Band-type brake power supply driving circuit

Abstract

According to the band-type brake power supply driving circuit provided by the utility model, the MOS transistor is driven through the driving chip, the main control chip, the divider resistor and the detection module are arranged, the detection module is connected with the main control chip, and the main control chip collects the voltage passing through the divider resistor and controls the driving chip to be turned off, so that the reliability of the MOS transistor is ensured, and the service life of the band-type brake is prolonged. Meanwhile, the problem of contact adhesion caused by large current is avoided; a first detection end point, a second detection end point and a third detection end point are arranged in the detection module, the first detection end point is connected with a comparator, the driving chip is turned off during overcurrent, the third detection end point is connected with a base electrode of a triode, the triode is turned on according to voltage, and a collector electrode of the triode is connected with an interruption end of the main control chip; the first detection endpoint is connected with the instantaneous voltage detection module and the main control chip, the enabling end of the driving chip is controlled to complete interruption and reset of preset delay time, the problem that short-circuit protection is continuously triggered to burn out an MOS tube is avoided, and the second detection endpoint is connected with the instantaneous voltage detection module and the main control chip and controls on / off of the driving chip according to instantaneous voltage.

Description

Technical Field

[0001] The utility model belongs to the technical field of integrated circuits, and particularly relates to a brake power supply driving circuit. Background Art

[0002] With the progress of power electronics technology, the application of elevators in the field of industrial control has been increasing. Correspondingly, the brake device required for the elevator to stop running has become more critical, and the reliability requirements for the brake system have also increased.

[0003] The brake device is divided into two types: high-voltage brake and low-voltage brake. Among them, the low-voltage brake is usually controlled by a 24VDC power supply. In the current implementation scheme of the low-voltage brake, a relay is mainly used to control the start and stop of the low-voltage brake device. However, a relay is essentially a mechanical device, and its start or stop control depends on the reliability of the contacts and has a limited lifespan. Frequent operation for a long time may cause an increase in contact impedance and reduce reliability; in addition, frequent passing of a large current is more likely to cause the contacts to stick together, resulting in the failure of the relay, and then leading to a malfunction of the elevator brake device and inability to operate normally. Summary of the Utility Model

[0004] In order to overcome the deficiencies of the prior art solutions, the utility model provides a brake power supply driving circuit, which can effectively solve the problems raised in the background art.

[0005] According to the first aspect of the utility model, it includes a brake power supply input terminal, an RC circuit, a driving chip, a MOS transistor, a main control chip, a detection module, and a brake power supply output terminal; the driving chip includes a driving chip enable terminal for controlling the on / off of the driving chip output, a driving chip input signal terminal for controlling the conduction and cutoff of the MOS transistor according to the PWM input signal, and a driving chip output terminal for providing the current required for the gate of the MOS transistor; the drain of the MOS transistor is respectively connected to the brake power supply input terminal and the output terminal of the RC circuit, the input terminal of the RC circuit is connected to the brake power supply input terminal, and the brake power supply input terminal is respectively connected to the brake power supply output terminal through the series connection of a diode D1 and a storage inductor L1 and a capacitor C2; the gate of the MOS transistor is connected to the driving chip output terminal; the source of the MOS transistor is respectively connected to the input terminal of a voltage-dividing resistor and the input terminal of the detection module, the output terminal of the voltage-dividing resistor is grounded, the output terminal of the detection module is connected to the main control chip, and the main control chip is connected to the driving chip input signal terminal for adjusting the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor.

[0006] With the above technical solution, the MOS transistor is driven by a driving chip, and a main control chip, a voltage dividing resistor, and a detection module are provided. The detection module is connected to the main control chip. The main control chip adjusts the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor, ensuring the reliability of the MOS transistor. Moreover, without using a relay, the problem of contact adhesion of the relay caused by large current is avoided.

[0007] In some specific embodiments, the detection module includes a first detection terminal, an instantaneous voltage detection module, and a second detection terminal. The first detection terminal is connected to a comparator, and the output of the comparator is connected to the driving chip; the instantaneous voltage detection module includes a diode D2 in parallel with a resistor, and the detection module is connected to the main control chip through the second detection terminal.

[0008] With the above technical solution, a first detection terminal and a second detection terminal are provided in the detection module. The voltage across the capacitor C2 is input to the first detection terminal. The first detection terminal is connected to an external comparator or an internal comparator of the driving chip for the first layer of hardware protection. Then, it passes through the instantaneous voltage detection module and is input to the second detection terminal, and the second detection terminal is connected to the main control chip for the second layer of main control chip identification protection, ensuring the reliability of the MOS transistor.

[0009] In some specific embodiments, the source electrode of the MOS transistor is connected to the input end of the instantaneous voltage detection module, the output end of the instantaneous voltage detection module is connected to the input end of the first detection terminal, and the output end of the first detection terminal is connected to the enable end of the driving chip through an external comparison circuit to control the turning on / off of the driving chip according to the output of the external comparator circuit input by the voltage across the capacitor C2; the output end of the instantaneous voltage detection module is also connected to the input end of the second detection terminal, and the output end of the second detection terminal is connected to the main control chip to adjust the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor.

[0010] With the above technical solution, by connecting the first detection terminal to an external comparator, in case of short-circuit protection, hardware detection is first performed to control the turning on / off of the MOS transistor by the driving chip, and then the second detection terminal is connected to the main control chip. The connection between the second detection terminal and the main control chip provides the second layer of main control chip identification protection, ensuring the reliability of the MOS transistor.

[0011] In some specific embodiments, the driving chip includes a threshold voltage setting circuit for regulating the voltage at the output terminal, and an internal comparator for controlling the chip to turn on / off. The internal comparator has a positive comparator input terminal and a negative comparator input terminal externally provided to the driving chip; the source electrode of the MOS transistor is connected to the input terminal of the sampling resistor, the output terminal of the sampling resistor is connected to the input terminal of the first detection terminal, the output terminal of the first detection terminal is connected to the positive comparator input terminal of the driving chip, and the negative comparator input terminal is connected to the threshold voltage setting circuit; the input terminal of the first detection terminal is further connected to the input terminal of the instantaneous voltage detection module, the input terminal of the instantaneous voltage detection module is connected to the input terminal of the second detection terminal, and the output terminal of the second detection terminal is connected to the main control chip, which is used to adjust the PWM input signal according to the voltage across the capacitor C2 and control the conduction and cutoff of the MOS transistor.

[0012] Through the above technical solutions, by connecting the internal comparator of the driving chip through the first detection terminal and the main control chip through the second detection terminal, the internal comparator has a faster response speed compared to the external comparison circuit, further ensuring the reliability of the MOS transistor.

[0013] In some specific embodiments, the detection module includes a third detection terminal, a triode, and a 5V power supply. The main control chip includes an interrupt terminal. The input terminal of the third detection terminal is provided between the input terminal of the first detection terminal and the input terminal of the instantaneous voltage detection module. The output terminal of the third detection terminal is connected to the base of the triode. The collector of the triode is respectively connected to the 5V power supply, the interrupt terminal of the main control chip, and the 5V power supply, and the emitter of the triode is grounded.

[0014] In some specific embodiments, the output terminal of the third detection terminal is connected to a voltage dividing circuit and the base of the triode. The voltage dividing circuit is used to divide the voltage across the capacitor C2 to reach the base conduction voltage of the triode.

[0015] Through the above technical solutions, by connecting the internal comparator of the driving chip through the first detection terminal and the main control chip through the second detection terminal, a third detection terminal is provided between the first and second detection terminals. By connecting the third detection terminal to the triode and the interrupt terminal of the main control chip, the main control chip is used to complete the reset of the interruption and the preset delay time, control the reset of the enable terminal of the driving chip, prevent continuous triggering of the short-circuit protection, and burn out the MOS transistor, further ensuring the reliability of the MOS transistor.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] The MOS transistor is driven by a driving chip, and a main control chip, a voltage-dividing resistor, and a detection module are provided. The detection module is connected to the main control chip. The main control chip collects the voltage after passing through the voltage-dividing resistor and controls the driving chip to turn off, ensuring the reliability of the MOS transistor. And without using a relay, the problem of the relay contact sticking due to large current is avoided. Further, a first detection end point, a second detection end point, and a third detection end point are provided in the detection module. By using the structure of connecting the first detection end point to a comparator, the driving chip is turned off during overcurrent. The third detection end point uses the base of a triode to connect to the input end of a sampling resistor, turns on the triode according to the voltage, connects the collector of the triode to the interrupt end of the main control chip, and uses the main control chip to complete the reset of the interrupt and the preset delay time, and controls the reset of the enable end of the driving chip to prevent the MOS transistor from being burned out due to continuous triggering of short-circuit protection. The second detection end point is connected to an instantaneous voltage detection module and the main control chip, and the main control chip controls the turning on / off of the driving chip according to the instantaneous voltage. Description of the Drawings

[0018] The drawings are included to provide a further understanding of the embodiments and are incorporated into and form a part of this specification. The drawings illustrate the embodiments and, together with the description, are used to explain the principles of the present invention. Other embodiments and many of the intended advantages of the embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale with each other. Like reference numerals refer to corresponding like parts.

[0019] Figure 1 is a circuit block diagram according to Embodiment 1 of the present invention;

[0020] Figure 2 is a specific circuit diagram according to Embodiment 1 of the present invention;

[0021] Figure 3 is a connection block diagram of the main control chip according to Embodiment 1 of the present invention;

[0022] Figure 4 is a circuit block diagram according to Embodiment 2 of the present invention;

[0023] Figure 5 is a specific circuit diagram according to Embodiment 2 of the present invention.

[0024] The meanings of the numbers in the drawings:

[0025] Brake power input terminal 01, driving chip 02, MOS transistor 03, main control chip 04, detection module 05, brake power output terminal 06, voltage-dividing resistor 07, RC circuit 08. Detailed Embodiments

[0026] In the following detailed description, reference is made to the accompanying drawings, which form a part of the detailed description and illustrate illustrative specific embodiments in which the present utility model can be practiced. In this regard, directional terms such as "top", "bottom", "left", "right", "upper", "lower", etc. are used with reference to the orientation of the described figures. Since the components of the embodiments can be positioned in several different orientations, the directional terms are used for the purpose of illustration and are in no way limiting. It should be understood that other embodiments may be utilized or logical changes may be made without departing from the scope of the present utility model. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the present utility model is defined by the appended claims.

[0027] Embodiment 1:

[0028] The present utility model provides a brake power supply driving circuit. Figure 1 is a circuit block diagram according to an embodiment of the present utility model. Refer to Figure 1 , the brake power supply driving circuit includes a brake power supply input terminal 01, a driving chip 02, a MOS transistor 03, a main control chip 04, a detection module 05, a brake power supply output terminal 06, a voltage dividing resistor 07, and an RC circuit 08; the driving chip 02 includes a driving chip enable terminal for controlling the output of the driving chip to be turned on / off, a driving chip input signal terminal for controlling the conduction and cutoff of the MOS transistor 03 according to a PWM input signal, and a driving chip output terminal for providing the current required for the gate of the MOS transistor 03; the drain of the MOS transistor 03 is respectively connected to the brake power supply input terminal 01 and the output terminal of the RC circuit 08, the input terminal of the RC circuit 08 is connected to the brake power supply input terminal 01, and the brake power supply input terminal 01 is respectively connected to the brake power supply output terminal 06 through the series connection of a diode D1 and a storage inductor L1 and a capacitor C2; the gate of the MOS transistor 03 is connected to the driving chip output terminal 06; the source of the MOS transistor 03 is respectively connected to the input terminal of the voltage dividing resistor 07 and the input terminal of the detection module 05, the output terminal of the voltage dividing resistor 07 is grounded, the output terminal of the detection module 05 is connected to the main control chip 04, and the main control chip 04 is connected to the driving chip input signal terminal for adjusting the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor 03.

[0029] The actual circuit diagram formed is as shown in Figure 2 shown, and the connection of the main control chip is as shown in Figure 3 shown;

[0030] Specifically, the brake power supply input terminal 01 (DC_300V) is respectively connected to the brake power supply output terminal 06 (OUT_110V) through the series connection of a diode D1 and a storage inductor L1 and a capacitor C2, and the brake power supply input terminal 01 (DC_300V) is modulated to the brake power supply output terminal 06 (OUT_110V).

[0031] Specifically, the RC circuit 08 is composed of resistors R66, R50, and R58 connected in parallel, resistors R65, R49, and R51 connected in series with R66, R50, and R58 respectively, and a capacitor C30. The output ends of R65, R49, and R51 are connected to the input end of the capacitor C30. The negative electrode of the diode D1 and the output end of the capacitor C30 in the RC circuit 08 are connected to the drain of the MOS transistor 03 (Q2) together, which is used to absorb the spike voltage generated by the energy storage inductor L1 in the short - circuit state when the diode D1 recovers, so as to protect the MOS transistor 03 (Q2).

[0032] Specifically, the driving chip 02 (U1) is a MOS transistor base driving chip of the EG3001 model. This chip includes a driving chip input signal terminal (IN terminal) for controlling the conduction and cut - off of the MOS transistor 03 (Q2) according to the PWM input signal, a driving chip enable terminal (SD terminal) for controlling the on / off of the driving chip output, an NC empty pin, a GND port for grounding, a driving chip output terminal (divided into a driving output sink terminal OUTS and a driving output source terminal OUTD) for providing the current required by the MOS transistor gate, and a power supply VCC terminal for the driving chip and driving the MOS transistor.

[0033] The actual circuit components and connection methods of the driving chip 02 (U1) are as follows: The driving output source terminal OUTD included in the driving chip output terminal is connected to resistors R3 and R2, the driving output sink terminal OUTS is connected to the input end of R2, the output end of R2 is connected to the positive electrode of the diode D3, the diode D3 is connected in parallel with the resistor R7, the negative electrode of the diode D3 is grounded, and the output end of R2 is connected to the gate of the MOS transistor 03 (Q2) to control the conduction / cut - off of the MOS transistor 03 (Q2).

[0034] Specifically, the voltage - dividing resistor 07 is the resistor R14.

[0035] Specifically, the detection module 05 includes resistors R5, R6, R10, diode D2, capacitors C5 and C6, as well as a first detection terminal I_Ref110 and a second detection terminal AD-BZ-I; the instantaneous voltage detection module is composed of diode D2 in parallel with resistor R5 and is used to detect the instantaneous voltage; the first detection terminal I_Ref110 is connected to the positive input terminal IN2+ of the external comparator (U2), and the negative input terminal of the external comparator (U2) is connected to the threshold voltage setting circuit, which is used to determine whether the voltage at the first detection terminal is greater than the voltage adjusted by the threshold voltage setting circuit, and a signal is output from the output terminal (OUT2) of the external comparator (U2), and this output terminal (OUT2) is connected to the drive chip enable terminal (SD terminal) of the drive chip 02 (U1) to control the on / off of the output of the drive chip 02 (U1); the detection module 05 is connected to the main control chip 04 through the second detection terminal AD-BZ-I, and the main control chip 04 is connected to the drive chip input signal terminal (IN terminal) to adjust the PWM input signal according to the voltage across capacitor C2 and control the conduction and cutoff of the MOS transistor 03 (Q2).

[0036] Through the above technical solution, the first detection terminal I_Ref110 is connected to the external comparator (U2). During short-circuit protection, hardware detection is first performed to control the on / off of the MOS transistor 03 (Q2) by the drive chip 02 (U1), and then the main control chip 04 is connected through the second detection terminal AD-BZ-I. The second detection terminal AD-BZ-I is connected to the main control chip 04 for the second-layer main control chip identification protection, ensuring the reliability of the MOS transistor.

[0037] Embodiment 2

[0038] Reference Figure 4, the brake power supply drive circuit includes a brake power supply input terminal 01, a drive chip 02, a MOS transistor 03, a main control chip 04, a detection module 05, a brake power supply output terminal 06, a voltage dividing resistor 07, an RC circuit 08, and a threshold voltage setting circuit 09; the drive chip 02 includes a drive chip enable terminal for controlling the on / off of the output of the drive chip 02, a drive chip input signal terminal for controlling the conduction and cutoff of the MOS transistor 03 according to the PWM input signal, and a drive chip output terminal for providing the current required by the gate of the MOS transistor 03; the drain of the MOS transistor 03 is respectively connected to the brake power supply input terminal 01 and the output terminal of the RC circuit 08, the input terminal of the RC circuit 08 is connected to the brake power supply input terminal 01, and the brake power supply input terminal 01 is respectively connected to the brake power supply output terminal 06 through the series connection of a diode D1 and a storage inductor L1 and a capacitor C2; the gate of the MOS transistor 03 is connected to the drive chip output terminal 06; the source of the MOS transistor 03 is respectively connected to the input terminal of the voltage dividing resistor 07 and the input terminal of the detection module 05, the output terminal of the voltage dividing resistor 07 is grounded, the output terminal of the detection module 05 is connected to the main control chip 04, and the main control chip 04 is connected to the drive chip input signal terminal, and is used to adjust the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor 03.

[0039] Specifically, the RC circuit 08 is composed of a resistor R1 and a capacitor C30 connected in series; the positive electrode of the diode D1 is connected to the brake power supply input terminal 01 (DC_300V), and the negative electrode of the diode D1 and the output terminal of the capacitor C30 in the RC circuit 08 are connected to the drain of the MOS transistor 03 (Q2) together, and are used to absorb the spike voltage generated by the storage inductor L1 in the short-circuit state when the diode D1 recovers, so as to protect the MOS transistor 03 (Q2).

[0040] Specifically, the drive chip used is a MOS transistor base drive chip of the EG3002 model. Using the drive chip of the EG3002 model, the circuit diagram formed is as Figure 5 shown. The drive chip 02 includes a drive chip comparator positive port VCP+I and a negative port VCP-I for hardware protection, a drive chip input signal terminal (IN terminal) for controlling the conduction and cutoff of the MOS transistor according to the PWM input signal, a drive chip enable terminal (SD terminal) for controlling the on / off of the drive chip output, a drive chip output terminal (divided into a drive output sink terminal OUTS and a drive output source terminal OUTD) for providing the current required by the gate of the MOS transistor, and a power supply VCC terminal for the drive chip 02 and driving the MOS transistor 03.

[0041] The actual circuit diagram formed is as Figure 5 shown, and the connection of the main control chip is as Figure 3 shown;

[0042] The driving chip 02 includes a threshold voltage setting circuit 09 for regulating the voltage at the output terminal, and a built-in comparator for controlling the chip to turn on / off. The built-in comparator has a comparator positive input terminal VCP+I and a comparator negative input terminal VCP-I provided outside the driving chip; the source electrode of the MOS transistor 03 (Q2) is connected to the input terminal of the sampling resistor R6, the output terminal of the sampling resistor R6 is connected to the input terminal of the first detection terminal I_Ref110, the output terminal of the first detection terminal I_Ref110 is connected to the comparator positive input terminal VCP+I of the driving chip 02 (U1), and the comparator negative input terminal VCP-I is connected to the threshold voltage setting circuit 09; the input terminal of the first detection terminal I_Ref110 is also connected to the input terminal of the instantaneous voltage detection module, the input terminal of the instantaneous voltage detection module is connected to the input terminal of the second detection terminal AD-BZ-I, and the output terminal of the second detection terminal AD-BZ-I is connected to the main control chip 04, which is used to adjust the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cut-off of the MOS transistor 03 (Q2).

[0043] Specifically, the detection module includes a third detection terminal, a triode Q8, and a 5V power supply. The input terminal of the third detection terminal is set between the input terminal of the first detection terminal I_Ref110 and the input terminal of the instantaneous voltage detection module. The output terminal of the third detection terminal is connected to the base of the triode Q8. The collector of the triode Q8 is connected to the main control chip 04 and the 5V power supply respectively, and the emitter of the triode Q8 is grounded.

[0044] Specifically, the output terminal of the third detection terminal is connected to the input terminal of the resistor R49. The output terminal of the resistor R49 is connected to the resistor R51, the capacitor C8, and the resistor R50 and grounded. The output terminal of the resistor R49 is also connected to the base of the triode Q8. The voltage division circuit of the triode Q8 is used to divide the voltage across the capacitor C2 to reach the base conduction voltage of the triode Q8.

[0045] Specifically, the collector of the triode Q8 is connected to the EG_SD terminal of the main control chip 04 and connected to the 5V power supply through the resistor R13.

[0046] Through the settings of the first detection terminal, the second detection terminal, and the third detection terminal, the first detection terminal is connected to the built-in comparator of the driving chip, the second detection terminal is connected to the main control chip, and the third detection terminal is set between the first and second detection terminals. The third detection terminal is connected to the triode and the interrupt terminal of the main control chip. When a signal is generated by the main control chip 04, the boost pulse is turned off. By connecting the enable terminal of the driving chip 02, the driving chip 02 is turned off, and after a preset time, it is turned on again to reset the driving chip 02 to drive the MOS transistor 03 (Q2) to turn on / off, realizing the function of delay protection, avoiding continuous triggering of short-circuit protection and the problem of burning out the MOS transistor, and further ensuring the reliability of the MOS transistor.

[0047] The remaining connection methods and structures in the second embodiment are the same as those in the first embodiment.

[0048] The present application achieves the following beneficial effects:

[0049] By driving the MOS transistor with a driving chip, a main control chip, a voltage-dividing resistor, and a detection module are provided. The detection module is connected to the main control chip. The main control chip collects the voltage after passing through the voltage-dividing resistor and controls the driving chip to turn off, ensuring the reliability of the MOS transistor. And without using a relay, the problem of the relay contact sticking due to large current is avoided. Further, a first detection end point, a second detection end point, and a third detection end point are provided in the detection module. Using the structure of connecting the first detection end point to a comparator to turn off the driving chip during overcurrent. The third detection end point uses the base of a triode to connect to the input end of a sampling resistor, turns on the triode according to the voltage, connects the collector of the triode to the interrupt end of the main control chip, and uses the main control chip to complete the reset of the interrupt and the preset delay time, and controls the reset of the enable end of the driving chip to prevent the MOS transistor from being burned out due to continuous triggering of short-circuit protection. The second detection end point is connected to an instantaneous voltage detection module and the main control chip, and the main control chip controls the turning on / off of the driving chip according to the instantaneous voltage.

[0050] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present invention without departing from the spirit and scope of the present invention. In this way, if these modifications and changes are within the scope of the claims of the present invention and their equivalent forms, the present invention also aims to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A brake power drive circuit, characterized in that, It includes a brake power input terminal, an RC circuit, a driving chip, a MOS transistor, a main control chip, a detection module, and a brake power output terminal; the driving chip includes a driving chip enable terminal for controlling the on / off of the driving chip output, a driving chip input signal terminal for controlling the conduction and cutoff of the MOS transistor according to a PWM input signal, and a driving chip output terminal for providing the current required for the gate of the MOS transistor; the drain of the MOS transistor is respectively connected to the brake power input terminal and the output terminal of the RC circuit, the input terminal of the RC circuit is connected to the brake power input terminal, and the brake power input terminal is respectively connected to the brake power output terminal through the series connection of a diode D1 and a storage inductor L1 and a capacitor C2; the gate of the MOS transistor is connected to the driving chip output terminal; the source of the MOS transistor is respectively connected to the input terminal of a voltage-dividing resistor and the input terminal of the detection module, the output terminal of the voltage-dividing resistor is grounded, the output terminal of the detection module is connected to the main control chip, and the main control chip is connected to the driving chip input signal terminal for adjusting the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor.

2. The power drive circuit for a brake according to claim 1, wherein The detection module includes a first detection end point, an instantaneous voltage detection module, and a second detection end point. The first detection end point is connected to a comparator, and the output of the comparator is connected to the driving chip; the instantaneous voltage detection module includes a diode D2 in parallel with a resistor, and the detection module is connected to the main control chip through the second detection end point.

3. The power drive circuit for a brake according to claim 2, wherein, The source of the MOS transistor is connected to the input terminal of the instantaneous voltage detection module, the output terminal of the instantaneous voltage detection module is connected to the input terminal of the first detection end point, and the output terminal of the first detection end point is connected to the driving chip enable terminal through an external comparison circuit for controlling the on / off of the driving chip according to the output of the external comparator circuit input with the voltage across the capacitor C2; the output terminal of the instantaneous voltage detection module is also connected to the input terminal of the second detection end point, and the output terminal of the second detection end point is connected to the main control chip for adjusting the PWM input signal according to the voltage across the capacitor C2 to control the conduction and cutoff of the MOS transistor.

4. The power drive circuit for a brake according to claim 2, wherein, The driving chip includes a threshold voltage setting circuit for regulating the voltage at the output terminal, and a built-in comparator for controlling the chip to turn on / off. The built-in comparator is provided with a positive comparator input terminal and a negative comparator input terminal outside the driving chip; the source electrode of the MOS transistor is connected to the input terminal of the sampling resistor, the output terminal of the sampling resistor is connected to the input terminal of the first detection terminal, the output terminal of the first detection terminal is connected to the positive comparator input terminal of the driving chip, and the negative comparator input terminal is connected to the threshold voltage setting circuit; the input terminal of the first detection terminal is further connected to the input terminal of the instantaneous voltage detection module, the input terminal of the instantaneous voltage detection module is connected to the input terminal of the second detection terminal, and the output terminal of the second detection terminal is connected to the main control chip, for regulating the PWM input signal according to the voltage across the capacitor C2 and controlling the MOS transistor to conduct and cut off.

5. The power drive circuit for a brake according to claim 4, wherein The detection module includes a third detection terminal, a triode and a 5V power supply. The main control chip includes an interrupt terminal. The input terminal of the third detection terminal is arranged between the input terminal of the first detection terminal and the input terminal of the instantaneous voltage detection module. The output terminal of the third detection terminal is connected to the base electrode of the triode. The collector electrode of the triode is respectively connected to the 5V power supply, the interrupt terminal of the main control chip and the 5V power supply, and the emitter electrode of the triode is grounded.

6. The power drive circuit for a brake according to claim 5, wherein The output terminal of the third detection terminal is connected to a voltage dividing circuit and the base electrode of the triode. The voltage dividing circuit is used for dividing the voltage across the capacitor C2 to reach the base conduction voltage of the triode.

Images