Drive circuit of direct current motor

Abstract

The invention relates to a driving circuit of a direct current motor, which relates to the technical field of motor driving and comprises a power supply input module, a driving control module, an isolating circuit module and a motor driving module. The power supply input module adopts a DC-DC conversion circuit to be combined with an LDO linear power supply, and outputs adaptive voltage by adjusting a sliding resistor; the driving control module adopts a microcontroller to output a PWM control signal; the isolation circuit module adopts an SN74LVC125APWR chip to realize signal buffer isolation; the motor driving module controls a motor to operate through an H-bridge circuit. A single set of circuit is compatible with 48V and 24V motor driving, the equipment cost and size are reduced, the voltage conversion efficiency and the motor operation stability are improved, and the circuit is suitable for multiple fields such as industrial production, transportation and smart home.

Description

Technical Field

[0001] This invention relates to the field of motor drive technology, and in particular to a drive circuit for a DC motor. Background Technology

[0002] Electric motors are widely used as power output components in many fields such as industrial production, transportation, and smart homes. The rated voltage of motors varies depending on the application, with 48V and 24V motors being two of the most common types.

[0003] Currently, most motor drive circuits on the market are designed for motors with a single voltage rating. If you need to drive both 48V and 24V motors, you usually need to equip them with two different drive circuits. This not only increases the cost of the equipment, but also makes the equipment larger and more inconvenient to install and maintain.

[0004] Some drive circuits that attempt to achieve dual-voltage compatibility suffer from poor compatibility, low voltage conversion efficiency, and insufficient motor operating stability. For example, some circuits are prone to voltage fluctuations when switching between motors with different voltages, leading to difficulty in starting the motor, high operating noise, and even affecting the motor's lifespan. Other circuits have limited voltage adjustment ranges, making it impossible to accurately match the voltage requirements of 48V and 24V motors, thus failing to meet the high-performance requirements of practical applications.

[0005] Therefore, developing a drive circuit that can stably and efficiently support 48V and 24V motor drives, and that is simple in structure and low in cost, has become an urgent problem to be solved in the field of motor drive technology. Summary of the Invention

[0006] This invention proposes a drive circuit for a DC motor to solve the problems mentioned in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A DC motor drive circuit includes a power input module, a drive control module, an isolation circuit module, and a motor drive module that work in sequence. The power input module uses a DC-DC converter circuit with an LDO linear power supply and outputs a voltage adapted to the drive control module and the motor drive module by adjusting a sliding resistor. The drive control module uses a microcontroller to generate and output control signals for motor start / stop, speed, and direction. The isolation circuit module is connected to the drive control module and is used to buffer and isolate the control signals, enhance signal driving capability, and reduce electromagnetic interference. The motor drive module uses an H-bridge circuit to receive the isolated control signals and drive the motor by controlling the conduction and cutoff of the upper and lower arms of the H-bridge.

[0008] As a further aspect of the present invention: the LDO linear power supply of the power input module includes LM317HVT, CJ7805, and AMS1117-3.3 voltage regulator chips, which sequentially step down the 48V input voltage to 24V, 12V, 5V, and 3V3, or step down the 24V input voltage to 12V, 5V, and 3V3 by adjusting the resistor.

[0009] As a further aspect of the present invention: the drive control module adopts a CH32 series microcontroller, specifically the CH32V203, which can generate two PWM control signals.

[0010] As a further aspect of the present invention: the isolation circuit module adopts an SN74LVC125APWR chip, its power supply terminal is connected to a 3V3 DC power supply, its enable terminal is connected to GND, its input terminal is connected to the PWM output pin of the drive control module, and its output terminal is connected to the PWM control terminal of the motor drive module.

[0011] As a further aspect of the present invention: the motor drive module includes a gate driver IR2104STRPBF and a switching transistor STB15810. The gate driver receives a PWM control signal and controls the switching transistor to turn on and off to achieve forward and reverse rotation of the motor.

[0012] As a further aspect of the present invention: the power input module is also equipped with a filter capacitor, which includes a 100uF electrolytic capacitor, a 100nF ceramic capacitor and a 10uF capacitor.

[0013] As a further aspect of the present invention: the H-bridge circuit of the motor drive module realizes the forward rotation of the motor by controlling the switching transistors Q1 and Q4 to conduct, and realizes the reverse rotation of the motor by controlling the switching transistors Q2 and Q3 to conduct.

[0014] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention, by setting up a voltage detection module and a voltage regulation module, combined with the control function of the drive control module, can achieve compatible driving of 48V motors and 24V motors with a single drive circuit, eliminating the need for multiple drive circuits, effectively reducing equipment costs, shrinking equipment size, and facilitating installation and maintenance.

[0015] The voltage regulation module adopts a DC-DC conversion circuit, which adjusts the sliding resistor to output the required voltage to the drive control module. The output voltage is stable, avoiding the impact of voltage fluctuations on motor operation, improving the stability and reliability of motor operation, and extending the service life of the motor.

[0016] The circuit structure of this invention is simple, the connection logic between each module is clear, it is easy to manufacture and debug, and it has strong practicality and promotion value. It can be widely used in many fields such as industrial production, transportation, and smart homes. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is the circuit diagram for the power input module; Figure 2 The circuit diagram for the drive control module; Figure 3 This is the circuit diagram for the isolation circuit module; Figure 4 This is the circuit diagram of the motor drive module. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] This invention provides, for example Figure 1 The drawing shown is specifically a DC motor drive circuit, including a power input module, a drive control module, an isolation circuit module, and a motor drive module.

[0023] Power Input Module: This module employs a DC-DC converter circuit. Its input terminal connects to the power input module, using an LDO linear power supply for power conversion. The output voltage required by the drive control module is determined by adjusting the sliding resistor, and the output terminal connects to the motor drive module. This module stably converts the voltage input from the power input module into the voltage required by the drive control module.

[0024] Drive control module: Employs a microcontroller (such as the CH32 series microcontroller) connected to the input signal terminal of the isolation circuit module. Simultaneously, the output terminal of the isolation circuit module sends motor drive control signals to the motor drive module, enabling control of motor start / stop, speed, and direction.

[0025] The isolation circuit module uses the SN74LVC125APWR chip. Its power supply terminal is connected to a 3V DC power supply, its enable terminal is connected to GND, its input terminal is connected to the PWM output pin of the drive control module, and its output terminal is connected to the PWM control terminal of the motor driver chip in the motor interface module. This module buffers and isolates the PWM signal output from the drive control module, enhancing the driving capability of the PWM signal, reducing voltage surges and electromagnetic interference from subsequent high-voltage modules (such as voltage regulation modules and motor driver chips) to the microcontroller's I / O ports, and ensuring stable PWM signal transmission.

[0026] Motor drive module: It adopts H-bridge circuit drive. The drive control signal output by the drive control module is transmitted to the gate driver of the motor drive module to control the conduction and cutoff of the upper and lower bridge arms of the H-bridge, thereby driving the motor.

[0027] Among them, such as Figure 1 As shown, the power input module uses an LDO (Low Dropout Linear Regulator) power circuit. Regulator chips such as LM317HV, 7805, and ASM117-3.3 first step down the input 48V voltage to 24V, then to 12V, then to 5V, and finally to 3.3V. Similarly, if a 24V power input is used, the resistance values ​​of R21 and R24 can be adjusted to achieve the required 12V, 5V, and 3.3V, etc.

[0028] like Figure 2 The drive control circuit shown uses the CH32V203 chip to generate two PWM signals via software. These signals are then output to an isolation circuit.

[0029] like Figure 3 The isolation circuit shown uses the SN74LVC125APWR chip, which can enhance the driving capability of the PWM signal on the one hand, and isolate the voltage surge and electromagnetic interference of the subsequent high voltage module on the other hand, avoiding damage to the microcontroller I / O port due to high voltage backflow. At the same time, it reduces the distortion of the PWM signal caused by interference, and improves the accuracy of motor speed control and the output stability of the voltage regulation module.

[0030] like Figure 4 The circuit shown is a motor drive circuit. MOTORY1 and MOTORY2 input PWM to control the gate driver, thereby turning on Q1 and Q4, causing the motor to rotate forward, and controlling Q2 and Q3 to turn on, causing the motor to rotate in reverse.

[0031] The working principle is as follows: (I) Working process of power input module When a 48V power supply is connected, the power is first stepped down to 12V by the LM317HVT voltage regulator chip (U14, U17); then stepped down to 5V by the CJ7805 chip (U15), and subsequently stepped down to 3.3V by the AMS1117-3.3 chip (U7), providing stable power to the isolation circuit module, drive control module, and motor drive module respectively. When a 24V power supply is connected, the resistance values ​​of R21 and R24 are adjusted to allow the voltage regulator chip to output appropriate voltages such as 12V, 5V, and 3.3V, ensuring the normal operation of each module. Filter capacitors C42, C44, and C45 filter out noise in the voltage, ensuring a stable output voltage.

[0032] (II) Working process of the drive control module The CH32V203 chip generates two PWM control signals via software programming. The duty cycle of the PWM signals is used to adjust the motor speed, and the signal frequency is adapted to the motor drive requirements. The control signals are transmitted to the isolation circuit module via the chip's PWM output pin, while the chip controls the enable state of the isolation circuit module through I / O ports.

[0033] (III) Working process of the isolation circuit module After the SN74LVC125APWR chip is connected to a 3V3 power supply, it receives the PWM signal output from the drive control module. The chip buffers and amplifies the signal to enhance its driving capability, while isolating electromagnetic interference and voltage backflow generated by high-voltage components such as the motor drive module, preventing damage to the I / O ports of the CH32V203 chip, and ensuring that the PWM signal is accurately transmitted to the motor drive module.

[0034] (iv) Working process of motor drive module The isolated PWM signal is input to the gate driver IR2104STRPBF (U1, U3). The driver controls the switching transistors STB15810 (Q1, Q2, Q3, Q4) to turn on and off according to the signal. When the motor needs to rotate forward, the driver controls Q1 and Q4 to turn on, and the current flows through the motor to form a forward loop. When the motor needs to rotate in reverse, the driver controls Q2 and Q3 to turn on, and the current flows through the motor in reverse, realizing bidirectional operation of the motor. Rg1-Rg4 are gate resistors that limit the conduction current of the switching transistors and protect the device.

[0035] The drive circuit of this invention achieves stable and efficient driving of 48V and 24V DC motors through the coordinated operation of the above modules, and can be widely used in industrial production, transportation, smart home and other fields.

[0036] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0037] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment have been appropriately combined to form other embodiments that are easy for those skilled in the art to understand.

Claims

1. A drive circuit for a direct current motor, characterized by The application relates to a motor drive module, which comprises the following modules: a power input module: a DC-DC conversion circuit is adopted, the input end of which is connected with the power input module, an LDO linear power supply is adopted to convert the power supply, the required voltage of a drive control module is output through the adjustment of a sliding resistor, and the output end is connected with a motor drive module; a drive control module: a microcontroller is adopted, which is connected with an input signal end of an isolation circuit module. Meanwhile, an output end of the isolation circuit module sends a motor drive control signal to the motor drive module; an isolation circuit module: an SN74LVC125APWR chip is adopted, the power supply end of which is connected with a 3V3 direct current power supply, the chip is low-level enabled, the enabling end is connected with the ground, the input end is connected with a PWM output pin of the drive control module, and the output end is connected with a PWM control end of a motor drive chip in the motor interface module.

2. The drive circuit for a DC motor according to claim 1, wherein The LDO linear power supply of the power input module comprises an LM317HVT, a CJ7805 and an AMS1117-3.3 voltage stabilizing chip, and 48V input voltage is sequentially stepped down to 24V, 12V, 5V and 3V3, or 24V input voltage is stepped down to 12V, 5V and 3V3 through the adjustment of resistors.

3. The driving circuit of a direct current motor according to claim 1, wherein The drive control module adopts a CH32 series single-chip microcomputer, the model of which is CH32V203, and two-way PWM control signals can be generated.

4. The driving circuit of a direct current motor according to claim 1, wherein The isolation circuit module adopts an SN74LVC125APWR chip, the power supply end of which is connected with a 3V3 direct current power supply, the enabling end is connected with the ground, the input end is connected with a PWM output pin of the drive control module, and the output end is connected with a PWM control end of the motor drive module.

5. The driving circuit for supporting 48V and 24V DC motor according to claim 1, wherein, The motor drive module comprises a gate drive IR2104STRPBF and a switch tube STB15810, the gate drive receives a PWM control signal, controls the conduction and cut-off of the switch tube to realize the forward and reverse rotation of the motor.

6. The drive circuit for a DC motor according to claim 1, wherein The power input module is further provided with a filter capacitor, and the filter capacitor comprises a 100uF electrolytic capacitor, a 100nF ceramic capacitor and a 10uF capacitor.

7. The drive circuit for a DC motor according to claim 5, wherein The H-bridge circuit of the motor drive module realizes the forward rotation of the motor by controlling the conduction of the switch tube Q1 and the switch tube Q4, and realizes the reverse rotation of the motor by controlling the conduction of the switch tube Q2 and the switch tube Q3.

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