CN209344767U - A kind of BLDC speed-regulating control circuit - Google Patents

Abstract

The utility model discloses a kind of BLDC speed-regulating control circuit, the processor being connect including power module and respectively with the power module, commutation drive module, zero-crossing examination module and feedback control module, the input terminal of the commutation drive module is connected to the processor, first output end of the commutation drive module can be used for connecting BLDC motor, first output end of the commutation drive module is also connected to the processor by the zero-crossing examination module, the second output terminal of the commutation drive module is connected to the processor by the feedback control module, and the size of current for detecting and regulating and controlling BLDC motor, it realizes and overload protection is realized to BLDC motor.The circuit structure of the utility model is simple, by increasing the closed-loop control between feedback control module realization processor, commutation drive module and BLDC motor, to realize the overload protection to BLDC motor.

Description

A kind of BLDC speed-regulating control circuit

Technical field

The utility model relates to motor control technology fields, and in particular to a kind of BLDC speed-regulating control circuit.

Background technique

With increasingly developed, the BLDC motor, i.e. brshless DC motor of electric tool, all obtained extensively in many fields Application, BLDC motor have good speed adjustment features, it is small in size, it is high-efficient the advantages that.But existing BLDC speed-regulating control circuit Structure is complicated, and cannot carry out overload protection to BLDC motor.

Summary of the invention

In view of the deficiencies of the prior art, the utility model provides a kind of BLDC speed-regulating control circuit, existing for solving Structure is complicated for BLDC speed-regulating control circuit, and cannot to BLDC motor carry out overload protection the problem of.

The content of the utility model is as follows:

A kind of BLDC speed-regulating control circuit, the processor being connect including power module and respectively with the power module, Commutation drive module, zero-crossing examination module and feedback control module, the input terminal of the commutation drive module and the processing Device connection, the first output end of the commutation drive module can be used for connecting BLDC motor, and the commutation drive module is for connecing It receives the pwm signal of the processor and BLDC motor commutation and speed regulation is driven according to pwm signal, the of the commutation drive module One output end is also connected to the processor by the zero-crossing examination module, and the zero-crossing examination module is for detecting The back-emf signal of BLDC motor, and back-emf signal is passed into the zero passage that the processor carries out back-emf signal Point detection, the second output terminal of the commutation drive module are connected to the processor by the feedback control module, are used in combination In the size of current for detecting and regulating and controlling BLDC motor, realizes and overload protection is realized to BLDC motor.

Preferably, the processor is adopted including core cell, Power Management Unit, PWM generator unit, AFE(analog front end) list Member, data acquisition unit and interface unit, the analog front-end unit include high-pressure door driving unit, comparator unit and simulation Front-end control unit, the core cell are acquired with the PWM generator unit, the data respectively by AHB/APB bus Unit is connected with the interface unit, and the Power Management Unit is connected to the PWM generator list by SOC bus Member, high-pressure door actuator unit, comparator unit, AFE(analog front end) control unit and data acquisition unit, the AHB/APB bus It is connected with the SOC bus by bridge unit；

The PWM generator unit is for occurring pwm control signal；The high-pressure door actuator unit is for receiving and locating Pwm control signal is managed, and for driving the commutation drive module, the comparator unit is for receiving and handling the zero passage The back-emf signal of point detection module and the zero passage point data that back-emf signal is obtained compared with virtual stable state central point, and Zero passage point data is passed into the core cell；The AFE(analog front end) control unit is for receiving the commutation drive module Feedback signal realizes the overload protection to BLDC motor.

Preferably, the commutation drive module includes metal-oxide-semiconductor Q4, Q5, Q6, Q7, Q8 and Q9, source electrode, the MOS of metal-oxide-semiconductor Q4 The source electrode of pipe Q5 and the source electrode of metal-oxide-semiconductor Q7 are connected respectively the drain electrode in metal-oxide-semiconductor Q7, the drain electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9's Drain electrode, connecting node is respectively node a, node b and node c, the grid of metal-oxide-semiconductor Q4, the grid of metal-oxide-semiconductor Q5, metal-oxide-semiconductor Q6, MOS The grid of the grid of pipe Q7, the grid of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 pass through respectively resistance R70, R77, R84, R72, R79 and R86 with The high-pressure door actuator unit of the processor connects, and resistance R88, metal-oxide-semiconductor Q5 are connected between the grid and source electrode of metal-oxide-semiconductor Q4 Grid and source electrode between be connected with resistance R89, resistance R90 is connected between the grid and source electrode of metal-oxide-semiconductor Q6, metal-oxide-semiconductor Q7's It is connected with resistance R91 between grid and source electrode, resistance R92, the grid of metal-oxide-semiconductor Q9 are connected between the grid and source electrode of metal-oxide-semiconductor Q8 Be connected with resistance R93 between pole and source electrode, the drain electrode of metal-oxide-semiconductor Q4, the drain electrode of metal-oxide-semiconductor Q5 and the drain electrode of metal-oxide-semiconductor Q6 respectively with electricity Pressure side HV+ connection, the source electrode of the source electrode of metal-oxide-semiconductor Q7, the source electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 by pull down resistor R94 respectively with Voltage end HV- connection, the connection section of the source electrode of the source electrode of metal-oxide-semiconductor Q7, the source electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 and following resistance R94 Point is node d, and node a, node b and node c are connected respectively U, V, W phase coil input terminal in the BLDC motor.

Preferably, U, V, W phase coil input terminal of the BLDC motor are also connected with reference circuits, the voltage ginseng Examining circuit includes diode D1, D4 and D7, and the anode of the anode of diode D1, the anode of diode D4 and diode D7 leads to respectively It crosses resistance R21 and is connected to voltage end VHD, voltage end VHD passes through the capacitor C8 being connected in parallel and connects live end with capacitor C11 The cathode of the cathode of HV-, diode D1, the cathode of diode D4 and diode D7 is connected to the high-pressure door of the processor Actuator unit also respectively corresponds U, V, W phase that the BLDC motor is connected to by capacitor C48, capacitor C53 and capacitor C59 Coil input end.

Preferably, the feedback control module includes resistance R29, resistance R30 and capacitor C34, one end connection of resistance R30 In node d, also by being connect including the parallel circuit of capacitor C34, C35 and C38 with voltage end HV+, the other end of resistance R30 and The AFE(analog front end) control unit of the processor connects, and is also controlled respectively with the AFE(analog front end) of the processor by capacitor C34 Unit is connected with one end of resistance R29, and the other end of resistance R29 is connect with voltage end HV-.

Preferably, the zero-crossing examination module includes the partial pressure electricity for being connected to BLDC motor U, V, W phase input terminal Road, BLDC motor U phase input terminal are connected with one end of resistance R2, and the other end of R2 is connected to the comparator list of the processor Member, the other end of R2 are also connected to voltage end HV- by the parallel circuit including resistance R18 and capacitor C2, and BLDC motor V phase is defeated Enter one end that end is connected with resistance R3, the other end of R3 is connected to the comparator unit of the processor, and the other end of R3 is also logical It crosses the parallel circuit including resistance R19 and capacitor C3 and is connected to voltage end HV-, BLDC motor U phase input terminal is connected with resistance R4 One end, the other end of R4 is connected to the comparator unit of the processor, and the other end of R4 is also by including resistance R20 and electricity The parallel circuit for holding C4 is connected to voltage end HV-, and the comparator unit of the processor also passes through resistance R1 and is connected to voltage end HV+, the comparator unit of the processor are also connected to voltage end HV- by the parallel circuit including resistance R17 and capacitor C1.

Preferably, the interface unit of the processor is also connected with external interface module, and the external interface module includes PWM input test side P3, PWM output test side P5, serial ports end P4 and wire jumper end JP1, JP2 and JP3, the processor connect Mouth unit passes through isolation element respectively and is connected to PWM input test side P3, PWM output test side P5 and serial ports end P4.

The utility model has the following beneficial effects: the circuit structure of the utility model is simple, by increasing feedback control module The closed-loop control between processor, commutation drive module and BLDC motor is realized, to realize the overload protection to BLDC motor.

Detailed description of the invention

Fig. 1 show the functional block diagram of the best embodiment of the utility model；

Fig. 2 show the functional block diagram of the processor of the best embodiment of the utility model；

Fig. 3 show commutation drive module circuit theory Fig. 1 of the best embodiment of the utility model；

Fig. 4 show commutation drive module circuit theory Fig. 2 of the best embodiment of the utility model；

Fig. 5 show the circuit diagram of the zero-crossing examination module of the best embodiment of the utility model；

Fig. 6 show the processor interface unit external circuits schematic diagram of the best embodiment of the utility model.

Specific embodiment

The above description is merely an outline of the technical solution of the present invention, in order to better understand the skill of the utility model Art means, and being implemented in accordance with the contents of the specification, and in order to allow the above and other purpose, feature of the utility model It can be more clearly understood with advantage, it is special below to lift preferred embodiment, and cooperate attached drawing, detailed description are as follows.

Please refer to Fig. 1, a kind of BLDC speed-regulating control circuit disclosed in the present embodiment, including power module 1 and respectively with Processor 2, commutation drive module 3, zero-crossing examination module 5 and the feedback control module 4 that the power module 1 connects, it is described The input terminal of commutation drive module 3 is connect with the processor 2, and the first output end of the commutation drive module 3 can be used for connecting BLDC motor is connect, the commutation drive module 3 is used to receive the pwm signal of the processor 2 and drives BLDC according to pwm signal Motor commutation and speed regulation, the first output end of the commutation drive module 3 are also connected to institute by the zero-crossing examination module 5 State processor 2, the zero-crossing examination module 5 is used to detect the back-emf signal of BLDC motor, and by back-emf signal The zero-crossing examination that the processor 2 carries out back-emf signal is passed to, the second output terminal of the commutation drive module 3 is logical It crosses the feedback control module 4 and is connected to the processor 2, and the size of current for detecting and regulating and controlling BLDC motor, realize Overload protection is realized to BLDC motor.

Referring to figure 2., the processor 2 is adopted including core cell 2-1, Power Management Unit 2-2, PWM generator unit 2-3, analog front-end unit 2-4, data acquisition unit 2-5 and interface unit 2-6, the analog front-end unit 2-4 includes high pressure Door driving unit, comparator unit 2-4-2 and AFE(analog front end) control unit 2-4-3, the core cell 2-1 pass through AHB/APB Bus is connect with the PWM generator unit 2-3, the data acquisition unit 2-5 and the interface unit 2-6 respectively, described Power Management Unit 2-2 is connected to the PWM generator unit 2-3, high-pressure door actuator unit 2-4- by SOC bus 1, comparator unit 2-4-2, AFE(analog front end) control unit 2-4-3 and data acquisition unit 2-5, the AHB/APB bus and institute SOC bus is stated to connect by bridge unit 2-7；

The PWM generator unit 2-3 is for occurring pwm control signal；The high-pressure door actuator unit is for receiving With processing pwm control signal, and for driving the commutation drive module 3, the comparator unit 2-4-2 is for receiving and locating It manages the back-emf signal of the zero-crossing examination module 5 and obtains the mistake of back-emf signal compared with virtual stable state central point Zero data, and the zero passage point data is passed into the core cell 2-1；The AFE(analog front end) control unit is for receiving institute The feedback signal of commutation drive module 3 is stated, realizes that the overload protection to BLDC motor, the processor 2 of the present embodiment use model For the microcontroller of PAC5250, compared with existing STM32 series monolithic, it is possible to reduce the peripheral circuit of processor 2, letter Change the circuit structure between processor 2 and other modules, advantageously reduces power consumption.

Referring to figure 3. and Fig. 4, the commutation drive module 3 include metal-oxide-semiconductor Q4, Q5, Q6, Q7, Q8 and Q9, metal-oxide-semiconductor Q4's The source electrode of source electrode, the source electrode of metal-oxide-semiconductor Q5 and metal-oxide-semiconductor Q7 be connected respectively the drain electrode in metal-oxide-semiconductor Q7, the drain electrode of metal-oxide-semiconductor Q8 and The drain electrode of metal-oxide-semiconductor Q9, connecting node are respectively node a, node b and node c, the grid of metal-oxide-semiconductor Q4, metal-oxide-semiconductor Q5 grid, Metal-oxide-semiconductor Q6, the grid of metal-oxide-semiconductor Q7, the grid of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 grid pass through respectively resistance R70, R77, R84, R72, R79 and R86 are connect with the high-pressure door actuator unit 2-4-1 of the processor 2, between the grid and source electrode of metal-oxide-semiconductor Q4 It is connected with resistance R88, resistance R89 is connected between the grid and source electrode of metal-oxide-semiconductor Q5, is connected between the grid and source electrode of metal-oxide-semiconductor Q6 It is connected to resistance R90, resistance R91 is connected between the grid and source electrode of metal-oxide-semiconductor Q7, is connected between the grid and source electrode of metal-oxide-semiconductor Q8 Have resistance R92, be connected with resistance R93 between the grid and source electrode of metal-oxide-semiconductor Q9, the drain electrode of metal-oxide-semiconductor Q4, the drain electrode of metal-oxide-semiconductor Q5 and The drain electrode of metal-oxide-semiconductor Q6 is connect with voltage end HV+ respectively, and the source electrode of the source electrode of metal-oxide-semiconductor Q7, the source electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 is logical Cross connecting respectively with voltage end HV- for pull down resistor R94, the source electrode of the source electrode of metal-oxide-semiconductor Q7, the source electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 Connecting node with following resistance R94 is node d, and node a, node b and node c are connected respectively in the BLDC motor U, V, W phase coil input terminal.

Referring to figure 3., U, V, W phase coil input terminal of the BLDC motor are also connected with reference circuits, the electricity Pressure reference circuit includes diode D1, D4 and D7, the anode point of the anode of diode D1, the anode of diode D4 and diode D7 Voltage end VHD is not connected to by resistance R21, voltage end VHD passes through the capacitor C8 being connected in parallel and capacitor C11 is connected with electricity The cathode of the cathode of pressure side HV-, diode D1, the cathode of diode D4 and diode D7 is connected to the processor 2 High-pressure door actuator unit 2-4-1 is also respectively corresponded and is connected to the BLDC electricity by capacitor C48, capacitor C53 and capacitor C59 U, V, W phase coil input terminal of machine, the present embodiment are provided with reference circuits, can be to avoid being directly grounded when circle electromagnetic field Interference, that improves circuit sees interference performance.

Referring to figure 4., the feedback control module includes resistance R29, resistance R30 and capacitor C34, one end of resistance R30 It is connected to node d, is also connect by the parallel circuit including capacitor C34, C35 and C38 with voltage end HV+, resistance R30's is another End is connect with the AFE(analog front end) control unit 2-4-3 of the processor 2, also passes through the capacitor C34 mould with the processor 2 respectively Quasi- front-end control unit 2-4-3 is connected with one end of resistance R29, and the other end of resistance R29 is connect with voltage end HV-, processor 2 It is connect by port P1 with BLDC motor, realizes the closed-loop control between processor 2, commutation drive module 3 and BLDC motor, from And realize the overload protection of BLDC motor.

Referring to figure 5., the zero-crossing examination module includes being connected to the partial pressure of BLDC motor U, V, W phase input terminal Circuit, BLDC motor U phase input terminal are connected with one end of resistance R2, and the other end of R2 is connected to the comparator of the processor 2 The other end of unit 2-4-2, R2 are also connected to voltage end HV-, BLDC electricity by the parallel circuit including resistance R18 and capacitor C2 Machine V phase input terminal is connected with one end of resistance R3, and the other end of R3 is connected to the comparator unit 2-4-2, R3 of the processor 2 The other end also by being connected to voltage end HV-, BLDC motor U phase input terminal including the parallel circuit of resistance R19 and capacitor C3 It is connected with one end of resistance R4, the other end of R4 is connected to the other end of the comparator unit 2-4-2, R4 of the processor 2 also Voltage end HV-, the comparator unit 2-4-2 of the processor 2 are connected to by the parallel circuit including resistance R20 and capacitor C4 Voltage end HV+ is also connected to by resistance R1, the comparator unit 2-4-2 of the processor 2 is also by including resistance R17 and electricity The parallel circuit for holding C1 is connected to voltage end HV-, for providing reference voltage for the comparator unit 2-4-2 of processor 2.

Fig. 6 is please referred to, the interface unit 2-6 of the processor 2 is connected with external interface module 6, can be in order to circuit Debugged and detected, be conducive to faulty circuit carry out Quick overhaul, external interface module 6 include PWM input test side, PWM exports test side, serial ports end and wire jumper end, the interface unit 2-6 of the processor 2 pass through respectively isolation element U4, U6 and It is equal that U5 is connected to PWM input test side, the output test side PWM and serial ports end, isolation element U4, U6 and U5 that the present embodiment uses For two-channel digital isolator, it is advantageously implemented the isolation of signal, improves the anti-interference ability of circuit.

The above, the only preferred embodiment of the utility model, the utility model are not limited to above-mentioned implementation Mode, as long as its technical effect for reaching the utility model with identical means, all should belong to the protection scope of the utility model. Its technical solution and/or embodiment within the protection scope of the present utility model can have a variety of different modifications and variations.

Claims (7)

1. a kind of BLDC speed-regulating control circuit, it is characterised in that: including power module (1) and respectively with the power module (1) processor (2), commutation drive module (3), zero-crossing examination module (5) and the feedback control module (4) connected, it is described to change The input terminal of phase drive module (3) is connect with the processor (2), and the first output end of the commutation drive module (3) is available In connection BLDC motor, the commutation drive module (3) is for receiving the pwm signal of the processor (2) and according to pwm signal Driving BLDC motor commutation and speed regulation, the first output end of the commutation drive module (3) also pass through the zero-crossing examination mould Block (5) is connected to the processor (2), and the zero-crossing examination module (5) is used to detect the back-emf signal of BLDC motor, And back-emf signal is passed into the zero-crossing examination that the processor (2) carry out back-emf signal, the commutation driving The second output terminal of module (3) is connected to the processor (2) by the feedback control module (4), and for detecting and adjusting The size of current of BLDC motor is controlled, realizes and overload protection is realized to BLDC motor.

2. BLDC speed-regulating control circuit as described in claim 1, it is characterised in that: the processor (2) is adopted including core list Member (2-1), Power Management Unit (2-2), PWM generator unit (2-3), analog front-end unit (2-4), data acquisition unit (2-5) and interface unit (2-6), the analog front-end unit (2-4) include high-pressure door driving unit, comparator unit (2-4- 2) occurred respectively with the PWM with AFE(analog front end) control unit (2-4-3), the core cell (2-1) by AHB/APB bus Device unit (2-3), the data acquisition unit (2-5) and the interface unit (2-6) connection, the Power Management Unit (2- 2) the PWM generator unit (2-3), high-pressure door actuator unit (2-4-1), comparator are connected to by SOC bus Unit (2-4-2), AFE(analog front end) control unit (2-4-3) and data acquisition unit (2-5), the AHB/APB bus and described SOC bus is connected by bridge unit (2-7)；

The PWM generator unit (2-3) is for occurring pwm control signal；The high-pressure door actuator unit for receive and Handle pwm control signal, and for driving the commutation drive module (3), the comparator unit (2-4-2) for receiving and It handles the back-emf signal of the zero-crossing examination module (5) and obtains back-emf signal compared with virtual stable state central point Zero passage point data, and zero passage point data is passed into the core cell (2-1)；The AFE(analog front end) control unit is for connecing The feedback signal of the commutation drive module (3) is received, realizes the overload protection to BLDC motor.

3. BLDC speed-regulating control circuit as claimed in claim 2, it is characterised in that: the commutation drive module (3) includes MOS Pipe Q4, Q5, Q6, Q7, Q8 and Q9, the source electrode of the source electrode of metal-oxide-semiconductor Q4, the source electrode of metal-oxide-semiconductor Q5 and metal-oxide-semiconductor Q7 be connected respectively in The drain electrode of metal-oxide-semiconductor Q7, the drain electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 drain electrode, connecting node is respectively node a, node b and node c, The grid of metal-oxide-semiconductor Q4, the grid of metal-oxide-semiconductor Q5, metal-oxide-semiconductor Q6, the grid of metal-oxide-semiconductor Q7, the grid of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 grid Pole passes through the high-pressure door actuator unit (2-4- of resistance R70, R77, R84, R72, R79 and R86 Yu the processor (2) respectively 1) it connects, resistance R88 is connected between the grid and source electrode of metal-oxide-semiconductor Q4, is connected with resistance between the grid and source electrode of metal-oxide-semiconductor Q5 It is connected with resistance R90 between the grid and source electrode of R89, metal-oxide-semiconductor Q6, is connected with resistance between the grid and source electrode of metal-oxide-semiconductor Q7 It is connected with resistance R92 between the grid and source electrode of R91, metal-oxide-semiconductor Q8, is connected with resistance between the grid and source electrode of metal-oxide-semiconductor Q9 The drain electrode of R93, metal-oxide-semiconductor Q4, the drain electrode of metal-oxide-semiconductor Q5 and the drain electrode of metal-oxide-semiconductor Q6 are connect with voltage end HV+ respectively, the source of metal-oxide-semiconductor Q7 The source electrode of pole, the source electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 is connect with voltage end HV- respectively by pull down resistor R94's, metal-oxide-semiconductor Q7's The connecting node of the source electrode of source electrode, the source electrode of metal-oxide-semiconductor Q8 and metal-oxide-semiconductor Q9 and following resistance R94 are node d, node a, node b and Node c is connected respectively U, V, W phase coil input terminal in the BLDC motor.

4. BLDC speed-regulating control circuit as claimed in claim 3, it is characterised in that: U, V, W phase coil of the BLDC motor Input terminal is also connected with reference circuits, and the reference circuits include diode D1, D4 and D7, and diode D1 is just The anode of pole, the anode of diode D4 and diode D7 is connected to voltage end VHD by resistance R21 respectively, and voltage end VHD passes through The capacitor C8 being connected in parallel connects live end HV- with capacitor C11, the cathode and two of the cathode of diode D1, diode D4 The cathode of pole pipe D7 is connected to the high-pressure door actuator unit (2-4-1) of the processor (2), also respectively corresponds and passes through electricity Hold U, V, W phase coil input terminal that C48, capacitor C53 and capacitor C59 are connected to the BLDC motor.

5. BLDC speed-regulating control circuit as claimed in claim 2 or claim 3, it is characterised in that: the feedback control module includes electricity R29, resistance R30 and capacitor C34 are hindered, one end of resistance R30 is connected to node d, also by including capacitor C34, C35 and C38 Parallel circuit is connect with voltage end HV+, the AFE(analog front end) control unit (2-4- of the other end of resistance R30 and the processor (2) 3) connect, also by capacitor C34 respectively with the AFE(analog front end) control unit (2-4-3) of the processor (2) and resistance R29 one End connection, the other end of resistance R29 are connect with voltage end HV-.

6. BLDC speed-regulating control circuit as claimed in claim 2, it is characterised in that: the zero-crossing examination module includes difference It is connected to the bleeder circuit of BLDC motor U, V, W phase input terminal, BLDC motor U phase input terminal is connected with one end of resistance R2, R2 The other end be connected to the comparator units (2-4-2) of the processor (2), the other end of R2 also by include resistance R18 and The parallel circuit of capacitor C2 is connected to voltage end HV-, and BLDC motor V phase input terminal is connected with one end of resistance R3, and R3's is another End is connected to the comparator unit (2-4-2) of the processor (2), and the other end of R3 is also by including resistance R19 and capacitor C3 Parallel circuit be connected to voltage end HV-, BLDC motor U phase input terminal is connected with one end of resistance R4, the other end connection of R4 Comparator unit (2-4-2) in the processor (2), the other end of R4 also pass through the parallel connection including resistance R20 and capacitor C4 Circuit connection is also connected to voltage end by resistance R1 in voltage end HV-, the comparator unit (2-4-2) of the processor (2) HV+, the comparator unit (2-4-2) of the processor (2) are also connected to by the parallel circuit including resistance R17 and capacitor C1 Voltage end HV-.

7. BLDC speed-regulating control circuit as claimed in claim 2, it is characterised in that: the interface unit (2- of the processor (2) 6) it is also connected with external interface module (6), the external interface module (6) includes PWM input test side P3, PWM output detection End P5, serial ports end P4 and wire jumper end JP1, JP2 and JP3, the interface unit (2-6) of the processor (2) pass through isolation respectively Element is connected to PWM input test side P3, PWM output test side P5 and serial ports end P4.