Switch control circuit and method based on arc-free electronic switch

Abstract

The invention relates to a switch control circuit and method based on an arc-free electronic switch. Comprising a switch assembly and a control assembly, the switch assembly comprises a first IGBT and a second IGBT, a connection node between a collector electrode of the first IGBT and an emitter electrode of the second IGBT is electrically connected with an output end of power supply equipment, a connection node between an emitter electrode of the first IGBT and a collector electrode of the second IGBT is electrically connected with electric equipment, and when the switch assembly is switched on, the control assembly is switched on; when the switch assembly is switched off, the power supply equipment stops supplying power to the electric equipment; the signal output end of the control assembly is electrically connected with a connection node between the base electrode of the first IGBT and the base electrode of the second IGBT, and the control assembly controls the switch assembly to be switched on when the output signal is larger than a first critical value and controls the switch assembly to be switched off when the output signal is smaller than a second critical value. Therefore, the problem that electric arcs are generated when a mechanical contact switch is switched on and off is solved, and the electrical service life is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of electronic switches, and in particular to a switch control circuit and method based on an arc-free electronic switch. Background Art

[0002] Among all kinds of electrical equipment, the most commonly used switch is the mechanical contact switch, which relies on the contact and separation of mechanical contacts to realize the opening and closing of the switch device. This switch has a simple structure, but it also has disadvantages, such as easy arcing during the switching process, short electrical life, mechanical wear of internal components, large switch loss, false triggering, etc.

[0003] In the related art, various types of arc-free switches mainly use arc extinguishing devices to eliminate arcs. Commonly used arc extinguishing devices include vacuum arc extinguishing devices, magnetic blow-out arc extinguishing devices, and grid arc extinguishing devices.

[0004] However, this device can only reduce the existence time of the arc, but cannot completely eliminate the arc, which needs to be solved urgently. Summary of the invention

[0005] The present application provides a switch control circuit and method based on an arc-free electronic switch to solve the problem of arc generation when a mechanical contact switch is switched, thereby extending the electrical life of the switch.

[0006] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a switch control circuit based on an arc-free electronic switch, comprising:

[0007] A switch component, the switch component comprising a first IGBT (InsulateGate Bipolar Transistor) and a second IGBT, a connection node between the collector of the first IGBT and the emitter of the second IGBT is electrically connected to an output end of a power supply device, a connection node between the emitter of the first IGBT and the collector of the second IGBT is electrically connected to an electric device, when the switch component is in an on state, the electric device is powered by the power supply device, and when the switch component is in an off state, the power supply device stops being powered to the electric device;

[0008] A control component, wherein a signal output terminal of the control component is electrically connected to a connection node between a base of the first IGBT and a base of the second IGBT, and when an output signal of the control component is greater than a first critical value, the control component controls the switch component to be in the on state, and when the output signal is less than a second critical value, the control component controls the switch component to be in the off state.

[0009] According to one embodiment of the present application, the above-mentioned switch control circuit based on the arc-free electronic switch further includes:

[0010] A pressure sensor for generating the output signal based on the current pressure of the user;

[0011] A trigger component is used to output a first level signal or a first current signal when the output signal is greater than the first critical value, and to output a second level signal or a second current signal when the output signal is less than the second critical value, wherein the first level signal and the second level signal are opposite.

[0012] According to an embodiment of the present application, the pressure sensor comprises: a first piezoresistance, a second piezoresistance, a third piezoresistance, a fourth piezoresistance and a DC power supply, wherein:

[0013] One end of the first piezoresistance is respectively connected to one end of the third piezoresistance and one end of the DC power supply, and the other end of the first piezoresistance is respectively connected to one end of the second piezoresistance and the first input end of the trigger element;

[0014] The other end of the third piezoresistance is respectively connected to the second input end of the trigger element and one end of the fourth piezoresistance;

[0015] The other end of the second piezoresistance is connected to the other end of the fourth piezoresistance and the other end of the DC power supply respectively.

[0016] According to one embodiment of the present application, the pressure sensing element is a pressure sensor.

[0017] According to an embodiment of the present application, the trigger element is a Schmitt trigger.

[0018] According to an embodiment of the present application, the first level signal is a high level signal, and the second level signal is a low level signal.

[0019] According to an embodiment of the present application, a current value of the first current signal is greater than a current value of the second current signal.

[0020] According to one embodiment of the present application, the first critical value is greater than the second critical value.

[0021] According to the switch control circuit based on arc-free electronic switch proposed in the embodiment of the present application, it is composed of a switch component and a control component, wherein the switch component includes a first IGBT and a second IGBT, the connection node between the collector of the first IGBT and the emitter of the second IGBT is electrically connected to the output end of the power supply device, the connection node between the emitter of the first IGBT and the collector of the second IGBT is electrically connected to the power consumption device, when the switch component is turned on, the power supply device supplies power to the power consumption device, and when the switch is turned off, the power supply device stops supplying power to the power consumption device; the signal output end of the control component is electrically connected to the connection node between the base of the first IGBT and the base of the second IGBT, and the control component controls the switch component to be turned on when the output signal is greater than the first critical value, and controls the switch component to be turned off when the output signal is less than the second critical value. Thus, the problem of arc generation when the mechanical contact switch is turned on is solved, and the electrical life of the switch is extended.

[0022] To achieve the above-mentioned object, a second embodiment of the present application proposes a switch control method based on an arc-free electronic switch, using the switch control circuit based on the arc-free electronic switch described in the first embodiment, wherein the method comprises the following steps:

[0023] Collecting the output signal of the pressure sensor;

[0024] Determining whether the output signal is greater than the first critical value;

[0025] If the output signal is greater than the first critical value, a first level signal or a first current signal is generated;

[0026] The switch component is controlled to be in the on state according to the first level signal or the first current signal.

[0027] According to an embodiment of the present application, after determining whether the output signal is greater than the first critical value, the method further includes:

[0028] If the output signal is not greater than the first critical value, determining whether the output signal is less than the second critical value;

[0029] If the output signal is less than the second critical value, generating a second level signal or a second current signal;

[0030] The switch component is controlled to be in the disconnected state according to the second level signal or the second current signal.

[0031] According to the switch control method based on the arc-free electronic switch proposed in the embodiment of the present application, by collecting and judging whether the output signal of the pressure sensor is greater than the first critical value, a first level signal or a first current signal can be generated when the output signal is greater than the first critical value, so as to control the switch component to be in the on state according to the first level signal or the first current signal. Thus, by adopting the switch control circuit based on the arc-free electronic switch, the problem of arc generation in the mechanical contact switch during switching is solved, and the electrical life of the switch is extended.

[0032] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0034] Figure 1 A schematic diagram of the structure of a switch control circuit based on an arc-free electronic switch provided according to an embodiment of the present application;

[0035] Figure 2 A schematic diagram of the structure of another switch control circuit based on an arc-free electronic switch provided according to an embodiment of the present application;

[0036] Figure 3 A schematic diagram of the working mode of a pressure sensing element and a triggering element of a switch control circuit based on an arc-free electronic switch according to an embodiment of the present application;

[0037] Figure 4 A schematic diagram of the relationship between the on / off state of a switch component and an output signal according to an embodiment of the present application;

[0038] Figure 5 A schematic diagram of the structure of a pressure sensor provided according to an embodiment of the present application;

[0039] Figure 6 The present invention is a flowchart of a switch control method based on an arc-free electronic switch according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0041] The switch control circuit and method based on the arc-free electronic switch proposed in the embodiment of the present application will be described below with reference to the accompanying drawings. First, the switch control circuit based on the arc-free electronic switch proposed in the embodiment of the present application will be described with reference to the accompanying drawings.

[0042] Figure 1 It is a structural schematic diagram of a switch control circuit based on an arc-free electronic switch according to an embodiment of the present application.

[0043] Before introducing the switch control circuit based on the arc-free electronic switch proposed in the embodiment of the present application, the relevant technical background is first introduced.

[0044] The switches on electrical circuits are generally mechanical contact switches, which do not pose any safety hazards under normal circumstances. However, if there is a leak of flammable or explosive gas indoors, or in dangerous scenarios such as closed places such as mines containing flammable and explosive gases, or factories containing dust, if an arc is generated during the opening and closing process of the switch, it is very likely to cause production accidents. At the same time, mechanical contact switches will also produce metal debris, which may cause accidents such as short circuits.

[0045] An electronic switch refers to an operating unit that uses electronic circuits and switch tube devices to realize the on and off of a circuit. It includes at least one controllable electronic driver, such as a thyristor, transistor, field effect tube, thyristor, and relay. In actual use, electronic switches mainly refer to wall switches such as touch switches, induction switches, voice-activated switches, and wireless switches. Compared with traditional mechanical contact switches, electronic switches use switch tubes to control the on and off of circuits, and have the advantages of fast response speed, long switch life, and no arcing.

[0046] Among them, the switching tubes can be divided into semi-controlled switching tubes and fully-controlled switching tubes according to their controllability. The fully-controlled switching tubes can be divided into voltage-controlled and current-controlled types according to the switching control method. The voltage-controlled switching tube is turned off when the control end is at a low level and turned on when the control end is at a high level; the current-controlled switching tube is turned off when a small current is input to the control end and turned on when a large current is input to the control end.

[0047] Since mechanical contact switches generate arcs during the opening and closing process, arc extinguishing devices are often used in large switch devices such as relays to avoid this problem. Commonly used arc extinguishing devices include vacuum arc extinguishing devices, magnetic blowout arc extinguishing devices, grid arc extinguishing devices, etc., to reduce and eliminate arcs. These devices can reduce the existence time of arcs through various means, but they cannot completely eliminate arcs. Since relays are mainly used in high-power, high-voltage, and high-current scenarios, and are large in size, they cannot be used in low-power AC scenarios and are difficult to popularize.

[0048] Based on the above problems, the embodiment of the present application proposes a switch control circuit based on an arc-free electronic switch, which can effectively solve the problem of arc generation when the mechanical contact switch is switched, thereby extending the electrical life of the switch.

[0049] For example, Figure 1 As shown, the switch control circuit 10 based on the arc-free electronic switch includes: a switch component 100 and a control component 200, wherein the switch component 100 includes a first IGBT (such as Figure 1 IGBT1 shown) and the second IGBT (as Figure 1 The IGBT2 shown in the figure, the connection node between the collector of the first IGBT and the emitter of the second IGBT is electrically connected to the output end of the power supply device, and the connection node between the emitter of the first IGBT and the collector of the second IGBT is electrically connected to the power-consuming device. When the switch component 100 is in the on state, the power supply device is used to supply power to the power-consuming device. When the switch component 100 is in the off state, the power supply device is stopped from supplying power to the power-consuming device. The signal output end of the control component 200 is electrically connected to the connection node between the base of the first IGBT and the base of the second IGBT. When the output signal of the control component 200 is greater than the first critical value, the control component 200 controls the switch component 100 to be in the on state, and when the output signal is less than the second critical value, the control component 100 is controlled to be in the off state.

[0050] In some embodiments, the first critical value is greater than the second critical value.

[0051] Specifically, if Figure 1 As shown, the collector of the first IGBT is connected to a power supply device (such as Figure 1 The output end of the AC power supply shown in FIG. 1 is used as the input end of the current, the emitter of the second IGBT is connected to the collector of the first IGBT, and the collector of the second IGBT is connected to the electrical device (such as Figure 1The resistive-inductive load shown in the figure) is used as the output end of the current, and the emitter of the first IGBT is connected to the collector of the second IGBT. When the switch component 100 is turned on, the current can flow from the power supply device through the collector-emitter path of the first IGBT, and then through the emitter-collector path of the second IGBT, and finally reach the power consumption device to provide power to the power consumption device; when the switch component 100 is turned off, the circuit between the power supply device and the power consumption device is cut off, that is, the current path is cut off, and the power supply device stops supplying power to the power consumption device. The control component 200 is used to detect an external signal (such as an output signal). The base of the first IGBT is connected to the base of the second IGBT. The signal output end of the control component 200 is connected to the connection node between the base of the first IGBT and the base of the second IGBT. The on and off states of the switch component 100 are controlled by the control component 200. The first critical value is the threshold value for the control component 200 to determine whether to control the switch component 100 to enter the on state. When the output signal (i.e., the control signal) is greater than the first critical value, the control component 200 can control the switch component 100 to be in the on state. The second critical value is the threshold value for the control component 200 to determine whether to control the switch component 100 to enter the off state, and the second critical value is less than the first critical value. When the output signal (i.e., the control signal) is less than the second critical value, the control component 200 can control the switch component 100 to enter the off state.

[0052] It is understandable that IGBT, as a power electronic switch, has the characteristics of high-speed switching capability and low switching power consumption, which can effectively avoid the arc phenomenon generated during the switching process and improve the life of the switching electrical appliance.

[0053] Optionally, in some embodiments, the above-mentioned switch control circuit 10 based on the arc-free electronic switch further includes: a pressure sensor 300 and a trigger component 400, wherein the pressure sensor 300 is used to generate an output signal based on the current pressure of the user; the trigger component 400 is used to output a first level signal or a first current signal when the output signal is greater than a first critical value, and output a second level signal or a second current signal when the output signal is less than a second critical value, wherein the first level signal and the second level signal are opposite.

[0054] In some embodiments, the pressure sensing element 300 is a pressure sensor.

[0055] In some embodiments, the trigger element 400 is a Schmitt trigger.

[0056] It is understandable that sensors can usually detect changes in the environment or physical phenomena and convert these changes into measurable signals, usually electrical signals. Simple primary sensors can convert non-electrical quantities such as displacement and pressure into current or voltage, and then obtain a more accurate variable size through signal conditioning and processing.

[0057] Specifically, combined Figure 2 and Figure 3 As shown, the pressure sensing element 300 can be a pressure sensor, and the on and off of the switch assembly 100 can be understood as being manually controlled by the user by pressing, that is, when the user applies a pressure to the pressure sensing element 300, it can generate an output signal according to the user's current pressure, and the output signal is positively correlated with the pressure size; the trigger element 400 can be a Schmitt trigger, which is used to receive the output signal from the pressure sensing element 300, and generate a level signal (such as a high level and a low level) or a current signal according to the relationship between the output signal and two critical values ​​(that is, the aforementioned first critical value and the second critical value). The first critical value is slightly smaller than the maximum value of the output signal of the pressure sensor 300, and the second critical value is slightly larger than the minimum value of the output signal of the pressure sensor 300. When the output signal is greater than the first critical value, the trigger component 400 can output a first level signal (i.e., a high level signal) or a first current signal, which is transmitted to the control component 200, so that the control component 200 controls the switch component 100 to enter the on state; when the output signal is less than the second critical value, the trigger component 400 outputs a second level signal (i.e., a low level signal) or a second current signal, which is transmitted to the control component 200, so that the control component 200 controls the switch component 100 to enter the off state.

[0058] In some embodiments, the first level signal is a high level signal, and the second level signal is a low level signal.

[0059] In some embodiments, the current value of the first current signal is greater than the current value of the second current signal.

[0060] It is understandable that if Figure 4 As shown, when the switch component 100 is in the off state, the pressure is 0, the output signal of the pressure sensor 300 is less than the second critical value, and the trigger component 400 outputs a second level signal (i.e., a low level signal) or a second current signal (i.e., a small current), so that the base of the first IGBT and the base of the second IGBT are insufficient to maintain their on state; when the switch component 100 is in the on state, the pressure is the maximum value, the output signal of the pressure sensor 300 is greater than the first critical value, and the trigger component 400 outputs a first level signal (i.e., a high level signal) or a first current signal (i.e., a large current), so that the base of the first IGBT and the base of the second IGBT receive sufficient voltage to enter the on state.

[0061] That is to say, when the switch component 100 needs to be turned on (i.e., the process of turning the switch from off to on), the user applies pressure, and the output signal of the pressure sensor 300 gradually increases. When the output signal is greater than the first critical value, the trigger component 400 is triggered, and then a high-level signal or a large current is output, so that the switch component enters the on state; when the switch component 100 needs to be turned off (i.e., the process of turning the switch from on to off), the user applies pressure, and the output signal of the pressure sensor 300 gradually decreases. When the output signal is less than the second critical value, the trigger component 400 is reset, and then a low-level signal or a small current is output, so that the switch component enters the off state.

[0062] The pressure sensor 300 is described in detail below.

[0063] Optionally, in some embodiments, Figure 5 As shown, the pressure sensing element 300 includes: a first piezoresistor R1, a second piezoresistor R2, a third piezoresistor R3, a fourth piezoresistor R4 and a DC power supply E, wherein one end of the first piezoresistor R1 is respectively connected to one end of the third piezoresistor R3 and one end of the DC power supply E, the other end of the first piezoresistor R1 is respectively connected to one end of the second piezoresistor R2 and a first input end of the trigger element 400; the other end of the third piezoresistor R3 is respectively connected to the second input end of the trigger element 400 and one end of the fourth piezoresistor R4; the other end of the second piezoresistor R2 is respectively connected to the other end of the fourth piezoresistor R4 and the other end of the DC power supply E.

[0064] Specifically, if Figure 5 As shown, the pressure sensor 300 is composed of a first piezoresistor R1, a second piezoresistor R2, a third piezoresistor R3, a fourth piezoresistor R4 and a DC power supply E. The output signal of the pressure sensor 300 is received by a trigger component 400. The trigger component 400 is triggered only when the output signal is greater than a first critical value, and the trigger component 400 is reset only when the output signal is less than a second critical value.

[0065] According to the switch control circuit based on arc-free electronic switch proposed in the embodiment of the present application, it is composed of a switch component and a control component, wherein the switch component includes a first IGBT and a second IGBT, the connection node between the collector of the first IGBT and the emitter of the second IGBT is electrically connected to the output end of the power supply device, the connection node between the emitter of the first IGBT and the collector of the second IGBT is electrically connected to the power consumption device, when the switch component is turned on, the power supply device supplies power to the power consumption device, and when the switch is turned off, the power supply device stops supplying power to the power consumption device; the signal output end of the control component is electrically connected to the connection node between the base of the first IGBT and the base of the second IGBT, and the control component controls the switch component to be turned on when the output signal is greater than the first critical value, and controls the switch component to be turned off when the output signal is less than the second critical value. Thus, the problem of arc generation when the mechanical contact switch is turned on is solved, and the electrical life of the switch is extended.

[0066] Next, a switch control method based on an arc-free electronic switch proposed in an embodiment of the present application is described with reference to the accompanying drawings.

[0067] Figure 6 It is a flow chart of a switch control method based on an arc-free electronic switch according to an embodiment of the present application.

[0068] like Figure 6 As shown, the switch control method based on the arc-free electronic switch adopts Figure 1 The switch control circuit based on the arc-free electronic switch of the embodiment, wherein the method comprises the following steps:

[0069] In step S601, the output signal of the pressure sensor is collected.

[0070] In step S602, it is determined whether the output signal is greater than a first threshold.

[0071] In step S603 , if the output signal is greater than the first critical value, a first level signal or a first current signal is generated.

[0072] In step S604, the switch component is controlled to be in a conducting state according to the first level signal or the first current signal.

[0073] Furthermore, in some embodiments, after determining whether the output signal is greater than a first critical value, it also includes: if the output signal is not greater than the first critical value, determining whether the output signal is less than a second critical value; if the output signal is less than the second critical value, generating a second level signal or a second current signal; and controlling the switch component to be in a disconnected state according to the second level signal or the second current signal.

[0074] It should be noted that the aforementioned explanation of the embodiment of the switch control circuit based on the arc-free electronic switch is also applicable to the switch control method based on the arc-free electronic switch of this embodiment, which will not be repeated here.

[0075] According to the switch control method based on the arc-free electronic switch proposed in the embodiment of the present application, by collecting and judging whether the output signal of the pressure sensor is greater than the first critical value, a first level signal or a first current signal can be generated when the output signal is greater than the first critical value, so as to control the switch component to be in the on state according to the first level signal or the first current signal. Thus, by adopting the switch control circuit based on the arc-free electronic switch, the problem of arc generation in the mechanical contact switch during switching is solved, and the electrical life of the switch is extended.

[0076] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0078] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A switch control circuit based on an arc-free electronic switch, characterized in that: include: A switch component, the switch component comprising a first IGBT and a second IGBT, a connection node between the collector of the first IGBT and the emitter of the second IGBT being electrically connected to an output terminal of a power supply device, a connection node between the emitter of the first IGBT and the collector of the second IGBT being electrically connected to an electrical device, and when the switch component is in an on state, the electrical device is powered by the power supply device, and when the switch component is in an off state, the electrical device is stopped from being powered by the power supply device; A control component, wherein a signal output terminal of the control component is electrically connected to a connection node between a base of the first IGBT and a base of the second IGBT, and when an output signal of the control component is greater than a first critical value, the control component controls the switch component to be in the on state, and when the output signal is less than a second critical value, the control component controls the switch component to be in the off state.

2. The switch control circuit based on the arc-free electronic switch according to claim 1, characterized in that: Also includes: A pressure sensor for generating the output signal based on the current pressure of the user; A trigger component is used to output a first level signal or a first current signal when the output signal is greater than the first critical value, and to output a second level signal or a second current signal when the output signal is less than the second critical value, wherein the first level signal and the second level signal are opposite.

3. The switch control circuit based on the arc-free electronic switch according to claim 2, characterized in that: The pressure sensor comprises: a first piezoresistance, a second piezoresistance, a third piezoresistance, a fourth piezoresistance and a DC power supply, wherein: One end of the first piezoresistance is respectively connected to one end of the third piezoresistance and one end of the DC power supply, and the other end of the first piezoresistance is respectively connected to one end of the second piezoresistance and the first input end of the trigger element; The other end of the third piezoresistance is respectively connected to the second input end of the trigger element and one end of the fourth piezoresistance; The other end of the second piezoresistance is connected to the other end of the fourth piezoresistance and the other end of the DC power supply respectively.

4. The switch control circuit based on the arc-free electronic switch according to claim 2 or 3, characterized in that: The pressure sensing element is a pressure sensor.

5. The switch control circuit based on the arc-free electronic switch according to claim 2 or 3, characterized in that: The triggering element is a Schmitt trigger.

6. The switch control circuit based on the arc-free electronic switch according to claim 2, characterized in that: The first level signal is a high level signal, and the second level signal is a low level signal.

7. The switch control circuit based on the arc-free electronic switch according to claim 2, characterized in that: A current value of the first current signal is greater than a current value of the second current signal.

8. The switch control circuit based on the arc-free electronic switch according to claim 1, characterized in that: The first critical value is greater than the second critical value.

9. A switch control method based on an arc-free electronic switch, characterized in that: The switch control circuit based on the arc-free electronic switch according to any one of claims 1 to 8 is adopted, wherein the method comprises the following steps: Collecting the output signal of the pressure sensor; Determining whether the output signal is greater than the first critical value; If the output signal is greater than the first critical value, a first level signal or a first current signal is generated; The switch component is controlled to be in the on state according to the first level signal or the first current signal.

10. The method according to claim 9, characterized in that After determining whether the output signal is greater than the first critical value, the method further includes: If the output signal is not greater than the first critical value, determining whether the output signal is less than the second critical value; If the output signal is less than the second critical value, a second level signal or a second current signal is generated; The switch component is controlled to be in the disconnected state according to the second level signal or the second current signal.

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