharge current in the prior art, and can be applied to applications that require precise control of the discharge current. battery discharge products.

In addition, since the PTC resistor has the characteristics of low cost, light weight, and small size, the battery discharge device composed of the PTC resistor can solve the problems of complex structure, large volume and heavy weight of the constant current discharge circuit in the prior art.

Referring to FIG. 2, preferably, the voltage stabilizing circuit 7 includes inductors L1, L2, diodes V1, V2, N-channel depletion field effect transistors V5, V6, and a load resistor R21, wherein,

The anode of the battery to be discharged is connected to the anode of the diode V1 through the inductor L1, and connected to the anode of the diode V2 through the inductor L2. After the cathode of the diode V2 and V1 is connected, the positive power supply input terminal of the PTC resistance switch circuit is externally connected; to be discharged The negative pole of the battery is externally connected to the negative power supply input terminal of the PTC resistance switch circuit through the load resistor R21;

The gate of the N-channel depletion type field effect transistor V5 is empty, the drain is connected between the inductor L2 and the anode of the diode V2, and the source is connected between the load resistor R21 and the negative power supply input terminal of the PTC resistor switch circuit ; The gate of the N-channel depletion type field effect transistor V6 is vacant, the drain is connected between the anode of the inductor L1 and the diode V1, and the source is connected to the negative power supply input end of the load resistor R21 and the PTC resistance switch circuit; Wherein, a reverse-connected diode is respectively connected between the drains and the gates of the N-channel depletion field effect transistors V5 and V6.

It should be noted that X1 in FIG. 2 is the positive electrode of the battery to be discharged, and X2 is the negative electrode of the battery to be discharged.

Preferably, the voltage stabilizing circuit 7 also includes filter capacitors C2 and C3, wherein,

The positive pole of the filter capacitor C2 is connected between the positive pole of the battery to be discharged and the inductor L1, and the negative pole is connected between the negative pole of the battery to be discharged and the load resistor R21; the positive pole of the filter capacitor C3 is connected between the diode V2 and the load resistor R21. Between the cathode of V1 and the positive power supply input terminal of the PTC resistance switch circuit, its negative pole is connected between the load resistor R21 and the negative power supply input terminal of the PTC resistance switch circuit.

Preferably, the current sensor is arranged between the positive pole of the filter capacitor C2 and the inductors L1 and L2.

Referring to FIG. 3, preferably, the PTC resistance switch circuit includes N-channel enhancement type field effect transistors V7, V8, V9, V10 and RTC resistors R22, R23, R24, R25, wherein,

The gate of the N-channel enhanced field effect transistor V7 is connected to the first output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R22, and its source is connected to the negative power supply input terminal ; The N-channel enhanced field effect transistor V8 is connected to the second output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R23, and its source is connected to the negative power supply input terminal connection; the gate of the N-channel enhanced field effect transistor V9 is connected to the third output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R24, and its source is connected to the negative power supply input terminal terminal connection; the N-channel enhanced field effect transistor V10, its gate is connected to the fourth output terminal of the switch drive circuit, its drain is connected to the positive power supply input terminal through a resistor R25, and its source is connected to the negative power supply The input terminals are connected; wherein, the drains and gates of the N-channel enhanced field effect transistors V7, V8, V9, and V10 are respectively connected with a reversed connection diode.

Referring to FIG. 4, preferably, the switch driving circuit 5 includes an amplifier U1, an amplifier U2, an amplifier U3 and an amplifier U4, wherein,

Described amplifier U1, its non-inverting input end is connected with 5V DC power supply through resistance R7, its inverting input end is connected with the first output end of processor through resistance R8, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of the enhanced field effect transistor V10;

Described amplifier U2, its non-inverting input end is connected with 5V DC power supply through resistance R9, its inverting input end is connected with the second output end of processor through resistance R10, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of the enhanced field effect transistor V9;

Described amplifier U3, its non-inverting input end is connected with 5V DC power supply through resistance R17, its inverting input end is connected with the third output end of processor through resistance R18, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of the enhanced field effect transistor V8;

Described amplifier U4, its non-inverting input end is connected with 5V DC power supply through resistance R19, and its inverting input end is connected with the fourth output end of processor through resistance R20, and its output end is connected with the N channel in the PTC resistance switch circuit The gate connection of enhancement mode field effect transistor V7.

Referring to FIG. 5, preferably, the PTC resistance temperature detection circuit 1 includes a resistor R1 and a thermistor R2, wherein one end of the thermistor R2 is connected to the second input end of the processor, and connected in series with the resistor R1 It is connected with a 5V DC power supply, and the other end of the thermistor R2 is grounded.

Preferably, the processor is a single-chip microcomputer U5, and the fan group includes a first fan, a second fan, a third fan and a fourth fan,

The fifth output end of the single-chip microcomputer U5 is connected to the first blower fan, the sixth output end of the single-chip microcomputer U5 is connected to the second blower fan, the seventh output end of the single-chip microcomputer U5 is connected to the third blower fan, and the eighth output end of the single-chip microcomputer U5 is connected to the fourth blower fan;

The single-chip microcomputer U5 controls the air volume transmitted to the RTC resistance by the first fan, the second fan, the third fan and the fourth fan according to the output signal of the PTC resistance temperature detection circuit and the current sensor until the output of the current sensor is discharged. The current value reaches the preset current value.

Preferably, the battery discharge device further includes a PWM drive circuit; the input end of the PWM drive circuit is connected to the processor 3 , and the output end is connected to the fan unit 4 .

A battery discharge method, applied to the above-mentioned battery discharge device, comprising:

The voltage stabilizing circuit stabilizes the discharge voltage of the battery to be discharged at a preset voltage value, and outputs it to the PTC resistance switch circuit;

The processor calculates the difference between the RTC resistance operating temperature value and the preset temperature value according to the RTC resistance operating temperature value detected by the PTC resistance temperature detection circuit, and controls each fan in the fan unit to transmit to the RTC resistance value according to the difference value. At the same time, the processor controls the on-off of the branches of the RTC resistors in the PTC resistor switch circuit through the switch drive circuit until the discharge current value output by the current sensor reaches the preset current value.

The present invention is not limited to the above-mentioned best implementation mode, anyone can draw other various forms of products under the enlightenment of the present invention, but no matter make any changes in its shape or structure, all those with the same or similar features as the present application Approximate technical solutions all fall within the protection scope of the present invention. The terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance. The term "plurality" means two or more, unless otherwise clearly defined.

Claims (10)

1. a discharging device, it is characterised in that including: PTC resistor temperature sensing circuit, current sensor, processor, Blower fan group, switch driving circuit, PTC resistor on-off circuit and mu balanced circuit, wherein, described blower fan group comprises multiple extension set, institute State PTC resistor on-off circuit and comprise multiple PTC resistor,

Described mu balanced circuit, its input is connected with battery to be discharged, and outfan is defeated with the power supply of described PTC resistor on-off circuit Enter end to connect；Described current sensor is arranged on the loop at described mu balanced circuit and described battery place to be discharged, described electricity The outfan of flow sensor is connected with the first input end of described processor；Second input of described processor and described PTC Resistance temperature testing circuit connects, and the outfan of described processor is connected with described blower fan group and switch driving circuit respectively, institute The switch control terminal of the outfan and described PTC resistor on-off circuit of stating switch driving circuit is connected.

Discharging device the most according to claim 1, it is characterised in that described mu balanced circuit includes inductance L1, L2, two Pole pipe V1, V2, N-channel depletion field effect transistor V5, V6, load resistance R21, wherein,

The positive pole of battery to be discharged is connected by the anode of inductance L1 and diode V1 respectively, by inductance L2 and diode V2's Anode is connected, after the negative electrode of diode V2 with V1 is connected, and the positive energization input of external described PTC resistor on-off circuit；Wait to put The negative pole of the electricity battery negative energization input by the external described PTC resistor on-off circuit of load resistance R21；

The grid of described N-channel depletion field effect transistor V5 is vacant, and drain electrode is connected between the anode of inductance L2 and diode V2, Source electrode is connected between load resistance R21 and the negative energization input of PTC resistor on-off circuit；Described N-channel depletion type field is imitated Should the grid of pipe V6 vacant, drain electrode is connected between the anode of inductance L1 and diode V1, source electrode be connected to load resistance R21 with The negative energization input of PTC resistor on-off circuit；Wherein, the drain and gate of described N-channel depletion field effect transistor V5 and V6 Between be connected to the diode of a reversal connection.

Discharging device the most according to claim 2, it is characterised in that described mu balanced circuit also bag filter capacitor C2 and C3, wherein,

Described filter capacitor C2, its positive pole is connected between the positive pole of battery to be discharged and inductance L1, and its negative pole is connected to wait to put Between negative pole and the load resistance R21 of electricity battery；Described filter capacitor C3, its positive pole be connected to the negative electrode of diode V2 and V1 with Between the positive energization input of PTC resistor on-off circuit, its negative pole is connected to load resistance R21 and PTC resistor on-off circuit Between negative energization input.

Discharging device the most according to claim 3, it is characterised in that described current sensor is arranged on described filtering Between positive pole and inductance L1 and L2 of electric capacity C2.

Discharging device the most according to claim 4, it is characterised in that described PTC resistor on-off circuit includes N-channel Enhancement mode field effect transistor V7, V8, V9, V10 and RTC resistance R22, R23, R24, R25, wherein,

Described N-channel enhancement mode field effect transistor V7, its grid is connected with the first outfan of described switch driving circuit, its drain electrode Being connected with positive energization input by resistance R22, its source electrode is connected with negative energization input；Described N-channel enhancement mode field effect Pipe V8, its grid is connected with the second outfan of described switch driving circuit, and its drain electrode is by resistance R23 and positive energization input Connecting, its source electrode is connected with negative energization input；Described N-channel enhancement mode field effect transistor V9, its grid and described switch drive 3rd outfan of circuit connects, and its drain electrode is connected with positive energization input by resistance R24, its source electrode and negative energization input Connect；Described N-channel enhancement mode field effect transistor V10, its grid is connected with the 4th outfan of described switch driving circuit, its leakage Pole is connected with positive energization input by resistance R25, and its source electrode is connected with negative energization input；Wherein, described N-channel enhancement mode Field effect transistor V7, V8, V9, V10 drain and gate between be connected to the diode of a reversal connection.

Discharging device the most according to claim 5, it is characterised in that described switch driving circuit includes amplifier U1, amplifier U2, amplifier U3 and amplifier U4, wherein,

Described amplifier U1, its normal phase input end is connected by resistance R7 and 5V DC source, and its inverting input passes through resistance R8 is connected with the first outfan of processor, its outfan and the N-channel enhancement mode field effect transistor in PTC resistor on-off circuit The grid of V10 connects；

Described amplifier U2, its normal phase input end is connected by resistance R9 and 5V DC source, and its inverting input passes through resistance R10 is connected with the second outfan of processor, its outfan and the N-channel enhancement mode field effect transistor in PTC resistor on-off circuit The grid of V9 connects；

Described amplifier U3, its normal phase input end is connected by resistance R17 and 5V DC source, and its inverting input passes through resistance R18 is connected with the 3rd outfan of processor, its outfan and the N-channel enhancement mode field effect transistor in PTC resistor on-off circuit The grid of V8 connects；

Described amplifier U4, its normal phase input end is connected by resistance R19 and 5V DC source, and its inverting input passes through resistance R20 is connected with the 4th outfan of processor, its outfan and the N-channel enhancement mode field effect transistor in PTC resistor on-off circuit The grid of V7 connects.

Discharging device the most according to claim 6, it is characterised in that described PTC resistor temperature sensing circuit includes Resistance R1 and critesistor R2, wherein, one end of described critesistor R2 is connected with the second input of processor, and and resistance It is connected with 5V DC source after R1 series connection, the other end ground connection of described critesistor R2.

Discharging device the most according to claim 7, it is characterised in that described processor is single-chip microcomputer U5, described wind Unit includes the first blower fan, the second blower fan, the 3rd blower fan and four fan device,

5th outfan of single-chip microcomputer U5 connects the first blower fan, the 6th outfan of single-chip microcomputer U5 connects the second blower fan, single-chip microcomputer 7th outfan of U5 connects the 3rd blower fan, the 8th outfan of single-chip microcomputer U5 connects four fan device；

Single-chip microcomputer U5, according to described PTC resistor temperature sensing circuit and the output signal of current sensor, controls described first wind Machine, the second blower fan, the 3rd blower fan and four fan device are transferred to the air quantity of RTC resistance, until described current sensor output put Electricity current value reaches pre-set current value.

Discharging device the most according to claim 1, it is characterised in that also include PWM drive circuit；Described PWM drives Galvanic electricity road, its input is connected with described processor, and its outfan is connected with described blower fan group.

10. a battery discharging method, is applied in the discharging device described in any one of claim 1～9, and its feature exists In, including:

Mu balanced circuit is by stable for the discharge voltage of battery to be discharged after preset voltage value, and output is to PTC resistor on-off circuit；

The RTC resistance performance temperature value that processor detects according to PTC resistor temperature sensing circuit, calculates RTC resistance performance temperature Difference between angle value and preset temperature value, and according to each fan delivery in described difference control blower fan group to the wind of RTC resistance Amount, meanwhile, described processor controls each RTC resistance place branch road in described PTC resistor on-off circuit by switch driving circuit Break-make, until described current sensor output discharge current value reach pre-set current value.