CN214674317U - Reverse connection prevention turn-off circuit and motor driving circuit - Google Patents

Abstract

The embodiment of the utility model discloses prevent reverse connection turn-off circuit and motor drive circuit. The reverse connection prevention turn-off circuit includes: a first switching unit, a second switching unit, and a boosting unit; the first end of the first switch unit is electrically connected with the power supply input end, and the second end of the first switch unit is electrically connected with the power supply output end; the first end of the second switch unit is electrically connected with the power supply input end, the second end of the second switch unit is electrically connected with the control end of the first switch unit, and the control end of the second switch unit is electrically connected with the grounding end; the input end of the voltage boosting unit is electrically connected with the power output end, and the output end of the voltage boosting unit is electrically connected with the control end of the first switch unit. The embodiment of the utility model provides a technical scheme can provide circuit structure simple, with low costs and prevent reverse connection turn-off circuit.

Description

Reverse connection prevention turn-off circuit and motor driving circuit

Technical Field

The embodiment of the utility model provides a relate to motor drive technical field, especially relate to a prevent reverse connection turn-off circuit and motor drive circuit.

Background

In general, various functional circuits (such as a motor driving circuit) require an external power supply to supply power, and when the external power supply is reversely connected, devices in the functional circuits are likely to be damaged, so that an anti-reverse connection shutdown circuit is generally arranged in the functional circuits to cut off the connection between the external power supply and the functional circuits when the power supply is reversely connected.

However, the anti-reverse connection turn-off circuit provided in the prior art is complex in structure and high in cost. Therefore, it is desirable to provide an anti-reverse-connection shutdown circuit with a simple circuit structure and low cost.

SUMMERY OF THE UTILITY MODEL

The utility model provides a prevent reverse connection turn-off circuit and motor drive circuit to a reverse connection turn-off circuit is prevented to circuit structure is simple, with low costs is provided.

In a first aspect, an embodiment of the present invention provides an anti-reverse-connection turn-off circuit, which includes:

a first switching unit, a second switching unit, and a boosting unit;

the first end of the first switch unit is electrically connected with the power supply input end, and the second end of the first switch unit is electrically connected with the power supply output end;

the first end of the second switch unit is electrically connected with the power supply input end, the second end of the second switch unit is electrically connected with the control end of the first switch unit, and the control end of the second switch unit is electrically connected with the ground end; when the power supply is normally connected, the second switch unit is used for responding to the ground signal of the grounding terminal to be turned off, and when the power supply is reversely connected, the second switch unit is used for responding to the power supply voltage of the grounding terminal to be turned on so as to transmit the ground signal of the power supply input end to the control end of the first switch unit and turn off the first switch unit;

the input end of the boosting unit is electrically connected with the power output end, and the output end of the boosting unit is electrically connected with the control end of the first switch unit; when the power supply is normally connected, the boosting unit is used for boosting the power supply voltage at the power supply output end so as to enable the first switch unit to be conducted.

Optionally, the first switch unit includes a first transistor and a first capacitor;

the first end of the first transistor is electrically connected with the power input end, the second end of the first transistor is electrically connected with the power output end and the first end of the first capacitor respectively, and the control end of the first transistor is electrically connected with the second end of the second switch unit, the output end of the boosting unit and the second end of the first capacitor respectively.

Optionally, the first transistor is an N-type MOS transistor.

Optionally, the voltage boosting unit includes a bootstrap circuit and a first resistor;

the input end of the bootstrap circuit is electrically connected with the power output end, the output end of the bootstrap circuit is electrically connected with the first end of the first resistor, and the second end of the first resistor is electrically connected with the control end of the first switch unit.

Optionally, the device further includes a single chip microcomputer, where the single chip microcomputer includes a pre-drive bootstrap module, the pre-drive bootstrap module includes a bootstrap unit, and the bootstrap unit is used as the bootstrap circuit.

Optionally, the single chip microcomputer is multiplexed as a controller in the motor driving circuit.

Optionally, the second switching unit includes a second transistor, a diode, and a second resistor;

the cathode of the diode is electrically connected with the power supply input end, and the anode of the diode is electrically connected with the first end of the second transistor;

the control end of the second transistor is electrically connected with the first end of the second resistor, and the second end of the second transistor is electrically connected with the control end of the first switch unit;

and the second end of the second resistor is electrically connected with the grounding end.

Optionally, the second switch unit further includes a third resistor;

the first end of the third resistor is electrically connected with the first end of the second transistor, and the second end of the third resistor is electrically connected with the control end of the second transistor.

In a second aspect, an embodiment of the present invention further provides a motor driving circuit, where the reverse connection preventing turn-off circuit includes the first aspect.

Optionally, the motor driving circuit further includes a controller, and the controller is configured to output a control signal for driving the motor.

The embodiment of the utility model provides a prevent joining conversely turn-off circuit, through setting up it and including first switch unit, second switch unit and boost unit for when the power normally inserts, first switch unit switches on under the control of the signal of boost unit output, and second switch unit closes under the ground signal control of earthing terminal, thereby makes the mains voltage transmission of power input end to power output end; when the power supply is reversely connected, the second switch unit is switched on under the control of the power supply voltage of the grounding end, the ground signal of the power supply input end is transmitted to the control end of the first switch unit, and the first switch unit is switched off, so that the ground signal of the power supply input end cannot be transmitted to the power supply output end. The problems of complex circuit structure and high cost of the reverse connection prevention turn-off circuit in the prior art are solved, and the effects of simplifying the circuit structure and reducing the cost are achieved.

Drawings

Fig. 1 is a circuit component diagram of an anti-reverse connection shutdown circuit provided by the related art;

fig. 2 is a schematic structural diagram of an anti-reverse connection turn-off circuit provided by an embodiment of the present invention;

fig. 3 is a circuit component diagram of a first switch unit and a second switch unit according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a single chip microcomputer provided in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another single chip microcomputer provided by the embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a circuit component diagram of an anti-reverse connection shutdown circuit provided by the related art. Referring to fig. 1, the anti-reverse-connection turn-off circuit includes a resistor R1 ', a resistor R2 ', a resistor R3 ', a resistor R4 ', a voltage regulator D1 ', a Transistor Q1 ' and a Transistor Q2 ', wherein the Transistor Q1 ' is a P-type Metal Oxide Semiconductor Field Effect Transistor (Metal Oxide Semiconductor Field-Effect Transistor, MOSFET) (MOS Transistor for short), and the Transistor Q2 ' is an NPN-type triode, that is, the 1P-type MOS Transistor is controlled to be turned on and off by 1 NPN-type triode to realize an anti-reverse-connection control function. However, the reverse-connection prevention shutdown circuit shown in fig. 1 has the following disadvantages: in order to prevent the grid source voltage of the P-type MOS tube from being damaged beyond-20V, a voltage regulator tube is required to be arranged between the grid electrode and the source electrode, so that the circuit cost is increased, and the space of a PCB is occupied. In addition, the control signal CON of the triode is an I/O signal of the single chip microcomputer, and occupies pin resources of the single chip microcomputer (not shown in fig. 1).

In view of this, the utility model provides an anti-reverse connection turn-off circuit, this anti-reverse connection turn-off circuit includes: a first switching unit, a second switching unit, and a boosting unit; the first end of the first switch unit is electrically connected with the power supply input end, and the second end of the first switch unit is electrically connected with the power supply output end; the first end of the second switch unit is electrically connected with the power supply input end, the second end of the second switch unit is electrically connected with the control end of the first switch unit, and the control end of the second switch unit is electrically connected with the grounding end; when the power supply is normally connected, the second switch unit is used for responding to the ground signal of the grounding terminal to be turned off, and when the power supply is reversely connected, the second switch unit is used for responding to the power supply voltage of the grounding terminal to be turned on so as to transmit the ground signal of the power supply input end to the control end of the first switch unit to turn off the first switch unit; the input end of the boosting unit is electrically connected with the output end of the power supply, and the output end of the boosting unit is electrically connected with the control end of the first switch unit; when the power supply is normally connected, the boosting unit is used for boosting the power supply voltage at the output end of the power supply so as to enable the first switch unit to be conducted. By adopting the technical scheme, the problems of complex circuit structure and high cost of the reverse connection prevention turn-off circuit in the prior art can be solved, and the effects of simplifying the circuit structure and reducing the cost are realized.

The above is the core idea of the present application, and the technical solution in 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 only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, under the premise that creative work is not done by ordinary skilled in the art, all other embodiments obtained all belong to the protection scope of the present invention.

Fig. 2 is a schematic structural diagram of an anti-reverse connection turn-off circuit provided by an embodiment of the present invention. Referring to fig. 2, the reverse connection prevention turn-off circuit includes: a first switching unit 10, a second switching unit 20, and a boosting unit 30; a first end of the first switch unit 10 is electrically connected with the power input end 101, and a second end of the first switch unit 10 is electrically connected with the power output end 103; a first end of the second switch unit 20 is electrically connected to the power input terminal 101, a second end of the second switch unit 20 is electrically connected to the control terminal of the first switch unit 10, and the control terminal of the second switch unit 20 is electrically connected to the ground terminal 102; when the power supply is normally connected, the second switch unit 20 is configured to be turned off in response to a ground signal of the ground terminal 102, and when the power supply is reversely connected, the second switch unit 20 is configured to be turned on in response to a power supply voltage of the ground terminal 102 to transmit the ground signal of the power supply input terminal 101 to the control terminal of the first switch unit 10, so as to turn off the first switch unit 10; the input end of the boosting unit 30 is electrically connected with the power output end 103, and the output end of the boosting unit 30 is electrically connected with the control end of the first switching unit 10; when the power supply is normally connected, the voltage boosting unit 30 is configured to boost the power supply voltage at the power supply output terminal 103 so as to turn on the first switching unit 10.

Specifically, when the power supply is normally connected, the positive electrode of the external power supply is electrically connected to the power input terminal 101, the negative electrode of the external power supply is electrically connected to the ground terminal 102, the control terminal of the second switch unit 20 is a ground signal, the second switch unit 20 is turned off, meanwhile, the power voltage input by the power input terminal 101 is transmitted to the power output terminal 103 through the first switch unit 10, the voltage boosting unit 30 boosts the power voltage, the voltage of the control terminal of the first switch unit 10 is greater than the voltage of the first terminal of the first switch unit 10, the first switch unit 10 is completely turned on, and the external power supply can normally supply power. The first switching unit 10 may include a diode, and the power voltage input from the power input terminal 101 may be transmitted to the power output terminal 103 through the diode before the first switching unit 10 is completely turned on.

Specifically, when the power supply is reversely connected, the positive electrode of the external power supply is electrically connected to the ground terminal 102, the negative electrode of the external power supply is electrically connected to the power input terminal 101, the control terminal of the second switch unit 20 is the power supply voltage, the second switch unit 20 is turned on, the ground signal of the power input terminal 101 is transmitted to the control terminal of the first switch unit 10, the first switch unit 10 is turned off, the electrical connection between the external power supply and the subsequent circuit is cut off, and the subsequent circuit is prevented from being burnt out.

The embodiment of the utility model provides a prevent joining conversely turn-off circuit, through setting up it and including first switch element 10, second switch element 20 and boost unit 30 for when the power normally inserts, first switch element 10 switches on under the control of the signal of boost unit 30 output, and second switch element 20 switches off under the control of the ground signal of earthing terminal 102, thereby makes the mains voltage transmission of power input end 101 to power output end 103; when the power is reversely connected, the second switch unit 20 is turned on under the control of the power voltage of the ground terminal 102, the ground signal of the power input terminal 101 is transmitted to the control terminal of the first switch unit 10, and the first switch unit 10 is turned off, so that the ground signal of the power input terminal 101 cannot be transmitted to the power output terminal 103. The problems of complex circuit structure and high cost of the reverse connection prevention turn-off circuit in the prior art are solved, and the effects of simplifying the circuit structure and reducing the cost are achieved.

Specifically, the specific implementation manner of the first switching unit 10, the second switching unit 20, and the voltage boosting unit 30 can be set by a person skilled in the art according to practical situations, and is not limited herein. The following description is of exemplary embodiments and should not be construed as limiting the present application.

Fig. 3 is a circuit component diagram of a first switch unit and a second switch unit according to an embodiment of the present invention. Referring to fig. 3, optionally, the first switching unit 10 includes a first transistor Q1 and a first capacitor C; a first terminal of the first transistor Q1 is electrically connected to the power input terminal 101, a second terminal of the first transistor Q1 is electrically connected to the power output terminal 103 and a first terminal of the first capacitor C, respectively, and a control terminal of the first transistor Q1 is electrically connected to a second terminal of the second switching unit 20, an output terminal of the voltage boosting unit 30, and a second terminal of the first capacitor C, respectively.

Specifically, the first capacitor C functions to prevent overshoot.

Specifically, the specific implementation manner of the first transistor Q1 can be set by a person skilled in the art according to practical situations, and is not limited herein. Optionally, the first transistor Q1 is an N-type MOS transistor. It can be understood that the reverse connection prevention turn-off circuit shown in fig. 1 uses a P-type MOS transistor, but when the load current of the power loop is larger than that of an N-type MOS transistor, the selection of the P-type MOS transistor type is more difficult and the cost is higher. However, the embodiment of the present invention selects the N-type MOS transistor for use, so that the model selection is simple and the cost is low. It can be further understood that, in the embodiment of the present invention, by providing the first switch unit 10 including the first transistor Q1 and the first capacitor C, it is not necessary to connect a voltage regulator tube in parallel between the gate and the source of the P-type MOS transistor (transistor Q1') in the reverse connection prevention turn-off circuit shown in fig. 1, so that the circuit structure of the first switch unit 10 is simple, which is beneficial to reducing the cost.

With continued reference to fig. 3, optionally, the second switching unit 20 includes a second transistor Q2, a diode D, and a second resistor R2; the cathode of the diode D is electrically connected with the power input end 101, and the anode of the diode D is electrically connected with the first end of the second transistor Q2; a control end of the second transistor Q2 is electrically connected with a first end of the second resistor R2, and a second end of the second transistor Q2 is electrically connected with a control end of the first switching unit 10; the second end of the second resistor R2 is electrically connected to the ground terminal 102.

Specifically, the second resistor R2 functions as a current limiting function, and prevents the second transistor Q2 from being burned out due to a large current.

Specifically, when the power supply is normally connected, the diode D may prevent the power supply voltage at the power supply input terminal 101 from being transmitted to the first terminal of the second transistor Q2; when the power is reversely connected, the ground signal of the power input terminal 101 may be transmitted to the first terminal of the second transistor Q2 through the diode D, and further transmitted to the control terminal of the first switch unit 10 through the turned-on second transistor Q2.

Specifically, the specific implementation manner of the second transistor Q2 can be set by a person skilled in the art according to practical situations, and is not limited herein. Optionally, the first transistor Q1 is an NPN transistor.

It can be understood that the second transistor Q2 can be turned on or off by the signal of the ground terminal 102, and it is not necessary to output the signal of the control NPN transistor (transistor Q2') from the I/O pin occupying the single chip in the reverse connection preventing circuit shown in fig. 1, so that the reverse connection preventing circuit does not occupy the I/O pin resource of the single chip 40. It can also be understood that, by providing the second switch unit 20 including the second transistor Q2, the diode D, and the second resistor R2, the circuit structure of the voltage boost unit 30 can be simplified, which is beneficial to reducing the cost.

With continued reference to fig. 3, optionally, the second switching unit 20 further includes a third resistor R3; a first terminal of the third resistor R3 is electrically connected to a first terminal of the second transistor Q2, and a second terminal of the third resistor R3 is electrically connected to a control terminal of the second transistor Q2.

Specifically, the third resistor R3 functions as a current limiting function, and further prevents the second transistor Q2 from being burned out due to a large current.

With continued reference to fig. 3, optionally, the voltage boost unit 30 includes a bootstrap circuit 31, and a first resistor R1; an input end of the bootstrap circuit 31 is electrically connected to the power output end 103, an output end of the bootstrap circuit 31 is electrically connected to a first end of the first resistor R1, and a second end of the first resistor R1 is electrically connected to a control end of the first switch unit 10.

Specifically, the first resistor R1 functions as a current limiting function, and prevents the first transistor Q1 from being burned out due to a large current.

Specifically, the specific implementation manner of the bootstrap circuit 31 can be set by those skilled in the art according to practical situations, and is not limited herein. When the power supply is normally connected, the power supply voltage at the power supply input terminal 101 is transmitted to the power supply output terminal 103 through the in-body diode D of the first transistor Q1 in the first switch unit 10, and the bootstrap circuit 31 boosts the power supply voltage, so that the voltage at the control terminal of the first switch unit 10 is greater than the voltage at the first terminal of the first switch unit 10, and the first switch unit 10 is completely turned on.

It can be understood that, by providing the voltage boost unit 30 with the bootstrap circuit 31 and the first resistor R1, the circuit structure of the voltage boost unit 30 can be simplified, which is beneficial to reducing the cost.

Fig. 4 is a schematic structural diagram of a single chip microcomputer provided by the embodiment of the present invention. Referring to fig. 4, the reverse connection preventing turn-off circuit further includes a single chip microcomputer 40, the single chip microcomputer 40 includes a pre-drive bootstrap module, the pre-drive bootstrap module includes a bootstrap unit 41, and the bootstrap unit 41 is used as the bootstrap circuit 31.

Specifically, the single chip microcomputer 40 usually has a pre-drive bootstrap module 31, the pre-drive bootstrap module 31 includes a pre-drive unit 42 and a bootstrap unit 41, and the bootstrap unit 41 can be used as the bootstrap circuit 31. Exemplarily, fig. 5 is a schematic structural diagram of another single chip microcomputer provided by the embodiment of the present invention. Referring to fig. 4 and 5, the single chip microcomputer 40 includes a bootstrap unit 41 and a pre-drive unit 42, a power supply terminal VSD of the single chip microcomputer 40 is an input terminal of the bootstrap unit 41, and a serial port terminal VCP of the single chip microcomputer is an output terminal of the bootstrap unit 41. When the power supply is normally connected, the power supply voltage of the power supply input terminal 101 is transmitted to the power supply output terminal 103 through the in-vivo diode D of the first transistor Q1 in the first switch unit 10, and the bootstrap unit 41 in the single chip microcomputer 40 boosts the power supply voltage and outputs the boosted power supply voltage from the serial port terminal VCP, so that the voltage of the control terminal of the first switch unit 10 is greater than the voltage of the first terminal of the first switch unit 10, and the first switch unit 10 is completely turned on. When the power supply is reversely connected, the ground terminal of the pre-driving unit 42 in the single chip microcomputer 40 is connected with the power supply voltage, and the power supply voltage is transmitted to the serial port terminal VCP (current flow direction is shown by arrow in fig. 5) through the diode in the pre-driving circuit, and then transmitted to the control terminal of the first switch unit 10, however, since the second switch unit 20 is turned on in response to the power supply voltage of the ground terminal 102, the ground signal of the power supply input terminal 101 is also transmitted to the control terminal of the first switch unit 10, and the voltage of the control terminal of the first switch unit 10 is pulled low, so that the first switch unit 10 can be turned off in response to the ground signal without being affected by the pre-driving unit 42.

Optionally, the single chip microcomputer 40 is multiplexed as a controller in the motor driving circuit.

It can be understood that the reverse connection prevention turn-off circuit is generally applied to various functional circuits, for example, when the reverse connection prevention turn-off circuit is applied to a motor drive circuit, a controller is generally arranged in the motor drive circuit, the single chip microcomputer 40 is multiplexed as the controller, or the bootstrap unit 41 in the single chip microcomputer 40 multiplexed as the controller is used as the bootstrap circuit 31 of the reverse connection prevention turn-off circuit, so that the bootstrap circuit 31 in the reverse connection prevention turn-off circuit does not need to be separately built, which is beneficial to reducing the size of the motor drive circuit and reducing the cost.

Based on the same inventive concept, the embodiment of the utility model provides a still provide a motor drive circuit, this motor drive circuit includes the utility model discloses arbitrary embodiment prevent reverse connection turn-off circuit. Therefore, the motor driving circuit has the same functions and advantages as the reverse connection preventing circuit, and is not described herein again, and please refer to the foregoing for a detailed explanation.

On the basis of the above technical solution, optionally, the motor driving circuit further includes a controller, and the controller is configured to output a control signal for driving the motor.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. An anti-reverse turn-off circuit, comprising: a first switching unit, a second switching unit, and a boosting unit;

the first end of the first switch unit is electrically connected with the power supply input end, and the second end of the first switch unit is electrically connected with the power supply output end;

the first end of the second switch unit is electrically connected with the power supply input end, the second end of the second switch unit is electrically connected with the control end of the first switch unit, and the control end of the second switch unit is electrically connected with the ground end; when the power supply is normally connected, the second switch unit is used for responding to a ground signal of the grounding terminal to be switched off; when the power supply is reversely connected, the second switch unit is used for responding to the power supply voltage conduction of the grounding terminal to transmit the ground signal of the power supply input terminal to the control terminal of the first switch unit so as to turn off the first switch unit;

the input end of the boosting unit is electrically connected with the power output end, and the output end of the boosting unit is electrically connected with the control end of the first switch unit; when the power supply is normally connected, the boosting unit is used for boosting the power supply voltage at the power supply output end so as to enable the first switch unit to be conducted.

2. The reverse connection prevention turn-off circuit according to claim 1, wherein the first switching unit includes a first transistor and a first capacitor;

the first end of the first transistor is electrically connected with the power input end, the second end of the first transistor is electrically connected with the power output end and the first end of the first capacitor respectively, and the control end of the first transistor is electrically connected with the second end of the second switch unit, the output end of the boosting unit and the second end of the first capacitor respectively.

3. The reverse connection prevention turn-off circuit according to claim 2, wherein the first transistor is an N-type MOS transistor.

4. The reverse connection prevention turn-off circuit according to claim 1, wherein the boosting unit comprises a bootstrap circuit and a first resistor;

the input end of the bootstrap circuit is electrically connected with the power output end, the output end of the bootstrap circuit is electrically connected with the first end of the first resistor, and the second end of the first resistor is electrically connected with the control end of the first switch unit.

5. The reverse-connection-prevention turn-off circuit according to claim 4, further comprising a single chip microcomputer, wherein the single chip microcomputer comprises a pre-driving bootstrap module, the pre-driving bootstrap module comprises a bootstrap unit, and the bootstrap unit is used as the bootstrap circuit.

6. The reverse connection prevention turn-off circuit according to claim 5, wherein the single chip microcomputer is multiplexed as a controller in a motor drive circuit.

7. The reverse connection prevention turn-off circuit according to claim 1, wherein the second switching unit includes a second transistor, a diode, and a second resistor;

the cathode of the diode is electrically connected with the power supply input end, and the anode of the diode is electrically connected with the first end of the second transistor;

the control end of the second transistor is electrically connected with the first end of the second resistor, and the second end of the second transistor is electrically connected with the control end of the first switch unit;

and the second end of the second resistor is electrically connected with the grounding end.

8. The reverse connection prevention turn-off circuit according to claim 7, wherein the second switching unit further comprises a third resistor;

the first end of the third resistor is electrically connected with the first end of the second transistor, and the second end of the third resistor is electrically connected with the control end of the second transistor.

9. A motor drive circuit characterized by comprising the reverse-connection preventing turn-off circuit according to any one of claims 1 to 8.

10. The motor drive circuit of claim 9 further comprising a controller for outputting a control signal for driving the motor.

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