Stepping motor control device

Abstract

The utility model discloses a stepping motor control device. The stepping motor control device comprises a power supply circuit, a key acquisition circuit, a control chip and a driving chip, the key acquisition circuit comprises a voltage state input end and a pulse signal output end, the control chip comprises a pulse signal receiving end and a driving instruction output end, and the driving chip comprises a driving instruction receiving end and a rotation parameter output end; the pulse signal output end is electrically connected with the pulse signal receiving end, the driving instruction output end is electrically connected with the driving instruction receiving end, and the rotation parameter output end is electrically connected with the stepping motor; and the control chip is used for outputting a driving instruction to the driving chip according to the pulse signal received by the pulse signal receiving end so as to drive the stepping motor to rotate. By the adoption of the technical scheme, the stepping motor can be controlled to run through key operation, complex software programming is not needed, operation is simplified, and cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of stepping motors, in particular to a stepping motor control device. Background Art

[0002] A stepping motor is a motor that converts a pulse signal into a corresponding angular displacement or linear displacement.

[0003] Currently, for the automated stepping motors used in controlling the opening degree of the electronic expansion valve and the position of the air door in the automotive air conditioning system, the existing technical solutions have the following problems: First, software programming increases the complexity of the system and requires high technical personnel; Second, control errors may occur due to programming errors during software programming, resulting in poor reliability; Third, the later system maintenance cost is high. Content of the Utility Model

[0004] The utility model provides a stepping motor control device to realize controlling the operation of the stepping motor through button operations, without complex software programming, simplifying the operation and reducing costs.

[0005] The utility model provides a stepping motor control device, including: a power supply circuit, a button acquisition circuit, a control chip, and a driving chip;

[0006] The power supply circuit includes a power voltage output terminal, and the power voltage output terminal is electrically connected to the first power voltage receiving terminal of the button acquisition circuit, the power supply pin of the control chip, and the power supply voltage terminal of the driving chip respectively;

[0007] The button acquisition circuit includes a voltage state input terminal and a pulse signal output terminal, the control chip includes a pulse signal receiving terminal and a driving instruction output terminal, and the driving chip includes a driving instruction receiving terminal and a rotation parameter output terminal;

[0008] The pulse signal output terminal is electrically connected to the pulse signal receiving terminal, the driving instruction output terminal is electrically connected to the driving instruction receiving terminal, and the rotation parameter output terminal is electrically connected to the stepping motor; the control chip is used to output a driving instruction to the driving chip according to the pulse signal received by the pulse signal receiving terminal to drive the stepping motor to rotate.

[0009] Optionally, the button acquisition circuit includes a switch unit, a pull-up resistor, a current limiting resistor, and a capacitor;

[0010] The first end of the switch unit is grounded. The second end of the switch unit is electrically connected to the first end of the pull-up resistor and the first end of the current-limiting resistor respectively. The second end of the pull-up resistor is electrically connected to the power supply voltage output terminal. The second end of the current-limiting resistor is electrically connected to the first end of the capacitor and the pulse signal receiving terminal respectively. The second end of the capacitor is grounded. The second end of the current-limiting resistor is the pulse signal output terminal, and the second end of the pull-up resistor is the first power supply voltage receiving terminal.

[0011] Optionally, the drive chip further includes a first power supply pin and a second power supply pin. The rotation parameter output terminal includes a first rotation parameter output terminal, a second rotation parameter output terminal, a third rotation parameter output terminal, and a fourth rotation parameter output terminal.

[0012] The stepper motor includes a first coil and a second coil. The first coil includes a first end pin, a second end pin, and a first middle pin. The second coil includes a third end pin, a fourth end pin, and a second middle pin.

[0013] The first end pin is electrically connected to the first rotation parameter output terminal. The second end pin is electrically connected to the second rotation parameter output terminal. The third end pin is electrically connected to the third rotation parameter output terminal. The fourth end pin is electrically connected to the fourth rotation parameter output terminal.

[0014] The first middle pin is electrically connected to the first power supply pin and the second power supply pin respectively. The second middle pin is electrically connected to the first power supply pin and the second power supply pin respectively.

[0015] Optionally, the drive instruction includes a forward rotation instruction and a reverse rotation instruction.

[0016] When the drive instruction receiving terminal receives the forward rotation instruction, the drive chip is used to drive the stepper motor to rotate forward.

[0017] When the drive instruction receiving terminal receives the reverse rotation instruction, the drive chip is used to drive the stepper motor to rotate in reverse.

[0018] When the stepper motor rotates forward, the working states of the stepper motor include a first working state, a second working state, a third working state, and a fourth working state. The forward rotation angles of the stepper motor are different in different working states.

[0019] In the first working state, the second rotation parameter output terminal outputs a low-level signal to the second end pin, and the fourth rotation parameter output terminal outputs a low-level signal to the fourth end pin; in the second working state, the second rotation parameter output terminal outputs a low-level signal to the second end pin, and the third rotation parameter output terminal outputs a low-level signal to the third end pin; in the third working state, the first rotation parameter output terminal outputs a low-level signal to the first end pin, and the third rotation parameter output terminal outputs a low-level signal to the third end pin; in the fourth working state, the first rotation parameter output terminal outputs a low-level signal to the first end pin, and the fourth rotation parameter output terminal outputs a low-level signal to the fourth end pin;

[0020] When the stepping motor rotates in reverse, the working states of the stepping motor include a fifth working state, a sixth working state, a seventh working state, and an eighth working state, and the reverse rotation angles of the stepping motor are different in different working states;

[0021] In the fifth working state, the second rotation parameter output terminal outputs a low-level signal to the second end pin, and the fourth rotation parameter output terminal outputs a low-level signal to the fourth end pin; in the sixth working state, the first rotation parameter output terminal outputs a low-level signal to the first end pin, and the fourth rotation parameter output terminal outputs a low-level signal to the fourth end pin; in the seventh working state, the first rotation parameter output terminal outputs a low-level signal to the first end pin, and the third rotation parameter output terminal outputs a low-level signal to the third end pin; in the eighth working state, the second rotation parameter output terminal outputs a low-level signal to the second end pin, and the third rotation parameter output terminal outputs a low-level signal to the third end pin.

[0022] Optionally, the stepping motor control device further includes a current detection circuit;

[0023] The current detection circuit includes a voltage output and current acquisition terminal and a voltage signal output terminal; the control chip further includes a voltage signal receiving terminal;

[0024] The voltage output and current acquisition terminal is electrically connected to the first middle pin and the second middle pin respectively, and the voltage signal output terminal is electrically connected to the voltage signal receiving terminal.

[0025] Optionally, the current detection circuit includes a current detection chip, a first diode, a first capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a second capacitor, and a second diode; the anode of the first diode is electrically connected to the first voltage input terminal, and the anode of the second diode is electrically connected to the second voltage input terminal; the first end of the fourth resistor is the voltage output and current acquisition terminal;

[0026] The current detection chip includes a negative input pin, a positive input pin, a negative power supply pin, a positive power supply pin, and a voltage signal output pin; wherein, the voltage signal output pin is the voltage signal output terminal;

[0027] The first end of the first resistor is electrically connected to the second middle pin and the first end of the fourth resistor respectively, the second end of the first resistor is electrically connected to the first end of the second resistor and the negative input pin respectively, the second end of the second resistor is electrically connected to the voltage signal output pin, the second end of the fourth resistor is electrically connected to the first end of the third resistor, the cathode of the first diode, and the first end of the first capacitor respectively, the second end of the first capacitor is grounded, the second end of the third resistor is electrically connected to the positive input pin and the first end of the fifth resistor respectively, the second end of the fifth resistor is electrically connected to the negative power supply pin and the first end of the second capacitor respectively, the first end of the second capacitor is grounded, and the second end of the second capacitor is electrically connected to the positive power supply pin and the cathode of the second diode respectively.

[0028] Optionally, the stepping motor control device further includes a display circuit; the control chip further includes a motor status information output terminal and a pulse information output terminal, and the display circuit includes a motor status information receiving terminal, a pulse information receiving terminal, and a second power supply voltage receiving terminal;

[0029] The second power supply voltage receiving terminal is electrically connected to the power supply voltage output terminal;

[0030] The motor status information output terminal is electrically connected to the motor status information receiving terminal, and the pulse information output terminal is electrically connected to the pulse information receiving terminal.

[0031] Optionally, the display circuit further includes a display chip, a first rotary potentiometer, and a second rotary potentiometer;

[0032] The display chip includes a regulated voltage output terminal, a contrast pin, a backlight positive pin, and a backlight negative pin;

[0033] The backlight positive pin is electrically connected to the power supply voltage output terminal, the backlight negative pin is electrically connected to the first end of the first rotary potentiometer, and the second end of the first rotary potentiometer is grounded;

[0034] The contrast pin is electrically connected to the first end of the second rotary potentiometer. The second end of the second rotary potentiometer is grounded, and the third end of the second rotary potentiometer is electrically connected to the regulated voltage output terminal.

[0035] Optionally, the power supply circuit includes a power supply chip, a third diode, a first capacitor, a second capacitor, an inductor, and a zener diode;

[0036] The power supply chip includes a power input terminal, an output port, a ground port, a feedback port, and a switch port;

[0037] The anode of the third diode is the power voltage input terminal, and the first capacitor plate of the second capacitor is the power voltage output terminal;

[0038] The cathode of the third diode is electrically connected to the power input port and the first capacitor plate of the first capacitor respectively. The second capacitor plate of the first capacitor is electrically connected to the anode of the zener diode, the ground port, and the switch port respectively. The first capacitor plate of the second capacitor is electrically connected to the first end of the inductor. The second end of the inductor is electrically connected to the cathode of the zener diode, the output port, and the feedback port respectively. The second capacitor plate of the second capacitor is grounded.

[0039] Optionally, the driving chip includes a hexagon half-bridge driver.

[0040] In the key acquisition circuit according to the embodiment of the present invention, a pulse signal is generated according to the change of the voltage state and output to the control chip. The control chip generates a driving instruction according to the pulse signal and transmits the driving instruction to the driving chip. Further, the driving chip generates a rotation parameter according to the driving instruction to drive the stepping motor to operate. By adopting the above technical solution, the operation of the stepping motor can be controlled through key operation without complex software programming, so as to complete the control of the expansion valve opening and the determination of the air door position, simplify the operation, reduce the cost, and increase the stability of the stepping motor control.

[0041] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] To more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0043] Figure 1 It is a schematic structural diagram of a stepping motor control device provided according to an embodiment of the present utility model;

[0044] Figure 2 It is a circuit diagram of a key acquisition circuit provided according to an embodiment of the present utility model;

[0045] Figure 3 It is a schematic structural diagram of a control chip provided according to an embodiment of the present utility model;

[0046] Figure 4 It is a circuit diagram of a driving chip provided according to an embodiment of the present utility model;

[0047] Figure 5 It is a schematic structural diagram of another stepping motor control device provided according to an embodiment of the present utility model;

[0048] Figure 6 It is a schematic structural diagram of a current detection circuit provided according to an embodiment of the utility model;

[0049] Figure 7 It is a schematic structural diagram of yet another stepping motor control device provided according to an embodiment of the present utility model;

[0050] Figure 8 It is a circuit diagram of a display circuit provided according to an embodiment of the present utility model;

[0051] Figure 9 It is a circuit diagram of a power supply circuit provided according to an embodiment of the present utility model. Detailed implementation manners

[0052] In order to enable those skilled in the art to better understand the solutions of the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0053] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present utility model are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" any variations are intended to cover non-exclusive inclusion.

[0054] Figure 1 FIG. 1 is a schematic structural diagram of a stepping motor control device according to an embodiment of the present utility model. This embodiment is applicable to the control of the opening degree of an electronic expansion valve and the determination of the position of an air door in an automotive air conditioning system. As Figure 1 shown, the device includes: a power supply circuit 1, a key acquisition circuit 2, a control chip 3, and a driver chip 4; the power supply circuit 1 includes a power voltage output terminal 11, and the power voltage output terminal 11 is electrically connected to a first power voltage receiving terminal 21 of the key acquisition circuit 2, a power pin 31 of the control chip 3, and a power supply voltage terminal 41 of the driver chip 4 respectively; the key acquisition circuit 2 includes a voltage state input terminal 22 and a pulse signal output terminal 23, the control chip 3 includes a pulse signal receiving terminal 32 and a driving instruction output terminal 33, and the driver chip 4 includes a driving instruction receiving terminal 42 and a rotation parameter output terminal 43; the pulse signal output terminal 23 is electrically connected to the pulse signal receiving terminal 32, the driving instruction output terminal 33 is electrically connected to the driving instruction receiving terminal 42, and the rotation parameter output terminal 43 is electrically connected to the stepping motor 5; the control chip 3 is configured to output a driving instruction to the driver chip 4 according to the pulse signal received by the pulse signal receiving terminal 32 to drive the stepping motor 5 to rotate.

[0055] Specifically, the power supply circuit 1 can be a buck switch-mode integrated voltage regulator circuit, which is applied to DC buck conversion and can convert a high-voltage DC power supply into a low-voltage DC power supply. In this embodiment, the power supply circuit 1 can convert the 12V voltage into 5V voltage to supply power to the key acquisition circuit 2, the control chip 3, and the drive chip 4. The user changes the voltage state in the key acquisition circuit 2 through the voltage state input terminal 22 to generate a pulse signal, and outputs it through the pulse signal output terminal 23. The control chip 3 can be a high-performance microcontroller (MCU), which has a variety of integrated functions and high cost performance, and has a basis for the pulse signal. In this embodiment, the control chip 3 receives the pulse signal through the pulse signal receiving terminal 32, identifies and processes the pulse signal to generate a drive instruction, and further outputs it through the drive instruction output terminal 33. The drive chip 4 can be a six-phase half-bridge driver, and the six-phase half-bridge driver can provide H-bridge control of forward, reverse, braking, and high-impedance states. Among them, the H-bridge is an electronic circuit used to realize the forward and reverse control and speed control of the motor. In this embodiment, the drive instruction receiving terminal 42 of the drive chip 4 receives the drive instruction, generates rotation parameters according to the drive instruction, and further outputs the rotation parameters through the rotation parameter output terminal 43. The drive chip 4 outputs the rotation parameters to the stepping motor 5 to drive the stepping motor 5 to rotate forward or backward.

[0056] In the embodiment of the present invention, the key acquisition circuit generates a pulse signal according to the change of the voltage state and outputs it to the control chip. The control chip generates a drive instruction according to the pulse signal and transmits the drive instruction to the drive chip. Further, the drive chip generates rotation parameters according to the drive instruction, thereby driving the stepping motor to operate. By adopting the above technical solution, there is no need for complex software programming. By operating the key to control the operation of the stepping motor, the control of the expansion valve opening and the determination of the air door position can be completed, which simplifies the operation, reduces the cost, and increases the stability of the stepping motor control.

[0057] Based on the above embodiment, Figure 2 is the circuit diagram of the key acquisition circuit provided by the embodiment of the present invention, Figure 3 is the schematic structural diagram of the control chip provided by the embodiment of the present invention. As Figure 2 shown, the key acquisition circuit 2 includes a switch unit S, a pull-up resistor Rs, a current-limiting resistor Rx, and a capacitor C; the first end of the switch unit S is grounded, the second end of the switch unit S is electrically connected to the first end of the pull-up resistor Rs and the first end of the current-limiting resistor Rx respectively, the second end of the pull-up resistor Rs is electrically connected to the power supply voltage output terminal 11, the second end of the current-limiting resistor Rx is electrically connected to the first end of the capacitor C and the pulse signal receiving terminal 32 respectively, and the second end of the capacitor C is grounded; the second end of the current-limiting resistor Rx is the pulse signal output terminal 23, and the second end of the pull-up resistor Rs is the first power supply voltage receiving terminal 21.

[0058] Further, as Figure 2 shown, the switch unit S includes a first push-button switch S1, a second push-button switch S2, a third push-button switch S3, a fourth push-button switch S4, and a fifth push-button switch S5; the pull-up resistors Rs include a first pull-up resistor Rs1, a second pull-up resistor Rs2, a third pull-up resistor Rs3, a fourth pull-up resistor Rs4, and a fifth pull-up resistor Rs5; the current-limiting resistors Rx include a first current-limiting resistor Rx1, a second current-limiting resistor Rx2, a third current-limiting resistor Rx3, a fourth current-limiting resistor Rx4, and a fifth current-limiting resistor Rx5; the capacitor C includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. The pulse signal output terminal 23 includes a first pulse signal output terminal KEY-PULSE+, a second pulse signal output terminal KEY-PULSE-, a third pulse signal output terminal KEY-Dir+, a fourth pulse signal output terminal KEY-Dir-, and a fifth pulse signal output terminal SET.

[0059] As Figure 3 shown, the pulse signal receiving terminal 32 includes a first pulse signal receiving terminal PTA4PIA4ADP4, a second pulse signal receiving terminal PTB0PIB0ADP8, a third pulse signal receiving terminal PTA5PIA5ADP5, a fourth pulse signal receiving terminal PTA6PIA6ADP6, and a fifth pulse signal receiving terminal PTA7PIA7ADP7IRQ.

[0060] Further, the first pulse signal output terminal KEY-PULSE+ is electrically connected to the first pulse signal receiving terminal PTA4PIA4ADP4, the second pulse signal output terminal KEY-PULSE- is electrically connected to the second pulse signal receiving terminal PTB0PIB0ADP8, the third pulse signal output terminal KEY-Dir+ is electrically connected to the third pulse signal receiving terminal PTA5PIA5ADP5, the fourth pulse signal output terminal KEY-Dir- is electrically connected to the fourth pulse signal receiving terminal PTA6PIA6ADP6, and the fifth pulse signal output terminal SET is electrically connected to the fifth pulse signal receiving terminal PTA7PIA7ADP7IRQ.

[0061] The first end of the first push-button switch S1 is grounded, the second end of the first push-button switch S1 is electrically connected to the first end of the first pull-up resistor Rs1 and the first end of the first current-limiting resistor Rx1 respectively, the second end of the first pull-up resistor Rs1 is electrically connected to the power supply voltage output terminal 11, the second end of the first current-limiting resistor Rx1 is electrically connected to the first end of the first capacitor C1 and the pulse signal receiving terminal 32 respectively, and the second end of the first capacitor C1 is grounded; the second end of the first current-limiting resistor Rx1 is the first pulse signal output terminal KEY-PULSE+.

[0062] The first end of the second push-button switch S2 is grounded, and the second end of the second push-button switch S2 is electrically connected to the first end of the second pull-up resistor Rs2 and the first end of the second current-limiting resistor Rx2 respectively. The second end of the second pull-up resistor Rs2 is electrically connected to the power supply voltage output terminal 11, and the second end of the second current-limiting resistor Rx2 is electrically connected to the first end of the second capacitor C2 and the pulse signal receiving terminal 32 respectively. The second end of the second capacitor C2 is grounded; the second end of the second current-limiting resistor Rx2 is the second pulse signal output terminal KEY-PULSE-.

[0063] The first end of the third push-button switch S3 is grounded, and the second end of the third push-button switch S3 is electrically connected to the first end of the third pull-up resistor Rs3 and the first end of the third current-limiting resistor Rx3 respectively. The second end of the third pull-up resistor Rs3 is electrically connected to the power supply voltage output terminal 11, and the second end of the third current-limiting resistor Rx3 is electrically connected to the first end of the third capacitor C3 and the pulse signal receiving terminal 32 respectively. The second end of the third capacitor C3 is grounded; the second end of the third current-limiting resistor Rx3 is the third pulse signal output terminal KEY-Dir+.

[0064] The first end of the fourth push-button switch S4 is grounded, and the second end of the fourth push-button switch S4 is electrically connected to the first end of the fourth pull-up resistor Rs4 and the first end of the fourth current-limiting resistor Rx4 respectively. The second end of the fourth pull-up resistor Rs4 is electrically connected to the power supply voltage output terminal 11, and the second end of the fourth current-limiting resistor Rx4 is electrically connected to the first end of the fourth capacitor C4 and the pulse signal receiving terminal 32 respectively. The second end of the fourth capacitor C4 is grounded; the second end of the fourth current-limiting resistor Rx4 is the fourth pulse signal output terminal KEY-Dir-.

[0065] The first end of the fifth push-button switch S5 is grounded, and the second end of the fifth push-button switch S5 is electrically connected to the first end of the fifth pull-up resistor Rs5 and the first end of the fifth current-limiting resistor Rx5 respectively. The second end of the fifth pull-up resistor Rs5 is electrically connected to the power supply voltage output terminal 11, and the second end of the fifth current-limiting resistor Rx5 is electrically connected to the first end of the fifth capacitor C4 and the pulse signal receiving terminal 32 respectively. The second end of the fifth capacitor C5 is grounded; the second end of the fifth current-limiting resistor Rx5 is the fifth pulse signal output terminal SET.

[0066] Specifically, the second end of the pull-up resistor Rs is used as the first power supply voltage receiving terminal 21 and is electrically connected to the power supply voltage output terminal 11, so as to ensure that the voltage in the circuit is high level in the default state. When the user presses the switching unit, the switching unit closes. At this time, since the first end of the switching unit is grounded, the voltage in the circuit becomes low level. At this time, the state of the voltage in the circuit changes from high level to low level to generate a pulse signal, and is output to the pulse signal receiving terminal of the control chip 3 through the pulse signal output terminal.

[0067] Exemplarily, the user can set the positive pulse time, negative pulse time, number of pulses, power-on delay, and rotation direction of the pulse signal through buttons. The positive pulse time + or power-on delay + can be adjusted through the first button switch S1; the positive pulse time - or negative pulse time + can be adjusted through the second button switch S2; the number of pulses + or negative pulse time + can be adjusted through the third button switch S3; the number of pulses - or negative pulse time - can be adjusted through the fourth button switch S4; the fifth button switch S5 is used to control on or off.

[0068] If the first button switch S1 and the second button switch S2 are pressed for more than 6 seconds, the pulse time setting option is entered; the positive pulse time is adjusted through the first button switch S1 and the first button switch S2; the negative pulse time is adjusted through the third button switch S3 and the fourth button switch S4.

[0069] If the third button switch S3 and the fourth button switch S4 are pressed for more than 6 seconds, the pulse number and power-on delay setting option is entered. The power-on delay is set by adjusting the first button switch S1 and the second button switch S2; the pulse number is set by adjusting the third button switch S3 and the fourth button switch S4.

[0070] If the first button switch S1 and the third button switch S3 are pressed for more than 3 seconds, the motor is set to rotate forward; if the second button switch S2 and the fourth button switch S4 are pressed for more than 3 seconds, the motor is set to rotate backward.

[0071] For example, through the above adjustment method, the positive pulse time is adjusted to 0.005 s, the negative pulse time is adjusted to 0.005 s, the number of pulses is adjusted to 7200, then the first button switch S1 and the third button switch S3 are long-pressed for more than 3 seconds, and finally the fifth button switch S5 is pressed. In this way, the stepping motor 5 can be made to rotate forward one circle.

[0072] In the embodiment of the present invention, the user adjusts the switch unit to set parameters such as positive pulse time, negative pulse time, power-on delay, number of pulses, and rotation direction to control the rotation of the stepping motor. By adopting the above technical solution, complex software programming is not required, and the operation of the stepping motor is controlled through button operations, so that the control of the expansion valve opening and the determination of the damper position can be completed, the operation is simplified, the cost is reduced, and the stability of the stepping motor control is increased.

[0073] On the basis of the above embodiment, Figure 4 is a circuit diagram of a driving chip provided according to an embodiment of the present invention. As Figure 4As shown, the drive chip 4 further includes a first power supply pin VS1 and a second power supply pin VS2; the rotation parameter output terminals include a first rotation parameter output terminal OUT1, a second rotation parameter output terminal OUT5, a third rotation parameter output terminal OUT6, and a fourth rotation parameter output terminal OUT4; the stepper motor 5 includes a first coil A and a second coil B; the first coil A includes a first end pin A1, a second end pin A2, and a first middle pin A3, and the second coil B includes a third end pin B1, a fourth end pin B2, and a second middle pin B3; the first end pin A1 is electrically connected to the first rotation parameter output terminal OUT1, the second end pin A2 is electrically connected to the second rotation parameter output terminal OUT5, the third end pin B1 is electrically connected to the third rotation parameter output terminal OUT6, and the fourth end pin B2 is electrically connected to the fourth rotation parameter output terminal OUT4; the first middle pin A3 is electrically connected to the first power supply pin VS1 and the second power supply pin VS2 respectively, and the second middle pin B3 is electrically connected to the first power supply pin VS1 and the second power supply pin VS2 respectively.

[0074] Furthermore, the SI pin of the drive chip 4 is electrically connected to the PTE4 / MOSI pin of the control chip 3, the SO pin is electrically connected to the PTE5 / MISO pin, the EN pin is electrically connected to the PTF7 pin, the SCLK pin is electrically connected to the PTE3 / SPSCK pin, and the CSB pin is electrically connected to the PTE2 / SS pin.

[0075] It is used to realize the synchronous transmission of data. This connection method ensures that data can be smoothly sent from the MCU to the drive chip 4 to realize the control of the drive chip 4 and the transmission of drive instructions.

[0076] In addition, the VCC pin on the drive chip 4 is the power supply voltage terminal 41 of the drive chip 4 and is electrically connected to the power supply voltage output terminal 11 to obtain the necessary operating voltage for the drive chip 4. It should be noted that the connection method of the GND grounding and the 0.1 μF capacitor C6 in the drive chip 4 is a conventional setting, and the NC pin, OUT2 pin, RESERVED pin, and OUT3 pin are conventional pins and will not be specifically explained. DGND is the ground wire in the digital circuit.

[0077] In the embodiment of the present utility model, by electrically connecting the drive chip to the stepper motor, the drive parameters are transmitted to the stepper motor to control the operation of the stepper motor, realizing the control of the expansion valve opening and the determination of the damper position, simplifying the operation, reducing the cost, and increasing the stability of the stepper motor control.

[0078] Based on the above embodiment, this embodiment further explains how the drive chip controls the operation of the drive motor. Continue to refer to Figure 4, the drive instructions include a forward rotation instruction and a reverse rotation instruction; when the drive instruction receiving end 42 receives the forward rotation instruction, the drive chip 4 is used to drive the stepper motor 5 to rotate forward; when the drive instruction receiving end 42 receives the reverse rotation instruction, the drive chip 4 is used to drive the stepper motor 5 to rotate in reverse; when the stepper motor 5 rotates forward, the working states of the stepper motor 5 include a first working state, a second working state, a third working state, and a fourth working state, and the forward rotation angles of the stepper motor 5 are different in different working states;

[0079] In the first working state, the second rotation parameter output terminal OUT5 outputs a low-level signal to the second end pin A2, and the fourth rotation parameter output terminal OUT4 outputs a low-level signal to the fourth end pin B2;

[0080] In the second working state, the second rotation parameter output terminal OUT5 outputs a low-level signal to the second end pin A2, and the third rotation parameter output terminal OUT6 outputs a low-level signal to the third end pin B1;

[0081] In the third working state, the first rotation parameter output terminal OUT1 outputs a low-level signal to the first end pin A1, and the third rotation parameter output terminal OUT6 outputs a low-level signal to the third end pin B1;

[0082] In the fourth working state, the first rotation parameter output terminal OUT1 outputs a low-level signal to the first end pin A1, and the fourth rotation parameter output terminal OUT4 outputs a low-level signal to the fourth end pin B2;

[0083] When the stepper motor 5 rotates in reverse, the working states of the stepper motor 5 include a fifth working state, a sixth working state, a seventh working state, and an eighth working state, and the reverse rotation angles of the stepper motor 5 are different in different working states;

[0084] In the fifth working state, the second rotation parameter output terminal OUT5 outputs a low-level signal to the second end pin A2, and the fourth rotation parameter output terminal OUT4 outputs a low-level signal to the fourth end pin B2;

[0085] In the sixth working state, the first rotation parameter output terminal OUT1 outputs a low-level signal to the first end pin A1, and the fourth rotation parameter output terminal OUT4 outputs a low-level signal to the fourth end pin B2;

[0086] In the seventh working state, the first rotation parameter output terminal OUT1 outputs a low-level signal to the first end pin A1, and the third rotation parameter output terminal OUT6 outputs a low-level signal to the third end pin B1;

[0087] In the eighth working state, the second rotation parameter output terminal OUT5 outputs a low-level signal to the second end pin A2, and the third rotation parameter output terminal OUT6 outputs a low-level signal to the third end pin B1.

[0088] Specifically, in the forward rotation state, the stepping motor 5 rotates from 0 degrees to 90 degrees in the first working state, from 90 degrees to 180 degrees in the second working state, from 180 degrees to 270 degrees in the third state, and from 270 degrees to 360 degrees in the fourth state. That is to say, the stepping motor 5 rotates one full circle in the forward direction from the first state to the end of the fourth state.

[0089] In the reverse rotation state, the stepping motor 5 rotates from 0 degrees to -90 degrees in the fifth working state, from -90 degrees to -180 degrees in the sixth working state, from -180 degrees to -270 degrees in the seventh state, and from -270 degrees to -360 degrees in the eighth state. That is to say, the stepping motor 5 rotates one full circle in the reverse direction from the fifth state to the end of the sixth state.

[0090] It should be noted that in the first to fourth working states in the forward rotation state, both the first intermediate pin A3 and the second intermediate pin B3 are connected to 12V voltage to make them in a high-level state; in the fifth to eighth working states in the reverse rotation state, both the first intermediate pin A3 and the second intermediate pin B3 are connected to 12V voltage to make them in a high-level state.

[0091] In the embodiment of the present utility model, by connecting high levels to the first intermediate pin A3 and the second intermediate pin B3, and simultaneously controlling multiple rotation parameter output terminals to input low levels to the corresponding end pins in different working states, the rotation direction and rotation angle of the stepping motor are controlled. Furthermore, the control of the expansion valve opening degree and the determination of the air door position are realized, the operation is simplified, the cost is reduced, and the stability of the stepping motor control is increased.

[0092] Based on the above embodiment, this embodiment describes the current detection circuit of the stepping motor control device. Figure 5 It is a schematic structural diagram of another stepping motor control device provided according to the embodiment of the present utility model. As Figure 5 shown, the stepping motor control device further includes a current detection circuit 6; the current detection circuit 6 includes a voltage output and current acquisition terminal 61 and a voltage signal output terminal 62; the control chip 3 further includes a voltage signal receiving terminal 34; the voltage output and current acquisition terminal 61 is electrically connected to the first intermediate pin A3 and the second intermediate pin B3 respectively, and the voltage signal output terminal 62 is electrically connected to the voltage signal receiving terminal 34.

[0093] Specifically, the voltage output and current acquisition terminal 61 is electrically connected to the first intermediate part pin A3 and the second intermediate part pin B3 to provide a high level for the stepper motor 5 while acquiring the current of the stepper motor 5. The current detection circuit 6 amplifies and calculates the current of the stepper motor 5 and converts it into a voltage signal for transmission to the control chip 3. The control chip 3 processes the received voltage signal to determine whether the stepper motor 5 is jammed.

[0094] In the embodiment of the present invention, on the one hand, the current detection circuit provides a voltage of 12V to the stepper motor to ensure that the first intermediate part pin and the second intermediate part pin of the stepper motor are continuously in a high level state. On the other hand, by detecting the current of the stepper motor to determine whether the stepper motor is faulty, it helps to improve the reliability and stability of the stepper motor control device.

[0095] Based on the above embodiment, Figure 6 is a schematic structural diagram of the current detection circuit provided by the embodiment of the present invention. As Figure 6 shown, the current detection circuit includes a current detection chip, a first diode D1, a first capacitor C61, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second capacitor C62, and a second diode D2; the anode of the first diode D1 is electrically connected to the first voltage input terminal, and the anode of the second diode D2 is electrically connected to the second voltage input terminal; the first end of the fourth resistor R4 is the voltage output and current acquisition terminal 61;

[0096] The current detection chip includes a negative input pin -IN, a positive input pin +IN, a negative power supply pin V-, a positive power supply pin V+, and a voltage signal output pin out; among them, the voltage signal output pin OUT is the voltage signal output terminal 62;

[0097] The first end of the first resistor R1 is electrically connected to the second intermediate part pin B3 and the first end of the fourth resistor R4 respectively. The second end of the first resistor R1 is electrically connected to the first end of the second resistor R2 and the negative input pin -in respectively. The second end of the second resistor R2 is electrically connected to the voltage signal output pin OUT. The second end of the fourth resistor R4 is electrically connected to the first end of the third resistor R3, the cathode of the first diode D1, and the first end of the first capacitor C61 respectively. The second end of the first capacitor C61 is grounded. The second end of the third resistor R3 is electrically connected to the positive input pin +IN and the first end of the fifth resistor R5 respectively. The second end of the fifth resistor R5 is electrically connected to the negative power supply pin V- and the first end of the second capacitor C62 respectively. The first end of the second capacitor C62 is grounded. The second end of the second capacitor C62 is electrically connected to the positive power supply pin V+ and the cathode of the second diode D2 respectively.

[0098] Specifically, the first end of the fourth resistor R4 is electrically connected to the first middle part pin A3 and the second middle part pin B3 respectively. On the one hand, it provides a 12V voltage for the stepper motor 5 to keep it in a high level state continuously. On the other hand, it collects the current of the stepper motor 5. When the current passes through the fourth resistor R4, the current detection circuit amplifies the voltage across the two ends of the fourth resistor R4 and inputs it to the current detection chip. Through the voltage signal output pin OUT of the current detection chip, it is transmitted to the control chip 3, and the control chip 3 compares and judges the voltage signal to detect whether the stepper motor 5 is stalled. The voltage signal output pin OUT is electrically connected to the voltage signal receiving end 34 of the control chip 3, that is, the PTB3PIB3ADP11 pin on the control chip 3, as the voltage signal output end 62 for transmitting the voltage signal.

[0099] Exemplarily, when the stepper motor 5 is stalled, it will cause the current inside the motor to increase, and the current flowing through the fourth resistor R4 will increase. According to Ohm's law, the voltage across the two ends of the fourth resistor R4 will increase. The voltage across the two ends of the fourth resistor R4 is amplified by the current detection circuit 6 and then transmitted to the control chip 3. The control chip 3 compares the collected voltage signal with the pre-stored threshold. When the voltage signal is greater than the threshold, it is judged that the stepper motor 5 has a stalling fault.

[0100] The NC pin on the current detection chip is a conventional pin and will not be specifically explained.

[0101] In the embodiment of the present invention, through the current detection circuit, on the one hand, a 12V voltage is provided to the stepper motor to ensure that the first middle part pin and the second middle part pin of the stepper motor are continuously in a high level state. On the other hand, by converting the current of the stepper motor into the voltage across the two ends of the fourth resistor, and processing and judging the voltage across the two ends of the fourth resistor to detect the stalling fault of the stepper motor, which helps to improve the reliability and stability of the stepper motor control device.

[0102] On the basis of the above embodiment, the display circuit of the stepper motor control device is described in this embodiment; Figure 7 It is a schematic structural diagram of another stepper motor control device provided according to the embodiment of the present invention. As Figure 7 shown, the stepper motor control device further includes a display circuit; the control chip 3 further includes a motor state information output end 35 and a pulse information output end 36, and the display circuit includes a motor state information receiving end 71, a pulse information receiving end 72, and a second power supply voltage receiving end 73; the second power supply voltage receiving end 73 is electrically connected to the power supply voltage output end 11; the motor state information output end 35 is electrically connected to the motor state information receiving end 71, and the pulse information output end 36 is electrically connected to the pulse information receiving end 72.

[0103] Specifically, the motor status information may be motor locked-rotor fault information, and the pulse information may be the number of pulses, positive pulse time, negative pulse time, and power-on delay. The control chip 3 sends the motor status information to the display circuit 7, and the display circuit 7 presents it to the staff, facilitating the staff to timely detect the locked-rotor situation of the motor, take effective measures, and improve the stability and reliability of the stepping motor 5 control device. The control chip 3 can also send the pulse information to the display circuit 7 for presentation to the staff. The staff can adjust the pulse signal according to the information such as the number of pulses, positive pulse time, negative pulse time, and power-on delay displayed on the display screen, thereby controlling the operation of the stepping motor 5, and further realizing the control of the expansion valve opening and the determination of the air door position.

[0104] In the embodiment of the present utility model, by setting the display circuit to present the motor status information and pulse information to the staff, on the one hand, it is convenient for the staff to timely detect and take measures when the stepping motor has a locked-rotor fault, and on the other hand, it is convenient for the staff to adjust the pulse signal to control the operation of the stepping motor, thereby realizing the control of the expansion valve opening and the determination of the air door position, and improving the convenience of the stepping motor control device.

[0105] Based on the above embodiment, Figure 8 is a circuit diagram of a display circuit provided according to an embodiment of the present utility model. As Figure 8 shown, the display circuit further includes a display chip, a first rotary potentiometer K1, and a second rotary potentiometer K2; the display chip includes a regulated voltage output terminal Vout, a contrast pin V0, a backlight positive pin LEDA, and a backlight negative pin LEDK; the backlight positive pin LEDA is electrically connected to the power voltage output terminal 11, the backlight negative pin LEDK is electrically connected to the first end of the first rotary potentiometer K1, and the second end of the first rotary potentiometer K1 is grounded; the contrast pin V0 is electrically connected to the first end of the second rotary potentiometer K2, the second end of the second rotary potentiometer K2 is grounded, and the third end of the second rotary potentiometer K2 is electrically connected to the regulated voltage output terminal.

[0106] Specifically, the staff can adjust the backlight and contrast by adjusting the first rotary potentiometer K1 and the second rotary potentiometer K2. By adjusting the first rotary potentiometer K1, the current passing through the LED can be changed to adjust the backlight of the display screen; by adjusting the second rotary potentiometer K2, the voltage of the V0 pin can be changed to adjust the contrast of the display screen.

[0107] Further, the DB0 pin on the display chip is electrically connected to the PTC0ADP16 pin on the control chip 3, the DB1 pin is electrically connected to the PTC1ADP17 pin, the DB2 pin is electrically connected to the PTC2ADP18, the DB3 pin is electrically connected to the PTC3ADP19, the DB4 pin is electrically connected to the PTC4ADP20, the DB5 pin is electrically connected to the PTC5ADP21, the DB6 pin is electrically connected to the PTC6ADP22, the DB7 pin is electrically connected to the PTB7PIB7ADP15, the CS1 pin is electrically connected to the PTD0PID0TPM2CH0 pin, the CS2 pin is electrically connected to the PTD1PID1TPM2CH1 pin, the R / W pin is connected to

[0108] the PTD2PID2TPM1CH0 pin, the RS pin is electrically connected to the PTD3PID3TPM1CH1 pin, and the E pin is electrically connected to the PTD4PID4TPM1CH2 pin. Through the above connection method, it is ensured that the display circuit can correctly receive and process commands and data from the control chip 3. The / RST pin is a conventional pin and will not be specifically explained.

[0109] In the embodiment of the present invention, by setting the first rotary potentiometer and the second rotary potentiometer, the contrast and backlight of the display screen are adjusted so that the user can reasonably adjust the contrast and backlight according to needs, which can not only enhance the visual experience and protect the user's health, but also optimize the performance of the display screen.

[0110] Based on the above embodiment, Figure 9 is a circuit diagram of a power supply circuit provided according to an embodiment of the present invention. As Figure 9 shown, the power supply circuit 1 includes a power supply chip, a third diode D3, a first capacitor C91, a second capacitor C92, an inductor L1, and a zener diode D4; the power supply chip includes a power input terminal VIN, an output port Output, a ground port Gnd, a feedback port Feedback, and a switch port On / off; the anode of the third diode D3 is the power voltage input terminal, and the first capacitor plate of the second capacitor C92 is the power voltage output terminal; the cathode of the third diode D3 is electrically connected to both the power input port VIN and the first capacitor plate of the first capacitor C91, the second capacitor plate of the first capacitor C91 is electrically connected to the anode of the zener diode D4, the ground port Gnd, and the switch port On / off, the first capacitor plate of the second capacitor C92 is electrically connected to the first end of the inductor L1, the second end of the inductor L1 is electrically connected to the cathode of the zener diode D4, the output port Output, and the feedback port Feedback, and the second capacitor plate of the second capacitor C92 is grounded.

[0111] Specifically, the input voltage can be converted into a stable output voltage through the above connection method. Exemplarily, a 12V voltage is input to the anode of the third diode D3, and a stable voltage of 5V is output through the first capacitor plate of the second capacitor C92. Among them, the first capacitor plate of the second capacitor C92 serves as the power supply voltage output terminal and is electrically connected to the VDD pin of the control chip 3, the second end of the pull-up resistor Rs, and the VCC pin of the driving chip 4, providing the required stable and reliable power supply for the key acquisition circuit 2, the control chip 3, and the driving chip 4.

[0112] In the embodiment of the present invention, by setting up a power supply circuit to convert the input voltage into a stable output voltage, a stable and reliable power supply required for the key acquisition circuit, the control chip, and the driving chip is provided, thereby ensuring the stable operation of the stepping motor control device.

[0113] The above specific implementation manners do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A stepper motor control device, characterized in that: include: Power supply circuit, key acquisition circuit, control chip and driver chip; The power supply circuit comprises a power supply voltage output terminal, and the power supply voltage output terminal is electrically connected to the first power supply voltage receiving terminal of the key acquisition circuit, the power supply pin of the control chip and the power supply voltage terminal of the driving chip respectively; The key acquisition circuit includes a voltage state input terminal and a pulse signal output terminal, the control chip includes a pulse signal receiving terminal and a drive instruction output terminal, and the drive chip includes a drive instruction receiving terminal and a rotation parameter output terminal; The pulse signal output end is electrically connected to the pulse signal receiving end, the drive instruction output end is electrically connected to the drive instruction receiving end, and the rotation parameter output end is electrically connected to the stepper motor; the control chip is used to output the drive instruction to the drive chip according to the pulse signal received by the pulse signal receiving end to drive the stepper motor to rotate.

2. The stepper motor control device according to claim 1, characterized in that: The key acquisition circuit includes a switch unit, a pull-up resistor, a current limiting resistor and a capacitor; The first end of the switch unit is grounded, the second end of the switch unit is electrically connected to the first end of the pull-up resistor and the first end of the current limiting resistor respectively, the second end of the pull-up resistor is electrically connected to the power supply voltage output end, the second end of the current limiting resistor is electrically connected to the first end of the capacitor and the pulse signal receiving end respectively, and the second end of the capacitor is grounded; the second end of the current limiting resistor is the pulse signal output end, and the second end of the pull-up resistor is the first power supply voltage receiving end.

3. The stepper motor control device according to claim 1, characterized in that: The driving chip further includes a first power pin and a second power pin; the rotation parameter output end includes a first rotation parameter output end, a second rotation parameter output end, a third rotation parameter output end and a fourth rotation parameter output end; The stepper motor comprises a first coil and a second coil; the first coil comprises a first end pin, a second end pin and a first middle pin, and the second coil comprises a third end pin, a fourth end pin and a second middle pin; The first end pin is electrically connected to the first rotation parameter output end, the second end pin is electrically connected to the second rotation parameter output end, the third end pin is electrically connected to the third rotation parameter output end, and the fourth end pin is electrically connected to the fourth rotation parameter output end; The first middle portion pin is electrically connected to the first power pin and the second power pin respectively, and the second middle portion pin is electrically connected to the first power pin and the second power pin respectively.

4. The stepper motor control device according to claim 3, characterized in that: The driving instructions include a forward rotation instruction and a reverse rotation instruction; When the drive instruction receiving end receives a forward rotation instruction, the drive chip is used to drive the stepper motor to rotate forward; When the driving instruction receiving end receives a reverse rotation instruction, the driving chip is used to drive the stepping motor to reverse rotation; When the stepper motor rotates forward, the working state of the stepper motor includes a first working state, a second working state, a third working state and a fourth working state, and the forward rotation angle of the stepper motor is different in different working states; In the first working state, the second rotation parameter output end outputs a low level signal to the second end pin, and the fourth rotation parameter output end outputs a low level signal to the fourth end pin; in the second working state, the second rotation parameter output end outputs a low level signal to the second end pin, and the third rotation parameter output end outputs a low level signal to the third end pin; in the third working state, the first rotation parameter output end outputs a low level signal to the first end pin, and the third rotation parameter output end outputs a low level signal to the third end pin; in the fourth working state, the first rotation parameter output end outputs a low level signal to the first end pin, and the fourth rotation parameter output end outputs a low level signal to the fourth end pin; When the stepper motor is reversed, the working state of the stepper motor includes a fifth working state, a sixth working state, a seventh working state and an eighth working state, and the reversal angle of the stepper motor is different in different working states; In the fifth working state, the second rotation parameter output terminal outputs a low level signal to the second end pin, and the fourth rotation parameter output terminal outputs a low level signal to the fourth end pin; in the sixth working state, the first rotation parameter output terminal outputs a low level signal to the first end pin, and the fourth rotation parameter output terminal outputs a low level signal to the fourth end pin; in the seventh working state, the first rotation parameter output terminal outputs a low level signal to the first end pin, and the third rotation parameter output terminal outputs a low level signal to the third end pin; in the eighth working state, the second rotation parameter output terminal outputs a low level signal to the second end pin, and the third rotation parameter output terminal outputs a low level signal to the third end pin.

5. The stepper motor control device according to claim 4, characterized in that: The stepper motor control device also includes a current detection circuit; The current detection circuit includes a voltage output and current collection terminal and a voltage signal output terminal; the control chip also includes a voltage signal receiving terminal; The voltage output and current collection end are electrically connected to the first middle portion pin and the second middle portion pin respectively, and the voltage signal output end is electrically connected to the voltage signal receiving end.

6. The stepper motor control device according to claim 5, characterized in that: The current detection circuit includes a current detection chip, a first diode, a first capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a second capacitor and a second diode; the anode of the first diode is electrically connected to the first voltage input terminal, and the anode of the second diode is electrically connected to the second voltage input terminal; the first end of the fourth resistor is the voltage output and current collection terminal; The current detection chip includes a negative input pin, a positive input pin, a negative power pin, a positive power pin and a voltage signal output pin; wherein the voltage signal output pin is the voltage signal output end; The first end of the first resistor is electrically connected to the second middle portion pin and the first end of the fourth resistor, respectively; the second end of the first resistor is electrically connected to the first end of the second resistor and the negative input pin, respectively; the second end of the second resistor is electrically connected to the voltage signal output pin, the second end of the fourth resistor is electrically connected to the first end of the third resistor, the cathode of the first diode and the first end of the first capacitor, respectively; the second end of the first capacitor is grounded; the second end of the third resistor is electrically connected to the positive input pin and the first end of the fifth resistor, respectively; the second end of the fifth resistor is electrically connected to the negative power supply pin and the first end of the second capacitor, respectively; the first end of the second capacitor is grounded; and the second end of the second capacitor is electrically connected to the positive power supply pin and the cathode of the second diode, respectively.

7. The stepper motor control device according to claim 1, characterized in that: The stepper motor control device further includes a display circuit; the control chip further includes a motor state information output terminal and a pulse information output terminal, and the display circuit includes a motor state information receiving terminal, a pulse information receiving terminal and a second power supply voltage receiving terminal; The second power supply voltage receiving terminal is electrically connected to the power supply voltage output terminal; The motor state information output terminal is electrically connected to the motor state information receiving terminal, and the pulse information output terminal is electrically connected to the pulse information receiving terminal.

8. The stepper motor control device according to claim 7, characterized in that: The display circuit also includes a display chip, a first knob potentiometer and a second knob potentiometer; The display chip includes a regulated voltage output terminal, a contrast pin, a backlight positive pin and a backlight negative pin; The backlight positive pin is electrically connected to the power supply voltage output terminal, the backlight negative pin is electrically connected to the first end of the first knob potentiometer, and the second end of the first knob potentiometer is grounded; The contrast pin is electrically connected to a first end of the second knob potentiometer, a second end of the second knob potentiometer is grounded, and a third end of the second knob potentiometer is electrically connected to the regulated voltage output end.

9. The stepper motor control device according to claim 1, characterized in that: The power supply circuit includes a power supply chip, a third diode, a first capacitor, a second capacitor, an inductor and a voltage regulator diode; The power supply chip includes a power input terminal, an output port, a ground port, a feedback port and a switch port; The anode of the third diode is a power supply voltage input terminal, and the first capacitance plate of the second capacitor is an output terminal of the power supply voltage; The cathode of the third diode is electrically connected to the power input port and the first capacitor plate of the first capacitor, respectively; the second capacitor plate of the first capacitor is electrically connected to the anode of the Zener diode, the ground port and the switch port, respectively; the first capacitor plate of the second capacitor is electrically connected to the first end of the inductor, the second end of the inductor is electrically connected to the cathode of the Zener diode, the output port and the feedback port, respectively; and the second capacitor plate of the second capacitor is grounded.

10. The stepper motor control device according to claim 1, characterized in that: The driving chip includes a hexagonal half-bridge driver.

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