Motor control circuit with arc suppression function

Abstract

The utility model discloses a motor control circuit with an arc suppression function. The motor control circuit comprises a motor. The power supply unit is used for providing working voltage for the whole circuit system; the current detection unit is connected between the power supply unit and the motor and is used for detecting the working current of the motor and generating an overcurrent signal when the current exceeds a preset threshold value; the protection unit is connected with the current detection unit and responds to the overcurrent signal to cut off or limit the current supply of the motor; the control switch unit is connected with the motor and used for controlling forward and reverse switching and stopping of the motor; the arc suppression unit is connected with the control switch unit and is used for suppressing an arc caused by the operation of the control switch unit in the running process of the motor and smoothing the current change; the utility model has the advantages of effectively reducing the generation of electric arc and improving the reliability and safety of the circuit.

Description

Technical Field

[0001] This utility model relates to a motor control circuit, and more particularly to a motor control circuit with arc suppression function. Background Technology

[0002] Motor control circuits are widely used in various mechanical equipment to control the starting, stopping, forward and reverse rotation of motors. Traditional motor control circuits typically use relays or mechanical switches to achieve these functions. However, these switches generate electric arcs when they are disconnected, which can damage the switch itself, affect other components in the circuit, and even cause safety accidents.

[0003] For example, traditional H-bridge circuits use transistors as switching devices. While these offer fast response and high control precision, arcing can still occur during transistor switching under high current or high voltage conditions. This is particularly true during motor startup and shutdown, where the induced electromotive force within the motor generates a reverse voltage in the circuit, potentially causing transient transistor breakdown and subsequent arcing. Furthermore, mechanical switches are more prone to arcing upon disconnection, especially in high-power motor applications. The contact points of mechanical switches are subjected to high voltage and current surges at the moment of disconnection, easily generating sparks or arcs. This not only damages the switch contacts and shortens their lifespan but also affects other components in the circuit, potentially leading to safety accidents.

[0004] Therefore, how to effectively suppress the generation of electric arcs and improve the reliability and safety of motor control circuits has become a technical problem that urgently needs to be solved. Utility Model Content

[0005] The purpose of this invention is to provide a motor control circuit with arc suppression function, which can effectively reduce the generation of electric arcs and improve the reliability and safety of the circuit.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a motor control circuit with arc suppression function, comprising a motor;

[0007] The power supply unit is used to provide operating voltage to the entire circuit system;

[0008] A current detection unit is connected between the power supply unit and the motor, and is used to detect the operating current of the motor and generate an overcurrent signal when the current exceeds a preset threshold.

[0009] A protection unit, connected to the current detection unit, responds to an overcurrent signal to cut off or limit the current supply to the motor;

[0010] A control switch unit, connected to the motor, is used to control the forward and reverse switching and stopping of the motor;

[0011] An arc suppression unit, connected to the control switch unit, is used to suppress the arc caused by the operation of the control switch unit during the operation of the motor and to smooth current changes.

[0012] Preferably, the power supply unit is provided with an output VCC, and the current detection unit and the protection unit are two sets respectively;

[0013] The first group of current detection units includes a transistor Q1. The collector of transistor Q1 is connected to the output VCC through a diode D11. The negative terminal of the motor is connected to GND through a diode D3. The first group of protection units includes a resistor R11, a resistor R12, a transistor Q2, a resistor R13, a capacitor C11, and a capacitor C12. One end of resistor R11 is connected to the collector of transistor Q1, and the other end of resistor R11 is connected to the base of transistor Q1 and the collector of transistor Q2. One end of resistor R12 is connected to the collector of transistor Q1. The base of transistor Q2 is connected to the other end of resistor R12, one end of resistor R13, one end of capacitor C11, and one end of capacitor C12. The emitter of transistor Q2 is connected to the emitter of transistor Q1, the other end of resistor R13, the other end of capacitor C11, and the other end of capacitor C12.

[0014] Another set of current detection units includes a transistor Q3, the collector of which is connected to GND via a diode D4. The anode of diode D4 is connected to the cathode of diode D3. A diode D12 is connected to the positive terminal of the motor, the cathode of which is connected to the output VCC and also to the anode of diode D11. The second set of protection units includes a resistor R14, a resistor R5, a transistor Q4, a resistor R6, a capacitor C3, and a capacitor C4. One end of resistor R14 is connected to the collector of transistor Q3. The electrodes are connected together. The other end of the resistor R4 is connected to the base and collector of the transistor Q3. One end of the resistor R5 is connected to the collector of the transistor Q3. The base of the transistor Q4 is connected to the other end of the resistor R5, one end of the resistor R6, one end of the capacitor C3, and one end of the capacitor C14. The emitter of the transistor Q4 is connected to the emitter of the transistor Q3, the other end of the resistor R6, the other end of the capacitor C3, and the other end of the capacitor C14.

[0015] Preferably, the control switch unit includes a single-pole double-throw switch S1 and a single-pole double-throw switch S2. The single-pole double-throw switch S1 has a first terminal, a second terminal, and a third terminal, wherein the second terminal is a common terminal. The single-pole double-throw switch S2 also has a first terminal, a second terminal, and a third terminal, wherein the second terminal is also a common terminal. The arc suppression unit includes a capacitor C2, a resistor R2, a diode D1, a diode D2, a capacitor C1, and a resistor R1. The second terminal of the single-pole double-throw switch S1 is connected to one end of the motor. The first terminal of the single-pole double-throw switch S1 is connected to one end of the capacitor C2 and the positive terminal of the diode D1. The third terminal of the single-pole double-throw switch S1 is connected to the negative terminal of the power supply unit. The other end of the capacitor C2 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the negative terminal of the power supply unit. The negative terminal of the diode D1 is connected to the negative terminal of the power supply unit and the negative terminal of the diode D2.

[0016] The second terminal of the single-pole double-throw switch S2 is connected to one end of the motor. The first terminal of the single-pole double-throw switch S2 is connected to one end of the capacitor C1 and the positive terminal of the diode D2. The third terminal of the single-pole double-throw switch S2 is connected to the negative terminal of the power supply unit. The other end of the capacitor C1 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the negative terminal of the power supply unit.

[0017] Compared with existing technologies, the advantages of this utility model are as follows: The motor control circuit, through its rational design and modular structure, achieves efficient collaborative operation of motor control and protection. The power supply unit provides a stable operating voltage, supporting the entire circuit system. The current detection unit, connected between the power supply and the motor, can monitor the current status of the motor in real time and generate an overcurrent signal when the current exceeds a preset threshold. This real-time monitoring mechanism enables the circuit to respond quickly, effectively preventing damage to the motor from current overload. The protection unit, working in conjunction with the current detection unit, immediately cuts off or limits the current supply upon receiving an overcurrent signal, thereby protecting the motor and other components in the circuit from overcurrent impact. The control switch unit, connected to the motor, enables forward and reverse switching and stopping functions through switching operations, adapting to different operating conditions. This design improves the flexibility and controllability of motor operation.

[0018] During the operation of the control switch unit, instantaneous electric arcs may be triggered by circuit switching, which can damage the circuit and motor. To solve this problem, the circuit is equipped with an arc suppression unit. This unit is connected to the control switch unit and can effectively suppress the generation of electric arcs during motor operation. It also uses components such as capacitors and resistors to smooth rapid changes in current, reduce voltage and current surges caused by electric arcs, thereby extending the service life of the switching devices and motor, and ensuring the stability and safety of the circuit.

[0019] In summary, this circuit combines current detection, overcurrent protection, flexible switching control, and arc suppression to form a complete motor control and protection system. It has significant advantages such as efficient motor protection, improved circuit stability, and extended service life, and is suitable for motor control applications requiring high reliability and high safety. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the principle of this utility model;

[0022] Figure 2 This is a circuit diagram of the control switch unit and the arc suppression unit working together in this utility model;

[0023] Figure 3 This is a circuit diagram showing the current detection unit and protection unit working together in this utility model;

[0024] In the diagram, 1 is the motor; 2 is the power supply unit; 3 is the current detection unit; 4 is the protection unit; 5 is the control switch unit; and 6 is the arc suppression unit. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Example: As shown in the figure, a motor control circuit with arc suppression function includes a motor 1;

[0027] Power supply unit 2 is used to provide operating voltage to the entire circuit system;

[0028] The current detection unit 3 is connected between the power supply unit 2 and the motor 1. It is used to detect the operating current of the motor 1 and generate an overcurrent signal when the current exceeds a preset threshold.

[0029] Protection unit 4 is connected to current detection unit 3 and responds to overcurrent signals to cut off or limit the current supply to the motor.

[0030] The control switch unit 5 is connected to the motor 1 and is used to control the forward and reverse switching and stopping of the motor;

[0031] The arc suppression unit 6 is connected to the control switch unit 5 and is used to suppress the arc caused by the operation of the control switch unit 5 during the operation of the motor 1, and to smooth the current change.

[0032] Preferably, the power supply unit 2 is provided with an output VCC, and the current detection unit 3 and the protection unit 4 are two sets respectively;

[0033] The first current detection unit includes transistor Q1. The collector of transistor Q1 is connected to the output VCC through diode D11. The negative terminal of the motor is connected to GND through diode D3. The first protection unit includes resistor R11, resistor R12, transistor Q2, resistor R13, capacitor C11, and capacitor C12. One end of resistor R11 is connected to the collector of transistor Q1, and the other end of resistor R11 is connected to the base of transistor Q1 and the collector of transistor Q2. One end of resistor R12 is connected to the collector of transistor Q1. The base of transistor Q2 is connected to the other end of resistor R12, one end of resistor R13, one end of capacitor C11, and one end of capacitor C12. The emitter of transistor Q2 is connected to the emitter of transistor Q1, the other end of resistor R13, the other end of capacitor C11, and the other end of capacitor C12.

[0034] Another set of current detection units includes transistor Q3. The collector of transistor Q3 is connected to GND through diode D4. The anode of diode D4 is connected to the cathode of diode D3. Diode D12 is connected to the positive terminal of the motor. The cathode of diode D12 is connected to the output VCC and also to the anode of diode D11. The second set of protection units includes resistors R14 and R5, transistor Q4, resistor R6, capacitors C3 and C4. One end of resistor R14 is connected to transistor Q3. The collector of transistor Q3 is connected to the base of transistor Q3 and the collector of transistor Q4. One end of resistor R5 is connected to the collector of transistor Q3. The base of transistor Q4 is connected to the other end of resistor R5, one end of resistor R6, one end of capacitor C3, and one end of capacitor C3. The emitter of transistor Q4 is connected to the emitter of transistor Q3, the other end of resistor R6, the other end of capacitor C3, and the other end of capacitor C14.

[0035] This circuit design includes two sets of current detection units and protection units, used for current monitoring and protection during forward and reverse motor rotation, respectively. The first set of current detection units uses transistor Q1, whose collector is connected to the power output VCC through diode D11, while the motor negative terminal is grounded through diode D3. When the motor is running, if the load is too large or other reasons cause the current to exceed the threshold, transistor Q1 conducts, outputting an overcurrent signal to the first set of protection units. The protection unit includes resistors R11, R12, and R13, capacitors C11 and C12, and transistor Q2. Through cooperation with Q1, it processes the overcurrent signal, thereby cutting off or limiting the current supply, thus protecting the motor and circuit from damage.

[0036] The second current detection unit is similar, using transistor Q3, whose collector is grounded through diode D4. At the same time, the positive terminal of the motor is connected to the power supply VCC through diode D12. When the motor reverses, if an overcurrent occurs, transistor Q3 will conduct, triggering the second protection unit. The second protection unit consists of resistors R14, R5, and R6, capacitors C3 and C4, and transistor Q4. Similar to the protection mechanism of the first group, it processes the overcurrent signal to ensure the safety of the circuit when the motor is running in reverse.

[0037] This circuit design demonstrates high safety and reliability. Firstly, it employs two independent current detection and protection units, respectively monitoring and protecting the motor during forward and reverse rotation. This dual-unit design effectively adapts to different operating requirements, avoiding delays or failures that might occur with a single protection unit when switching directions, thus improving the circuit's adaptability and fault tolerance. Secondly, each protection unit incorporates a resistor-capacitor network (RC network), using the charging and discharging characteristics of the capacitor to smooth the overcurrent signal, reducing the impact of transient current changes on the protection circuit. This design not only improves the sensitivity of current detection and protection but also ensures system stability, preventing false triggering caused by current fluctuations.

[0038] Furthermore, diodes D11, D12, D3, and D4 are used in the circuit to create reasonable guiding paths for forward and reverse currents, ensuring that overcurrent signals can correctly trigger the corresponding protection units. These diodes also prevent reverse currents that may be generated during motor operation from damaging circuit components. Through comprehensive protection of both the positive and negative terminals of the motor, this circuit can quickly respond to overcurrent conditions, promptly cutting off or limiting the motor current when an overcurrent occurs, preventing damage to the motor and control circuitry due to overcurrent.

[0039] Overall, this design achieves precise monitoring and protection of current in different directions during the forward and reverse rotation of the motor. It features rapid response, stable operation, and strong adaptability. At the same time, the combination of arc suppression and protection mechanisms enables the circuit to maintain high reliability during long-term operation, making it particularly suitable for scenarios with high requirements for motor control safety.

[0040] Preferably, the control switch unit 5 includes a single-pole double-throw switch S1 and a single-pole double-throw switch S2. The single-pole double-throw switch S1 has a first terminal, a second terminal, and a third terminal, wherein the second terminal is a common terminal. The single-pole double-throw switch S2 also has a first terminal, a second terminal, and a third terminal, wherein the second terminal is also a common terminal. The arc suppression unit 6 includes a capacitor C2, a resistor R2, a diode D1, a diode D2, a capacitor C1, and a resistor R1. The second terminal of the single-pole double-throw switch S1 is connected to one end of the motor. The first terminal of the single-pole double-throw switch S1 is connected to one end of the capacitor C2 and the positive terminal of the diode D1. The third terminal of the single-pole double-throw switch S1 is connected to the negative terminal of the power supply unit. The other end of the capacitor C2 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the negative terminal of the power supply unit. The negative terminal of the diode D1 is connected to the negative terminal of the power supply unit and the negative terminal of the diode D2.

[0041] The second terminal of the single-pole double-throw switch S2 is connected to one end of the motor. The first terminal of the single-pole double-throw switch S2 is connected to one end of the capacitor C1 and the positive terminal of the diode D2. The third terminal of the single-pole double-throw switch S2 is connected to the negative terminal of the power supply unit. The other end of the capacitor C1 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the negative terminal of the power supply unit.

[0042] The control switch unit in this structural design consists of two single-pole double-throw switches, S1 and S2, used to control the motor's forward, reverse, and stop states, respectively. The second terminal of each switch serves as a common terminal connected to both ends of the motor, while the first and third terminals are connected to the arc suppression unit and the negative terminal of the power supply, respectively. This design ensures that during motor operation, switching the states of S1 and S2 allows for convenient switching of the motor direction and circuit connection / disconnection.

[0043] To further improve the system's safety and stability, an arc suppression unit is incorporated into the design, consisting of capacitor C2, resistor R2, diodes D1 and D2, capacitor C1, and resistor R1. When switching between S1 and S2, the arc suppression unit effectively absorbs transient overvoltages caused by the inductive load of the motor, thereby protecting the switch contacts from damage by high-voltage arcs. Specifically, when switching between S1 and S2 disconnects the circuit, the induced electromotive force at both ends of the motor is conducted through diodes D1 and D2 and absorbed and dispersed by capacitors C1 and C2 and resistors R1 and R2, reducing the impact of the arc on the switch. This not only extends the switch's lifespan but also reduces noise and interference during circuit operation.

[0044] In addition, the combination of capacitors C1 and C2 and resistors R1 and R2 forms an RC damping network, which can smooth the changes in motor current and avoid large current spikes in the circuit caused by switching operations, thereby further improving the stability of motor operation and the reliability of the system.

[0045] The advantage of this design lies in combining the control switch unit with the arc suppression unit, effectively solving various problems existing in traditional motor control circuits. First, the control switch unit, through the cooperation of single-pole double-throw switches S1 and S2, simply achieves flexible control of the motor's forward, reverse, and stop functions without the need for complex multi-stage circuit switching. Second, by introducing the arc suppression unit at both ends of the switch, the RC damping network composed of capacitor C2, resistor R2, diodes D1 and D2, capacitor C1, and resistor R1 effectively absorbs transient overvoltages generated by the inductive load of the motor during switch switching, thereby suppressing damage to the switch contacts from high-voltage arcs and significantly extending the switch's service life. Furthermore, it smooths current changes, reduces the impact of current spikes on the circuit and motor, reduces electromagnetic interference caused by motor switching operations, and further improves the stability of motor operation and the reliability of the system.

[0046] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A motor control circuit with arc suppression function, characterized in that: include, Electric motor; The power supply unit is used to provide operating voltage to the entire circuit system; A current detection unit is connected between the power supply unit and the motor, and is used to detect the operating current of the motor and generate an overcurrent signal when the current exceeds a preset threshold. A protection unit, connected to the current detection unit, responds to an overcurrent signal to cut off or limit the current supply to the motor; A control switch unit, connected to the motor, is used to control the forward and reverse switching and stopping of the motor; An arc suppression unit, connected to the control switch unit, is used to suppress the arc caused by the operation of the control switch unit during the operation of the motor and to smooth current changes.

2. The motor control circuit with arc suppression function according to claim 1, characterized in that: The power supply unit is equipped with an output VCC, and the current detection unit and the protection unit are two sets respectively; The first group of current detection units includes a transistor Q1. The collector of transistor Q1 is connected to the output VCC through a diode D11. The negative terminal of the motor is connected to GND through a diode D3. The first group of protection units includes a resistor R11, a resistor R12, a transistor Q2, a resistor R13, a capacitor C11, and a capacitor C12. One end of resistor R11 is connected to the collector of transistor Q1, and the other end of resistor R11 is connected to the base of transistor Q1 and the collector of transistor Q2. One end of resistor R12 is connected to the collector of transistor Q1. The base of transistor Q2 is connected to the other end of resistor R12, one end of resistor R13, one end of capacitor C11, and one end of capacitor C12. The emitter of transistor Q2 is connected to the emitter of transistor Q1, the other end of resistor R13, the other end of capacitor C11, and the other end of capacitor C12. Another set of current detection units includes a transistor Q3, the collector of which is connected to GND via a diode D4. The anode of diode D4 is connected to the cathode of diode D3. A diode D12 is connected to the positive terminal of the motor, the cathode of which is connected to the output VCC and also to the anode of diode D11. The second set of protection units includes a resistor R14, a resistor R5, a transistor Q4, a resistor R6, a capacitor C3, and a capacitor C4. One end of resistor R14 is connected to the collector of transistor Q3. The electrodes are connected together. The other end of the resistor R4 is connected to the base and collector of the transistor Q3. One end of the resistor R5 is connected to the collector of the transistor Q3. The base of the transistor Q4 is connected to the other end of the resistor R5, one end of the resistor R6, one end of the capacitor C3, and one end of the capacitor C14. The emitter of the transistor Q4 is connected to the emitter of the transistor Q3, the other end of the resistor R6, the other end of the capacitor C3, and the other end of the capacitor C14.

3. A motor control circuit with arc suppression function according to claim 1 or 2, characterized in that: The control switch unit includes a single-pole double-throw switch S1 and a single-pole double-throw switch S2. The single-pole double-throw switch S1 has a first terminal, a second terminal, and a third terminal, wherein the second terminal is a common terminal. The single-pole double-throw switch S2 also has a first terminal, a second terminal, and a third terminal, wherein the second terminal is also a common terminal. The arc suppression unit includes a capacitor C2, a resistor R2, a diode D1, a diode D2, a capacitor C1, and a resistor R1. The second terminal of the single-pole double-throw switch S1 is connected to one end of the motor. The first terminal of the single-pole double-throw switch S1 is connected to one end of the capacitor C2 and the positive terminal of the diode D1. The third terminal of the single-pole double-throw switch S1 is connected to the negative terminal of the power supply unit. The other end of the capacitor C2 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the negative terminal of the power supply unit. The negative terminal of the diode D1 is connected to the negative terminal of the power supply unit and the negative terminal of the diode D2. The second terminal of the single-pole double-throw switch S2 is connected to one end of the motor. The first terminal of the single-pole double-throw switch S2 is connected to one end of the capacitor C1 and the positive terminal of the diode D2. The third terminal of the single-pole double-throw switch S2 is connected to the negative terminal of the power supply unit. The other end of the capacitor C1 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the negative terminal of the power supply unit.

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