A motor brake control circuit and a motor driver

Abstract

This utility model discloses a motor brake control circuit and a motor driver. The motor brake control circuit includes a DC power supply and a voltage conversion circuit. The input terminal of the voltage conversion circuit is connected to the DC power supply via a DC bus, and its output terminal is connected to the brake coil. The voltage conversion circuit converts the voltage of the DC power supply into a first driving voltage and outputs it to the brake coil. The motor brake control circuit of this application can output a corresponding voltage according to the magnitude of the output voltage of the motor driver to drive the motor brake to open and close, thereby adapting to motor brakes with various different loads and having higher applicability.

Description

Technical Field

[0001] This utility model relates to the field of motor brake technology, and in particular to a motor brake control circuit and a motor driver. Background Technology

[0002] A brake is a mechanical device primarily used to quickly stop a motor's rotation when power is lost. Brakes are widely used in various equipment requiring safe braking, especially in lifting machinery. Currently, the control of brake motors in low-voltage servo and low-voltage stepper systems typically involves designing a DC-DC switching power supply to output 24V DC power, which is then used to drive the brake's opening and closing. However, the load-carrying capacity of a DC-DC switching power supply is fixed, making it unsuitable for brakes with diverse loads. Furthermore, the design cost of DC-DC switching power supplies is relatively high. Therefore, traditional motor brake control circuits face numerous limitations. Utility Model Content

[0003] This utility model provides a motor brake control circuit and a motor driver, which solves the problems of high cost and inability to adapt to different load brakes in the traditional method of using a switching power supply to drive the brake.

[0004] In a first aspect, this utility model provides a motor brake control circuit, which includes: a DC power supply and a voltage conversion circuit. The input terminal of the voltage conversion circuit is connected to the DC power supply through a DC bus, and its output terminal is connected to the brake coil. The voltage conversion circuit is used to convert the voltage of the DC power supply into a first driving voltage and output it to the brake coil.

[0005] In the motor brake control circuit provided in this embodiment of the utility model, the voltage conversion circuit includes a detection control module and a transformer module. The input terminal of the detection control module is connected to the DC bus, and the output terminal is connected to the input terminal of the transformer module. The input terminal of the transformer module is connected to the detection control module, and the output terminal is connected to the brake coil. The detection control module is used to detect the voltage output by the DC power supply to generate PWM signals with different duty cycles according to its magnitude. The transformer module is used to convert the voltage output by the DC power supply into the first driving voltage according to the PWM signal.

[0006] In the motor brake control circuit provided in this embodiment of the utility model, the detection and control module includes a voltage detection module and an MCU module. The input terminal of the voltage detection module is connected to the DC bus, and the output terminal is connected to the MCU module. The input terminal of the transformer module is connected to the MCU module. The voltage detection module is used to detect the voltage output by the DC power supply, and the MCU module is used to generate the PWM signal according to the voltage detected by the voltage detection module.

[0007] In the motor brake control circuit provided in this embodiment of the utility model, the transformer module includes a switching device and a drive module. The input terminal of the switching device is connected to the DC bus, and the output terminal is connected to the brake coil. The input terminal of the drive module is connected to the MCU module, and the output terminal is connected to the control terminal of the switching device. The drive module is used to drive the switching device to periodically switch on and off according to the PWM signal to chop the voltage output by the DC power supply to generate the first drive voltage.

[0008] In the motor brake control circuit provided in this embodiment of the utility model, the switching device is a MOS transistor. The gate of the MOS transistor is connected to the output terminal of the drive module, the drain of the MOS transistor is connected to the positive terminal of the DC bus, and the source of the MOS transistor is grounded through the brake coil.

[0009] In the motor brake control circuit provided in this embodiment of the present invention, the voltage conversion circuit further includes a diode, the cathode of which is connected between the source of the MOS transistor and the brake coil, and the anode of which is grounded.

[0010] In the motor brake control circuit provided in this embodiment of the utility model, the voltage conversion circuit further includes an overcurrent protection module. The input terminal of the overcurrent protection module is connected to the brake coil, and the output terminal is connected to the drive module. The overcurrent protection module is used to detect the current of the brake coil and control the drive module to drive the switching device to disconnect when the current of the brake coil exceeds a preset value.

[0011] In the motor brake control circuit provided in this embodiment of the utility model, the voltage conversion circuit further includes a current sampling module. The input terminal of the current sampling module is connected to one end of the brake coil, and the output terminal is connected to the MCU module. The current sampling module is used to sample the current of the brake coil, and the MCU module outputs a warning signal when the current sampled by the current sampling module is abnormal.

[0012] In the motor brake control circuit provided in this embodiment of the present invention, the voltage conversion circuit further includes a sampling resistor, which is connected in series with one end of the brake coil, and the input terminal of the current sampling module is connected to the sampling resistor.

[0013] Secondly, this utility model provides a motor driver that includes the motor brake control circuit described in the first aspect.

[0014] This utility model provides a motor brake control circuit and a motor driver. The motor brake control circuit includes a DC power supply and a voltage conversion circuit. The input terminal of the voltage conversion circuit is connected to the DC power supply via a DC bus, and its output terminal is connected to the brake coil. The voltage conversion circuit converts the voltage of the DC power supply into a first driving voltage and outputs it to the brake coil. This motor brake control circuit uses a voltage conversion circuit to convert the voltage of the DC power supply into a first driving voltage and output it to the brake coil of the motor brake. The first driving voltage drives the opening and closing of the motor brake, allowing the output voltage level of the motor driver to be adapted to the load level of the motor brake. Compared with the traditional switching power supply method of driving the brake, this method is lower in cost and has higher adaptability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A structural block diagram of a motor brake control circuit provided in an embodiment of this utility model;

[0017] Figure 2 Another structural block diagram of the motor brake control circuit provided in this embodiment of the utility model;

[0018] Figure 3 A circuit diagram of the motor brake control circuit provided in this embodiment of the utility model.

[0019] The labels for the attached figures are as follows:

[0020] 1. Voltage conversion circuit; 2. DC power supply; 10. Detection and control module; 11. Voltage detection module; 12. MCU module; 20. Transformer module; 21. Switching transistor device; 22. Drive module; 30. Overcurrent protection module; 40. Current sampling module; 200. Brake coil. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0022] The directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings. Therefore, the directional terms used are for explanation and understanding of this invention, and not for limiting it. Furthermore, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0023] To facilitate understanding of this utility model, the motor brake control circuit provided in the embodiment of this utility model will be described first. (Refer to...) Figures 1 to 3 The motor brake control circuit includes a DC power supply 2 and a voltage conversion circuit 1. The input terminal of the voltage conversion circuit 1 is connected to the DC power supply 2 via a DC bus, and its output terminal is connected to the brake coil 200. The voltage conversion circuit 1 is used to convert the voltage of the DC power supply 2 into a first driving voltage and output it to the brake coil 200.

[0024] A motor brake is a device used to quickly stop a motor. It is typically installed on the external shaft or internal rotor of the motor, becoming an integral part of the motor. A motor brake mainly consists of a braking electromagnet and a brake shoe. The braking electromagnet comprises a core, armature, and brake coil, while the brake shoe includes a brake wheel, brake shoes, and springs. Different power motors typically have different braking requirements. Traditional motor brakes are mostly driven by DC-DC switching power supplies. However, the load capacity of a switching power supply is fixed; one power supply can only be used with a motor brake of a corresponding load level. Different load levels require different switching power supplies, which themselves have many components, require a large PCB area, and have high design costs.

[0025] To address the aforementioned problems, this embodiment provides a motor brake control circuit, which is applied to a motor driver, such as... Figure 1As shown, the motor brake control circuit mainly includes a DC power supply 2 and a voltage conversion circuit 1. The input terminal of the voltage conversion circuit 1 is connected to the DC power supply 2 via a DC bus. The DC power supply 2 provides voltage input to the motor driver system, while the output terminal of the voltage conversion circuit 1 is connected to the brake coil 200. Specifically, the brake coil 200 is the coil that forms the internal braking electromagnet of the motor brake. When the brake coil 200 is energized, the braking electromagnet operates, causing the motor brake to open and enter a non-braking state, allowing the motor shaft to rotate normally. When the brake coil 200 is de-energized, the braking electromagnet does not operate, the motor brake closes, and enters a braking state, clamping the motor shaft and restricting its rotation. In practical applications, when the motor is stopped, the brake coil 200 of the motor brake has no voltage input, and the motor brake is in a closed state by default, i.e., the motor brake is in braking mode. When the motor driver controls the motor to run, the voltage of DC power supply 2 is input to the motor through the DC bus of the motor driver, causing the motor to start running. At the same time, the voltage conversion circuit 1 converts the voltage output from DC power supply 2 on the DC bus into a first driving voltage, which is output to the brake coil 200. The first driving voltage drives the motor brake to open, the braking mode is released, and the motor shaft can rotate normally. The first driving voltage is positively correlated with the output voltage of DC power supply 2. The larger the voltage output from DC power supply 2 on the DC bus, the larger the first driving voltage output by voltage conversion circuit 1, thereby enabling the driving of a motor brake of corresponding load size. It can be adapted to motor brakes of various power ratings.

[0026] In one embodiment, the voltage conversion circuit 1 includes a detection and control module 10 and a transformer module 20. The input terminal of the detection and control module 10 is connected to the DC bus, and the output terminal is connected to the input terminal of the transformer module 20. The input terminal of the transformer module 20 is connected to the detection and control module 10, and the output terminal is connected to the brake coil 200. The detection and control module 10 is used to detect the voltage output by the DC power supply 2 to generate PWM signals with different duty cycles according to its magnitude. The transformer module 20 is used to convert the voltage output by the DC power supply 2 into the first driving voltage according to the PWM signal. In specific implementation, the voltage conversion circuit 1 mainly consists of a detection and control module 10 and a transformer module 20. The input terminal of the detection and control module 10 is connected to the DC bus. The detection and control module 10 has detection and logic control functions. It detects the output voltage of the DC power supply 2 on the DC bus and generates PWM signals with different duty cycles according to the detected voltage magnitude. PWM (Pulse Width Modulation) signal is a digital signal that controls the average value by changing the pulse width. The duty cycle of the PWM signal is the ratio of the pulse high-level time to the entire cycle. The larger the output voltage of the DC power supply 2, the larger the duty cycle of the PWM signal generated by the detection and control module 10; conversely, the smaller the output voltage of the DC power supply 2, the smaller the duty cycle of the PWM signal generated by the detection and control module 10. The detection and control module can dynamically adjust the duty cycle of the PWM signal according to the detected voltage. The input terminal of transformer module 20 is connected to the output of detection and control module 10, and the output terminal of transformer module 20 is connected to the brake coil 200 inside the motor brake. Transformer module 20 is specifically a circuit module capable of step-up and step-down voltage conversion. It processes the voltage output from the DC bus according to the PWM signal output by detection and control module 10. Specifically, transformer module 20 converts the voltage output from DC power supply 2 on the DC bus into a first drive voltage based on the duty cycle of the PWM signal and outputs it to brake coil 200, thereby closing the motor brake. Generally, the larger the duty cycle of the PWM signal, the larger the first drive voltage; conversely, the smaller the duty cycle of the PWM signal, the smaller the first drive voltage. Overall, the first drive voltage is dynamically adjusted by the output voltage on the DC bus of the motor driver. Each voltage level of the DC bus output corresponds to a first drive voltage level, allowing for adaptation to different load levels of motor brakes used with different power motors and meeting the motor's braking requirements.

[0027] Furthermore, referring to Figures 1 to 3The detection and control module 10 includes a voltage detection module 11 and an MCU module 12. The input terminal of the voltage detection module 11 is connected to the DC bus, and the output terminal is connected to the MCU module 12. The input terminal of the transformer module 20 is connected to the MCU module 12. The voltage detection module 11 is used to detect the voltage output by the DC power supply 2, and the MCU module 12 is used to generate the PWM signal based on the voltage detected by the voltage detection module 11. In specific implementation, the detection and control module 10 mainly consists of a voltage detection module 11 and an MCU module 12. The input terminal of the voltage detection module 11 is connected to the DC bus, and the output terminal is connected to the input of the MCU module 12. The input terminal of the transformer module 20 is connected to the MCU module 12, specifically to the I / O port of the MCU module 12. The MCU module 12, as the core control module of the entire drive circuit, can realize logic control, data processing and other functions. In practical applications, the voltage detection module 11 detects the voltage output from the DC power supply 2 on the DC bus. The detected voltage data is sent to the MCU module 12. The MCU module 12 generates a PWM signal according to the voltage detected by the voltage detection module 11 and the system-set logic. Specifically, the duty cycle of the PWM signal generated by the MCU module 12 varies depending on the voltage detected by the voltage detection module 11. The PWM signal generated by the MCU module 12 is output to the transformer module 20, which then converts the voltage output from the DC power supply 2 on the DC bus into the corresponding first drive voltage, thereby driving and controlling the motor brake.

[0028] Furthermore, referring to Figures 1 to 3The transformer module 20 includes a switching device 21 and a drive module 22. The input terminal of the switching device 21 is connected to the DC bus, and the output terminal is connected to the brake coil 200. The input terminal of the drive module 22 is connected to the MCU module 12, and the output terminal is connected to the control terminal of the switching device 21. The drive module 22 is used to drive the switching device 21 to periodically switch on and off according to the PWM signal to chop the voltage output by the DC power supply 2 to generate the first drive voltage. In specific implementation, the transformer module 20 mainly consists of the switching device 21 and the drive module 22. The input terminal of the switching device 21 is connected to the DC bus, and the output terminal is connected to the brake coil 200. The switching device 21 can be designed using switching devices such as MOSFETs or IGBTs. The input terminal of the drive module 22 is connected to the MCU module 12 to receive the PWM signal output by the MCU module 12, and the output terminal of the drive module 22 is connected to the control terminal of the switching device 21. The drive module 22 is mainly a drive circuit that can drive the switching transistor to turn on and off. Specifically, it can be a drive circuit composed of transistors or an IC used to implement the drive function. In practical applications, the drive module 22 drives the switching transistor 21 to periodically turn on and off according to the PWM signal output by the MCU module 12. The periodic on and off of the switching transistor 21 chops the voltage output by the DC power supply 2 on the DC bus. The continuous DC voltage on the DC bus is chopped into discontinuous DC voltage output, thereby generating a first drive voltage of a certain magnitude.

[0029] Furthermore, referring to Figure 3 The switching device 21 is a MOSFET Q1. The gate of the MOSFET Q1 is connected to the output terminal of the driving module 22, the drain of the MOSFET Q1 is connected to the positive terminal of the DC bus, and the source of the MOSFET Q1 is grounded through the brake coil 200. In specific implementation, the switching device 21 is designed using a MOSFET Q1, with the gate of the MOSFET Q1 connected to the output terminal of the driving module 22, the drain of the MOSFET Q1 connected to the positive terminal of the DC bus, and the source of the MOSFET Q1 grounded through the brake coil 200. Figure 3The coil L1 shown is the brake coil 200, which is connected in series between the source of MOSFET Q1 and ground. In practical applications, the drive module 22 drives the gate of MOSFET Q1 according to the duty cycle of the PWM signal, causing MOSFET Q1 to switch on and off at high frequency. The source of MOSFET Q1 generates a corresponding level of voltage as the first drive voltage. The larger the duty cycle of the PWM signal, the longer the conduction time of MOSFET Q1, and thus the larger the voltage generated at the source of MOSFET Q1. The MCU module 12 dynamically adjusts the duty cycle of the PWM signal according to the voltage output of DC power supply 2 on the DC bus. The drive module 22 drives MOSFET Q1 to switch on and off according to the duty cycle of the PWM signal, so that the source of MOSFET Q1 generates a first drive voltage adapted to the load level of the motor brake.

[0030] Furthermore, referring to Figure 3 The voltage conversion circuit 1 further includes a diode D1. The cathode of diode D1 is connected between the source of MOSFET Q1 and the brake coil 200, and the anode of diode D1 is grounded. In a specific implementation, the voltage conversion circuit 1 also includes a diode D1 connected in parallel across the electromagnet of the motor brake. The cathode of diode D1 is connected between the source of MOSFET Q1 and the brake coil 200, and the anode of diode D1 is grounded. In practical applications, the brake coil 200 generates a magnetic field when energized, and this magnetic field disappears rapidly when de-energized, resulting in a back electromotive force (EMF) in the brake coil 200. Diode D1 can eliminate this back EMF generated after the brake coil 200 is de-energized, thereby protecting other components in the circuit from damage.

[0031] In one embodiment, reference is made to Figure 2 and Figure 3 The voltage conversion circuit 1 further includes an overcurrent protection module 30. The input terminal of the overcurrent protection module 30 is connected to the brake coil 200, and the output terminal is connected to the drive module 22. The overcurrent protection module 30 is used to detect the current of the brake coil 200 and control the drive module 22 to drive the switching device 21 to disconnect when the current of the brake coil 200 exceeds a preset value. In specific implementation, the voltage conversion circuit 1 further includes an overcurrent protection module 30, the input terminal of which is connected to the brake coil 200, and the output terminal is connected to the drive module 22. The overcurrent protection module 30 is mainly used to provide overcurrent protection for the motor brake. In practical applications, the overcurrent protection module 30 detects the current on the brake coil 200 in real time, which can promptly detect abnormal current increases. According to the set protection logic, when the current on the brake coil 200 exceeds the preset value, it controls the drive module 22 to drive the switching device 21 to disconnect, forcibly cutting off the input of the brake coil 200 to prevent damage to the motor or motor brake due to overcurrent.

[0032] In one embodiment, reference is made to Figure 2 and Figure 3 The voltage conversion circuit 1 further includes a current sampling module 40. The input terminal of the current sampling module 40 is connected to one end of the brake coil 200, and the output terminal is connected to the MCU module 12. The current sampling module 40 is used to sample the current of the brake coil 200. The MCU module 12 outputs a warning signal when the current sampled by the current sampling module 40 is abnormal. In a specific implementation, the voltage conversion circuit 1 further includes a current sampling module 40, with its input terminal connected to the brake coil 200 and its output terminal connected to the MCU module 12. In practical applications, the overcurrent protection module 30 samples the current on the brake coil 200 in real time and sends the sampled current data to the MCU module 12. The MCU module 12 outputs a warning signal when the current sampled by the current sampling module 40 is abnormal, according to a pre-set judgment logic. Specifically, the abnormal current sampled by the current sampling module 40 is mainly manifested as the current of the brake coil 200 being too large and exceeding the safe value, or the current of the brake coil 200 being too small and unable to meet the normal opening of the motor brake. The MCU module 12 can output a warning signal by means of a buzzer alarm or LED lighting, so that users can discover the abnormal current of the brake coil 200 and take corresponding measures in a timely manner.

[0033] In one embodiment, reference is made to Figure 3 The voltage conversion circuit 1 further includes a sampling resistor R1, which is connected in series at one end of the brake coil 200. The input terminal of the current sampling module 40 is connected to the sampling resistor. In a specific implementation, the voltage conversion circuit 1 further includes a sampling resistor R1, which is connected in series at one end of the brake coil 200. It can be connected in series at either end of the brake coil 200. When the brake coil 200 is energized, the resistance value of the sampling resistor R1 is fixed, and a voltage is generated across the sampling resistor R1. The current sampling module 40 samples the voltage across the sampling resistor R1, thereby more conveniently obtaining the current flowing through the brake coil 200.

[0034] The motor brake control circuit provided in this application embodiment uses a voltage conversion circuit to convert the DC power output on the DC bus into a first driving voltage, which is then output to the brake coil of the motor brake. The first driving voltage drives the opening and closing of the motor brake, so that the output voltage level of the motor driver can be adapted to the load level of the motor brake. Compared with the traditional switching power supply method of driving the brake, it has lower cost and higher adaptability.

[0035] This utility model also provides a motor driver, which includes the motor brake control circuit described in the above embodiments. The motor brake control circuit is integrated into the motor driver, and the motor driver as a whole can realize the operation control of the motor and the opening and closing drive of the motor brake. When the motor is powered on, the motor brake control circuit drives the motor brake to open, allowing the motor to run. When the motor is powered off, the motor brake control circuit drives the motor brake to close, causing the motor to stop rotating quickly, thus achieving braking of the motor. Since the specific structure and working principle of the motor brake control circuit have been described in detail in the previous specification, they will not be repeated here for the sake of brevity.

[0036] The motor driver in this embodiment, by employing the motor brake control circuit provided in this embodiment, can be adapted to motor systems of different power, thus improving its applicability.

[0037] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A motor brake control circuit, characterized in that, include: A DC power supply and a voltage conversion circuit, wherein the input terminal of the voltage conversion circuit is connected to the DC power supply via a DC bus, and its output terminal is connected to a brake coil; The voltage conversion circuit is used to convert the voltage of the DC power supply into a first driving voltage and output it to the brake coil.

2. The motor brake control circuit according to claim 1, characterized in that, The voltage conversion circuit includes a detection and control module and a transformer module. The input terminal of the detection and control module is connected to the DC bus, and the output terminal is connected to the input terminal of the transformer module. The input terminal of the transformer module is connected to the detection and control module, and the output terminal is connected to the brake coil. The detection and control module is used to detect the voltage output by the DC power supply to generate PWM signals with different duty cycles according to its magnitude, and the transformer module is used to convert the voltage output by the DC power supply into the first driving voltage according to the PWM signal.

3. The motor brake control circuit according to claim 2, characterized in that, The detection and control module includes a voltage detection module and an MCU module. The input terminal of the voltage detection module is connected to the DC bus, and the output terminal is connected to the MCU module. The input terminal of the transformer module is connected to the MCU module. The voltage detection module is used to detect the voltage output by the DC power supply, and the MCU module is used to generate the PWM signal based on the voltage detected by the voltage detection module.

4. The motor brake control circuit according to claim 3, characterized in that, The transformer module includes a switching device and a drive module. The input terminal of the switching device is connected to the DC bus, and the output terminal is connected to the brake coil. The input terminal of the drive module is connected to the MCU module, and the output terminal is connected to the control terminal of the switching device. The drive module is used to drive the switching device to periodically switch on and off according to the PWM signal to chop the voltage output by the DC power supply to generate the first drive voltage.

5. The motor brake control circuit according to claim 4, characterized in that, The switching device is a MOSFET. The gate of the MOSFET is connected to the output terminal of the drive module, the drain of the MOSFET is connected to the positive terminal of the DC bus, and the source of the MOSFET is grounded through the brake coil.

6. The motor brake control circuit according to claim 5, characterized in that, The voltage conversion circuit also includes a diode, the cathode of which is connected between the source of the MOS transistor and the brake coil, and the anode of which is grounded.

7. The motor brake control circuit according to any one of claims 4-6, characterized in that, The voltage conversion circuit also includes an overcurrent protection module. The input terminal of the overcurrent protection module is connected to the brake coil, and the output terminal is connected to the drive module. The overcurrent protection module is used to detect the current of the brake coil and control the drive module to drive the switching device to disconnect when the current of the brake coil exceeds a preset value.

8. The motor brake control circuit according to any one of claims 3-6, characterized in that, The voltage conversion circuit further includes a current sampling module. The input terminal of the current sampling module is connected to one end of the brake coil, and the output terminal is connected to the MCU module. The current sampling module is used to sample the current of the brake coil. When the current sampled by the current sampling module is abnormal, the MCU module outputs a warning signal.

9. The motor brake control circuit according to claim 8, characterized in that, The voltage conversion circuit also includes a sampling resistor connected in series at one end of the brake coil, and the input terminal of the current sampling module is connected to the sampling resistor.

10. A motor driver, characterized in that, Includes the motor brake control circuit as described in any one of claims 1-9.

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