Circuit structure for controlling operation of single-phase motor

Abstract

The utility model provides a circuit structure for controlling operation of a single-phase motor, which comprises an operation winding and a starting winding which form a stator coil in the single-phase motor, and further comprises a timer and a timing switch. The starting winding and the timing switch are connected in series and then connected in parallel with the timer and the operation winding between two ends of the AC power supply. Wherein the timer is in signal connection with the timing switch, and the timing switch is in a normally closed state; and after the preset time countdown of the timer is finished, the timer sends a turn-off signal to the timing switch, so that the timing switch is converted from a normally-closed state to an off state. According to the circuit structure for technically controlling the operation of the single-phase motor, the timer and the timing switch ensure that the starting winding is accurately disconnected within the preset time, the motor is prevented from being overheated, and the starting efficiency and durability are improved.

Description

Technical Field

[0001] The present application relates to the technical field of single-phase motor circuit structure design, and in particular, to a circuit structure for controlling the operation of a single-phase motor. Background Art

[0002] With the rapid development of modern industry, single-phase motors have been widely used in various automation equipment and household appliances. Single-phase motors have become the preferred power source for many devices due to their simple structure, low cost and easy maintenance.

[0003] Currently, single-phase motors generally use centrifugal switches as their starting and running control mechanism. The centrifugal switch remains closed when the motor starts, helping the motor to start smoothly. When the motor reaches normal operating speed, the centrifugal switch can automatically disconnect the starting winding, thereby achieving the purpose of saving power and improving efficiency. This control method performs well when the motor load is normal and the operating speed is high, and it is a conventional technology in the field of single-phase motor control.

[0004] However, centrifugal switches have obvious limitations. When the motor encounters a continuous low-speed overload operation, since the centrifugal switch relies on the motor's rotation speed to generate centrifugal force, when the motor speed is insufficient, the centrifugal force of the centrifugal hammer is insufficient to disconnect the starting winding in time, causing the starting winding to be energized for a long time, resulting in overheating and even burning the motor. For example, for the base lifting motor of some types of epitaxial machines in semiconductor manufacturing, when the friction between the lead screw and the guide rail increases or the load is too heavy, the speed of the single-phase motor will decrease, which may cause the motor to be damaged within a few minutes. Utility Model Content

[0005] The purpose of the embodiment of the present application is to provide a circuit structure for controlling the operation of a single-phase motor, which ensures that the starting winding is accurately disconnected within a preset time through a timer and a timing switch, prevents the motor from overheating, and improves starting efficiency and durability.

[0006] The present application provides a circuit structure for controlling the operation of a single-phase motor, including a running winding and a starting winding constituting a stator coil in a single-phase motor, and also including a timer and a timing switch. After the starting winding and the timing switch are connected in series, they are connected in parallel with the timer and the running winding between the two ends of an AC power supply. Among them, the timer is connected to the timing switch signal, and the timing switch is in a normally closed state; after the countdown of the preset time of the timer ends, the timer sends a closing signal to the timing switch to turn the timing switch from a normally closed state to an open state.

[0007] In an implementable solution, a circuit structure for controlling the operation of a single-phase motor includes a starting capacitor, which is connected in series with a starting winding and a timing switch.

[0008] In an implementable solution, the circuit structure for controlling the operation of the single-phase motor further includes a centrifugal switch, which is mounted on the rotor of the single-phase motor and connected in series with the starting winding and the timing switch;

[0009] The centrifugal switch is in a normally closed state. When the rotation speed of the rotor of the single-phase motor reaches a preset rotation speed or above, the centrifugal switch changes from the normally closed state to the open state.

[0010] In an implementable solution, the circuit structure for controlling the operation of the single-phase motor further includes a running capacitor, and the running capacitor is connected in parallel with a circuit in which the timing switch and the starting capacitor are connected in series.

[0011] In an implementable solution, the circuit structure for controlling the operation of the single-phase motor also includes an access switch, which is connected in series with the running capacitor and then connected in parallel with the circuit in which the timing switch and the starting capacitor are connected in series.

[0012] In an implementable solution, the capacitance value of the running capacitor of the circuit structure for controlling the operation of the single-phase motor is smaller than the capacitance value of the starting capacitor.

[0013] In an implementable solution, the starting capacitor of the circuit structure for controlling the operation of the single-phase motor is a capacitor with an adjustable capacitance value.

[0014] In an implementable solution, the operating capacitor of the circuit structure for controlling the operation of the single-phase motor is a capacitor with an adjustable capacitance value.

[0015] In an implementable solution, the circuit structure for controlling the operation of the single-phase motor further includes a speed meter, a controller and a main switch;

[0016] The main switch is installed on the line before the AC power enters the running winding and starting winding of the unidirectional motor;

[0017] The controller and the speed meter are connected in parallel with the running winding between the two ends of the AC power supply, and the speed meter is used to measure the speed of the rotor of the single-phase motor;

[0018] The controller is connected with the speed meter and the main switch signal, and the controller obtains the real-time speed value of the rotor of the single-phase motor through the speed meter;

[0019] After the main switch is closed and reaches the preset threshold time, the controller determines whether the real-time speed value is less than the preset speed; if so, the controller sends a disconnect signal to the main switch to disconnect the main switch; if not, the state of the main switch is maintained.

[0020] Compared with the prior art, the beneficial effects of the present application include at least:

[0021] The circuit structure for controlling the operation of a single-phase motor proposed in the embodiment of the present application mainly includes a running winding and a starting winding, which together constitute the stator coil of the single-phase motor. In addition, the circuit also includes a timer and a timing switch, which are connected in parallel with the winding of the motor between the two ends of the AC power supply. The starting winding and the timing switch are connected in series, and then connected in parallel with the timer and the running winding. The initial state of the timing switch is normally closed to ensure that the circuit is closed at startup.

[0022] When the power is connected, the starting winding and the running winding work together to generate the torque required for starting, causing the motor to start rotating. At the same time, the timer begins to count down to the preset time. As the motor accelerates, the timer sends a closing signal to the time switch after reaching the preset time. This signal causes the time switch to switch from the normally closed state to the open state, thereby cutting off the power supply to the starting winding, so that the motor no longer obtains additional torque from the starting winding. At this point, the motor has reached sufficient speed and can continue to operate solely on the running winding, entering normal operation.

[0023] The advantage of this control method is that the starting winding can be disconnected in time regardless of whether the motor reaches the normal operating speed within the predetermined time, avoiding overheating or damage caused by long-term power-on, while improving the starting efficiency and service life of the motor. This innovative circuit structure not only improves the performance of single-phase motors, but also enhances their reliability and durability in various applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the principle of a first circuit structure for controlling the operation of a single-phase motor according to an embodiment of the present application;

[0026] Figure 2 It is a schematic diagram of the principle of a second circuit structure for controlling the operation of a single-phase motor according to an embodiment of the present application;

[0027] Figure 3 It is a schematic diagram of the principle of a third circuit structure for controlling the operation of a single-phase motor according to an embodiment of the present application;

[0028] Figure 4 It is a schematic diagram of the principle of a fourth circuit structure for controlling the operation of a single-phase motor according to an embodiment of the present application;

[0029] Figure 5 This is a schematic diagram of the principle of a fifth circuit structure for controlling the operation of a single-phase motor according to an embodiment of the present application.

[0030] In the figure: 1. running winding; 2. starting winding; 3. timer; 4. timing switch; 5. starting capacitor; 6. centrifugal switch; 7. running capacitor; 8. access switch; 9. tachometer; 10. controller; 11. main switch. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0033] like Figure 1 As shown, the embodiment of the present application provides a circuit structure for controlling the operation of a single-phase motor, including a running winding 1 and a starting winding 2 constituting a stator coil in a single-phase motor, and also including a timer 3 and a timing switch 4. After the starting winding 2 and the timing switch 4 are connected in series, they are connected in parallel with the timer 3 and the running winding 1 between the two ends of the AC power supply. Among them, the timer 3 is connected to the timing switch 4 signal, and the timing switch 4 is in a normally closed state; after the countdown of the preset time of the timer 3 ends, the timer 3 sends a closing signal to the timing switch 4 to turn the timing switch 4 from the normally closed state to the open state.

[0034] The circuit structure for controlling the operation of a single-phase motor proposed in the embodiment of the present application mainly includes a running winding 1 and a starting winding 2, which together constitute the stator coil of the single-phase motor. In addition, the circuit also includes a timer 3 and a timing switch 4, which are connected in parallel with the winding of the motor between the two ends of the AC power supply. The starting winding 2 and the timing switch 4 are connected in series, and then connected in parallel with the timer 3 and the running winding 1. The initial state of the timing switch 4 is normally closed to ensure that the circuit is closed at startup.

[0035] When the power is connected, the starting winding 2 and the running winding 1 work together to generate the torque required for starting, so that the motor starts to rotate. At the same time, the timer 3 starts to count down to the preset time. As the motor accelerates, the timer 3 sends a closing signal to the time switch 4 after reaching the preset time. This signal causes the time switch 4 to switch from the normally closed state to the open state, thereby cutting off the power supply to the starting winding 2, so that the motor no longer obtains additional torque from the starting winding. At this point, the motor has reached a sufficient speed and can continue to operate only relying on the running winding 1, entering the normal operating state.

[0036] The advantage of this control method is that, regardless of whether the motor reaches the normal operating speed within the predetermined time, the starting winding 2 can be disconnected in time, avoiding overheating or damage caused by long-term power-on, while improving the starting efficiency and service life of the motor. This innovative circuit structure not only improves the performance of the single-phase motor, but also enhances its reliability and durability in various applications.

[0037] It should be noted that, in the absence of a starting capacitor, the following are examples of methods for generating phase difference and rotating magnetic field in a single-phase motor. For example, split-phase starting windings may be designed, which are electrically separated from the running windings but physically adjacent to the running windings. This design can generate the necessary phase difference without additional capacitors. As another example, a resistor connected in series with the starting winding is set inside the single-phase motor to generate a phase difference. The introduction of the resistor changes the impedance of the winding, thereby generating the required phase difference. As another example, an electronic controller can be used: the use of an electronic controller or a frequency converter can accurately control the starting and operation of the motor. The electronic controller can provide the required phase difference and frequency control to generate a rotating magnetic field, achieving smooth starting and efficient operation. As another example, a single-phase motor can adopt an induction starting method, using the induction characteristics of the motor itself to generate a phase difference at startup.

[0038] In this embodiment, if Figure 2 As shown, the circuit structure for controlling the operation of the single-phase motor may include a starting capacitor 5 , and the starting capacitor 5 is connected in series with the starting winding 2 and the timing switch 4 .

[0039] Among them, the starting capacitor 5 not only provides the necessary phase difference to generate a rotating magnetic field, but also has a constant current function to prevent the current in the starting winding 2 from being too large and protect the motor from overload damage. In addition, it enhances the magnetic field strength generated by the starting winding 2, thereby increasing the starting torque of the motor and making it easier to start the motor. By accurately controlling the capacity of the starting capacitor, the torque and current during the starting process can be optimized, the starting efficiency can be improved, the energy consumption can be reduced, and the noise and vibration generated during the starting process can be reduced. After the startup is completed, the starting capacitor 5 is disconnected from the circuit to avoid adverse effects on the normally running motor.

[0040] In this embodiment, if Figure 3 As shown, the circuit structure for controlling the operation of the single-phase motor may further include a centrifugal switch 6, which is mounted on the rotor of the single-phase motor and connected in series with the starting winding 2 and the timing switch 4. The centrifugal switch 6 is in a normally closed state, and when the speed of the rotor of the single-phase motor reaches a preset speed or above, the centrifugal switch 6 changes from a normally closed state to an open state.

[0041] In the circuit structure for controlling the operation of a single-phase motor, a dual start-up and operation control mechanism is provided by combining the centrifugal switch 6 and the timing switch 4. At startup, the starting winding 2, the timing switch 4 and the centrifugal switch 6 are connected in series to form a closed circuit, allowing current to flow through the starting winding 2 to generate the necessary starting torque. As the motor accelerates, the centrifugal switch 6 will change from a normally closed state to an open state because the rotor reaches a preset speed, automatically cutting off the power supply of the starting winding to prevent the motor from continuing to obtain additional torque from the starting winding after normal operation. At the same time, the timing switch 4, as a backup guarantee, is controlled by the timer 3 and automatically disconnects after the preset time is reached. Even if the centrifugal switch 6 fails to respond in time, it can ensure that the motor will not be overheated or damaged due to the long-term power supply of the starting winding 2. This design not only improves the reliability of motor control, but also allows the preset time of the timer 3 to be adjusted according to the starting characteristics and application requirements of the motor, achieving more precise control. In addition, this dual guarantee mechanism also provides built-in protection to prevent the motor from being damaged under abnormal conditions, ensuring stable startup and efficient operation of the motor under various loads and operating conditions.

[0042] In this embodiment, if Figure 4 As shown, the circuit structure for controlling the operation of the single-phase motor may further include a running capacitor 7, which is connected in parallel with the circuit in which the timing switch 4 and the starting capacitor 5 are connected in series. It may further include an access switch 8, which is connected in series with the running capacitor 7 and then connected in parallel with the circuit in which the timing switch 4 and the starting capacitor 5 are connected in series. The access switch 8 may selectively connect or not connect the running capacitor 7.

[0043] The circuit structure for controlling the operation of a single-phase motor in the embodiment of the present application realizes flexible adjustment of the motor operation characteristics by introducing the operation capacitor 7. In the circuit structure, the operation capacitor 7 is connected in parallel with the circuit of the timing switch 4 and the starting capacitor 5 in series, and the access switch 8 allows the operation capacitor 7 to be selectively connected or not connected to the circuit as needed. This design brings many beneficial effects: it not only optimizes the operating efficiency of the motor, but also enhances the adaptability of the motor to different load conditions, allowing fine adjustment at different operating stages.

[0044] In some scenarios, the running capacitor 7 may have the following advantages. The running capacitor 7 can improve the power factor during the operation phase of the motor, and reduce reactive power by forming resonance with the inductance of the winding, thereby improving the efficiency of electric energy use. The running capacitor 7 helps to smooth the current fluctuations during the operation of the motor, reduce the fluctuations of voltage and current, and provide a more stable operating environment. The running capacitor 7 can help reduce harmonic interference in the power grid and improve the power quality of the motor operation. Although the running capacitor 7 mainly plays a role when the motor is operating normally, in some designs, it can also provide auxiliary effects during the starting phase, especially after the starting capacitor 5 is disconnected, the running capacitor 7 can continue to maintain the necessary phase difference. By reducing current surges and voltage fluctuations, the running capacitor 7 helps to reduce the heat loss of the motor windings and other components, thereby extending the service life of the motor. The running capacitor 7 can improve the stability of the motor under different load conditions, especially when the load changes, helping the motor maintain a stable operating state. The running capacitor 7 can also reduce the electromagnetic interference generated when the motor is running and improve the electromagnetic compatibility of the motor.

[0045] In this embodiment, the capacitance value of the running capacitor 7 is smaller than the capacitance value of the starting capacitor 5 .

[0046] The starting capacitor 5 and the running capacitor 7 in a single-phase motor usually have a significant difference in size. The capacity of the starting capacitor 5 is generally much larger than that of the running capacitor 7. This is because the starting capacitor 5 is mainly used to provide additional starting torque when the motor starts to help the motor overcome the effects of inertia and load, while the running capacitor 7 is used to provide a phase difference when the motor is running normally to ensure that the motor can run smoothly. For example, the starting capacitor 5 may be 200 microfarads (μF), while the running capacitor 7 may be 20 microfarads (μF). When selecting a capacitor, you also need to pay attention to the withstand voltage of the capacitor, which should be higher than the peak value of the motor's operating voltage. In addition, the selection of the capacitor capacity should be strictly calculated according to parameters such as the rated power, voltage, current density, and wire cross-sectional area of ​​the motor to ensure the normal starting and operation of the motor and avoid damage to the motor or performance degradation due to improper capacitor selection.

[0047] In this embodiment, the starting capacitor 5 may be a capacitor with an adjustable capacitance value, and the running capacitor 7 may also be a capacitor with an adjustable capacitance value.

[0048] In the circuit structure for controlling the operation of a single-phase motor, the starting capacitor 5 and the running capacitor 7 are designed as capacitors with adjustable capacitance values, providing a highly flexible and adaptable motor control scheme. This design allows the capacitance value to be dynamically adjusted according to specific application requirements, motor characteristics or operating conditions to optimize the starting performance and operating efficiency of the motor. By accurately controlling the value of the starting capacitor, the phase difference at startup can be adjusted, thereby changing the starting torque and starting current, achieving smooth startup and reducing the current impact at startup. Similarly, the adjustability of the running capacitor allows the power factor to be adjusted and harmonics to be suppressed during the operation of the motor to adapt to different load changes and grid conditions, reduce reactive power consumption, and improve overall energy efficiency. In addition, the use of adjustable capacitors simplifies motor design because one motor can be suitable for a variety of different operating conditions without having to design a specific motor for each condition. This flexibility also helps with motor maintenance and commissioning because by adjusting the capacitance value, technicians can quickly respond to any changes or faults in the operation of the motor without replacing hardware. In summary, the application of capacitors with adjustable capacitance values ​​provides an efficient, economical and easy-to-maintain control method for single-phase motors that can meet the needs of diverse industrial applications.

[0049] In this embodiment, if Figure 5 As shown, the circuit structure for controlling the operation of the single-phase motor may further include a tachometer 9, a controller 10 and a main switch 11. The main switch 11 is installed on the line before the AC power source enters the running winding 1 and the starting winding 2 of the unidirectional motor. The controller 10 and the tachometer 9 are connected in parallel with the running winding 1 between the two ends of the AC power source, and the tachometer 9 is used to measure the rotation speed of the rotor of the single-phase motor.

[0050] The controller 10 is connected to the speed meter 9 and the main switch 11 by signals, and the controller 10 obtains the real-time speed value of the rotor of the single-phase motor through the speed meter 9. After the main switch 11 is closed and reaches a preset threshold time, the controller 10 determines whether the real-time speed value is less than the preset speed; if so, the controller 10 sends a disconnection signal to the main switch 11 to disconnect the main switch 11; if not, the state of the main switch 11 is maintained.

[0051] In the circuit structure for controlling the operation of a single-phase motor, the configuration of an integrated tachometer 9, a controller 10 and a main switch 11 provides a motor operation monitoring and protection mechanism. This design allows real-time monitoring of the motor speed, and the data obtained by the tachometer 9 is analyzed by the controller 10 to ensure that the motor operates in a safe and efficient state. When the main switch 11 is closed and after a preset threshold time, the controller 10 will determine whether the real-time speed of the motor is lower than the preset safety or performance threshold. If the speed is too low, the controller 10 will send a disconnect signal to the main switch 11 to automatically cut off the power supply to prevent the motor from being damaged due to overload or stalling. If the speed is within the normal range, the main switch 11 remains closed and the motor continues to run. This intelligent control strategy not only improves the safety of the motor, but also extends the service life of the motor through preventive protection measures, while ensuring the reliability and stability of the motor under different loads and operating conditions. In addition, this configuration also facilitates remote monitoring and automatic control, improves the intelligence level of the entire system, and provides strong support for industrial automation and intelligent control systems.

[0052] At the same time, if the centrifugal switch 6 and the timing switch 4 both fail, the configuration of the tachometer 9, the controller 10 and the main switch 11 can also provide the final safety guarantee to prevent the motor from burning out.

[0053] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A circuit structure for controlling the operation of a single-phase motor, characterized in that: It comprises a running winding (1) and a starting winding (2) constituting a stator coil in a single-phase motor, and also comprises a timer (3) and a time switch (4); The starting winding (2) and the timing switch (4) are connected in series and then connected in parallel with the timer (3) and the running winding (1) between the two ends of the AC power supply; The timer (3) is connected to the timing switch (4) by signal, and the timing switch (4) is in a normally closed state; after the countdown of the preset time of the timer (3) ends, the timer (3) sends a closing signal to the timing switch (4), so that the timing switch (4) changes from the normally closed state to the open state.

2. The circuit structure for controlling the operation of a single-phase motor according to claim 1, characterized in that: It comprises a starting capacitor (5), wherein the starting capacitor (5) is connected in series with the starting winding (2) and the timing switch (4).

3. The circuit structure for controlling the operation of a single-phase motor according to claim 2, characterized in that: It also includes a centrifugal switch (6), which is mounted on the rotor of the single-phase motor and is connected in series with the starting winding (2) and the timing switch (4); The centrifugal switch (6) is in a normally closed state. When the rotation speed of the rotor of the single-phase motor reaches a preset rotation speed or above, the centrifugal switch (6) changes from the normally closed state to an open state.

4. The circuit structure for controlling the operation of a single-phase motor according to claim 2, characterized in that: It also includes a running capacitor (7), which is connected in parallel with a circuit in which the timing switch (4) and the starting capacitor (5) are connected in series.

5. The circuit structure for controlling the operation of a single-phase motor according to claim 4, characterized in that: It also includes an access switch (8), which is connected in series with the running capacitor (7) to form a parallel circuit with the timing switch (4) and the starting capacitor (5) connected in series.

6. The circuit structure for controlling the operation of a single-phase motor according to claim 5, characterized in that: The capacitance value of the running capacitor (7) is smaller than the capacitance value of the starting capacitor (5).

7. The circuit structure for controlling the operation of a single-phase motor according to claim 6, characterized in that: The starting capacitor (5) is a capacitor with an adjustable capacitance value.

8. The circuit structure for controlling the operation of a single-phase motor according to claim 6, characterized in that: The operating capacitor (7) is a capacitor with an adjustable capacitance value.

9. The circuit structure for controlling the operation of a single-phase motor according to any one of claims 2 to 8, characterized in that: It also includes a speed meter (9), a controller (10) and a main switch (11); The main switch (11) is installed on the line before the AC power source enters the running winding (1) and the starting winding (2) of the unidirectional motor; The controller (10) and the speed meter (9) are connected in parallel with the running winding (1) between two ends of an AC power supply, and the speed meter (9) is used to measure the rotation speed of a rotor of a single-phase motor; The controller (10) is signal-connected to the speed meter (9) and the main switch (11), and the controller (10) obtains the real-time speed value of the rotor of the single-phase motor through the speed meter (9); After the main switch (11) is closed and reaches a preset threshold time, the controller (10) determines whether the real-time rotation speed value is less than the preset rotation speed; if so, the controller (10) sends a disconnection signal to the main switch (11) to disconnect the main switch (11); if not, the state of the main switch (11) is maintained.

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