CN217956681U - Motor forward and reverse rotation protection circuit - Google Patents

Abstract

The utility model provides a motor is protection circuit just reversing, include: the device comprises a first signal input unit, an H bridge, a second signal input unit, a current protection unit and a voltage protection unit; when a corotation signal is sent to the first signal input unit and the second signal input unit through an external signal source, the received corotation signal or a reverse rotation signal is sent to the H bridge through the first signal input unit and the second signal input unit, the H bridge corotation or reverse rotation is carried out according to the corotation signal or the reverse rotation signal, when the motor stops rotating, the current is prevented from being overlarge through the current protection unit, the overcurrent protection of the H bridge is realized, when the motor generates overvoltage, the overhigh voltage of the H bridge is prevented through the voltage protection unit, the overvoltage protection of the H bridge is realized, and the problem that when the motor in the prior art generates overcurrent or overvoltage, the motor or an MOS tube is damaged is solved.

Description

Motor forward and reverse rotation protection circuit

Technical Field

The utility model relates to a motor control technical field especially relates to a motor is protection circuit just reversing.

Background

In the prior art, the positive and negative rotation of a motor needs to be controlled to drive a corresponding load to perform positive and negative conversion work. The Chinese patent document number is CN205336166U, the application date is 2016.06.22, and the patent names are as follows: the utility model provides a can give novel direct current motor drive control circuit of MOS pipe, the technical scheme who adopts is "there is two passageway push-pull power amplifier circuit that 4 MOSFETs constitute, through controlling 4 MOSFETs, MOSFET1 promptly, MOSFET2, MOSFET3, MOSFET4 switch on and cut off, come corotation, reversal and the stop of control motor: when the MOSFET1 and the MOSFET4 are switched on and the MOSFET2 and the MOSFET3 are switched off, the motor rotates forwards; when the MOSFET1 and the MOSFET4 are turned off and the MOSFET2 and the MOSFET3 are turned on, the motor rotates reversely; when both the MOSFET3 and the MOSFET4 are turned off, the motor is stopped; the MOSFET1 and the MOSFET2 are P channels; MOSFET3 and MOSFET4 are N-channels; the N-type MOS tube and the P-type MOS tube form an H-bridge driving circuit. "

In the scheme, when overcurrent or overvoltage occurs to the motor, the motor or the MOS tube is damaged.

SUMMERY OF THE UTILITY MODEL

Not enough to exist among the prior art, the utility model provides a motor is protection circuit just reversing, when overcurrent or overvoltage appear in its motor of having solved existence among the prior art, will make the problem that motor or MOS pipe damaged.

A motor forward and reverse rotation protection circuit, the circuit comprising: the device comprises a first signal input unit, an H bridge, a second signal input unit, a current protection unit and a voltage protection unit; the input end of the first signal input unit and the input end of the second signal input unit are respectively connected with an external signal source and used for receiving a forward rotation signal or a reverse rotation signal sent by the external signal source; the input end of the H bridge is respectively connected with the output end of the first signal input unit and the output end of the second signal, the first output end of the H bridge is connected with the first end of the motor, the second output end of the H bridge is connected with the second end of the motor, and the H bridge is used for carrying out forward rotation according to the received forward rotation signal and carrying out reverse rotation according to the received reverse rotation signal; the first end of the current protection unit is connected with the first output end of the H bridge, and the second end of the current protection unit is connected with the second output end of the H bridge, so that the generated current is prevented from being overlarge when the motor stops rotating; the first end of the voltage protection unit is connected with the first output end of the H bridge, and the second end of the voltage protection unit is connected with the second output end of the H bridge, so that the voltage of the H bridge is prevented from being too high.

Optionally, the first signal input unit includes: the circuit comprises a first resistor, a first MOS (metal oxide semiconductor) tube, a second resistor and a second MOS tube; the first end of the first resistor is respectively connected with the external signal source and the second signal input unit, and the second end of the first resistor is grounded; the grid electrode of the first MOS tube is connected with the second signal input unit, the drain electrode of the first MOS tube is connected with the external signal source, and the source electrode of the first MOS tube is connected with the grid electrode of the second MOS tube; the drain electrode of the second MOS tube is connected with the input end of the H bridge, and the source electrode of the second MOS tube is grounded; and two ends of the second resistor are respectively connected with the grid electrode and the source electrode of the second MOS tube.

Optionally, the second signal input unit protects: the MOS transistor comprises a third resistor, a third MOS transistor, a fourth MOS transistor and a fourth resistor; the first end of the third resistor is respectively connected with the external signal source and the first signal input unit, and the second end of the third resistor is grounded; the grid electrode of the third MOS tube is connected with the first signal input unit, the drain electrode of the third MOS tube is connected with the external signal source, and the source electrode of the third MOS tube is connected with the grid electrode of the fourth MOS tube; the drain electrode of the fourth MOS tube is connected with the input end of the H bridge, and the source electrode of the fourth MOS tube is grounded; and two ends of the fourth resistor are respectively connected with the grid electrode and the source electrode of the fourth MOS tube.

Optionally, the H-bridge unit comprises: the fifth resistor, the sixth resistor, the fifth MOS tube, the sixth MOS tube, the seventh MOS tube and the eighth MOS tube; a grid electrode of the fifth MOS tube is connected with the input end of the first signal input unit, a drain electrode of the fifth MOS tube is connected with a first power supply end, and a source electrode of the fifth MOS tube is respectively connected with a first end of the motor and a drain electrode of the sixth MOS tube; two ends of the fifth resistor are respectively connected with the grid electrode and the drain electrode; the grid electrode of the sixth MOS tube is connected with the second signal input unit, and the source electrode of the sixth MOS tube is grounded; the grid electrode of the seventh MOS tube is connected with the input end of the second signal unit, the drain electrode of the seventh MOS tube is connected with a first power supply end, and the source electrode of the seventh MOS tube is connected with the drain electrode of the eighth MOS tube; two ends of the sixth resistor are respectively connected with the grid electrode and the source electrode of the seventh MOS tube; and the grid electrode of the eighth MOS tube is connected with the first signal input unit, and the source electrode of the eighth MOS tube is grounded.

Optionally, the current protection unit includes: the seventh resistor, the first diode and the second diode; the first end of the seventh resistor is connected with the first end of the motor, and the second end of the seventh resistor is respectively connected with the anode of the first diode and the cathode of the second diode; and the cathode of the first diode is connected with the second end of the motor, and the anode of the first diode is connected with the second end of the motor.

Optionally, the voltage protection unit is a bidirectional voltage regulator tube; and two ends of the bidirectional voltage-stabilizing tube are respectively connected with the first end and the second end of the motor.

Optionally, the circuit further comprises: the motor rotating speed control unit is connected with the motor and used for controlling the rotating speed of the motor; the motor rotation speed control unit includes: the device comprises an eighth resistor, a variable resistor, a tenth resistor, a ninth MOS (metal oxide semiconductor) transistor, an eleventh resistor and a third diode; the first end of the eighth resistor is connected with the first power supply end, and the second end of the eighth resistor is connected with the first end of the variable resistor; the second end of the variable resistor is grounded, the control end of the variable resistor is connected with the first end of the variable resistor, and the control end of the variable resistor is also connected with the grid electrode of the eighth MOS transistor; the drain electrode of the ninth MOS tube is connected with the anode of the first diode, and the source electrode of the ninth MOS tube is grounded through an eleventh resistor; two ends of the tenth resistor are respectively connected with the grid electrode and the source electrode of the ninth MOS tube; the cathode of the third diode is connected with the first power supply end; and the first end of the motor is connected with the first power supply end, and the second end of the motor is connected with the drain electrode of the ninth MOS tube.

Optionally, the circuit further comprises: the power supply unit is connected with the H bridge and is used for providing working electric energy for the H bridge; the power supply unit includes: the power supply comprises a fuse, a twelfth resistor, a voltage stabilizing source, a first capacitor, a thirteenth resistor, a fourteenth resistor, an operational amplifier, a fifteenth resistor, a sixteenth resistor, a tenth MOS (metal oxide semiconductor) transistor and an eleventh MOS transistor; the first end of the fuse is connected with the anode of an external power supply, and the second end of the fuse is connected with the drain electrode of the tenth MOS tube; the first end of the twelfth resistor is connected with the second end of the fuse, and the second end of the twelfth resistor is connected with the first end of the voltage stabilizing source; the second end of the voltage-stabilizing source is connected with the negative electrode of an external power supply, and the third end of the voltage-stabilizing source is connected with the first end of the voltage-stabilizing source; two ends of the first capacitor are connected with the first end and the second end of the voltage stabilizing source; a first end of the thirteenth resistor is connected with a second end of the fuse, and a second end of the thirteenth resistor is connected with a first end of the fourteenth resistor; a second end of the fourteenth resistor is grounded; the non-inverting input end of the operational amplifier is connected with the first end of the voltage stabilizing source, the inverting input end of the operational amplifier is connected with the inverting input end of the voltage stabilizing source, and the power supply ends of the operational amplifier are respectively connected with the anode and the cathode of the external power supply; a grid electrode of the tenth MOS tube is connected with a drain electrode of the eleventh MOS tube, and a source electrode of the tenth MOS tube is connected with the H bridge; two ends of the fifteenth resistor are respectively connected with the drain electrode and the grid electrode of the tenth MOS tube; the grid electrode of the eleventh MOS tube is connected with the output end of the operational amplifier through the sixteen resistors, and the source electrode of the eleventh MOS tube is grounded.

Optionally, the power supply unit further comprises: a seventeenth resistor and a light emitting diode; a first end of the seventeenth resistor is connected with a source electrode of the tenth MOS transistor, and a second end of the seventeenth resistor is connected with an anode of the light emitting diode; and the cathode of the light-emitting diode is grounded.

Optionally, the power supply unit further comprises: a fifth diode; and the cathode of the fifth diode is connected with the second end of the fuse, and the anode of the fifth diode is connected with the cathode of the external power supply.

Compared with the prior art, the utility model discloses following beneficial effect has:

when an external signal source sends forward rotation signals to the first signal input unit and the second signal input unit, the received forward rotation signals or reverse rotation signals are sent to the H bridge through the first signal input unit and the second signal input unit, the H bridge forwards or reversely rotates according to the forward rotation signals or the reverse rotation signals, when the motor stops rotating, the current is prevented from being too large through the current protection unit, overcurrent protection on the H bridge is achieved, when the motor generates overvoltage, the voltage protection on the H bridge is achieved, and the problem that the motor or an MOS (metal oxide semiconductor) transistor is damaged when the motor generates overcurrent or overvoltage in the prior art is solved.

Drawings

Fig. 1 is a structural diagram of a forward and reverse rotation protection circuit of a motor according to an embodiment of the present invention;

fig. 2 is a circuit diagram of a forward and reverse rotation protection circuit of a motor according to an embodiment of the present invention;

fig. 3 is a circuit diagram of a motor rotation speed unit according to an embodiment of the present invention;

fig. 4 is a circuit diagram of a power supply unit according to an embodiment of the present invention.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

Fig. 1 is a structure diagram of a forward and reverse rotation protection circuit of a motor M provided in an embodiment of the present invention, as shown in fig. 1, the circuit includes: a first signal input unit 100, an H-bridge 300, a second signal input unit 200, a current protection unit, and a voltage protection unit 400;

the input end of the first signal input unit 100 and the input end of the second signal input unit 200 are respectively connected to an external signal source, and are configured to receive a forward rotation signal or a reverse rotation signal sent by the external signal source;

an input end of the H-bridge 300 is connected to an output end of the first signal input unit 100 and an output end of the second signal, respectively, a first output end of the H-bridge 300 is connected to a first end of the motor M, and a second output end of the H-bridge 300 is connected to a second end of the motor M, and is configured to perform forward rotation according to the received forward rotation signal and perform reverse rotation according to the received reverse rotation signal;

a first end of the current protection unit is connected with a first output end of the H-bridge 300, and a second end of the current protection unit is connected with a second output end of the H-bridge 300, so as to prevent the generated current from being too large when the motor M stops rotating;

a first end of the voltage protection unit 400 is connected to the first output end of the H-bridge 300, and a second end of the voltage protection unit 400 is connected to the second output end of the H-bridge 300, so as to prevent the voltage of the H-bridge 300 from being too high.

In this embodiment, when an external signal source sends a forward rotation signal to the first signal input unit 100 and the second signal input unit 200, the first signal input unit 100 and the second signal input unit 200 send the received forward rotation signal or reverse rotation signal to the H bridge 300, the H bridge 300 performs forward rotation or reverse rotation according to the forward rotation signal or reverse rotation signal, when the motor M stops rotating, the current protection unit prevents the current from being too large, so as to implement overcurrent protection on the H bridge 300, and when the motor M generates an overvoltage, the voltage protection unit 400 prevents the voltage of the H bridge 300 from being too high, so as to implement overvoltage protection on the H bridge 300.

Fig. 2 is a circuit diagram of a forward and reverse rotation protection circuit of a motor M according to an embodiment of the present invention, as shown in fig. 2, the first signal input unit 100 includes: the device comprises a first resistor R1, a first MOS transistor Q1, a second resistor R2 and a second MOS transistor Q2; a first end of the first resistor R1 is connected to the external signal source and the second signal input unit 200, respectively, and a second end of the first resistor R1 is grounded; the gate of the first MOS transistor Q1 is connected to the second signal input unit 200, the drain of the first MOS transistor Q1 is connected to the external signal source, and the source of the first MOS transistor Q1 is connected to the gate of the second MOS transistor Q2; the drain electrode of the second MOS transistor Q2 is connected to the input end of the H-bridge 300, and the source electrode of the second MOS transistor Q2 is grounded; and two ends of the second resistor R2 are respectively connected with the grid electrode and the source electrode of the second MOS transistor Q2.

In this embodiment, when performing forward rotation, the external signal source sends a forward rotation signal to the first signal input unit 100 and the second signal input unit 200, that is, the first signal unit receives a high level signal, the drain of the first MOS transistor Q1 receives a high level signal, the gate of the first MOS transistor Q1 receives a low level signal to be turned on, and outputs a high level signal to the H-bridge 300, so that the gate of the second MOS transistor Q2 receives a high level signal and outputs a low level signal to the H-bridge 300. When inversion is performed, an external signal source sends an inversion signal to the first signal input unit 100 and the second signal input unit 200, that is, the first signal input unit 100 receives a low-level signal, the drain of the first MOS transistor Q1 receives the low-level signal, the gate of the first MOS transistor Q1 receives a high-level signal through the second signal input unit 200, the first MOS transistor Q1 is turned off, and a low-level signal is sent to the H-bridge 300; the grid electrode of the second MOS tube Q2 also receives a low level signal sent by the first MOS tube Q1, and the second MOS tube Q2 is cut off; the H-bridge 300 receives a high level signal.

As shown in fig. 2, the second signal input unit 200 protects: a third resistor R3, a third MOS transistor Q3, a fourth MOS transistor Q4 and a fourth resistor R4; a first end of the third resistor R3 is connected to the external signal source and the first signal input unit 100, respectively, and a second end of the third resistor R3 is grounded; a gate of the third MOS transistor Q3 is connected to the first signal input unit 100, a drain of the third MOS transistor Q3 is connected to the external signal source, and a source of the third MOS transistor Q3 is connected to a gate of the fourth MOS transistor Q4; the drain electrode of the fourth MOS transistor Q4 is connected to the input end of the H-bridge 300, and the source electrode of the fourth MOS transistor Q4 is grounded; and two ends of the fourth resistor R4 are respectively connected with the grid electrode and the source electrode of the fourth MOS transistor Q4.

In this embodiment, when the forward rotation is performed, the external signal source sends a forward rotation signal to the first signal input unit 100 and the second signal input unit 200, that is, the gate of the third MOS transistor Q3 receives a high level signal, the drain of the third MOS transistor Q3 receives a low level signal, the third MOS transistor Q3 is turned off, and outputs a low level signal to the H-bridge 300, the gate of the fourth MOS transistor Q4 also receives a low level signal, the fourth MOS transistor Q4 is turned off, and the input of the H-bridge 300 receives a high level signal. When the inversion is performed, an external signal source sends an inversion signal to the first signal input unit 100 and the second signal input unit 200, a drain of the third MOS transistor Q3 receives a high level signal, a gate of the third MOS transistor Q3 receives a low level signal, the third MOS transistor Q3 is turned on and outputs a high level signal to the H-bridge 300, a gate of the fourth MOS transistor Q4 also receives a low level signal, and the third MOS transistor Q3 is turned on and sends a low level signal to the H-bridge 300.

As shown in fig. 2, the H-bridge 300 unit includes: a fifth resistor R5, a sixth resistor R6, a fifth MOS transistor Q5, a sixth MOS transistor Q6, a seventh MOS transistor Q7 and an eighth MOS transistor Q8; a gate of the fifth MOS transistor Q5 is connected to the input terminal of the first signal input unit 100, a drain of the fifth MOS transistor Q5 is connected to a first power supply terminal VCC, and a source of the fifth MOS transistor Q5 is connected to the first end of the motor M and the drain of the sixth MOS transistor Q6, respectively; two ends of the fifth resistor R5 are respectively connected with the grid electrode and the drain electrode; the gate of the sixth MOS transistor Q6 is connected to the second signal input unit 200, and the source of the sixth MOS transistor Q6 is grounded; the gate of the seventh MOS transistor Q7 is connected to the input terminal of the second signal unit, the drain of the seventh MOS transistor Q7 is connected to the first power supply terminal VCC, and the source of the seventh MOS transistor Q7 is connected to the drain of the eighth MOS transistor Q8; two ends of the sixth resistor R6 are respectively connected with the grid electrode and the source electrode of the seventh MOS transistor Q7; the gate of the eighth MOS transistor Q8 is connected to the first signal input unit 100, and the source of the eighth MOS transistor Q8 is grounded.

In this embodiment, when the forward rotation is performed, the gate of the fifth MOS transistor Q5 receives a low-level signal, and the fifth MOS transistor Q5 is turned on; the grid electrode of the sixth MOS transistor Q6 receives the low level signal, and the sixth MOS transistor Q6 is cut off; the grid electrode of the seventh MSO tube receives the high level signal, and the seventh MOS tube Q7 is cut off; the grid electrode of the eighth MOS transistor Q8 receives the high-level signal, and the eighth MOS transistor Q8 is cut off; therefore, the current generated by the first current end flows through the fifth MOS tube Q5, the motor M and the eighth MOS tube Q8, and the forward rotation control of the motor M is realized. When the inversion is carried out, the grid electrode of the fifth triode receives a high-level signal, and the fifth MSOS tube is cut off; the grid electrode of the sixth MOS transistor Q6 receives the high-level signal, and the sixth MOS transistor Q6 is conducted; the grid electrode of the seventh MOS transistor Q7 receives the low level signal, and the seventh MOS transistor Q7 is conducted; the gate of the eighth MOS transistor Q8 receives the low level signal, and the eighth MOS transistor Q8 is turned off, so that the current generated by the first power supply terminal VCC controls the reverse rotation of the motor M from the seventh MOS transistor Q7, the motor M, and the sixth MOS transistor Q6.

As shown in fig. 2, the current protection unit includes: a seventh resistor R7, a first diode D1 and a second diode D2; a first end of the seventh resistor R7 is connected to a first end of the motor M, and a second end of the seventh resistor R7 is connected to an anode of the first diode D1 and a cathode of the second diode D2, respectively; the negative electrode of the first diode D1 is connected with the second end of the motor M, and the positive electrode of the first diode D1 is connected with the second end of the motor M.

In this embodiment, a follow current may occur when the motor M stops rotating, and an excessive follow current may cause overheating of the motor M, so that the motor M may age, the life of the motor M may be reduced, and an excessive current may be prevented from flowing into the H-bridge 300 to damage the MOS transistor; when the forward rotation is stopped, the motor M generates a follow current, the follow current flows through the first diode D1 and the seventh resistor R7, and the follow current is continued; when the reverse-reverse stop is performed, the freewheeling current flows through the seventh resistor R7 and the second diode D2, and the heat is prevented from being generated.

As shown in fig. 2, the voltage protection unit 400 is a bidirectional voltage regulator tube V1; and two ends of the bidirectional voltage-stabilizing tube V1 are respectively connected with the first end and the second end of the motor M.

In the embodiment, when the voltage across the motor M is too high, the voltage is stabilized at the rated value by the bidirectional regulator V1, and the MOS transistors in the H-bridge 300 are prevented from being damaged by the too high voltage.

The circuit also comprises a motor M rotating speed control unit, wherein the motor M rotating speed control unit is connected with the motor M and is used for controlling the rotating speed of the motor M; fig. 3 is a circuit diagram of a motor M rotation speed unit provided by an embodiment of the present invention, as shown in fig. 3, the motor M rotation speed control unit includes: an eighth resistor R8, a variable resistor R9, a tenth resistor R10, a ninth MOS transistor Q9, an eleventh resistor R11 and a third diode D3; a first end of the eighth resistor R8 is connected to a first power supply terminal VCC, and a second end of the eighth resistor R8 is connected to a first end of the variable resistor R9; the second end of the variable resistor R9 is grounded, the control end of the variable resistor R9 is connected to the first end of the variable resistor R9, and the control end of the variable resistor R9 is further connected to the gate of the ninth MOS transistor Q9; the drain of the ninth MOS transistor Q9 is connected to the anode of the third diode D3, and the source of the ninth MOS transistor Q9 is grounded through an eleventh resistor R11; two ends of the tenth resistor R10 are connected to the gate and the source of the ninth MOS transistor Q9, respectively; the cathode of the third diode D3 is connected with the first power supply end VCC; the first end of the motor M is connected with the first power supply end VCC, and the second end of the motor M is connected with the drain electrode of the ninth MOS transistor Q9.

In this embodiment, when the rotation speed of the motor M needs to be adjusted, the gate voltage of the ninth MOS transistor Q9 is changed by controlling the variable resistor R9, and when the gate voltage of the ninth MOS transistor Q9 is changed, the source current of the ninth MOS transistor Q9 is changed accordingly, so as to control the operating current of the motor M, thereby adjusting the rotation speed of the motor M.

The circuit further comprises: a power supply unit connected to the H-bridge 300, for supplying operating power to the H-bridge 300;

fig. 4 is a circuit diagram of a power supply unit provided by an embodiment of the present invention, as shown in fig. 4, the power supply unit includes: the circuit comprises a fuse F1, a twelfth resistor R12, a voltage stabilizing source U1, a first capacitor C1, a thirteenth resistor R13, a fourteenth resistor R14, an operational amplifier U2, a thirteenth resistor R13, a sixteenth resistor R16, a tenth MOS tube Q10 and an eleventh MOS tube Q11; a first end of the fuse F1 is connected with the anode of an external power supply, and a second end of the fuse F1 is connected with the drain electrode of the tenth MOS tube Q10; a first end of the twelfth resistor R12 is connected with a second end of the fuse F1, and a second end of the twelfth resistor R12 is connected with a first end of the voltage regulator U1; the second end of the voltage-stabilizing source U1 is connected with the negative electrode of an external power supply, and the third end of the voltage-stabilizing source U1 is connected with the first end of the voltage-stabilizing source U1; two ends of the first capacitor C1 are connected with the first end and the second end of the voltage-stabilizing source U1; a first end of the thirteenth resistor R13 is connected to the second end of the fuse F1, and a second end of the thirteenth resistor R13 is connected to a first end of the fourteenth resistor R14; a second end of the fourteenth resistor R14 is grounded; the non-inverting input end of the operational amplifier U2 is connected with the first end of the voltage stabilizing source U1, the inverting input end of the operational amplifier U2 is connected with the inverting input end of the voltage stabilizing source U1, and the power supply ends of the operational amplifier U2 are respectively connected with the anode and the cathode of the external power supply; the gate of the tenth MOS transistor Q10 is connected to the drain of the eleventh MOS transistor Q11, and the source of the tenth MOS transistor Q10 is connected to the H-bridge 300; two ends of the thirteenth resistor R13 are connected to the drain and the gate of the tenth MOS transistor Q10, respectively; the grid electrode of the eleventh MOS tube Q11 is connected with the output end of the operational amplifier U2 through the sixteen resistors, and the source electrode of the eleventh MOS tube Q11 is grounded.

In the present embodiment, the fuse F1 is used to be blown when an overcurrent is generated, thereby preventing the current from continuing to increase to damage the circuit; the voltage stabilizing source U1 maintains the voltage at the positive input terminal of the operational amplifier U2 at a rated value, which may be 2.5V; when the external power supply voltage is normal, the voltage of the inverting input terminal of the operational amplifier U2 is lower than that of the non-inverting input terminal, the output terminal of the operational amplifier U2 outputs a high level, the gate of the eleventh MOS transistor Q11 receives a high level signal, the eleventh MOS transistor Q11 is turned on, the gate of the tenth MOS transistor Q10 receives a low level voltage, and the tenth MOS transistor Q10 is turned on, so that the external power supply provides a working voltage to the H bridge 300; when the external power supply voltage is too high, the voltage of the inverting input end of the operational amplifier U2 is higher than the voltage of the non-inverting input end, the output end of the operational amplifier U2 outputs a low level, the gate of the eleventh MOS transistor Q11 receives a low level signal, the eleventh MOS transistor Q11 is turned off, the gate voltage of the tenth MOS transistor Q10 is equal to the external power supply voltage, and the tenth MOS transistor Q10 is turned off, so that the supply of electric energy to the H-bridge 300 is stopped, and the overvoltage protection of the power supply voltage of the motor M is realized. It should be noted that the required power supply range of the motor M may be 3-6V. The source of the tenth MOS transistor Q10 serves as the first power supply terminal VCC.

In another embodiment of the present invention, as shown in fig. 4, the power supply unit further includes: a seventeenth resistor R17 and a light emitting diode D4; a first end of the seventeenth resistor R17 is connected to the source of the tenth MOS transistor Q10, and a second end of the seventeenth resistor R17 is connected to the anode of the light emitting diode D4; the cathode of the light emitting diode D4 is grounded.

In this embodiment, when the power supply unit supplies power to the H-bridge 300, the light emitting diode D4 also receives the working voltage to emit light, thereby indicating that the power supply unit is supplying power normally; when the power supply unit stops supplying power to the H-bridge 300, the light emitting diode D4 also receives the operating voltage, and the light emitting diode D4 is turned off.

In another embodiment of the present invention, as shown in fig. 4, the power supply unit further includes: a fifth diode D5; and the cathode of the fifth diode D5 is connected with the second end of the fuse F1, and the anode of the fifth diode D5 is connected with the cathode of the external power supply.

In the present embodiment, the fifth diode D5 is used to prevent the reverse connection of the protection circuit. It should be noted that the power supply unit further includes: the third capacitor C3 and the fourth capacitor C4, and the third capacitor C3 and the fourth capacitor C4 are used for filtering the voltage provided by the power supply unit to the H-bridge 300, so that the operating voltage of the H-bridge 300 is more stable.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or replaced by other means without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims.

Claims (10)

1. The utility model provides a motor is protection circuit just reversing, its characterized in that, the circuit includes: the device comprises a first signal input unit, an H bridge, a second signal input unit, a current protection unit and a voltage protection unit;

the input end of the first signal input unit and the input end of the second signal input unit are respectively connected with an external signal source and used for receiving a forward rotation signal or a reverse rotation signal sent by the external signal source;

the input end of the H bridge is respectively connected with the output end of the first signal input unit and the output end of the second signal, the first output end of the H bridge is connected with the first end of the motor, the second output end of the H bridge is connected with the second end of the motor, and the H bridge is used for carrying out forward rotation according to the received forward rotation signal and carrying out reverse rotation according to the received reverse rotation signal;

the first end of the current protection unit is connected with the first output end of the H bridge, and the second end of the current protection unit is connected with the second output end of the H bridge, so that the generated current is prevented from being overlarge when the motor stops rotating;

the first end of the voltage protection unit is connected with the first output end of the H bridge, and the second end of the voltage protection unit is connected with the second output end of the H bridge, so that the voltage of the H bridge is prevented from being too high.

2. The motor forward-reverse rotation protection circuit according to claim 1, wherein the first signal input unit comprises: the circuit comprises a first resistor, a first MOS (metal oxide semiconductor) tube, a second resistor and a second MOS tube;

the first end of the first resistor is respectively connected with the external signal source and the second signal input unit, and the second end of the first resistor is grounded;

the grid electrode of the first MOS tube is connected with the second signal input unit, the drain electrode of the first MOS tube is connected with the external signal source, and the source electrode of the first MOS tube is connected with the grid electrode of the second MOS tube;

the drain electrode of the second MOS tube is connected with the input end of the H bridge, and the source electrode of the second MOS tube is grounded;

and two ends of the second resistor are respectively connected with the grid electrode and the source electrode of the second MOS tube.

3. The motor forward-reverse rotation protection circuit according to claim 1, wherein the second signal input unit protects: the third resistor, the third MOS tube, the fourth MOS tube and the fourth resistor;

the first end of the third resistor is respectively connected with the external signal source and the first signal input unit, and the second end of the third resistor is grounded;

the grid electrode of the third MOS tube is connected with the first signal input unit, the drain electrode of the third MOS tube is connected with the external signal source, and the source electrode of the third MOS tube is connected with the grid electrode of the fourth MOS tube;

the drain electrode of the fourth MOS tube is connected with the input end of the H bridge, and the source electrode of the fourth MOS tube is grounded;

and two ends of the fourth resistor are respectively connected with the grid electrode and the source electrode of the fourth MOS tube.

4. The motor forward and reverse rotation protection circuit according to claim 1, wherein the H-bridge unit comprises: the fifth resistor, the sixth resistor, the fifth MOS tube, the sixth MOS tube, the seventh MOS tube and the eighth MOS tube;

the grid electrode of the fifth MOS tube is connected with the input end of the first signal input unit, the drain electrode of the fifth MOS tube is connected with a first power supply end, and the source electrode of the fifth MOS tube is respectively connected with the first end of the motor and the drain electrode of the sixth MOS tube;

two ends of the fifth resistor are respectively connected with the grid electrode and the drain electrode;

the grid electrode of the sixth MOS tube is connected with the second signal input unit, and the source electrode of the sixth MOS tube is grounded;

the grid electrode of the seventh MOS tube is connected with the input end of the second signal unit, the drain electrode of the seventh MOS tube is connected with a first power supply end, and the source electrode of the seventh MOS tube is connected with the drain electrode of the eighth MOS tube;

two ends of the sixth resistor are respectively connected with the grid electrode and the source electrode of the seventh MOS tube;

and the grid electrode of the eighth MOS tube is connected with the first signal input unit, and the source electrode of the eighth MOS tube is grounded.

5. The motor forward and reverse rotation protection circuit according to claim 4, wherein the current protection unit comprises: a seventh resistor, a first diode and a second diode;

the first end of the seventh resistor is connected with the first end of the motor, and the second end of the seventh resistor is respectively connected with the anode of the first diode and the cathode of the second diode;

and the cathode of the first diode is connected with the second end of the motor, and the anode of the first diode is connected with the second end of the motor.

6. The motor forward and reverse rotation protection circuit according to claim 1, wherein the voltage protection unit is a bidirectional voltage regulator tube;

and two ends of the bidirectional voltage-stabilizing tube are respectively connected with the first end and the second end of the motor.

7. The motor forward and reverse rotation protection circuit according to claim 5, further comprising: the motor rotating speed control unit is connected with the motor and used for controlling the rotating speed of the motor;

the motor rotation speed control unit includes: the circuit comprises an eighth resistor, a variable resistor, a tenth resistor, a ninth MOS (metal oxide semiconductor) tube, an eleventh resistor and a third diode;

the first end of the eighth resistor is connected with the first power supply end, and the second end of the eighth resistor is connected with the first end of the variable resistor;

the second end of the variable resistor is grounded, the control end of the variable resistor is connected with the first end of the variable resistor, and the control end of the variable resistor is also connected with the grid electrode of the eighth MOS transistor;

the drain electrode of the ninth MOS tube is connected with the anode of the first diode, and the source electrode of the ninth MOS tube is grounded through an eleventh resistor;

two ends of the tenth resistor are respectively connected with the grid electrode and the source electrode of the ninth MOS tube;

the cathode of the third diode is connected with the first power supply end;

and the first end of the motor is connected with the first power supply end, and the second end of the motor is connected with the drain electrode of the ninth MOS tube.

8. The motor forward and reverse rotation protection circuit according to claim 1, further comprising: the power supply unit is connected with the H bridge and used for providing working electric energy for the H bridge;

the power supply unit includes: the circuit comprises a fuse, a twelfth resistor, a voltage-stabilizing source, a first capacitor, a thirteenth resistor, a fourteenth resistor, an operational amplifier, a fifteenth resistor, a sixteenth resistor, a tenth MOS (metal oxide semiconductor) transistor and an eleventh MOS transistor;

the first end of the fuse is connected with the anode of an external power supply, and the second end of the fuse is connected with the drain electrode of the tenth MOS tube;

the first end of the twelfth resistor is connected with the second end of the fuse, and the second end of the twelfth resistor is connected with the first end of the voltage stabilizing source;

the second end of the voltage-stabilizing source is connected with the negative electrode of an external power supply, and the third end of the voltage-stabilizing source is connected with the first end of the voltage-stabilizing source;

two ends of the first capacitor are connected with the first end and the second end of the voltage stabilizing source;

a first end of the thirteenth resistor is connected with a second end of the fuse, and a second end of the thirteenth resistor is connected with a first end of the fourteenth resistor;

a second end of the fourteenth resistor is grounded;

the non-inverting input end of the operational amplifier is connected with the first end of the voltage stabilizing source, the inverting input end of the operational amplifier is connected with the inverting input end of the voltage stabilizing source, and the power supply ends of the operational amplifier are respectively connected with the anode and the cathode of the external power supply;

the grid electrode of the tenth MOS tube is connected with the drain electrode of the eleventh MOS tube, and the source electrode of the tenth MOS tube is connected with the H bridge;

two ends of the fifteenth resistor are respectively connected with the drain electrode and the grid electrode of the tenth MOS tube;

the grid electrode of the eleventh MOS tube is connected with the output end of the operational amplifier through the sixteen resistors, and the source electrode of the eleventh MOS tube is grounded.

9. The motor forward/reverse rotation protection circuit according to claim 8, wherein the power supply unit further comprises: a seventeenth resistor and a light emitting diode;

a first end of the seventeenth resistor is connected with the source electrode of the tenth MOS transistor, and a second end of the seventeenth resistor is connected with the anode of the light emitting diode;

and the cathode of the light emitting diode is grounded.

10. The motor forward/reverse rotation protection circuit according to claim 8, wherein the power supply unit further comprises: a fifth diode;

and the cathode of the fifth diode is connected with the second end of the fuse, and the anode of the fifth diode is connected with the cathode of the external power supply.

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