阅读说明：本技术 接触器及其供电方法 (Contactor and power supply method thereof ) 是由 王接兆 谢娟 毛自方 毕宝云 于 2019-11-15 设计创作，主要内容包括：本公开涉及一种能够低功耗低成本地产生辅助电压的接触器及其供电方法。所述接触器包括：线圈单元,包括线圈和线圈供电单元,其中所述线圈供电单元接收输入电源线的输入电压并向所述线圈提供低于所述输入电压的线圈电压；控制单元,用于控制所述线圈供电单元；第一电源单元,用于接收所述输入电压并输出用于所述控制单元的第一输出电压；以及第二电源单元,用于接收所述线圈上的线圈电压并输出用于所述控制单元的第二输出电压,其中,所述第二电源单元输出所述第二输出电压后,所述第一电源单元停止输出电力。(The present disclosure relates to a contactor capable of generating an auxiliary voltage with low power consumption and low cost and a power supply method thereof. The contactor includes: a coil unit including a coil and a coil power supply unit, wherein the coil power supply unit receives an input voltage of an input power line and supplies a coil voltage lower than the input voltage to the coil; a control unit for controlling the coil power supply unit; a first power supply unit for receiving the input voltage and outputting a first output voltage for the control unit; and a second power supply unit for receiving the coil voltage on the coil and outputting a second output voltage for the control unit, wherein the first power supply unit stops outputting power after the second power supply unit outputs the second output voltage.)

1. A contactor, comprising:

a coil unit including a coil and a coil power supply unit, wherein the coil power supply unit receives an input voltage of an input power line and supplies a coil voltage lower than the input voltage to the coil;

a control unit for controlling the coil power supply unit;

a first power supply unit for receiving the input voltage and outputting a first output voltage for the control unit; and

a second power supply unit for receiving a coil voltage on the coil and outputting a second output voltage for the control unit,

after the second power supply unit outputs the second output voltage, the first power supply unit stops outputting power.

2. The contactor of claim 1, wherein

The output end of the first power supply unit is connected with the anode of the first diode;

the output end of the second power supply unit is connected with the anode of the second diode;

the cathode of the first diode is connected with the cathode of the second diode and used for providing power for the control unit; and is

The second output voltage is greater than the first output voltage, so that the first power supply unit stops outputting power after the second power supply unit outputs the second output voltage.

3. The contactor of claim 1, wherein

The control unit is further configured to detect whether the second power supply unit outputs the second output voltage, and control the first power supply unit to stop outputting power after a predetermined time when it is detected that the second power supply unit outputs the second output voltage.

4. The contactor of claim 1, wherein

The coil power supply unit comprises a first electronic switch and a freewheeling diode;

the first electronic switch is connected between the coil and the input power line and is controlled by the control unit;

the coil is connected between the first electronic switch and the ground wire;

the freewheeling diode is connected between the first electronic switch and the ground wire; and

the control unit controls the first electronic switch in a pulse width modulation mode to control the coil voltage on the coil.

5. The contactor of claim 4, wherein

The coil power supply unit further comprises a second electronic switch connected between the coil and the ground wire.

6. The contactor of claim 4, wherein

The first electronic switch is an Insulated Gate Bipolar Transistor (IGBT).

7. The contactor of any one of claims 1 to 6, wherein

The first power supply unit comprises a third electronic switch, a first voltage stabilizing diode, a first capacitor, a first resistor and a second resistor;

the first resistor is connected between the control end of the third electronic switch and the input power line;

the first voltage stabilizing diode is connected between the control end of the third electronic switch and the ground wire;

the first capacitor is connected between the first end of the third electronic switch and the ground wire, and the third electronic switch is controlled by the voltage difference between the control end and the first end of the third electronic switch;

the second resistor is connected between the second end of the third electronic switch and the input power line; and

the first end of the third electronic switch is the output end of the first power supply unit.

8. The contactor of any one of claims 1 to 6, wherein

The second power supply unit comprises a fourth electronic switch, a second voltage stabilizing diode, a second capacitor, a third resistor and a fourth resistor;

the first end of the second capacitor, the first end of the third resistor and the first end of the fourth resistor are connected with the coil unit and used for receiving the coil voltage;

the second end of the second capacitor is connected with the ground wire;

the second end of the third resistor is connected with the control end of the fourth electronic switch;

the second voltage stabilizing diode is connected between the control end of the fourth electronic switch and the ground wire;

the third capacitor is connected between the first end of the fourth electronic switch and the ground wire; the fourth electronic switch is controlled by the voltage difference between the control end and the first end of the fourth electronic switch;

a second end of the fourth resistor is connected with a second end of the fourth electronic switch; and

the first end of the fourth electronic switch is the output end of the second power supply unit.

9. The contactor of claim 8, wherein

The second capacitor, the third resistor and the fourth resistor are connected with the coil unit through an inductor.

10. A power supply method of a contactor including a coil, a coil power supply unit, and a control unit, the power supply method comprising:

the input voltage is reduced and then a first output voltage is output to supply power to the control unit;

the coil power supply unit supplies coil voltage to the coil under the control of the control unit; and

and outputting a second output voltage to supply power to the control unit after the voltage of the coil is reduced, and stopping supplying power to the control unit through the first output voltage.

Technical Field

The present disclosure relates to a contactor and a power supply method of the contactor, and more particularly, to a contactor generating an auxiliary voltage and a power supply method thereof.

Background

Contactors are commonly used in the industry to control the opening and closing of electrical circuits. The contactor generates a magnetic field by injecting current into the coil to control the movement of the contactor contacts, thereby controlling the opening and closing of the circuit by the contact and the opening of the contacts.

Contactors often require a control circuit in order to control the voltage or current applied to the coil, and therefore, the design of the contactor needs to take into account the power supply issues of the control circuit. Since the voltage of the control circuit is low, if the auxiliary voltage is generated by directly stepping down the high input voltage and supplied to the control circuit, the requirements on the step-down module and the device are high, and large power consumption and heat are often generated.

Disclosure of Invention

The present disclosure relates to a contactor capable of generating an auxiliary voltage with low power consumption and low cost and a power supply method thereof.

According to an aspect of the present disclosure, there is provided a contactor including: a coil unit including a coil and a coil power supply unit, wherein the coil power supply unit receives an input voltage of an input power line and supplies a coil voltage lower than the input voltage to the coil; a control unit for controlling the coil power supply unit; a first power supply unit for receiving the input voltage and outputting a first output voltage for the control unit; and a second power supply unit for receiving the coil voltage on the coil and outputting a second output voltage for the control unit, wherein the first power supply unit stops outputting power after the second power supply unit outputs the second output voltage.

According to still another aspect of the present disclosure, there is provided a power supply method of a contactor including a coil, a coil power supply unit, and a control unit, the power supply method including: the input voltage is reduced and then a first output voltage is output to supply power to the control unit; the coil power supply unit supplies coil voltage to the coil under the control of the control unit; and outputting a second output voltage to supply power to the control unit after the voltage of the coil is reduced, and stopping supplying power to the control unit through the first output voltage.

According to the embodiment of the disclosure, the first power supply unit which converts the high input voltage into the low auxiliary voltage only works in a short time in the initial power-on period of the contactor, so that large power consumption and heat can be avoided, and the device requirement and cost of the first power supply unit can be reduced. Meanwhile, the second power supply unit which is mainly used for supplying power to the control unit converts lower coil voltage into auxiliary voltage, so that the power consumption is good, and the device requirement and the cost are low.

Drawings

The aspects, features and advantages of the disclosure will become more apparent and readily appreciated from the following description of the embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a schematic circuit block diagram of a contactor according to an embodiment of the present disclosure;

FIG. 2 shows a schematic circuit block diagram of a contactor according to another embodiment of the present disclosure;

FIG. 3 shows a schematic circuit diagram of a contactor according to an embodiment of the present disclosure;

fig. 4 shows a schematic circuit diagram of a coil unit according to an embodiment of the present disclosure;

fig. 5 illustrates a flow chart of a method of powering a contactor according to an embodiment of the present disclosure.

Detailed Description

The present disclosure will be described in detail below with reference to exemplary embodiments thereof. However, the present disclosure is not limited to the embodiments described herein, which may be embodied in many different forms. The described embodiments are intended only to be exhaustive and complete of the disclosure and to fully convey the concept of the disclosure to those skilled in the art. Features of the various embodiments described may be combined with each other or substituted for each other unless expressly excluded or otherwise excluded in context.

For contactors with high input voltages, it is often necessary to obtain a low voltage for the control unit in a complex and expensive way. For example, when the input voltage is 200V or more, in order to obtain a low voltage of about 15V for the control unit, it is generally necessary to use an Insulated Gate Bipolar Transistor (IGBT) with a large rated power to add a heat sink for voltage reduction.

The present disclosure proposes a solution to generate an auxiliary voltage for a control unit from the coil voltage of the contactor. The coil voltage is usually much lower than the input voltage, for example 20V, and therefore, when the auxiliary voltage is generated from the coil voltage, the requirements on the device are low, and excessive power consumption and heat are not generated, so that the auxiliary voltage can be supplied at low cost with low power consumption. According to the embodiment of the present disclosure, the auxiliary voltage for the control unit is not always generated by directly stepping down the input voltage, but only needs to be generated by directly stepping down the input voltage before the coil voltage of the contactor is formed, and after the coil voltage of the contactor is formed, the auxiliary voltage generated by stepping down the coil voltage is supplied to the control unit, and the direct supply from the input voltage is stopped. In this case, although it is still necessary to generate the auxiliary voltage by directly stepping down the input voltage at the time of relay activation, since the process is short, the power consumption and heat generated are small, a heat dissipation system is not required, and the requirement and cost of the apparatus are low.

Fig. 1 is a schematic circuit block diagram of a contactor 100 according to an embodiment of the present disclosure. The contactor 100 includes a coil unit 101. The coil unit 101 includes a coil power supply unit 1011 and a coil 1012. The coil unit 101 is a basic component of a contactor circuit, and the coil power supply unit 101 receives an input voltage Vin of an input power line Li and supplies a coil voltage Vc lower than the input voltage to the coil, so that the coil power supply unit 1011 can inject a current into the coil 1012 to generate a magnetic field to drive the contact to move. According to an embodiment of the present disclosure, the input voltage Vin may be a direct current voltage directly received from outside the contactor 100; or the contactor 100 may further include a rectifying and filtering unit for receiving the ac power from the outside and converting it into the dc input voltage Vin. The input power line Li indicates a power line connected to the coil power supply unit 1011 for transmitting the input voltage Vin. In the case of receiving the direct-current input voltage Vin directly from outside the contactor 100, the input power line Li is connected to a power supply outside the contactor 100; in case the contactor 100 comprises a rectifying and smoothing unit, the input power line Li is connected to the rectifying and smoothing unit for receiving a dc input voltage from the rectifying and smoothing unit.

The contactor 100 further includes a control unit 102 for controlling the coil power supply unit 1011. The power supply to the coil 1012 from the coil power supply unit 1011 can be controlled by a control signal from the control unit 102. The control unit 102 may for example comprise a Micro Control Unit (MCU). According to an embodiment of the present disclosure, the contactor 100 further includes a first power supply unit 103 and a second power supply unit 104 for supplying power to the control unit 102. Specifically, the first power supply unit 103 receives an input voltage Vin and steps down the input voltage Vin to a first output voltage Vout1 for the control unit 102; the second power supply unit 104 receives the coil voltage Vc across the coil 1012 and steps down the coil voltage Vc to a second output voltage Vout2 for the control unit 102. The first output voltage Vout1 and the second output voltage Vout2 may be the same or different, as long as the power supply to the control unit 102 is satisfied. In addition, depending on the specific structure and devices of the control unit 102, the first output voltage Vout1 and the second output voltage Vout2 may need to be further reduced, for example, the power supply voltage of the MCU is usually 3.3V, so if the control unit 102 includes an MCU, the first output voltage Vout1 and the second output voltage Vout2 need to be further reduced to about 3.3V to be provided to the MCU.

As mentioned above, the input voltage Vin is typically high, e.g. 500V, the coil voltage Vc is typically low, e.g. 20V, and the auxiliary voltage for the control unit is typically lower, e.g. 15V. The first power supply unit 103 directly converts the input voltage Vin into the first output voltage Vout1 as an auxiliary voltage, which generates large power consumption and heat if operated for a long time and has high requirements for devices. In contrast, the second power supply unit 104 converts the lower coil voltage Vc into the second output voltage Vout2 as an auxiliary voltage, so that the device requirement is low and no excessive power consumption and heat are generated even after long-time operation. Therefore, according to the embodiment of the present disclosure, after the second power supply unit 104 outputs the second output voltage Vout2, the first power supply unit 103 stops outputting power. In other words, the first power supply unit 103 operates only for a short time during the initial power-up period of the contactor 100. Once the coil 1012 of the contactor 100 is charged to obtain the coil voltage Vc, the second power supply unit 104 may generate the second output voltage Vout2 to be supplied to the control unit as an auxiliary voltage, at which time the power supply of the first power supply unit 103 may be stopped. The manner of stopping the power supply of the first power supply unit 103 may be various, for example, the connection between the first power supply unit 103 and the control unit 102 is disconnected by a switch, the operation of the first power supply unit 103 is stopped, the power supply of the first power supply unit 103 is disconnected, and the like.

The switching of the power supply of the first power supply unit 103 and the second power supply unit 104 may be performed by a control circuit, for example, by the control unit 102. In one embodiment, the control unit 102 may detect whether the second power supply unit 104 outputs the second output voltage Vout2, and control the first power supply unit 103 to stop outputting power after a predetermined time when it is detected that the second power supply unit 104 outputs the second output voltage Vout2, for example, by disconnecting the first power supply unit 103 from the control unit 102 through a switch, stopping the operation of the first power supply unit 103, disconnecting the power supply of the first power supply unit 103, and the like. The predetermined time may be set by the control unit 102, which may be 0, i.e., the power supply of the first power supply unit 103 is immediately stopped when the second output voltage Vout2 is detected; it may also set a small waiting time, for example a few milliseconds, for stopping the power supply of the first power supply unit 103 after the second output voltage Vout2 is more stable.

In another embodiment, the power supply switching of the first power supply unit 103 and the second power supply unit 104 may be realized by a simple diode circuit, as shown in fig. 2. Fig. 2 is a schematic circuit block diagram of a contactor 200 according to another embodiment of the present disclosure, and fig. 2 is different from fig. 1 in that the contactor 200 in fig. 2 further includes a first diode D1 and a second diode D2. The output end of the first power supply unit 103 is connected with the anode of a first diode D1; the output end of the second power supply unit 104 is connected with the anode of a second diode D2; the cathode of the first diode D1 is connected to the cathode of the second diode D2 and to the control unit 102 for providing power to the control unit 102. In addition, in the present embodiment, the second output voltage Vout2 is greater than the first output voltage Vout1, so that the first power supply unit 103 stops outputting power after the second power supply unit 104 outputs the second output voltage Vout 2. In the configuration of the present embodiment, when the first power supply unit 103 outputs the first output voltage Vout1 and the second power supply unit 104 does not output the second voltage Vout2, the first diode D1 is turned on, the second diode D2 is turned off, and power is supplied from the first power supply unit 103 to the control unit 102; when the second power supply unit 104 also outputs the second output voltage Vout2, since Vout2 is greater than Vout1, the second diode D2 is turned on, the first diode D1 is turned off, power is supplied from the second power supply unit 104 to the control unit 102, and the first power supply unit 103 stops supplying power to the control unit 102.

According to the above embodiments of the present disclosure, the first power supply unit that converts the high input voltage into the low auxiliary voltage only operates in a short time in the initial power-on period of the contactor, so that large power consumption and heat can be avoided, and the device requirements and cost of the first power supply unit can be reduced. Meanwhile, the second power supply unit which is mainly used for supplying power to the control unit converts lower coil voltage into auxiliary voltage, so that the power consumption is low, and the device requirement and the cost are low.

The various elements of the contactor of the present disclosure may be implemented by various specific circuits. Fig. 3 shows a schematic circuit diagram of a contactor 300 according to an embodiment of the present disclosure. It should be noted that the specific structure of each unit in fig. 3 can be individually applied or replaced by other suitable structures.

As shown in fig. 3, the coil unit 301 includes a coil power supply unit 3011 and a coil 3012. The coil power supply unit 3011 includes a first electronic switch T1 and a freewheel diode FD, the first electronic switch T1 being connected between the coil 3012 and the input power supply line Li and being controlled by the control unit 302. The coil 3012 is connected between the first electronic switch T1 and the ground, and the freewheel diode FD is connected between the first electronic switch T1 and the ground. In the present embodiment, the coil power supply unit 3011 supplies a voltage to the coil through an electronic switch T1 controlled by the control unit 302. The electronic switch T1 has a control terminal connected to the control unit 302. The control voltage provided by the control unit 302 may control the on and off of the electronic switch T1, that is, may control the connection and disconnection of the input power line Li connected across the electronic switch T1 and the coil 3012, thereby controlling the current injection and voltage of the coil 3012. For example, the control unit 302 may control the first electronic switch T1 in a Pulse Width Modulation (PWM) manner to control the coil voltage on the coil 3012. In the case of controlling the electronic switch T1 using PWM, the control unit 302 may include, for example, a logic device such as an MCU to output a PWM control signal, and, if necessary, an electronic switch driving unit that drives the electronic switch T1 based on the PWM control signal. The commonly used electronic switches are various, such as IGBTs, GTOs (turn-off thyristors), triodes, MOS (metal oxide semiconductor) transistors, etc., and those skilled in the art can select the switch according to the actual application scenario, for example, in high-voltage and high-power applications, the IGBTs can be used. When the electronic switch is an IGBT, the gate of the IGBT is a control terminal, and is connected to the control unit 302, and the source and the drain of the IGBT are connected to the coil 3012 and the input power line Li, respectively. The use of the freewheeling diode FD in the coil unit 301 together with the coil 3012 prevents sudden changes in current and voltage and ensures proper operation of the circuit.

Furthermore, in some applications there may be multiple contactor coils, in which case one electronic switch may be added for gating of the corresponding coil. Fig. 4 shows a schematic circuit diagram of a coil unit 401 according to an embodiment of the present disclosure. In fig. 4, the coil power supply unit 4011 may further include a second electronic switch T2 connected between the coil 3012 and the ground. The second electronic switch T2 is used to gate the coil 3012, when the second electronic switch T2 is turned on, the coil 3012 is gated, and when the second electronic switch T2 is turned off, the coil 3012 is not gated. The second electronic switch T2 may be controlled by a control circuit, for example by the control unit 302.

Referring back to fig. 3, the first power supply unit 303 includes a third electronic switch T3, a first zener diode ZD1, a first capacitor C1, a first resistor R1, and a second resistor R2. The first resistor R1 is connected between the control terminal of the third electronic switch T3 and the input power line Li. The first zener diode ZD1 is connected between the control terminal of the third electronic switch T3 and ground. The first capacitor C1 is connected between the first terminal of the third electronic switch T3 and ground. The third electronic switch T3 is controlled by the voltage difference between its control terminal and the first terminal. The second resistor R2 is connected between the second terminal of the third electronic switch T3 and the input power line Li. A first terminal of the third electronic switch T3 is an output terminal of the first power supply unit 303 for outputting a voltage supplied to the control unit 302.

The first power supply unit 303 steps down through the third electronic switch T3. The on and off of the third electronic switch T3 is controlled by the voltage difference between the control terminal and the first terminal. Due to the presence of the zener diode ZD1, the voltage of the control terminal of the third electronic switch T3 is constant, and at the same time, when the third electronic switch T3 is turned on, the voltage drop between the control terminal and the first terminal is also constant, so that when the first power supply unit 303 has a load such that the third electronic switch T3 is turned on, the voltage of the first terminal of the third electronic switch T3 (i.e., the output terminal of the first power supply unit 303) is constant. The required auxiliary voltage can thus be output by selecting a zener diode ZD1 of an appropriate voltage. For example, when the third electronic switch T3 is an IGBT, the control terminal of the third electronic switch T3 is the gate of the IGBT, the first terminal is the source, and the second terminal is the drain. The output terminal of the first power supply unit 303 is the source of the IGBT, and the output voltage thereof is the voltage of the zener diode ZD1 minus the voltage drop between the gate and the drain. As described above, the first power supply unit 303 directly drops the voltage from the input voltage to the auxiliary voltage for the control unit, the voltage drop is large, and if it operates for a long time, the power consumption and the heat generation amount of the power supply unit are large. Accordingly, the contactor of the present disclosure further includes a second power supply unit.

The second power supply unit 304 shown in fig. 3 includes a fourth electronic switch T4, a second zener diode ZD2, a second capacitor C2, a third capacitor C3, a third resistor R3, and a fourth resistor R4. A first terminal of the second capacitor C2, a first terminal of the third resistor R3, and a first terminal of the fourth resistor R4 are connected to the coil unit 301 for receiving the coil voltage, and specifically, may be connected to a connection point of the coil 3012 and the first electronic switch T1, for example. A second terminal of the second capacitor C2 is connected to ground. The second capacitor C2 may smooth-filter the coil voltage output from the coil unit 301. Optionally, in order to better filter the fluctuation of the coil voltage, the second capacitor C2, the third resistor R3, and the fourth resistor R4 may be further connected to the coil unit 3012 through the inductor L. The inductance L is shown in fig. 3, but is optional. A second terminal of the third resistor R3 is connected to the control terminal of the fourth electronic switch T4, and the second zener diode ZD2 is connected between the control terminal of the fourth electronic switch T4 and the ground. The third capacitor C3 is connected between the first terminal of the fourth electronic switch T4 and the ground, the fourth electronic switch T4 is controlled by the voltage difference between the control terminal and the first terminal, and the first terminal of the fourth electronic switch T4 is the output terminal of the second power unit 304. A second terminal of the fourth resistor R4 is connected to a second terminal of the fourth electronic switch T4.

The second power supply unit 304 steps down through the fourth electronic switch T4. The on and off of the fourth electronic switch T4 is controlled by the voltage difference between the control terminal and the first terminal. The presence of the zener diode ZD2 makes the voltage of the control terminal of the fourth electronic switch T4 constant, and at the same time, when the fourth electronic switch T4 is turned on, the voltage drop between the control terminal and the first terminal is also constant, and therefore, when the second power supply unit 304 has a load such that the fourth electronic switch T4 is turned on, the voltage of the first terminal of the fourth electronic switch T4 (i.e., the output terminal of the second power supply unit 304) is constant. It is thus possible to output a desired voltage by selecting a zener diode ZD2 of an appropriate voltage. In addition, since the input voltage of the second power supply unit 304 is low, the fourth electronic switch T4 may use a transistor or a MOS transistor with low price. When the fourth electronic switch T4 is a triode, the control terminal of the fourth electronic switch T4 is the base of the triode, the first terminal is the emitter, and the second terminal is the collector, at this time, the output terminal of the second power supply unit 304 is the emitter of the triode, and the output voltage is the voltage of the zener diode ZD2 minus the voltage drop between the base and the emitter. When the fourth electronic switch T4 is a MOS transistor, the control terminal of the fourth electronic switch T4 is the gate of the MOS transistor, the first terminal is the source, and the second terminal is the drain, at this time, the output terminal of the second power unit 304 is the source of the MOS, and the output voltage is the voltage of the zener diode ZD2 minus the voltage drop between the gate and the source.

In the example shown in fig. 3, the power supply switching of the first power supply unit 303 and the second power supply unit 304 is implemented using diodes D1 and D2. As shown in fig. 3, the output terminal of the first power supply unit 303 (i.e., the first terminal of the third electronic switch T3) is connected to the anode of the first diode D1; the output terminal of the second power supply unit 304 (i.e., the first terminal of the fourth electronic switch T4) is connected to the anode of the second diode D2; the cathode of the first diode D1 is connected to the cathode of said second diode D2 and to the value control unit 302 for providing power to the control unit 102. The second output voltage Vout2 is set to be greater than the first output voltage Vout1, so that the first power supply unit 303 stops outputting power after the second power supply unit 304 outputs the second output voltage Vout2, for example, the second output voltage Vout2 is set to 16V and the first output voltage Vout1 is set to 14V. Therefore, when the first power supply unit 303 outputs the first output voltage Vout1 and the second power supply unit 304 does not output the second voltage Vout2, the first diode D1 is turned on, the second diode D2 is turned off, and the control unit 302 is supplied with power from the first power supply unit 303; when the second power supply unit 304 also outputs the second output voltage Vout2, since Vout2 is greater than Vout1, the second diode D2 is turned on, the first diode D1 is turned off, power is supplied from the second power supply unit 304 to the control unit 302, and the first power supply unit 303 stops supplying power to the control unit 302.

Of course, as described above, in the example of fig. 3, the switching of the power supply of the first power supply unit 303 and the second power supply unit 304 may also be implemented by a control circuit such as the control unit 302 instead. For example, when the control unit 302 detects that the second power supply unit 104 outputs the second output voltage Vout2, the first power supply unit 303 is controlled to stop outputting power after a predetermined time by disconnecting the first power supply unit 303 from the control unit 302, stopping the operation of the first power supply unit 303, or disconnecting the power supply of the first power supply unit 303.

Fig. 5 shows a flow chart of a method 500 of powering a contactor according to an embodiment of the present disclosure. The method may be applied to a contactor comprising a coil, a coil power supply unit and a control unit, such as the contactor described above with reference to fig. 1-3. The power supply method 500 includes steps S501-S503. In step S501, the contactor steps down the input voltage and outputs a first output voltage to supply power to the control unit; in step S502, the coil power supply unit supplies a coil voltage to the coil under the control of the control unit; in step S503, the contactor outputs a second output voltage to the control unit after the voltage of the coil is reduced, and stops supplying power to the control unit through the first output voltage. The above steps may be performed by any suitable hardware of the contactor or hardware in combination with software. For example, step S501 may be performed by the first power supply unit, step S502 may be performed by the coil power supply unit, and step S503 may be performed by the second power supply unit in combination with the control unit or the diode circuit.

According to the power supply method of the embodiment of the present disclosure, the conversion of the high input voltage into the low auxiliary voltage is performed only for a short time in an initial stage of the power-on of the contactor, and after the coil voltage of the contactor is formed, the auxiliary voltage is generated by the coil voltage step-down and supplied to the control unit, and the power supply directly from the input voltage step-down is stopped. In this case, although it is still necessary to generate the auxiliary voltage by directly stepping down the input voltage at the time of relay activation, since the process is short, the power consumption and heat generated are small, a heat dissipation system is not required, and the requirement and cost of the apparatus are low.

The whole of the hardware computing device described in this disclosure or its components may be implemented by various suitable hardware means including, but not limited to, FPGAs, ASICs, socs, discrete gate or transistor logic, discrete hardware components, or any combinations between them.

The block diagrams of circuits, devices, apparatus, devices, systems referred to in this disclosure are provided as illustrative examples only and are not intended to require or imply that the circuits, devices, apparatus, devices, systems, etc., must be connected, arranged, or configured in the manner illustrated in the block diagrams. As will be appreciated by one skilled in the art, these circuits, devices, apparatus, devices, systems may be connected, arranged, configured in any manner that achieves the intended purposes.

Those skilled in the art will appreciate that the specific embodiments described above are by way of example only and not by way of limitation, and that various modifications, combinations, sub-combinations, and substitutions are possible in the embodiments of the disclosure, depending upon design requirements and other factors, insofar as they are within the scope of the appended claims or the equivalents thereof, as defined in the claims of the disclosure.