A low-voltage stable control circuit for motor control

Abstract

This invention discloses a low-voltage stable control circuit for motor control, comprising a main chip control section and a main chip drive section. The main chip control section includes a resistor R39, one end of which is connected to an I / O port of the MCU, and the other end of which is connected to one end of a power supply R40 and the base of a transistor Q7. The collector of the transistor Q7 is connected to one end of the resistor R37. This invention, by controlling the power supply first and then the drive, ensures that the stepper motor only receives power when needed, significantly extending its lifespan. It avoids damage to the control circuit from reverse induced voltage generated by the stepper motor, and provides stable low-voltage control of the high-voltage stepper motor, improving product stability, reducing resource waste, and lowering maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of stepper motor control technology, and more specifically, to a low-voltage stable control circuit that can be used for motor control. Background Technology

[0002] A stepper motor is a DC motor capable of outputting displacement. It consists of multiple electromagnets symmetrically distributed around a center, coils wound around the electromagnets, and a permanent magnet rotating around a center. When a set of coils is energized, the rotor deflects according to Ampere's law. Cutting off the current to this set of coils and energizing the adjacent coils causes the rotor to continue deflecting. This process is repeated until the rotor returns to its starting position. Each set of coils is called a motor phase. By sequentially energizing each phase, one cycle of electrical excitation is achieved for the motor. A stepper motor converts a series of input pulses into precise increments of shaft position. Each pulse corresponds to a fixed angle, and the motor's output depends only on the frequency and number of pulse signals. Because computer-controlled stepper motors can achieve very precise positioning outputs, and because stepper motors have advantages such as low cost, high reliability, and high torque at low speeds, they are widely used in precision positioning equipment.

[0003] However, the conventional way to drive stepper motors in the industry is to connect the stepper motor directly to the power supply and then make the stepper motor work by giving pulse signals with different numbers of phases. During this process, the stepper motor is always energized regardless of whether it is moving or not, which increases the power consumption of the stepper motor. In addition, the reverse induced voltage generated by the motor can damage the subsequent control circuit, which is not conducive to the long-term use of the stepper motor.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] In view of the above-mentioned technical problems in related technologies, the present invention proposes a low-voltage stable control circuit that can be used for motor control, which can overcome the above-mentioned shortcomings of the prior art.

[0006] To achieve the above-mentioned technical objectives, the technical solution of the present invention is implemented as follows:

[0007] A low-voltage stable control circuit that can be used for motor control includes a main chip control section and a main control chip drive section;

[0008] The main chip control section includes a resistor R39. One end of the resistor R39 is connected to the I / O port of the MCU. The other end of the resistor R39 is connected to one end of the power supply R40 and the base of the transistor Q7. The collector of the transistor Q7 is connected to one end of the resistor R37. The other end of the resistor R37 is connected to one end of the resistor R36 and the gate of the field-effect transistor Q6. The other end of the resistor R36 and the source of the field-effect transistor Q6 are both connected to a +12V DC power supply. The drain of the field-effect transistor Q6 is connected to one end of the capacitor C34 and the positive terminal of the rectifier diode D13.

[0009] The main control chip driver section includes a driver U4. Pin 1 of the driver U4 is connected to I / O port 2 of the MCU and one end of resistor R41. Pin 2 of the driver U4 is connected to I / O port 3 of the MCU and one end of resistor R42. Pin 3 of the driver U4 is connected to I / O port 4 of the MCU and one end of resistor R43. Pin 4 of the driver U4 is connected to I / O port 5 of the MCU and one end of resistor R44. Pin 8 of the driver U4 is connected to one end of capacitor C36 and ground.

[0010] Pin 16 of the driver U4 is connected to pin 1 of the stepper motor connector XH3, pin 15 of the driver U4 is connected to pin 2 of the stepper motor connector XH3, pin 14 of the driver U4 is connected to pin 3 of the stepper motor connector XH3, pin 13 of the driver U4 is connected to pin 4 of the stepper motor connector XH3, and pin 9 of the driver U4, the negative terminal of the rectifier diode D13, and the other end of the capacitor C36 are all connected to pin 5 of the stepper motor connector XH3.

[0011] Furthermore, the emitter of the transistor Q7 and the other end of the resistor R40 are both connected to ground.

[0012] Furthermore, the other end of the capacitor C34 is connected to ground.

[0013] Furthermore, the other ends of resistors R41, R42, R43, and R44 are all connected to ground.

[0014] Furthermore, pins 10, 11, and 12 of the driver U4 are all connected to ground.

[0015] The beneficial effects of this invention are as follows: By controlling the power supply first and then the drive, this invention ensures that the stepper motor only receives power when needed, which greatly extends the service life of the stepper motor. It also avoids damage to the control circuit caused by the reverse induced voltage generated by the stepper motor, and plays a role in stabilizing the control of the high-voltage stepper motor under low voltage, thereby improving the stability of the product, reducing resource waste, and lowering the maintenance cost of the product. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0017] Figure 1 This is a circuit diagram of a low-voltage stable control circuit that can be used for motor control according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of a low-voltage stable control circuit that can be used for motor control according to an embodiment of the present invention;

[0019] Figure 3 This is a test waveform diagram of a low-voltage stable control circuit that can be used for motor control according to an embodiment of the present invention. Detailed Implementation

[0020] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0021] like Figure 1-2 As shown, a low-voltage stable control circuit for motor control according to an embodiment of the present invention includes a main chip control section and a main control chip drive section.

[0022] The main chip control section includes a resistor R39. One end of the resistor R39 is connected to the I / O port of the MCU. The other end of the resistor R39 is connected to one end of the power supply R40 and the base of the transistor Q7. The collector of the transistor Q7 is connected to one end of the resistor R37. The other end of the resistor R37 is connected to one end of the resistor R36 and the gate of the field-effect transistor Q6. The other end of the resistor R36 and the source of the field-effect transistor Q6 are both connected to a +12V DC power supply. The drain of the field-effect transistor Q6 is connected to one end of the capacitor C34 and the positive terminal of the rectifier diode D13.

[0023] The main control chip driver section includes a driver U4. Pin 1 of the driver U4 is connected to I / O port 2 of the MCU and one end of resistor R41. Pin 2 of the driver U4 is connected to I / O port 3 of the MCU and one end of resistor R42. Pin 3 of the driver U4 is connected to I / O port 4 of the MCU and one end of resistor R43. Pin 4 of the driver U4 is connected to I / O port 5 of the MCU and one end of resistor R44. Pin 8 of the driver U4 is connected to one end of capacitor C36 and ground.

[0024] Pin 16 of the driver U4 is connected to pin 1 of the stepper motor connector XH3, pin 15 of the driver U4 is connected to pin 2 of the stepper motor connector XH3, pin 14 of the driver U4 is connected to pin 3 of the stepper motor connector XH3, pin 13 of the driver U4 is connected to pin 4 of the stepper motor connector XH3, and pin 9 of the driver U4, the negative terminal of the rectifier diode D13, and the other end of the capacitor C36 are all connected to pin 5 of the stepper motor connector XH3.

[0025] In this embodiment, the emitter of transistor Q7 and the other end of resistor R40 are both connected to ground. The other end of capacitor C34 is connected to ground. The other ends of resistors R41, R42, R43, and R44 are all connected to ground. Pins 10, 11, and 12 of driver U4 are all connected to ground.

[0026] To facilitate understanding of the above technical solutions of the present invention, the following detailed description of the above technical solutions of the present invention will be provided through specific usage methods.

[0027] In practical application, according to the low-voltage stable control circuit for motor control described in this invention, when the I / O of the MCU connected to resistor R39 is set to a high level, current flows through the base of transistor Q7, causing conduction between the collector and emitter of transistor Q7. At this time, a voltage drop is generated between the source and gate of field-effect transistor Q6, causing conduction between the drain and source of field-effect transistor Q6. Driver U4 and stepper motor receive voltage. By controlling the power-on sequence of the I / O of the MCU connected to pins 1, 2, 3, and 4 of driver U4, the stepper motor can be driven to rotate. When the I / O of the MCU connected to resistor R39 is set to a low level, the collector and emitter of transistor Q7 are open, and the source and drain of field-effect transistor Q6 are no longer conducting, causing driver U4 and stepper motor to stop working. Figure 3 This is a waveform diagram for motor control testing.

[0028] The main chip control section incorporates a field-effect transistor (FET) and related circuitry, enabling the 12V power supply to be accurately divided through resistors R36 and R37 after the MCU outputs a high-level signal. At this point, the parameter V of the FET Q6... GS When the activation value is reached, the stepper motor receives power and enters a standby state. Diode D13 prevents the stepper motor from generating reverse induced voltage that could damage the control circuit.

[0029] Traditional motors are current-driven components, and the I / O output current of traditional MCUs is generally around 10mA, which is far from sufficient for driving capability. Therefore, a driver device U4 is needed to control the motor. The U4 driver output can reach 500mA / 50V. The MCU performs multi-phase timing control on the driver chip U4, providing different pulse signals to the four phases of the stepper motor to drive it to rotate precisely in a clockwise direction.

[0030] This design uses different I / O ports of the MCU to control the power supply and drive components separately. When the MCU provides a high-level signal to the control unit, the stepper motor receives power and enters a standby state. Only when the MCU provides the corresponding level signal to the motor drive through another I / O port can the motor operate. This design is applied to the adjustment of the air valve in a fresh air system, allowing precise adjustment of the valve's rotation angle to change the ratio of indoor to outdoor air received by the fan, achieving the user's desired state.

[0031] In summary, by utilizing the above-mentioned technical solution of the present invention, and by controlling the power supply first and then the drive, the stepper motor is only powered when needed, which greatly extends the service life of the stepper motor. This avoids damage to the control circuit caused by the reverse induced voltage generated by the stepper motor, and also plays a role in stabilizing the control of the high-voltage stepper motor under low voltage, thereby improving the stability of the product, reducing resource waste, and lowering the maintenance cost of the product.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-voltage stable control circuit for motor control, characterized in that, This includes the main chip control section and the main control chip driver section; The main chip control section includes a resistor R39. One end of the resistor R39 is connected to the I / O port of the MCU. The other end of the resistor R39 is connected to one end of the resistor R40 and the base of the transistor Q7. The collector of the transistor Q7 is connected to one end of the resistor R37. The other end of the resistor R37 is connected to one end of the resistor R36 and the gate of the field-effect transistor Q6. The other end of the resistor R36 and the source of the field-effect transistor Q6 are both connected to a +12V DC power supply. The drain of the field-effect transistor Q6 is connected to one end of the capacitor C34 and the positive terminal of the rectifier diode D13. The main control chip driver section includes a driver U4. Pin 1 of the driver U4 is connected to I / O port 2 of the MCU and one end of resistor R41. Pin 2 of the driver U4 is connected to I / O port 3 of the MCU and one end of resistor R42. Pin 3 of the driver U4 is connected to I / O port 4 of the MCU and one end of resistor R43. Pin 4 of the driver U4 is connected to I / O port 5 of the MCU and one end of resistor R44. Pin 8 of the driver U4 is connected to one end of capacitor C36 and ground. Pin 16 of the driver U4 is connected to pin 1 of the stepper motor connector XH3, pin 15 of the driver U4 is connected to pin 2 of the stepper motor connector XH3, pin 14 of the driver U4 is connected to pin 3 of the stepper motor connector XH3, pin 13 of the driver U4 is connected to pin 4 of the stepper motor connector XH3, and pin 9 of the driver U4, the negative terminal of the rectifier diode D13, and the other end of the capacitor C36 are all connected to pin 5 of the stepper motor connector XH3. The emitter of transistor Q7 and the other end of resistor R40 are both connected to ground; the other end of capacitor C34 is also connected to ground.

2. The low-voltage stable control circuit for motor control according to claim 1, characterized in that, The other ends of resistors R41, R42, R43, and R44 are all connected to ground.

3. The low-voltage stable control circuit for motor control according to claim 1, characterized in that, Pins 10, 11, and 12 of the driver U4 are all connected to ground.

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