CN216872842U

CN216872842U - Direct current motor drive protection circuit

Info

Publication number: CN216872842U
Application number: CN202220412289.8U
Authority: CN
Inventors: 卢家伟; 顾敏明
Original assignee: Zhejiang Sci Tech University ZSTU
Current assignee: Zhejiang Sci Tech University ZSTU
Priority date: 2022-02-28
Filing date: 2022-02-28
Publication date: 2022-07-01
Anticipated expiration: 2032-02-28

Abstract

The utility model discloses a direct current motor drive protection circuit, which adopts reverse connection prevention and surge prevention processing at a port of a chip power supply input, can play a role in protecting positive and negative connection, and simultaneously carries out smooth processing on peak voltage suddenly appearing at an input end so as to protect a subsequent circuit. The RC series circuit used by the motor spark-eliminating circuit is connected in parallel with the motor with the inductive load, so that the larger electromagnetic energy Q generated by the inductive load due to the influence of the sudden change current can be discharged quickly, the phenomenon of spark generation in the circuit is effectively avoided, and the stability and the safety of the driving circuit are further improved. TB6612FNG is used as a driving chip, the efficiency is higher than that of a common transistor H-bridge driver, and the output load capacity is improved.

Description

Direct current motor drive protection circuit

Technical Field

The utility model relates to a direct current electric drive technology, in particular to a direct current motor drive protection circuit.

Background

The operation of the dc motor is dependent on the control device to which multiple PWM drive signals are input through the power unit. When the direct current motor is operated, phenomena such as overcurrent or spark generation and the like possibly occur due to load or circuit starting, and when the phenomena occur, the main control device is damaged, and even the power components are burnt. In view of the above-mentioned phenomenon, the dc motor protection has technologies such as short-circuit protection, overload protection, underexcitation protection, and overvoltage protection, and an overspeed protection is also required for some high-power dc motors. In the anti-surge protection, some schemes including devices with special performance, such as a TVS diode (a high-performance protection device) for absorbing high surge energy or a thermistor NTC for suppressing high surge current, are mainly adopted at present. Due to the cost of high performance devices and the thermal inertia of thermistors, the operating efficiency may be affected by environmental factors in practical applications, and the cost of circuit design is also increased. Because the direct current motor is convenient to use and used in various working occasions, related working protection circuits are infinite, but the circuit structure is generally complex, and a simple and effective working protection circuit is lacked.

SUMMERY OF THE UTILITY MODEL

The utility model provides a low-cost and high-reliability direct current motor driving protection circuit which can effectively improve the safety performance of a driving chip and a motor.

A dc motor drive protection circuit comprising: the anti-reverse connection circuit, the anti-surge circuit, the peripheral connection circuit of the driving chip and the motor spark-eliminating circuit are connected in series; the anti-reverse connection circuit protects the input terminal of the driver chip U1, wherein VCC_inIs input to VCC pin of the driver chip through the first field effect transistor M1, and the motor supplies voltage VM_inThe anti-reverse-connection circuit is input into the anti-surge circuit, the anti-surge circuit is formed by connecting the grid of a third field effect tube M3 with a fifth resistor R5 in series, connecting the grid of the third field effect tube M3 with a first capacitor C1 in parallel, connecting the grid of the third field effect tube M3 in parallel and connecting the grid of the third field effect tube M3632 with a fourth resistor R4 in series, after the third field effect tube M3 is conducted, loop current charges a second capacitor C2 connected in parallel, filtering the loop current by a second capacitor C2 and then connecting the filtered loop current into the input ends of VM1, VM2 and VM3 of a driving chip U1, and PWMA, AIN1, AIN2, STBY, PWMB, and R4 of the driving chip U1,The BIN1 and the BIN2 are respectively connected with corresponding control pins of a single chip microcomputer, a PGND1, a PGND1', a PGND2 and a PGND2' of the single chip microcomputer are grounded, an A-end first output pin A01 is connected with one end of a circuit formed by connecting a sixth resistor R6 and a third capacitor C3 in series, an A-end second output pin A02 is connected with the other end of the circuit formed by connecting the sixth resistor R6 and a third capacitor C3 in series, and is finally connected with two ends O1 of a direct current motor, a B-end first output pin B01 is connected with one end of a circuit formed by connecting a seventh resistor R7 and a fourth capacitor C4 in series, and a B-end second output pin B02 is connected with the other end of the circuit formed by connecting the seventh resistor R7 and the fourth capacitor C4 in series, and is finally connected with two ends O2 of the direct current motor.

The circuit of the utility model adopts reverse connection prevention and surge prevention processing at the port of the chip power supply input, can play a role in protecting positive and negative connection, and simultaneously carries out smooth processing on the peak voltage suddenly appearing at the input end, thereby protecting the subsequent circuit. The RC series circuit used by the motor spark-eliminating circuit is connected in parallel with the motor with the inductive load, so that the larger electromagnetic energy Q generated by the inductive load due to the influence of the sudden change current can be discharged quickly, the phenomenon of spark generation in the circuit is effectively avoided, and the stability and the safety of the driving circuit are further improved.

Drawings

Fig. 1 is a circuit diagram according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments; all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a dc motor driving protection circuit includes an anti-reverse connection circuit, an anti-surge circuit, a driving chip peripheral connection circuit, and a motor spark-eliminating circuit.

The reverse connection preventing circuit protects the input voltage of the driving chip U1, the driving chip U1 adopts TB6612FNG, VCCin is conducted through the diode D1 when the driving chip U1 is correctly connected, the source electrode and the grid electrode of the first field effect tube M1 form negative voltage, the first field effect tube M1 is conducted, voltage drop at two ends of the drain electrode and the source electrode of the first field effect tube M1 is small, the diode D1 is caused to be short-circuited, and when the driving chip U1 is wrongly connected, the first field effect tube M1 is not conducted, so that the safety of a subsequent circuit is protected.

And the positive voltage VMin supplied by the motor is input into the anti-surge circuit through the anti-reverse connection circuit, and the anti-surge circuit is formed by connecting the grid of the third field effect transistor M3 with the fifth resistor R5 in series, connecting the grid of the third field effect transistor M3 with the first capacitor C1 in parallel, connecting the grid of the third field effect transistor M3 in parallel and connecting the grid of the third field effect transistor M3 with the fourth resistor R4 in series. At the moment of power-on, the first capacitor C1 is short-circuited, the voltage across the gate source of the third fet M3 is 0, the third fet M3 is not turned on, no current flows through the second capacitor C2, the voltage across the gate source gradually rises with the charging of the first capacitor C1, when the starting voltage is reached, the third fet M3 is turned on, the current gradually increases on the third fet M3 with the gradually rising of the voltage of the first capacitor C1 to charge the second capacitor C2, and when the voltage across the first capacitor C1 reaches the voltage across the third resistor R3, the charging is finished. The process prevents the generation of peak voltage due to the input voltage to the capacitor, and protects the subsequent circuit elements.

After the third field effect transistor M3 is turned on, the loop current charges a second capacitor C2 connected in parallel, the current is filtered by a second capacitor C2 and then is connected to the input ends of VM1, VM2 and VM3 of TB6612FNG, PWMA, AIN1, AIN2, STBY, PWMB, BIN1 and BIN2 of TB6612FNG are respectively connected to corresponding pins of the single chip, and PGND1, PGND1', PGND2 and PGND2' are connected to the ground GND. The first output pin A01 at the A end is connected with one end of a series circuit consisting of a sixth resistor R6 and a third capacitor C3, the second output pin A02 at the A end is connected with the other end of the series circuit and is finally connected with two ends of the direct current motor, and the third capacitor C3 is charged by larger current generated by sudden change of voltage at two ends of the inductive load first direct current motor O1, so that the current on a loop formed by the motors is reduced, the phenomenon of sparks at contacts in the circuit is avoided, the safety of the driving circuit is enhanced, and the performance of the direct current motor is improved.

In the anti-surge part, the first capacitor C1, the third resistor R3 and the fourth resistor R4 can be adjusted. When the first capacitor C1 or the fourth resistor R4 and the third resistor R3 are increased, the surge current can be reduced. In the spark-extinguishing part, the DC motors with different models can be compatible by adjusting the values of the third capacitor C3, the fourth capacitor C4, the sixth resistor R6 and the seventh resistor R7.

Compared with the prior art, the scheme has the advantages that the anti-reverse connection circuit is added at the port of the power input, the anti-surge is added in the circuit, the effect of the field effect tube is utilized, the surge current is well inhibited, the safety and the reliability of the circuit are ensured at the spark removing part, and the performances of the driving chip TB6612FNG and the DC motor are improved.

Claims

1. A dc motor drive protection circuit, comprising: the anti-reverse-connection circuit, the anti-surge circuit, the peripheral connection circuit of the driving chip and the motor spark-eliminating circuit are connected; the anti-reverse connection circuit protects the input terminal of the driver chip U1, wherein VCC_inIs input to VCC pin of the driver chip through the first field effect transistor M1, and the motor supplies voltage VM_inThe anti-reverse-connection circuit is input into the anti-surge circuit, the anti-surge circuit is formed by connecting the grid of a third field effect tube M3 with a fifth resistor R5 in series, connecting the grid of the third field effect tube M3 with a first capacitor C1 in parallel, connecting the grid of the third field effect tube M466 with a third resistor R3 in parallel and connecting the grid of the third field effect tube M5475 with a fourth resistor R4 in series, loop current charges a second capacitor C2 in parallel after the third field effect tube M3 is conducted, filtering the loop current by a second capacitor C2 and then connecting the loop current into the input ends of VM2, VM2 and VM2 of a driving chip U2, connecting the PWMA, AIN2, STBY, PWMB 2, BIN2 and BIN2 of the driving chip U2 with corresponding control pins of the single chip respectively, connecting the PGND2, PGND2 'and PGND2' with the ground, connecting a first output pin A2 at the A end to one end of a circuit formed by connecting a sixth resistor R2 in series with a third capacitor C2 and a circuit, connecting the second output pin A2 with a second resistor C2 at the other end of the second resistor C2 in series, and a resistor C2 in series, and a resistor C2 at the other end of the second end of the third capacitor C2 in series, and a second output pin B02 at the B end is connected with the other end of the circuit formed by connecting the seventh resistor R7 and the fourth capacitor C4 in series, and is finally connected with two ends O2 of the direct current motor.

2. The direct current motor drive protection circuit according to claim 1, wherein the drive chip U1 is TB6612 FNG.