Control circuit of low-power ultra-strong light target searching device

By combining the main control circuit with the motor drive circuit, combined with the PWM signal and position sensor, the control accuracy problem of the low-power, ultra-high-intensity target search light is solved, and the precise speed and rotation angle control of the lamp is achieved, thereby improving the operational reliability and illumination efficiency.

CN223309987UActive Publication Date: 2025-09-05JIANGSU HOWDY PHOTOELECTRIC TECH CO LTD
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Patent Information

Application Number
CN202422643700.4
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-10-31
Publication Date
2025-09-05
Estimated Expiration
2034-10-31

AI Technical Summary

Technical Problem

The existing low-power, ultra-high-intensity target search lights have low control accuracy, cannot achieve precise adjustment of rotation angle and speed, are inconvenient to operate, and are difficult to meet the needs of modern ships.

Method used

The combination of the main control circuit, handle interface circuit, and the first and second motor drive circuits is used to accurately control the lamp speed and rotation angle through PWM signals. A position sensor is also equipped to achieve limit monitoring to ensure the reliability of the lamp.

Benefits of technology

It achieves precise control of lamps, improves irradiation efficiency and operational reliability, and can accurately illuminate designated locations.

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Abstract

The utility model discloses a control circuit of a low-power ultra-strong light target searching device, and belongs to the technical field of marine lamps. The target searching device comprises a holder, a lamp tube arranged on the holder and a handle used for controlling the holder to rotate left and right and up and down, the control circuit comprises a main control circuit, and the main control circuit is electrically connected with a power circuit, a handle interface circuit, a first motor driving circuit, a second motor driving circuit and an external driving circuit. The first motor driving circuit is electrically connected with a first motor for controlling the lamp tube to rotate left and right, the second motor driving circuit is electrically connected with a second motor for controlling the lamp tube to rotate up and down, the handle interface circuit is electrically connected with a handle, receives a rotation signal of the lamp tube and transmits the rotation signal to the main control circuit, and the main control circuit converts the rotation signal into a PWM signal; and the external driving circuit is electrically connected with the light source. The lamp has the advantages that the rotating speed and the rotating angle of the lamp are accurately controlled, the light source can accurately irradiate a designated place, and the irradiation control efficiency is improved.
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Description

Technical Field

[0001] The utility model belongs to the technical field of marine lamps, and particularly relates to a control circuit of a low-power ultra-strong light target searching device. Background Art

[0002] With the increasing frequency of maritime activities in my country, ships are placing increasingly stringent demands on lighting. Ultra-high-intensity target search lights, as ship lighting fixtures, offer advantages such as high light efficiency, a wide illumination range, and long illumination distance. They are widely used for illumination during marine search and rescue operations and patrol operations at night and under poor visual conditions. Existing low-power ultra-high-intensity target search lights suffer from low control accuracy, making precise adjustment of rotation angle and speed impossible. Furthermore, they are difficult to operate and require a high level of operator proficiency, making them difficult to meet the operational requirements of modern ships.

[0003] In view of the above-mentioned existing technologies, the applicant has made a beneficial design and improved the control part of the low-power ultra-high-intensity target search light. The technical solution to be introduced below was produced in this context. Utility Model Content

[0004] The purpose of the utility model is to provide a control circuit for a low-power ultra-strong light target search device, which can accurately control the rotation speed and rotation angle of the lamp and has high reliability in use.

[0005] The purpose of the utility model is achieved in this way. A control circuit for a low-power and ultra-strong light target search device, the low-power and ultra-strong light target search device includes a pan-tilt platform, a lamp tube rotatably arranged on the pan-tilt platform, and a handle for controlling the left and right rotation and up and down rotation of the pan-tilt platform, the control circuit includes a main control circuit, the main control circuit is electrically connected with a power supply circuit, a handle interface circuit, a first motor drive circuit, a second motor drive circuit and an external drive circuit, the first motor drive circuit is electrically connected to the first motor that controls the left and right rotation of the lamp tube, the second motor drive circuit is electrically connected to the second motor that controls the up and down rotation of the lamp tube, the handle interface circuit is electrically connected to the handle, receives the rotation signal of the lamp tube and transmits it to the main control circuit, the main control circuit converts the rotation signal into a PWM signal, controls the operation of the first and second motors, and the external drive circuit is electrically connected to the light source.

[0006] In a specific embodiment of the present invention, the main control circuit is also electrically connected to the position sensor in the pan-tilt head, and the position sensor detects the rotation position of the lamp tube. When the lamp tube rotates to the extreme position, the position sensor sends a limit signal to the main control circuit, and the main control circuit stops sending PWM signals to the first and second motor drive circuits, and the first and second motors stop rotating.

[0007] In another specific embodiment of the present invention, it also includes an external power supply circuit, which includes a resistor R1, a transistor Q1, a diode D1 and a relay U1. The relay U1 adopts JQC-3FF / 05. One end of the resistor R1 is connected to the main control circuit, and the other end of the resistor R1 is connected to the base of the transistor Q1. The collector of the transistor Q1 is connected to the negative electrode of the diode D1 and one end of the coil of the relay U1. The emitter of the transistor Q1 and the moving contact of the relay U1 are commonly connected to a +24V DC power supply. The normally closed contact of the relay U1 is suspended, and the normally open contact of the relay U1 forms an output end. After the main control circuit is powered on, power is provided to the external device. The positive electrode of the diode D1 and the other end of the coil of the relay U1 are commonly grounded.

[0008] In another specific embodiment of the present invention, the main control circuit includes a microprocessor U4, a crystal oscillator Y1, a reset switch SW1, resistors R3~R5 and capacitors C8~C12, the microprocessor U4 adopts GD32F303RE, the 60th pin of the microprocessor U4 is connected to one end of the resistor R4, the 5th pin is connected to one end of the resistor R3, one end of the crystal oscillator Y1 and one end of the capacitor C11, the 6th pin is connected to the other end of the resistor R3, the other end of the crystal oscillator Y1 and one end of the capacitor C12, one end of the resistor R5, one end of the reset switch SW1 and one end of the capacitor C9 are connected to the 7th pin of the microprocessor U4, and the external power supply circuit is connected to the microprocessor U4. Pin 22 of the microprocessor U4, the external drive circuit is connected to pins 23 to 30 of the microprocessor U4, the first motor drive circuit is connected to pins 58 and 59 of the microprocessor U4, the second motor drive circuit is connected to pins 43 and 44 of the microprocessor U4, pins 48 and 64 of the microprocessor U4, one end of capacitor C8, one end of capacitor C10 and the other end of resistor R5 are commonly connected to a +3.3V DC power supply, and pins 47 and 63 of the microprocessor U4, the other end of capacitor C8, the other end of resistor R4, the other end of capacitor C10, the other end of capacitor C11, the other end of capacitor C12, the other end of capacitor C9 and the other end of the reset switch SW1 are commonly grounded.

[0009] In another specific embodiment of the present invention, the handle interface circuit includes a resistor R6, a resistor R7 and an optocoupler U5, the optocoupler U5 is a 3H7 optocoupler, one end of the resistor R7 constitutes the input end of the handle interface circuit, connected to the handle, the other end of the resistor R7 is connected to pin 1 of the optocoupler U5, pin 4 of the optocoupler U5 is connected to one end of the resistor R6, and together constitute the output end of the handle interface circuit, connected to the main control circuit, the other end of the resistor R6 is connected to a +3.3V DC power supply, and pins 2 and 3 of the optocoupler U5 are grounded together.

[0010] In another specific embodiment of the present invention, the handle interface circuit has a total of eight channels, wherein the input of the first channel is connected to the handle upward signal, and the output is connected to pin 30 of the microprocessor U4; the input of the second channel is connected to the handle downward signal, and the output is connected to pin 29 of the microprocessor U4; the input of the third channel is connected to the handle left signal, and the output is connected to pin 28 of the microprocessor U4; the input of the fourth channel is connected to the handle right signal, and the output is connected to pin 27 of the microprocessor U4; the input of the fifth channel is connected to the handle upward limit signal, and the output is connected to pin 26 of the microprocessor U4; the input of the sixth channel is connected to the handle downward limit signal, and the output is connected to pin 23 of the microprocessor U4; the input of the seventh channel is connected to the handle left limit signal, and the output is connected to pin 25 of the microprocessor U4; the input of the eighth channel is connected to the handle right limit signal, and the output is connected to pin 24 of the microprocessor U4.

[0011] In a further specific embodiment of the present invention, the first motor drive circuit includes an optocoupler U6, an optocoupler U7, resistors R8 to R11 and a motor driver U8. The motor driver U8 adopts AT8870, one end of the resistor R8 and one end of the resistor R10 are respectively connected to the main control circuit to receive the PWM signal, the other end of the resistor R8 is connected to pin 1 of the optocoupler U6, the 4th pin of the optocoupler U6 is connected to one end of the resistor R9 and is jointly connected to pin 2 of the motor driver U8, the other end of the resistor R10 is connected to pin 1 of the optocoupler U7, the 4th pin of the optocoupler U7 is connected to one end of the resistor R11 and is jointly connected to the motor driver Pin 3 of U8, pins 5 and 7 of motor driver U8 are connected to the first motor, one end of resistor R12 is connected to pin 5 of motor driver U8, the other end of resistor R9, the other end of resistor R10, pin 4 of motor driver U8 and one end of capacitor C13 are commonly connected to a +5V DC power supply, pin 8 of motor driver U8, one end of capacitor C14 and one end of capacitor C15 are commonly connected to a +24V DC power supply, pin 1 of motor driver U8, pins 2 and 3 of optocoupler U6, pins 2 and 3 of optocoupler U7, the other end of capacitor C13, the other end of capacitor C14, the other end of capacitor C15 and the other end of resistor R12 are commonly grounded.

[0012] Due to the adoption of the above structure, the present invention has the following beneficial effects compared with the prior art: the main control circuit adopts PWM technology according to the handle instruction, and accurately controls the first and second motors to achieve accurate control of the rotation speed and rotation angle of the lamp, so that the light source can accurately illuminate the designated place, thereby improving the efficiency of controlling the illumination; and a limit position monitoring is also provided to ensure the reliability of the lamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a circuit block diagram of the utility model;

[0014] Figure 2This is a schematic diagram of the electrical connection of the external power supply circuit described in the present utility model;

[0015] Figure 3 This is a schematic diagram of the electrical connection of the power supply circuit described in the present utility model;

[0016] Figure 4 This is a schematic diagram of the electrical connection of the main control circuit of the present utility model;

[0017] Figure 5 This is a schematic diagram of the electrical connection of one circuit of the handle interface circuit described in the present invention;

[0018] Figure 6 This is a schematic diagram of the electrical connection of the first motor drive circuit described in the present invention. DETAILED DESCRIPTION

[0019] The specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings. However, the description of the embodiments does not limit the technical solution. Any changes in form rather than substance based on the concept of the present invention should be regarded as within the scope of protection of the present invention.

[0020] In the following description, all concepts related to directionality (or orientation) such as up, down, left, right, front and back are with respect to the position state of the figure being described, and are intended to facilitate public understanding. Therefore, they should not be understood as special limitations on the technical solutions provided by the present invention.

[0021] See also Figure 1 The present invention relates to a control circuit for a low-power, ultra-intense light target search device. The low power here currently mainly refers to 40W and 50W. The low-power, ultra-intense light target search device includes a pan-tilt platform, a lamp tube rotatably mounted on the pan-tilt platform, and a handle for controlling the left and right and up and down rotations of the pan-tilt platform. The control circuit includes a main control circuit, to which a power supply circuit, a handle interface circuit, a first motor drive circuit, a second motor drive circuit, and an external drive circuit are electrically connected. The first motor drive circuit is electrically connected to a first motor that controls the left and right rotation of the lamp tube, and the second motor drive circuit is electrically connected to a second motor that controls the up and down rotation of the lamp tube. The control circuit is used to precisely control the lamp by controlling the first and second motors. The first and second motors are stepper motors. The handle interface circuit is electrically connected to the handle, receives the lamp tube's rotation signal, and transmits it to the main control circuit. The main control circuit converts the rotation signal into a PWM signal, and precisely controls the operation of the first and second motors through pulse width modulation of the PWM signal, thereby driving the lamp tube to rotate to the corresponding position. The external driving circuit is electrically connected to the light source and is used to drive the power supply. Since a conventional circuit is used here, it will not be described in detail.

[0022] Furthermore, the main control circuit is electrically connected to a position sensor within the pan / tilt head. The position sensor detects the rotational position of the lamp tube. When the lamp tube reaches its limit position, the position sensor sends a limit signal to the main control circuit. Specifically, when the lamp tube reaches its limit position in the vertical direction, the main control circuit stops sending PWM signals to the first motor drive circuit, causing the first motor to stop rotating. When the lamp tube reaches its limit position in the horizontal direction, the main control circuit stops sending PWM signals to the second motor drive circuit, causing the second motor to stop rotating.

[0023] See Figure 2 Furthermore, the present invention also includes an external power supply circuit, comprising a resistor R1, a transistor Q1, a diode D1, and a relay U1. Relay U1 is JQC-3FF / 05. One end of resistor R1 is connected to the main control circuit, the other end of resistor R1 is connected to the base of transistor Q1, the collector of transistor Q1 is connected to the cathode of diode D1 and one end of the coil of relay U1, the emitter of transistor Q1 and the moving contact of relay U1 are connected to a +24V DC power supply, the normally closed contact of relay U1 is suspended, and the normally open contact of relay U1 forms an output terminal. After the main control circuit is powered on, after a period of delay, the external power supply circuit provides +24V DC power to the external device.

[0024] See Figure 3 The power supply circuit includes a power module U2, a voltage regulator module U3, capacitors C1-C7, an inductor L1, and a light-emitting diode D2. The power module U2 uses the KW1-24S05E, and the voltage regulator module U3 uses the MCP1702T-3302E. The power module U2 receives a +24V DC power supply and converts it into a +5V DC power supply to power the first and second motor drive circuits. After receiving the +5V DC power supply, the voltage regulator module U3 outputs a +3.3V regulated DC power supply to power the main control circuit, the handle interface circuit, and the external drive circuit. The light-emitting diode D2 serves as a power indicator.

[0025] See Figure 4The main control circuit includes a microprocessor U4, a crystal oscillator Y1, a reset switch SW1, resistors R3-R5, and capacitors C8-C12. The microprocessor U4 uses the GD32F303RE. One end of resistor R1 in the external power supply circuit is connected to pin 22 of the microprocessor U4; the external drive circuit is connected to pins 23-30 of the microprocessor U4; the first motor drive circuit is connected to pins 58 and 59 of the microprocessor U4; and the second motor drive circuit is connected to pins 43 and 44 of the microprocessor U4. The external drive circuit is connected to pin 55 of the microprocessor U4. The microprocessor U4 receives and analyzes the rotation signal, outputting the corresponding control command. The process of the microprocessor U4 outputting the PWM signal is conventional and will not be described in detail.

[0026] See also Figure 5 The handle interface circuit includes resistors R6, R7, and an optocoupler U5. The optocoupler U5 is a 3H7 optocoupler. One end of the resistor R7 constitutes the input end of the handle interface circuit, connected to the handle. The other end of the resistor R7 is connected to pin 1 of the optocoupler U5. Pin 4 of the optocoupler U5 is connected to one end of the resistor R6, and together they constitute the output end of the handle interface circuit, connected to the main control circuit. The other end of the resistor R6 is connected to a +3.3V DC power supply, and pins 2 and 3 of the optocoupler U5 are grounded. The handle command is transmitted to the main control circuit through optocoupler isolation. Specifically, the handle interface circuit is used to convert the handle action into a signal and send it to the main control circuit. Since the lamp tube has four rotation directions, up, down, left and right, and each direction has a corresponding limit position, correspondingly, the handle interface circuit has a total of eight channels, among which the input terminal of the first channel is connected to the handle upward signal, and the output terminal is connected to pin 30 of the microprocessor U4, the input terminal of the second channel is connected to the handle downward signal, and the output terminal is connected to pin 29 of the microprocessor U4, the input terminal of the third channel is connected to the handle left signal, and the output terminal is connected to pin 28 of the microprocessor U4, the input terminal of the fourth channel is connected to the handle right signal, and the output terminal is connected to pin 27 of the microprocessor U4, the input terminal of the fifth channel is connected to the handle upward limit signal, and the output terminal is connected to pin 26 of the microprocessor U4, the input terminal of the sixth channel is connected to the handle downward limit signal, and the output terminal is connected to pin 23 of the microprocessor U4, the input terminal of the seventh channel is connected to the handle left limit signal, and the output terminal is connected to pin 25 of the microprocessor U4, and the input terminal of the eighth channel is connected to the handle right limit signal, and the output terminal is connected to pin 24 of the microprocessor U4.

[0027] See also Figure 6The first motor drive circuit includes an optocoupler U6, an optocoupler U7, resistors R8-R11, and a motor driver U8. The optocouplers U6 and U7 use 3H7, and the motor driver U8 uses an AT8870. One end of resistor R8 is connected to pin 58 of microprocessor U4, and one end of resistor R10 is connected to pin 59 of microprocessor U4 for receiving PWM signals. The other end of resistor R8 is connected to pin 1 of optocoupler U6. Pin 4 of optocoupler U6 is connected to one end of resistor R9 and together to pin 2 of motor driver U8. The other end of resistor R10 is connected to pin 1 of optocoupler U7. Pin 4 of optocoupler U7 is connected to one end of resistor R11 and together to pin 3 of motor driver U8. Pins 5 and 7 of motor driver U8 are connected to the positive and negative electrodes of the first motor. The second motor drive circuit has the same structure as the first motor drive circuit. The input of the second motor drive circuit is connected to pins 44 and 43 of microprocessor U4. Optocouplers U6 and U7 provide isolation.

[0028] The working principle of the present utility model is as follows: after power is turned on, the main control circuit receives external port signals: including external power supply signal, left rotation signal, right rotation signal, upward rotation signal, downward rotation signal, left limit signal, right limit signal, upper limit signal, and lower limit signal. After the above signals are processed by the microprocessor U4 in the main control circuit, PWM signals are generated and sent to the first and second motors to control the left and right rotation and up and down rotation of the lamp tube. The main control circuit can precisely control the first and second motors through pulse width modulation of the PWM signal, thereby precisely controlling the rotation speed and rotation angle of the lamp tube, so that the light source can accurately illuminate the designated place.

Claims

1. A control circuit for a low-power, ultra-intense light target search device, comprising a pan / tilt platform, a lamp rotatably mounted on the pan / tilt platform, and a handle for controlling the pan / tilt platform's left-right and up-and-down rotation, characterized in that: The control circuit includes a main control circuit, and the main control circuit is electrically connected to a power supply circuit, a handle interface circuit, a first motor drive circuit, a second motor drive circuit and an external drive circuit. The first motor drive circuit is electrically connected to the first motor that controls the left and right rotation of the lamp tube, and the second motor drive circuit is electrically connected to the second motor that controls the up and down rotation of the lamp tube. The handle interface circuit is electrically connected to the handle, receives the rotation signal of the lamp tube and transmits it to the main control circuit. The main control circuit converts the rotation signal into a PWM signal to control the operation of the first and second motors. The external drive circuit is electrically connected to the light source.

2. The control circuit of the low-power ultra-intense light target search device according to claim 1, characterized in that: The main control circuit is also electrically connected to the position sensor inside the pan-tilt head. The position sensor detects the rotation position of the lamp tube. When the lamp tube rotates to the extreme position, the position sensor sends a limit signal to the main control circuit. The main control circuit stops sending PWM signals to the first and second motor drive circuits, and the first and second motors stop rotating.

3. The control circuit of the low-power ultra-intense light target search device according to claim 1, characterized in that: It also includes an external power supply circuit, which includes a resistor R1, a transistor Q1, a diode D1 and a relay U1. The relay U1 adopts JQC-3FF / 05. One end of the resistor R1 is connected to the main control circuit, and the other end of the resistor R1 is connected to the base of the transistor Q1. The collector of the transistor Q1 is connected to the negative electrode of the diode D1 and one end of the coil of the relay U1. The emitter of the transistor Q1 and the moving contact of the relay U1 are commonly connected to a +24V DC power supply. The normally closed contact of the relay U1 is suspended, and the normally open contact of the relay U1 forms an output end. After the main control circuit is powered on, power is provided to the external device. The positive electrode of the diode D1 and the other end of the coil of the relay U1 are commonly grounded.

4. The control circuit of the low-power ultra-intense light target search device according to claim 3, characterized in that: The main control circuit includes a microprocessor U4, a crystal oscillator Y1, a reset switch SW1, resistors R3 to R5, and capacitors C8 to C12. The microprocessor U4 adopts GD32F303RE. Pin 60 of the microprocessor U4 is connected to one end of the resistor R4, pin 5 is connected to one end of the resistor R3, one end of the crystal oscillator Y1, and one end of the capacitor C11, pin 6 is connected to the other end of the resistor R3, the other end of the crystal oscillator Y1, and one end of the capacitor C12, one end of the resistor R5, one end of the reset switch SW1, and one end of the capacitor C9 are connected to pin 7 of the microprocessor U4. The external power supply circuit is connected to pin 22 of the microprocessor U4. The first motor drive circuit is connected to pins 23 to 30 of the microprocessor U4, the first motor drive circuit is connected to pins 58 and 59 of the microprocessor U4, the second motor drive circuit is connected to pins 43 and 44 of the microprocessor U4, pins 48 and 64 of the microprocessor U4, one end of capacitor C8, one end of capacitor C10 and the other end of resistor R5 are commonly connected to a +3.3V DC power supply, and pins 47 and 63 of the microprocessor U4, the other end of capacitor C8, the other end of resistor R4, the other end of capacitor C10, the other end of capacitor C11, the other end of capacitor C12, the other end of capacitor C9 and the other end of the reset switch SW1 are commonly grounded.

5. The control circuit of the low-power ultra-intense light target search device according to claim 4, characterized in that: The handle interface circuit includes resistor R6, resistor R7 and optocoupler U5. The optocoupler U5 is a 3H7 optocoupler. One end of the resistor R7 constitutes the input end of the handle interface circuit and is connected to the handle. The other end of the resistor R7 is connected to pin 1 of the optocoupler U5. Pin 4 of the optocoupler U5 is connected to one end of the resistor R6 and together constitutes the output end of the handle interface circuit and is connected to the main control circuit. The other end of the resistor R6 is connected to a +3.3V DC power supply. Pins 2 and 3 of the optocoupler U5 are grounded together.

6. The control circuit of the low-power ultra-intense light target search device according to claim 5, characterized in that: The handle interface circuit has a total of eight channels, among which the input terminal of the first channel is connected to the handle upward signal, and the output terminal is connected to pin 30 of the microprocessor U4, the input terminal of the second channel is connected to the handle downward signal, and the output terminal is connected to pin 29 of the microprocessor U4, the input terminal of the third channel is connected to the handle left signal, and the output terminal is connected to pin 28 of the microprocessor U4, the input terminal of the fourth channel is connected to the handle right signal, and the output terminal is connected to pin 27 of the microprocessor U4, the input terminal of the fifth channel is connected to the handle upward upper limit signal, and the output terminal is connected to pin 26 of the microprocessor U4, the input terminal of the sixth channel is connected to the handle downward limit signal, and the output terminal is connected to pin 23 of the microprocessor U4, the input terminal of the seventh channel is connected to the handle left limit signal, and the output terminal is connected to pin 25 of the microprocessor U4, and the input terminal of the eighth channel is connected to the handle right limit signal, and the output terminal is connected to pin 24 of the microprocessor U4.

7. The control circuit of the low-power ultra-intense light target search device according to claim 1, characterized in that: The first motor drive circuit includes an optocoupler U6, an optocoupler U7, resistors R8 to R12, capacitors C13 to C15, and a motor driver U8. The optocoupler U6 and the optocoupler U7 adopt 3H7, and the motor driver U8 adopts AT8870. One end of the resistor R8 and one end of the resistor R10 are respectively connected to the main control circuit to receive the PWM signal. The other end of the resistor R8 is connected to pin 1 of the optocoupler U6, and pin 4 of the optocoupler U6 is connected to one end of the resistor R9 and connected to pin 2 of the motor driver U8. The other end of the resistor R10 is connected to pin 1 of the optocoupler U7, and pin 4 of the optocoupler U7 is connected to one end of the resistor R11 and connected to pin 2 of the motor driver U8. Pin 3 of the motor driver U8, pins 5 and 7 of the motor driver U8 are connected to the first motor, one end of the resistor R12 is connected to pin 5 of the motor driver U8, the other end of the resistor R9, the other end of the resistor R10, pin 4 of the motor driver U8 and one end of the capacitor C13 are commonly connected to the +5V DC power supply, pin 8 of the motor driver U8, one end of the capacitor C14 and one end of the capacitor C15 are commonly connected to the +24V DC power supply, pin 1 of the motor driver U8, pins 2 and 3 of the optocoupler U6, pins 2 and 3 of the optocoupler U7, the other end of the capacitor C13, the other end of the capacitor C14, the other end of the capacitor C15 and the other end of the resistor R12 are commonly grounded.