Motor control circuit, circuit board and clothes airing machine

Abstract

The embodiment of the utility model discloses a motor control circuit, a circuit board and a clothes airing machine. The motor control circuit comprises a forward and reverse rotation switch module, a first energy release module, a second energy release module and a slow start and slow stop module, forward rotation or reverse rotation of a motor can be achieved by arranging the forward and reverse rotation switch module, and when the motor is started, the motor can be controlled to be started slowly through the slow start and slow stop module and the forward and reverse rotation switch module. When the motor stops, back electromotive force energy generated when the motor stops rotating forwards or reversely can be released through the first energy release module and the second energy release module, and therefore the forward and reverse rotation switch module is protected, normal starting and stopping of the motor control circuit are guaranteed, and the safety of the motor control circuit is improved.

Description

Technical Field

[0001] This utility model relates to the field of motor control, and in particular to a motor control circuit, a circuit board, and a clothes drying rack. Background Technology

[0002] As a crucial driving component, electric motors are widely used in various fields, such as industrial production, home appliances, transportation, and medical equipment. In specific applications, motors need to be able to rotate flexibly in both directions to adapt to different operational needs. For example, in industrial production, the forward and reverse rotation of a motor in conveyor equipment enables bidirectional material transport. Similarly, in home appliances, the forward and reverse rotation of a motor in clothes-drying equipment allows the clothesline to be raised and lowered for convenient hanging of clothes.

[0003] However, the inventors discovered that in related technologies, motors capable of both forward and reverse rotation sometimes experience sudden damage to the switch module that controls the motor's start and stop when the motor starts or stops, affecting the normal operation of the motor. Summary of the Invention

[0004] This utility model provides a motor control circuit, circuit board, and clothes drying rack, solving the problem in the prior art where the switch module controlling the start and stop of the motor suddenly fails when the motor starts or stops, affecting the normal operation of the motor. By setting a forward and reverse switch module, the motor can be made to rotate forward or reverse. When the motor starts, the slow start and slow stop module and the forward and reverse switch module can control the motor to start slowly, reducing the starting current. When the motor stops, the first energy release module and the second energy release module can release the back electromotive force energy generated when the motor stops rotating forward or in reverse, respectively. Thus, the forward and reverse switch module is protected, the normal start and stop of the motor control circuit is ensured, and the safety of the motor control circuit is improved.

[0005] In a first aspect, embodiments of the present invention provide a motor control circuit, comprising:

[0006] The system includes a forward / reverse switch module, a first energy release module, a second energy release module, and a soft start / stop module.

[0007] The first end of the forward / reverse switch module and the first end of the first energy release module are respectively used to connect to the first end of the motor. The second end of the forward / reverse switch module and the second end of the first energy release module are respectively used to connect to the second end of the motor. The forward / reverse switch module is used to control the motor to rotate forward or reverse. The first energy release module is used to release the back electromotive force energy generated after the motor stops rotating forward.

[0008] The first end of the second energy release module is connected to the third end of the forward and reverse switch module and is used to connect to the first power supply voltage. The second end of the second energy release module is connected to the fourth end of the forward and reverse switch module and is used to release the back electromotive force energy generated after the motor stops reversing.

[0009] The first end of the slow start / stop module is connected to the second end of the second energy release module, and the second end of the slow start / stop module is grounded, which is used to control the motor to start or stop slowly.

[0010] Optionally, the forward / reverse switch module includes a first single-pole double-throw (SPD) relay and a second SPD relay. The moving contact of the first SPD relay serves as the first terminal of the forward / reverse switch module, the moving contact of the second SPD relay serves as the second terminal, the first stationary contact of the first SPD relay and the first stationary contact of the second SPD relay serve as the third terminal, and the second stationary contact of the first SPD relay and the second stationary contact of the second SPD relay serve as the fourth terminal. The power supply terminals of the first SPD relay and the second SPD relay are respectively used to connect to a first power supply voltage. The input terminal of the first SPD relay is used to receive a first level signal output by the control unit for controlling the motor to rotate forward, and the input terminal of the second SPD relay is used to receive a second level signal output by the control unit for controlling the motor to rotate in reverse.

[0011] Optionally, the first energy release module includes a first diode and a first resistor, the negative terminal of the first diode is connected to the first terminal of the forward / reverse switch module, the positive terminal of the first diode is connected to the first terminal of the first resistor, and the second terminal of the first resistor is connected to the second terminal of the forward / reverse switch module.

[0012] Optionally, the second energy release module includes a second diode, the negative terminal of which is connected to the third terminal of the forward / reverse switch module, and the positive terminal of which is connected to the fourth terminal of the forward / reverse switch module.

[0013] Optionally, the slow start / stop module includes a first MOSFET, a second resistor, and a third resistor. The drain terminal of the first MOSFET is connected to the second terminal of the second energy release module, the source terminal of the first MOSFET is connected to the first terminal of the second resistor and ground, the gate terminal of the first MOSFET is connected to the second terminal of the second resistor and the first terminal of the third resistor, and the second terminal of the third resistor is used to receive a PWM signal output by the control unit for controlling the motor to start or stop slowly.

[0014] Optionally, it also includes a fourth resistor, a first inductor, a first capacitor, a third diode, a fourth diode, and a fifth resistor. The first end of the fourth resistor is connected to the second end of the soft start / stop module, and the second end of the fourth resistor is grounded. The first end of the first inductor is connected to the second end of the soft start / stop module, and the second end of the first inductor is connected to the first end of the first capacitor and the positive terminal of the third diode. The second end of the first capacitor is grounded. The negative terminal of the third diode is used to connect to a second power supply voltage. The positive terminal of the third diode is connected to the negative terminal of the fourth diode and the first end of the fifth resistor. The positive terminal of the fourth diode is grounded. The second end of the fifth resistor is used to output a current detection signal to the control unit.

[0015] Optionally, a sixth resistor and a second capacitor are also included, wherein the first end of the sixth resistor is used to connect to the first end of the motor, the second end of the sixth resistor is connected to the first end of the second capacitor, and the second end of the second capacitor is used to connect to the second end of the motor.

[0016] Optionally, a fifth diode is also included, the negative terminal of which is connected to the first terminal of the second energy release module, and the positive terminal of which is used to connect to the first power supply voltage.

[0017] Secondly, the present invention provides a circuit board including the motor control circuit described in any one of the present invention embodiments.

[0018] Thirdly, this utility model embodiment provides a clothes drying rack, a motor, and a motor control circuit as described in any one of this utility model embodiments, wherein the first end of the motor is connected to the first end of the forward and reverse switch module, and the second end of the motor is connected to the second end of the forward and reverse switch module.

[0019] The present invention provides a motor control circuit, including a forward / reverse switch module, a first energy release module, a second energy release module, and a slow start / stop module. By setting the forward / reverse switch module, the motor can be made to rotate forward or reverse. When the motor starts, the slow start / stop module and the forward / reverse switch module can control the motor to start slowly, reducing the starting current. When the motor stops, the first energy release module and the second energy release module can release the back electromotive force energy generated when the motor stops rotating forward or in reverse, respectively. This protects the forward / reverse switch module, ensures the normal start and stop of the motor control circuit, and improves the safety of the motor control circuit. Attached Figure Description

[0020] Figure 1 A schematic diagram of a motor control circuit provided in an embodiment of this utility model;

[0021] Figure 2 A circuit diagram of a motor control circuit provided for an embodiment of this utility model;

[0022] Figure 3 A schematic diagram of a motor control circuit for achieving slow motor start-up and forward rotation, provided for an embodiment of this utility model;

[0023] Figure 4 A schematic diagram of a motor control circuit provided for an embodiment of the present invention, which realizes the release of back electromotive force energy after the motor slowly stops rotating in the forward direction;

[0024] Figure 5 A schematic diagram of a motor control circuit for achieving slow motor start-up and reverse rotation, provided for an embodiment of this utility model;

[0025] Figure 6 This is a schematic diagram of a motor control circuit provided in an embodiment of the present invention, which realizes the release of back electromotive force energy after the motor slowly stops in reverse. Detailed Implementation

[0026] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this utility model are further described in detail below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] During practical application of motors, the inventors discovered that the switching module controlling motor start-stop sometimes malfunctions during motor startup or shutdown, affecting normal motor operation. Analyzing the motor startup and shutdown control process to explore the underlying cause of this sudden switch module failure, the inventors found that motor startup requires overcoming static friction and rotational inertia to rotate the rotor from rest. To achieve this, the motor must generate sufficiently large torque during startup, which directly depends on the current. Therefore, the current during startup is significantly greater than the current during normal operation, typically 2-3 times greater, easily causing relay contact burning or MOSFET breakdown. Furthermore, the back electromotive force (EMF) of the motor is an electromotive force generated during operation, its direction opposite to the EMF of the motor's power supply. When the motor rotor rotates, a magnetic field is generated in the motor windings. This magnetic field interacts with the fixed magnetic field of the motor stator, inducing an EMF in the windings—the back EMF—which is exactly opposite to the voltage initially applied across the coils. Specifically, when a motor is powered on, electrical energy is converted into magnetic energy; when the motor is powered off, the stored magnetic energy is converted back into electrical energy. At the instant the circuit is de-energized, for relays, the back electromotive force (EMF) energy will generate an electric spark between the relay contacts, causing contact erosion. For MOSFETs, the back EMF energy will break down and damage them, preventing the release of back EMF energy and affecting the normal operation of the circuit. Therefore, this invention provides a motor control circuit, circuit board, and clothes dryer, solving the problem in existing motor control circuits where the switching module is easily damaged during motor start-up or shutdown, affecting the normal operation of the motor control circuit.

[0030] Figure 1 A schematic diagram of a motor control circuit provided in an embodiment of this utility model is shown below. Figure 1 As shown, the motor control circuit 110 includes a forward / reverse switch module 111, a first energy release module 112, a second energy release module 113, and a slow start / stop module 114.

[0031] The first end of the forward / reverse switch module 111 and the first end of the first energy release module 112 are respectively used to connect to the first end of the motor 120, and the second end of the forward / reverse switch module 111 and the second end of the first energy release module 112 are respectively used to connect to the second end of the motor 120. The forward / reverse switch module 111 is used to control the motor 120 to rotate forward or reverse, and the first energy release module 112 is used to release the back electromotive force energy generated after the motor stops rotating forward. The motor 120 can be a single-phase motor. When the first end is positive and the second end is negative, the motor rotates forward; when the first end is negative and the second end is positive, the motor rotates in reverse.

[0032] Please refer to Figure 2This is a circuit diagram of a motor control circuit provided in an embodiment of the present invention. In this embodiment, as an optional implementation, the forward / reverse switch module 111 includes a first single-pole double-throw relay REL1 and a second single-pole double-throw relay REL2. The moving contact of the first single-pole double-throw relay REL1 serves as the first end of the forward / reverse switch module 111, the moving contact of the first single-pole double-throw relay REL2 serves as the second end of the forward / reverse switch module 111, and the first stationary contact of the first single-pole double-throw relay REL1 and the first stationary contact of the first single-pole double-throw relay REL2 serve as the third end of the forward / reverse switch module 111. The second stationary contact of the first single-pole double-throw relay REL1 and the second stationary contact of the first single-pole double-throw relay REL2 serve as the fourth terminal of the forward / reverse switch module 111. The power supply terminals of the first single-pole double-throw relay REL1 and the first single-pole double-throw relay REL2 are respectively used to connect to the first power supply voltage. The input terminal of the first single-pole double-throw relay REL1 is used to receive the first level signal output by the control unit 130 for controlling the motor 120 to rotate forward, and the input terminal of the first single-pole double-throw relay REL2 is used to receive the second level signal output by the control unit 130 for controlling the motor 120 to rotate in reverse. Specifically, the moving contact of the first single-pole double-throw relay REL1 is connected to the first terminal of the first energy release module, the first stationary contact of the first single-pole double-throw relay REL1 is connected to the first terminal of the second energy release module, the second stationary contact of the first single-pole double-throw relay REL1 is connected to the second terminal of the second energy release module, the power supply terminal of the first single-pole double-throw relay REL1 is used to connect to the first power supply voltage 24V, and the input terminal of the first single-pole double-throw relay REL1 is used to receive the first level signal M_UP output by the control unit 130 for controlling the motor 120 to rotate forward. The moving contact of the second single-pole double-throw relay REL2 is connected to the second terminal of the first energy release module, the first stationary contact of the second single-pole double-throw relay REL2 is connected to the first terminal of the second energy release module, the second stationary contact of the second single-pole double-throw relay REL2 is connected to the second terminal of the second energy release module, the power supply terminal of the second single-pole double-throw relay REL2 is used to connect to the first power supply voltage 24V, and the input terminal of the second single-pole double-throw relay REL2 is used to receive the second level signal M_DWN output by the control unit 130 for controlling the motor 120 to rotate in reverse.The first terminal of the control unit 130 is connected to the base terminal of the first transistor Q1 to control whether the first transistor Q1 is turned on. The emitter terminal of the first transistor Q1 is grounded. The collector terminal of the first transistor Q1 is connected to the input terminal of the first single-pole double-throw relay REL1 to input a first level signal M_UP to control the motor 120 to rotate forward. For example, if the first level signal M_UP is a low level signal, the first single-pole double-throw relay REL1 is turned on. The second terminal of the control unit 130 is connected to the second power supply voltage 5V. The fourth terminal of the control unit 130 is connected to the base terminal of the second transistor Q2 to control whether the second transistor Q2 is turned on. The emitter terminal of the second transistor Q2 is grounded. The collector terminal of the second transistor Q2 is connected to the input terminal of the second single-pole double-throw relay REL2 to input a second level signal M_DWN to control the motor 120 to rotate backward. For example, if the second level signal M_DWN is a low level signal, the second single-pole double-throw relay REL2 is turned on. The sixth terminal of the control unit 130 is grounded.

[0033] In one specific implementation, such as Figure 2 As shown, the first energy release module 112 includes a first diode D1 and a first resistor R1. The negative terminal of the first diode D1 is connected to the first terminal of the forward / reverse switch module 111, and the positive terminal of the first diode D1 is connected to the first terminal of the first resistor R1. The second terminal of the first resistor R1 is connected to the second terminal of the forward / reverse switch module 111. Specifically, the first diode D1 can be a transient suppression diode with a cutoff voltage greater than the motor operating voltage. The first resistor R1 is a resistor with a small resistance and high power rating, for example, a resistance less than 500Ω and a power rating greater than 3W. When the motor 120 stops rotating forward, the back electromotive force current of the motor 120 returns from the second terminal of the motor 120 through the first resistor R1 and the first diode D1 to the first terminal of the motor 120, forming a loop to release energy.

[0034] The first end of the second energy release module 113 is connected to the third end of the forward / reverse switch module 111 and is used to connect to the first power supply voltage. The second end of the second energy release module 113 is connected to the fourth end of the forward / reverse switch module 111 and is used to release the back electromotive force energy generated after the motor 120 stops reversing.

[0035] In one embodiment, such as Figure 2As shown, the second energy release module 113 includes a second diode D2, the negative terminal of which is connected to the third terminal of the forward / reverse switch module 111, and the positive terminal of which is connected to the fourth terminal of the forward / reverse switch module 111 for connecting to the first power supply voltage 24V. When the motor 120 stops reversing, the back electromotive force current of the motor flows from the first terminal of the motor 120 through the fourth terminal of the forward / reverse switch module 111, the first diode D1, and the third terminal of the forward / reverse switch module 111, and returns to the second terminal of the motor 120, forming a loop to release energy.

[0036] The first end of the slow start and slow stop module 114 is connected to the second end of the second energy release module 113, and the second end of the slow start and slow stop module 114 is grounded, which is used to control the motor 120 to start or stop slowly.

[0037] In one specific implementation, such as Figure 2 As shown, the slow start / stop module 114 includes a first MOSFET Q3, a second resistor R2, and a third resistor R3. The drain terminal of the first MOSFET Q3 is connected to the second terminal of the second energy release module 113. The source terminal of the first MOSFET Q3 is connected to the first terminal of the second resistor R2 and ground. The gate terminal of the first MOSFET Q3 is connected to the second terminal of the second resistor R2 and the first terminal of the third resistor R3. The second terminal of the third resistor R3 is used to receive the PWM signal M_SP output by the control unit 130 for controlling the motor 120 to start or stop slowly. The third terminal of the control unit 130 is connected to the second terminal of the third resistor R3 to input the PWM signal M_SP for controlling the motor 120 to start or stop slowly. This PWM signal M_SP can control the switching speed of the first MOSFET Q3, thereby achieving slow start or stop of the motor and reducing the starting current. The second resistor R2 is used for voltage clamping between the gate and source terminals of the first MOSFET Q3 to prevent false triggering. The third resistor R3 is used to provide damping to the PWM signal M_SP to eliminate interference.

[0038] Optional, such as Figure 2As shown, the motor control circuit 110 can also be equipped with a current detection and protection module 115. This current detection and protection module 115 includes a fourth resistor R4, a first inductor L1, a first capacitor C1, a third diode D3, a fourth diode D4, and a fifth resistor R5. The first end of the fourth resistor R4 is connected to the second end of the soft start / stop module 114, and the second end of the fourth resistor R4 is grounded. The first end of the first inductor L1 is connected to the second end of the soft start / stop module 114, and the second end of the first inductor L1 is connected to the first end of the first capacitor C1 and the positive terminal of the third diode D3. The second end of the first capacitor C1 is grounded. The negative terminal of the third diode D3 is used to connect to the second power supply voltage 5V. The positive terminal of the third diode D3 is connected to the negative terminal of the fourth diode D4 and the first end of the fifth resistor R5, and the positive terminal of the fourth diode D4 is grounded. The second end of the fifth resistor R5 is used to output a current detection signal I_SEN to the control unit 130. The fifth terminal of the control unit 130 is connected to the second end of the fifth resistor R5 to receive the output current detection signal I_SEN. Specifically, the fourth resistor R4 is a sensing resistor. During normal motor operation, the current will create a voltage drop across the fourth resistor R4. After filtering by the combination of the first inductor L1 and the first capacitor C1, and damped by the fifth resistor R5, a voltage-form current detection signal I_SEN is output. The damping effect of the fifth resistor R5 prevents false detections by the control unit 130. The first capacitor C1 can be an electrolytic capacitor. Furthermore, if the voltage drop across the fourth resistor R4 is positive and exceeds 5V, the third diode D3 conducts, stabilizing the current detection signal I_SEN at approximately 5.7V. If the voltage drop across the fourth resistor R4 is negative, the fourth diode D4 conducts, stabilizing the current detection signal I_SEN at approximately -0.7V. This accurately detects the current during normal motor operation while protecting the control unit from abnormal current fluctuations. The control unit can better control the power of the motor 120 based on the received current detection signal I_SEN.

[0039] In one embodiment, such as Figure 2 As shown, the motor control circuit 110 also includes a sixth resistor R6 and a second capacitor C2. The first end of the sixth resistor R6 is connected to the first end of the motor 120, and the second end of the sixth resistor R6 is connected to the first end of the second capacitor C2. The second end of the second capacitor C2 is connected to the second end of the motor 120. The combination of the sixth resistor R6 and the second capacitor C2 can be used to absorb high-frequency spikes in the circuit.

[0040] In another embodiment, such as Figure 2As shown, the motor control circuit 110 also includes a fifth diode D5. The negative terminal of the fifth diode D5 is connected to the first terminal of the second energy release module 113, and the positive terminal of the fifth diode D5 is used to connect to the first power supply voltage 24V to isolate and prevent damage to 24V and the control unit.

[0041] It should be noted that, Figure 2 The circuit diagram shown is only a comprehensive implementation of each sub-module of the motor control circuit in this embodiment of the present invention, after each sub-module adopts one implementation method. Different implementation methods of each sub-circuit can lead to other comprehensive implementation methods, which correspond to the overall design concept of this solution and the implementation effect. This application does not limit this.

[0042] based on Figure 2 The circuit diagram shown indicates that the first single-pole double-throw relay REL1 and the second single-pole double-throw relay REL2 can control the forward and reverse rotation of the motor, while the first MOSFET Q3 can control the slow start and slow stop of the motor. For the slow start process, either the first single-pole double-throw relay REL1 or the second single-pole double-throw relay REL2 is turned on first, followed by the first MOSFET Q3. For the slow stop process, the first MOSFET Q3 is turned off first, followed by the first single-pole double-throw relay REL1 or the second single-pole double-throw relay REL2.

[0043] Please refer to Figure 3 This is a schematic diagram of a motor control circuit provided in an embodiment of the present invention, illustrating a slow start and forward rotation of a motor. Figure 2 On the basis of, such as Figure 3 As shown, the first terminal of the control unit 130 controls the first transistor Q1 to turn on and the fourth terminal controls the second transistor Q2 to turn off. The first level signal M_UP is a low level signal and the second level signal M_DWN is a high level signal. The first single-pole double-throw relay REL1 turns on first and the second single-pole double-throw relay REL2 turns off. Then, the PWM signal M_SP output by the control unit 130 controls the first MOSFET Q3 to turn on. The current flows from the M+ terminal through the first stationary contact and the moving contact of the first single-pole double-throw relay REL1 to the M1 terminal, then through the motor 120 to the M2 terminal, then through the moving contact and the second stationary contact of the second single-pole double-throw relay REL2 back to the M- terminal, and then through the first MOSFET Q3 and the fourth resistor R4 back to the ground terminal, forming a power circuit.

[0044] Please refer to Figure 4 This is a schematic diagram of a motor control circuit provided by an embodiment of the present invention, which realizes the release of back electromotive force energy after the motor slowly stops rotating in the forward direction. Figure 2 On the basis of, such as Figure 4As shown, the PWM signal M_SP output by the control unit 130 controls the first MOSFET Q3 to turn off, but the first single-pole double-throw relay REL1 and the second single-pole double-throw relay REL2 temporarily remain in their original states. The back electromotive force current of the motor 120 will return from the second terminal of the motor 120 through the first resistor R1 and the first diode D1 to the first terminal of the motor 120, forming a loop to release energy.

[0045] Please refer to Figure 5 This is a schematic diagram of a motor control circuit provided in an embodiment of the present invention, which realizes a slow start and reverse rotation of the motor. Figure 2 On the basis of, such as Figure 5 As shown, the first terminal of the control unit 130 controls the first transistor Q1 to turn off and the fourth terminal controls the second transistor Q2 to turn on. The first level signal M_UP is a high level signal and the second level signal M_DWN is a low level signal. The first single-pole double-throw relay REL1 is turned off and the second single-pole double-throw relay REL2 is turned on first. Then, the PWM signal M_SP output by the control unit 130 controls the first MOSFET Q3 to turn on. The current flows from the M+ terminal through the first stationary contact and the moving contact of the second single-pole double-throw relay REL2 to the M2 terminal, then through the motor 120 to the M1 terminal, then through the moving contact and the second stationary contact of the first single-pole double-throw relay REL1 back to the M- terminal, and then through the first MOSFET Q3 and the fourth resistor R4 back to the ground terminal, forming a power loop.

[0046] Please refer to Figure 6 This is a schematic diagram of a motor control circuit provided in this embodiment of the invention, which realizes the release of back electromotive force energy after the motor slowly stops in reverse rotation. Figure 2 On the basis of, such as Figure 6 As shown, the PWM signal M_SP output by the control unit 130 controls the first MOSFET Q3 to turn off, but the first single-pole double-throw relay REL1 and the second single-pole double-throw relay REL2 temporarily remain in their original states. The back electromotive force current of the motor 120 will return from the first terminal of the motor 120 through the first diode D1 and the first resistor R1 to the second terminal of the motor 120, forming a loop to release energy. However, since the first diode D1 is reverse-conducting, its reverse conduction voltage is high, and only part of the energy can be released. In addition, the back electromotive force current of the motor 120 will return from the first terminal of the motor 120 through the moving contact and the second stationary contact of the first single-pole double-throw relay REL1 to the M- terminal, then through the second diode D2 to the M+ terminal, and then through the first stationary contact and the moving contact of the second single-pole double-throw relay REL2 to the second terminal of the motor 120, forming another loop to release the main energy.

[0047] This embodiment of the invention also provides a circuit board, including any of the motor control circuits described in the above embodiments. The circuit board, based on the aforementioned motor control circuit, is capable of enabling the motor to rotate forward or reverse, releasing the back electromotive force energy generated when the motor stops rotating forward or reverse, and controlling the motor to start or stop slowly.

[0048] This utility model embodiment also provides a clothes drying rack, including: a motor, and any of the motor control circuits described in the above embodiments. The first end of the motor is connected to the first end of a forward / reverse switch module, and the second end of the motor is connected to the second end of the forward / reverse switch module. The clothes drying rack and the motor control circuits provided in any of the above embodiments have corresponding functions and beneficial effects.

[0049] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above are merely specific embodiments of this utility model and are not intended to limit the scope of protection of this utility model. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model for those skilled in the art.

Claims

1. A motor control circuit, characterized by comprising: The application relates to a motor control circuit. The first end of the forward-reverse switch module and the first end of the first energy release module are used for connecting the first end of a motor, the second end of the forward-reverse switch module and the second end of the first energy release module are used for connecting the second end of the motor, the forward-reverse switch module is used for controlling the motor to rotate forward or reversely, and the first energy release module is used for releasing the back electromotive force energy generated after the motor stops rotating forward. The first end of the second energy release module is connected with the third end of the forward-reverse switch module and used for connecting a first power supply voltage, and the second end of the second energy release module is connected with the fourth end of the forward-reverse switch module and used for releasing the back electromotive force energy generated after the motor stops rotating reversely. The first end of the slow start and stop module is connected with the second end of the second energy release module, and the second end of the slow start and stop module is grounded and used for controlling the motor to start slowly or stop slowly. The forward-reverse switch module comprises a first single-pole double-throw relay and a second single-pole double-throw relay, the moving contact of the first single-pole double-throw relay serves as the first end of the forward-reverse switch module, the moving contact of the second single-pole double-throw relay serves as the second end of the forward-reverse switch module, the first fixed contact of the first single-pole double-throw relay and the first fixed contact of the second single-pole double-throw relay serve as the third end of the forward-reverse switch module, the second fixed contact of the first single-pole double-throw relay and the second fixed contact of the second single-pole double-throw relay serve as the fourth end of the forward-reverse switch module, the power supply end of the first single-pole double-throw relay and the power supply end of the second single-pole double-throw relay are used for connecting the first power supply voltage, the input end of the first single-pole double-throw relay is used for receiving a first level signal output by a control unit and used for controlling the motor to rotate forward, and the input end of the second single-pole double-throw relay is used for receiving a second level signal output by the control unit and used for controlling the motor to rotate reversely.

2. A motor control circuit according to claim 1, wherein The first energy release module comprises a first diode and a first resistor, the negative end of the first diode is connected with the first end of the forward-reverse switch module, the positive end of the first diode is connected with the first end of the first resistor, and the second end of the first resistor is connected with the second end of the forward-reverse switch module.

3. A motor control circuit according to claim 1, wherein The second energy release module comprises a second diode, the negative end of the second diode is connected with the third end of the forward-reverse switch module, and the positive end of the second diode is connected with the fourth end of the forward-reverse switch module.

4. A motor control circuit according to claim 1, wherein The slow start and stop module comprises a first MOS tube, a second resistor and a third resistor, the drain end of the first MOS tube is connected with the second end of the second energy release module, the source end of the first MOS tube is connected with the first end of the second resistor and grounded, the gate end of the first MOS tube is connected with the second end of the second resistor and the first end of the third resistor, and the second end of the third resistor is used for receiving a PWM signal output by the control unit and used for controlling the motor to start slowly or stop slowly.

5. A motor control circuit according to claim 1, wherein ​ 6. A motor control circuit according to claim 1, wherein The fourth resistance, the first inductance, the first capacitance, the third diode, the fourth diode and the fifth resistance are further included, a first end of the fourth resistance is connected with a second end of the soft start and stop module, a second end of the fourth resistance is grounded, a first end of the first inductance is connected with the second end of the soft start and stop module, a second end of the first inductance is connected with a first end of the first capacitance and a positive electrode end of the third diode, a second end of the first capacitance is grounded, a negative electrode end of the third diode is used for connecting with a second power supply voltage, a positive electrode end of the third diode is connected with a negative electrode end of the fourth diode and a first end of the fifth resistance, a positive electrode end of the fourth diode is grounded, and a second end of the fifth resistance is used for outputting a current detection signal to the control unit.

7. A motor control circuit according to claim 1, wherein The sixth resistance and the second capacitance are further included, a first end of the sixth resistance is used for connecting with a first end of the motor, a second end of the sixth resistance is connected with a first end of the second capacitance, and a second end of the second capacitance is used for connecting with a second end of the motor.

8. A motor control circuit according to claim 1, wherein The fifth diode is further included, a negative electrode end of the fifth diode is connected with a first end of the second energy release module, and a positive electrode end of the fifth diode is used for connecting with the first power supply voltage.

9. A circuit board, characterized by The motor control circuit is included.

10. A clothes drying machine characterised in that, The motor control circuit is included. The motor and the motor control circuit are included, a first end of the motor is connected with a first end of the forward and reverse rotation switch module, and a second end of the motor is connected with a second end of the forward and reverse rotation switch module.

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