CN217159575U

CN217159575U - Motor drive circuit and tension control system

Info

Publication number: CN217159575U
Application number: CN202221097727.2U
Authority: CN
Inventors: 康小东; 豆大勇
Original assignee: Shanghai Ruiyouzhun Intelligent Control Technology Co ltd
Current assignee: Shanghai Ruiyouzhun Intelligent Control Technology Co ltd
Priority date: 2022-05-09
Filing date: 2022-05-09
Publication date: 2022-08-09
Anticipated expiration: 2032-05-09

Abstract

The utility model provides a motor drive circuit and pulling force control system. The motor drive circuit includes: first signal conversion module, second signal conversion module and drive module, drive module includes: the first switch unit, the second switch unit, the first bleeder unit, the second bleeder unit. The output end of the first signal conversion module is connected with the first end of the first switch unit and the second end of the first switch unit; the first end of the first bleeder unit is connected with the third end of the first switch unit, and the second end of the first bleeder unit is connected with the third end of the second switch unit; the second end of the second switch unit and the second end of the second bleeder unit are grounded, the first end of the second bleeder unit is connected with the first end of the first switch unit, and the first end of the second switch unit is connected with the output end of the second signal conversion module; the first end of the first switch unit and the third end of the second switch unit are also connected to two ends of the motor. The control of the pulling force is more flexible and convenient.

Description

Motor drive circuit and tension control system

Technical Field

The utility model relates to a motor drive technical field particularly, relates to a motor drive circuit and pulling force control system.

Background

The GM electromagnet control system can control the direct current motor to generate corresponding output torque according to a set value, and replaces heavy weights in the existing mechanical gravity training machine so as to reduce the volume and weight of the machine.

And a motor driving circuit of the GM electromagnet control system controls the pulling force of the motor by adjusting the current. In the prior art, a triode or a Metal-Oxide-Semiconductor field-Effect Transistor (MOS) is controlled to be in an amplification state in a motor driving circuit to realize constant current of a motor and adjust the current.

However, the triode or the MOS transistor in the motor driving circuit is always in an amplifying state, so that the loss is very large, the heat generation is huge, the effective work of the motor is less, and the efficiency of the electromagnet control system is low.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a motor drive circuit and pulling force control system can follow signal conversion module to drive module input control signal to through the size of electric current in the accurate control circuit of control signal, thereby change the pulling force size of motor.

The utility model provides a technical scheme:

in a first aspect, the present invention provides a motor driving circuit, the motor driving circuit includes: first signal conversion module, second signal conversion module and drive module, drive module includes: the first switch unit, the second switch unit, the first bleeder unit and the second bleeder unit.

The input end of the first signal conversion module is used for accessing a control signal sent by a controller, the output end of the first signal conversion module is connected with the first end and the second end of the first switch unit, the first end of the first bleeder unit is connected with the third end of the first switch unit, the second end of the first bleeder unit is connected with the third end of the second switch unit, the second end of the second switch unit and the second end of the second bleeder unit are grounded, the first end of the second bleeder unit is connected with the first end of the first switch unit, the first end of the second switch unit is connected with the output end of the second signal conversion module, and the input end of the second signal conversion module is used for accessing the control signal;

the first end of the first switch unit is also connected to one end of a driven motor, and the third end of the second switch unit is also connected to the other end of the motor;

the first switch unit and the second switch unit are used for outputting current to the motor under the control of the control signal.

In an alternative embodiment, the driving module further comprises: a first protection unit;

one end of the first protection unit is connected with the output end of the first signal conversion module, and the other end of the first protection unit is connected with the first end of the first switch unit.

In an alternative embodiment, the driving module further comprises: a second protection unit;

one end of the second protection unit is connected with the output end of the second signal conversion module, and the other end of the second protection unit is connected with the second end of the second switch unit.

In an alternative embodiment, the motor drive circuit further comprises: a third protection unit;

one end of the third protection unit is connected with the output end of the first signal conversion module, and the other end of the third protection unit is connected with the second end of the first switch unit and one end of the first protection unit.

In an alternative embodiment, the motor drive circuit further comprises: a fourth protection unit;

one end of the fourth protection unit is connected with the output end of the second signal conversion module, and the other end of the fourth protection unit is connected with the first end of the second switch unit and one end of the second protection unit.

In an alternative embodiment, the first signal conversion module comprises: a first chip;

the first pin of the first chip is used for accessing the control signal, the second pin and the third pin of the first chip are connected with one end of the third protection unit, and the fourth pin of the first chip is connected with the first end of the first switch unit.

In an alternative embodiment, the second signal conversion module comprises: a third switching unit and a fourth switching unit;

the first end of the third switching unit is used for accessing the control signal, the second end of the third switching unit is used for accessing a power supply voltage, and the third end of the third switching unit is connected with one end of the fourth protection unit;

the first end of the fourth switch unit is used for accessing the control signal, the second end of the fourth switch unit is connected with one end of the fourth protection unit, and the third end of the fourth switch unit is grounded.

In an alternative embodiment, the third switching unit and the fourth switching unit are transistors, respectively.

In an alternative embodiment, the first switching unit and the second switching unit are metal oxide semiconductor field effect transistors, respectively.

In a second aspect, the present invention provides a tension control system, including: a controller, a motor and a motor drive circuit as described in the foregoing first aspect.

The controller is connected with the motor driving circuit and used for outputting a control signal to the motor driving circuit;

the motor is connected with the motor driving circuit, and the motor driving circuit is used for outputting current to the motor.

The utility model has the advantages that:

the embodiment of the utility model provides an in, motor drive circuit includes first signal conversion module, second signal conversion module and drive module, through adjusting the switching on of first switch element and second switch element in can controlling the drive module from the PWM (Pu se width mod u at ion) signal of first signal conversion module and second signal conversion module input, thereby control circuit switches on, the pulse width through adjusting the PWM signal of input can control the size of electric current in the circuit, thereby the pulling force size of control motor. Can only increase and decrease control pulling force size difference one by one with traditional weight, pulse signal's width can more accurate control, consequently this embodiment can be through the width of adjusting the PWM signal of input motor drive circuit, realize the tensile stepless regulation of motor, thereby make tensile control more nimble, it is more convenient, compare with current drive circuit in messenger MOS pipe in the control current size of enlarged state, the motor drive circuit's of this embodiment design utilizes the conductivity of MOS pipe, consequently, the loss of generating heat is little, the effective doing work of motor is more, the efficiency and the stability of circuit have been improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic view illustrating an application scenario of a tension control system according to an embodiment of the present invention;

fig. 2 is a schematic diagram illustrating an architecture of a tension system according to an embodiment of the present invention;

fig. 3 shows a schematic structural diagram of a motor driving circuit according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another motor driving circuit provided in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a first conversion module according to an embodiment of the present invention;

fig. 6 shows a schematic structural diagram of a second conversion module according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or orientations or positional relationships that are conventionally placed when the products of the present invention are used, or orientations or positional relationships that are conventionally understood by those skilled in the art, and are merely for convenience of description of the present invention and for simplicity of description, and do not indicate or imply that the equipment or components that are referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

And a motor driving circuit of the GM electromagnet control system controls the pulling force of the motor by adjusting the current. In the prior art, a triode or an MOS transistor is controlled to be in an amplification state in a motor driving circuit to realize constant current of a motor and regulate the current.

However, the transistor or MOS transistor in the motor driving circuit is always in an amplifying state, which causes a very large loss and a large heat generation, and may cause a malfunction of the GM electromagnet control system.

Based on the above problems, the applicant has developed a motor driving circuit and a tension control system, where the motor driving circuit can be applied to the end of the tension control system, and under the action of a control signal of a computer device, an MOS transistor or a triode in the motor driving circuit correspondingly changes the on-off state, so as to accurately control the magnitude of current in the circuit, thereby changing the magnitude of tension of the motor, and meanwhile, the MOS transistor or the triode in the motor driving circuit can be prevented from being continuously in an amplification state.

The utility model discloses a motor drive circuit can be applied to among the pulling force control system, as the terminal drive circuit among this pulling force control system. Fig. 1 shows a possible application scenario of the tension control system, as shown in fig. 1, the scenario includes a tension control system 101 and an end device 102 thereof, the end device may include a handle portion of a tension trainer, so that a person 103 generates an outward force relative to the tension control system through the handle portion, and the tension control system 101 may generate a tension force in a direction opposite to that of the person 103, so as to replace the conventional tension force generated by the self-weight of a weight to complete tension training.

Fig. 2 is a schematic diagram of the tension control system, and as shown in fig. 2, the tension control system includes a controller 202, a motor driving circuit 203, and a motor 204. The controller 202 is in communication connection with the motor driving circuit 203, and the motor driving circuit 203 is in communication connection with the motor 204. The motor 204 may be connected to the end device shown in fig. 1, and when a person performs a tension training through the end device, the controller 202 causes the motor 204 to generate a force opposite to the tension of the person through the motor driving circuit 203, so as to complete the interaction with the person through the end device.

Optionally, the tension control system further includes: a computer device 201. The computer device 201 is in communication connection with the controller 202, the computer device 201 controls the motor driving circuit 203 through the controller 202, so that the motor 204 is controlled to generate pulling force, the generated pulling force is controlled, the pulling force control system completes interaction with a user through end equipment, and visual operation is performed on a software process in the controller through the computer device, so that the experience of human-computer interaction is improved.

Next, a motor drive circuit in the present embodiment will be specifically described.

Fig. 3 is a schematic structural diagram of a motor driving circuit provided in an embodiment of the present invention, as shown in fig. 3, the motor driving circuit includes: a first signal conversion module 301, a second signal conversion module 302 and a driving module 303.

Wherein the driving module 303 includes: a first switching unit Q1, a second switching unit Q2, a first bleeding unit D1, and a second bleeding unit D2.

The input end of the first signal conversion module 301 is configured to access a control signal sent by a controller, the output end of the first signal conversion module 301 is connected to the first end and the second end of the first switching unit Q1, the first end of the first bleeding unit D1 is connected to the third end of the first switching unit, the second end of the first bleeding unit D1 is connected to the third end of the second switching unit Q2, the second end of the second switching unit Q2 and the second end of the second bleeding unit D2 are grounded, the first end of the second bleeding unit D2 is connected to the first end of the first switching unit Q1, the first end of the second switching unit Q2 is connected to the output end of the second signal conversion module 302, and the input end of the second signal conversion module 302 is configured to access the control signal.

Optionally, the first switch unit Q1 and the second switch unit Q2 may be an I GBT, a MOS transistor or a triode, the first switch unit Q1 and the second switch unit Q2 may be the same components, or may be different components, for convenience of illustration, the first switch unit Q1 and the second switch unit Q2 both use a MOS transistor as an example.

For example, when the first switching unit Q1 and the second switching unit Q2 are MOS transistors, the first terminal of the first switching unit Q1 may be a source, the second terminal may be a gate, and the third terminal may be a drain; the first terminal of the second switching unit Q2 may be a gate, the second terminal may be a source, and the third terminal may be a drain.

Optionally, the first bleeding unit D1 and the second bleeding unit D2 in the embodiment of the present invention may also be the same or different components, and the first bleeding unit D1 and the second bleeding unit D2 may be insulated gate bipolar transistors, MOS transistors, triodes, or diodes, for example, the first bleeding unit D1 and the second bleeding unit D2 may both be diodes.

Optionally, the first signal conversion module 301 and the second signal conversion module 302 may be a driving chip or a push-pull driving circuit composed of two transistors.

In this embodiment, a PWM signal may be used as a control signal, and the purpose of controlling the current may be achieved by adjusting the PWM period and the PWM duty ratio, so that efficient control of the circuit may be achieved.

The first terminal of the first switching unit Q1 is also connected to one terminal of a driven motor, and the third terminal of the second switching unit Q2 is also connected to the other terminal of the motor.

Optionally, the motor may be connected between the source of the first switch unit Q1 and the drain of the second switch unit Q2 through interfaces M1 and M2, and the motor according to an embodiment of the present invention may be a dc motor.

For example, a voltage of 300V may be applied to the drain of the first switching unit Q1, and the source of the second switching unit Q2 may be grounded, so that a circuit is formed.

In the embodiment of the present invention, the PWM signal is inputted to the gate of the first switch unit Q1 in the driving module via the first signal conversion module 301, and the PWM signal is inputted to the gate of the second switch unit Q2 in the driving module via the second signal conversion module 302, the control signal inputted to the first signal conversion module controls the on-state of the first switch unit Q1, the control signal inputted to the second signal conversion module controls the on-state of the second switch unit Q2, the drain of the first switch unit Q1 is connected to the voltage, the source of the second switch unit Q2 is grounded, so that the driving circuit and the connected motor form a path.

The first and second switching units Q1 and Q2 are used to output current to the motor under the control of a control signal.

By adjusting the width of the PWM pulse of the control signal, the current in the circuit can be adjusted according to the formula of ampere force:

F＝BIL

wherein, F is the magnitude of the stress, I is the magnitude of the current, L is the length of the conducting wire, and B is the magnetic induction intensity, therefore, the force of the electrified conducting wire in the motor in the magnetic field is related to the magnitude of the current, so the magnitude of the current flowing through the motor can be adjusted by controlling the width of the PWM pulse, and the pulling force of the motor is controlled.

In a possible embodiment, when the pulse width of the input PWM signal is wider, the duty ratio is larger, the average voltage provided to the circuit is larger, and at this time, the first switch unit and the second switch unit in the motor driving circuit are turned on, and because the resistance value in the motor driving circuit is fixed, the current in the motor driving circuit is larger, and accordingly, the current flowing through the motor is larger, and therefore, the motor pull force is larger.

In another possible embodiment, when the pulse width of the input PWM signal is narrower, the duty ratio is smaller, the average voltage provided to the circuit is smaller, and at this time, the first switch unit and the second switch unit in the motor driving circuit are turned on, and because the resistance value in the motor driving circuit is constant, the current in the circuit is smaller, the motor pull force is smaller, and therefore, the adjustment of the motor pull force can be realized by adjusting the width of the PWM pulse signal.

It should be noted that, when no control signal is input, the first switch unit and the second switch unit are also in the off state, and no current passes through the motor, so that no pulling force is generated.

Optionally, the adjustment mode of the PWM pulse width may be implemented by a software process in the controller, which is not described herein again.

Optionally, the first and second bleeding units D1 and D2 are used to bleed off the charge generated by a person pulling on the motor.

The embodiment of the utility model provides an in, motor drive circuit includes first signal conversion module, second signal conversion module and drive module, can control switching on of first switch unit and second switch unit in the drive module through adjusting the PWM signal of following the input of first signal conversion module and second signal conversion module to switch on of control circuit, pulse width through adjusting the PWM signal of input can the size of control circuit internal current, thereby the pulling force size of control motor. With traditional weight can only add and subtract the control pulling force variation by one piece, pulse signal's width can more accurate control, consequently this embodiment can be through the width of the PWM signal of adjusting input motor drive circuit, realize the tensile stepless regulation of motor, thereby make tensile control more nimble, it is more convenient, compare with making MOS pipe be in amplified state control current size among the current drive circuit, the motor drive circuit's of this embodiment design has utilized switch element's conductivity, consequently, switch element in the circuit need not be in amplified state always, consequently, the loss of generating heat is little, the effective doing work of motor is more, the efficiency and the stability of circuit have been improved.

Fig. 4 is a schematic structural diagram of the motor driving circuit provided in this embodiment, and as shown in fig. 4, the driving module further includes a first protection unit R1. One end of the first protection unit R1 is connected to the output end of the first signal conversion module 301, and the other end of the first protection unit R1 is connected to the source of the first switch unit Q1.

Alternatively, the first protection unit R1 may be a resistor, a capacitor, or a transistor. In this embodiment, because the gate of the MOS transistor serving as the first switching unit Q1 has a characteristic of high input impedance, and a slight amount of static electricity or interference may cause the MOS transistor to be turned on by mistake, a protection unit is connected in parallel between the gate and the source of the MOS transistor Q1 to reduce the input impedance and prevent the MOS transistor from being turned on by mistake, for example, the first protection unit in this embodiment is a resistor R1.

With continued reference to fig. 4, the drive module further comprises: a second protection unit R2. One end of the second protection unit R2 is connected to the output end of the second signal conversion module 302, and the other end of the second protection unit R2 is connected to the source of the second switch unit Q2.

In this embodiment, the second protection unit R2 may also be a resistor, a capacitor or a transistor, because the gate of the MOS transistor as the second switching unit Q2 has a characteristic of high input impedance, and a slight amount of static electricity or interference may cause the MOS transistor to be turned on by mistake, so that a second protection unit is connected in parallel between the gate and the source of the MOS transistor Q1 to reduce the input impedance, thereby preventing the MOS transistor from being turned on by mistake, and exemplarily, a protection resistor R2 may be connected in parallel between two ends of the MOS transistor Q2 to reduce the input impedance, thereby preventing the MOS transistor from being turned on by mistake. Illustratively, a protection resistor R2 may be connected in parallel to two ends of the MOS transistor Q2 to reduce the input impedance, thereby preventing the mis-conduction of the MOS transistor.

In this embodiment, through setting up first protection unit R1 and second protection unit R2, can effectual reduction input impedance, prevent the misleading of MOS pipe, promote the stability of circuit.

With continued reference to fig. 4, the motor drive circuit of the present embodiment further includes a third protection unit R3.

One end of the third protection unit R3 is connected to the output end of the first signal conversion module 301, and the other end of the third protection unit R3 is connected to the gate of the first switching unit Q1 and one end of the first protection unit Q1.

Alternatively, the third protection unit R3 may be a resistor, a capacitor, or a transistor. In the motor driving circuit, since the driving circuit has parasitic inductance due to the routing, and the parasitic inductance and the junction capacitance of the MOS transistor form an LC oscillating circuit, if the output end of the first conversion module is directly connected to the gate of the MOS transistor, a large oscillation may be generated at the rising and falling edges of the PWM signal wave, which may cause the MOS transistor to generate heat rapidly or even explode, and affect the safety and stability of the circuit, therefore, the third protection unit R3 is disposed on the gate in this embodiment, which may reduce the Q value of the LC oscillating circuit, so that the oscillation may be attenuated rapidly, thereby protecting the MOS transistor better, exemplarily, the third protection unit R3 may be a resistor.

As shown in fig. 4, the motor drive circuit further includes: a fourth protection unit R4. One end of the fourth protection unit R4 is connected to the output end of the second signal conversion module 302, and the other end of the fourth protection unit R4 is connected to the first end of the second switch unit Q2 and one end of the second protection unit R2.

Optionally, the fourth protection unit R4 may be a resistor, a capacitor, or a transistor. Since the driving circuit has parasitic inductance in the trace and the parasitic inductance and junction capacitance of the MOS transistor form an LC oscillating circuit, if the output terminal of the second converting module is directly connected to the gate of the MOS transistor, a large oscillation may be generated at the rising and falling edges of the PWM signal wave, which may cause the MOS transistor to generate heat or even explode rapidly, which may affect the safety and stability of the circuit, for example, a resistor R4 may be connected in series between the gate of the second switching unit Q2 and the second signal converting module 302, which may prevent the MOS transistor from generating heat or even explode rapidly due to the oscillation generated at the rising and falling edges of the PWM signal wave.

In the embodiment of the application, the third protection unit R3 and the fourth protection unit R4 are arranged, so that the oscillation generated by the rising and falling edges of the PWM wave can be quickly attenuated, the MOS transistor can be better protected, and the stability and the safety of the circuit can be improved.

Fig. 5 is a schematic structural diagram of a possible first signal conversion module 301 according to this embodiment. As shown in fig. 5, the first signal conversion module 301 includes: a first chip.

The first pin a1 of the first chip is used for accessing a control signal, the second pin a2 and the third pin A3 of the first chip are connected with one end of the third protection unit, and the fourth pin a4 of the first chip is connected with the source of the first switch unit.

For example, the fifth pin of the first chip may be connected to a voltage of 15V, and the sixth pin may also be connected to a voltage of 5V, so that the chip operates normally.

Optionally, the first chip may be an MOS driver chip, and the driving capability may be enhanced by the MOS driver chip, and the stability of the circuit is improved.

Fig. 6 is a schematic structural diagram of a possible second conversion module provided in this embodiment. As shown in fig. 6, the second signal conversion module 302 includes: a third switching unit Q3 and a fourth switching unit Q4.

A first terminal of the third switching unit Q3 is used for receiving a control signal, a second terminal of the third switching unit Q3 is used for receiving a supply voltage, and a third terminal of the third switching unit Q3 is connected with one terminal of the fourth protection unit R4.

The first end of the fourth switching unit Q4 is used for accessing a control signal, the second end of the fourth switching unit Q4 is connected with one end of the fourth protection unit R4, and the third end of the fourth switching unit Q4 is grounded.

Optionally, the third switching unit Q3 and the fourth switching unit Q4 may be transistors, and the third switching unit Q3 and the fourth switching unit Q4 may form a push-pull driving circuit, and when the circuit operates, only one of the two symmetrical power switching tubes is turned on at a time.

Illustratively, when the input signal is at a high level, the third switching unit Q3 is turned on, while the fourth switching unit Q4 is turned off, so the output signal is at a high level; when the input signal is at a low level, the third switching unit Q3 is turned off, and the fourth switching unit Q4 is turned on, so that the output signal is at a low level. Therefore, only one of the two switch units is always conducted when the circuit works, so that the conduction loss is small and the efficiency is high.

Push-pull output in this embodiment both can infuse the electric current to the load, also can follow the load and draw current, through setting up the push-pull drive circuit that two triodes are constituteed, can promote the electric current and provide the ability, accomplish the charging process to the MOS pipe grid input capacitance charge of second switch unit rapidly, this kind of topology has increased the required time of switching on, but has reduced the turn-off time, and the switch tube can be opened fast and avoid the high frequency oscillation of rising edge.

In the embodiment of the application, the push-pull circuit formed by the first chip and the third and fourth switching units Q3 and Q4 can effectively improve the driving capability of the circuit and improve the stability of the circuit.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor drive circuit, comprising: first signal conversion module, second signal conversion module and drive module, drive module includes: the first switch unit, the second switch unit, the first bleeder unit and the second bleeder unit;

2. The motor drive circuit of claim 1, wherein the drive module further comprises: a first protection unit;

3. The motor drive circuit of claim 2, wherein the drive module further comprises: a second protection unit;

4. The motor drive circuit of claim 3, further comprising: a third protection unit;

5. The motor drive circuit according to claim 4, further comprising: a fourth protection unit;

6. The motor drive circuit of claim 5 wherein the first signal conversion module comprises: a first chip;

7. The motor drive circuit of claim 6 wherein the second signal conversion module comprises: a third switching unit and a fourth switching unit;

8. The motor drive circuit according to claim 7, wherein the third switching unit and the fourth switching unit are each a triode.

9. The motor drive circuit according to claim 1, wherein the first switching unit and the second switching unit are each a metal oxide semiconductor type field effect transistor.

10. A tension control system, comprising: a controller, a motor, and a motor drive circuit of any of claims 1-9;