Leakage protection device and electrical equipment

Abstract

An embodiment of the present invention provides a leakage protection device, which is used in an electrical device, wherein the housing of the electrical device is connected to a ground wire, and the leakage protection device includes: a power supply circuit, a detection circuit, a comparison circuit, and a switch circuit, wherein the detection circuit is configured to output a detection voltage according to the voltage on the housing; the comparison circuit is connected to the detection circuit, configured to compare the detection voltage with a preset voltage range, and output a first control signal when the detection voltage is within the preset voltage range; and output a second control signal when the detection voltage is outside the preset voltage range; the switch circuit connects the power supply circuit and the housing, and the switch circuit is configured to connect the power supply circuit to the housing in response to the first control signal, and disconnect the power supply circuit from the housing in response to the second control signal. An embodiment of the present invention also provides an electrical device. The present invention can prevent the housing of the electrical device from being charged and ensure the normal operation of the device.

Description

Technical Field

[0001] The present invention relates to the field of electrical system safety protection, and in particular to a leakage protection device and electrical equipment. Background Art

[0002] In Class I electrical equipment, in order to provide protection against electric shock, the easily accessible conductive parts of the equipment (such as the equipment housing) are usually connected to the grounding conductor. In Class I electrical equipment with a built-in power supply, in order to reduce the electromagnetic interference (EMI) of the equipment, a common-mode filter circuit is usually designed in the power supply. These common-mode filter circuits connect the internal circuit of the power supply with the metal housing of the equipment, thereby reducing the electromagnetic interference of the electrical equipment. However, when the external protective grounding wire of the equipment is missing or poorly connected, the common-mode filter circuit will cause the metal housing of the equipment to be charged, resulting in the risk of electric shock. Summary of the invention

[0003] The embodiments of the present invention provide a leakage protection device and an electrical device to prevent a casing from being electrified and causing electric shock to a person.

[0004] As one aspect of the present invention, there is provided a leakage protection device for use in an electrical device, wherein the housing of the electrical device is connected to a ground wire, and the leakage protection device comprises: a power supply circuit, a detection circuit, a comparison circuit and a switch circuit.

[0005] The detection circuit is configured to output a detection voltage according to the voltage on the housing;

[0006] The comparison circuit is connected to the detection circuit, and is configured to compare the detection voltage with a preset voltage range, and output a first control signal when the detection voltage is within the preset voltage range; and output a second control signal when the detection voltage is outside the preset voltage range;

[0007] The switch circuit connects the power circuit and the housing, and is configured to connect the power circuit and the housing in response to the first control signal, and disconnect the power circuit and the housing in response to the second control signal.

[0008] In some embodiments, the detection circuit comprises:

[0009] a first resistor, wherein a first end of the first resistor is connected to the housing, and a second end of the first resistor is connected to the comparison circuit at a first node;

[0010] a second resistor, the second resistor being connected between the first node and a first reference ground;

[0011] A filter capacitor is connected in parallel with the second resistor.

[0012] In some embodiments, the detection circuit also includes: a third resistor and a first transistor, the first end of the third resistor is connected to the first node, the second end of the third resistor is connected to the collector of the first transistor, and the emitter of the first transistor is connected to the first reference ground.

[0013] In some embodiments, the comparison circuit includes: a second transistor, a fourth resistor, a fifth resistor and an optocoupler device,

[0014] The base of the second transistor is connected to the output end of the detection circuit;

[0015] The collector of the second transistor is connected to the first end of the optocoupler, the second end of the optocoupler is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first working voltage terminal, the third end of the optocoupler is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the second working voltage terminal, and the fourth end of the optocoupler is connected to the second reference ground;

[0016] Wherein, the preset voltage range is: greater than or equal to the turn-on voltage of the second transistor.

[0017] In some embodiments, the comparison circuit further includes: a first diode connected between the emitter of the second transistor and the second reference ground.

[0018] In some embodiments, the switch circuit includes: a loop switch device and a control subcircuit,

[0019] The control subcircuit is connected to the loop switch device and a first reference ground, and the control subcircuit is configured to connect the first reference ground and the loop switch device in response to the first control signal;

[0020] The loop switch device connects the power supply circuit and the housing, and is configured to connect the power supply circuit and the housing in response to the voltage of the first reference ground, and to disconnect the power supply circuit from the housing in response to a disconnect signal of the control subcircuit.

[0021] In some embodiments, the control subcircuit includes: a first transistor, a sixth resistor and a seventh resistor, the first end of the sixth resistor is connected to the output end of the comparison circuit, the second end of the sixth resistor is connected to the gate of the first transistor, the first electrode of the first transistor is connected to the first reference ground, and the second electrode of the first transistor is connected to the loop switching device; the two ends of the seventh resistor are respectively connected to the gate and the first electrode of the first transistor.

[0022] In some embodiments, the power supply circuit comprises:

[0023] A common-mode filtering module, wherein the common-mode filtering module comprises at least one group of Y capacitors, each group of the Y capacitors comprises a first Y capacitor and a second Y capacitor, each of the first Y capacitors is connected in series with the loop switch device between the live wire and the housing, and each of the second Y capacitors is connected in series with the loop switch device between the neutral wire and the housing.

[0024] In some embodiments, the first end of the first Y capacitor is connected to the live wire, the second end of the first Y capacitor is connected to the first end of the loop switch device, and the second end of the loop switch device is connected to the housing; the first end of the second Y capacitor is connected to the neutral wire, the second end of the second Y capacitor is connected to the first end of the loop switch device, and the third end of the loop switch device is connected to the control subcircuit.

[0025] In some embodiments, the loop switch device includes any one of a relay, an optocoupler device, and a transistor.

[0026] As a second aspect of the present invention, an electrical device is provided, comprising a housing and the leakage protection device in the above embodiment.

[0027] In the leakage protection device and electrical equipment provided by the embodiment of the present invention, when the housing is well connected to the ground wire, the housing is not energized, the detection voltage is within the preset voltage range, and the comparison circuit outputs a first control signal, so that the switch circuit connects the power circuit to the housing; when the housing is poorly connected to the ground wire, the detection voltage exceeds the preset voltage range, and the comparison circuit outputs a second control signal, so that the switch circuit disconnects the power circuit from the housing to prevent the housing from being energized. In the embodiment of the present invention, the switch circuit does not affect the power supply circuit of the external electrical equipment, thereby ensuring the normal operation of the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 It is a schematic diagram of a common-mode filtering circuit in an electrical device in the related art.

[0030] Figure 2 A schematic diagram of a leakage protection device provided in an embodiment of the present invention.

[0031] Figure 3 The present invention provides a schematic diagram of the connection between a common-mode filter module and a switch circuit.

[0032] Figure 4The figure is a schematic diagram of a detection circuit and a comparison circuit provided in an embodiment of the present invention.

[0033] Figure 5 Schematic diagram of a switch circuit provided in an embodiment of the present invention.

[0034] Figure 6 It is a schematic diagram of a common-mode filtering module and a loop switching device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0036] In Class I electrical equipment with a built-in power supply, in order to reduce the electromagnetic interference (EMI) of the equipment, a common-mode filtering circuit is usually designed in the power supply, wherein the built-in power supply is connected to the live wire L / neutral wire N, and is used to convert the AC power connected to the input interface 1 into the voltage actually required by the internal components and loads of the equipment. Figure 1 Schematic diagram of a common mode filter circuit in an electrical device in the related art, such as Figure 1 As shown, the common mode filter circuit includes a common mode inductor (not shown) and a Y capacitor C1' / C2', wherein the common mode inductor is connected in series in the power supply circuit; one end of the Y capacitor C1' is connected to the live wire L, and the other end is connected to the housing 2; one end of the Y capacitor C2' is connected to the neutral wire N, and the other end is connected to the housing. The live wire L and the neutral wire N are connected to the housing 2 through the Y capacitor, so that when the housing 2 is well connected to the ground wire PE, the metal housing 2 is at the same potential as the earth, and the user is not in danger of electric shock. However, when the housing 2 is not connected to the ground wire PE or the contact is poor, the metal housing is charged, and the user is prone to electric shock when touching the housing 2.

[0037] In order to prevent the user from getting an electric shock due to the case 2 being energized, in some technologies, the leakage protection method adopted is to perform leakage detection on the ground wire PE. When leakage is detected in the ground wire PE, the live wire L, the neutral wire N and the ground wire PE are disconnected by controlling the on and off of the switch, thereby disconnecting the power supply circuit of the device to achieve the effect of leakage protection. However, the power-off process not only affects the user experience, but may also cause economic losses. When maintenance is performed without power outage, if the case 2 is energized, the maintenance personnel will be in danger of electric shock.

[0038] An embodiment of the present invention provides a leakage protection device for use in an electrical device, wherein a casing of the electrical device is connected to a ground wire PE. Figure 2 Schematic diagram of a leakage protection device provided in an embodiment of the present invention, such as Figure 2 As shown, the leakage protection device includes: a power supply circuit 31, a detection circuit 32, a comparison circuit 33 and a switch circuit 34.

[0039] The detection circuit 32 is connected to the housing 2 , and is configured to output a detection voltage according to a voltage on the housing 2 .

[0040] The comparison circuit 33 is connected to the detection circuit 32, and is configured to compare the detection voltage with a preset voltage range, and output a first control signal when the detection voltage is within the preset voltage range; and output a second control signal when the detection voltage is outside the preset voltage range.

[0041] The switch circuit 34 connects the power circuit 31 and the housing 2 , and is configured to connect the power circuit 31 and the housing 2 in response to a first control signal, and disconnect the power circuit 31 and the housing 2 in response to a second control signal.

[0042] Among them, the relationship between the preset voltage range, the detection voltage and the actual voltage on the casing 2 can be determined according to actual conditions to ensure that when the casing 2 is well connected to the ground wire PE, the detection voltage is within the preset voltage range, and when the casing 2 is poorly connected to the ground wire PE, the detection voltage is outside the preset voltage range.

[0043] In the embodiment of the present invention, when the housing 2 is well connected to the ground wire PE, the housing 2 is not charged, the detection voltage is within the preset voltage range, and the comparison circuit 33 outputs a first control signal, so that the switch circuit 34 connects the power circuit 31 with the housing 2; when the housing 2 is poorly connected to the ground wire PE, the detection voltage exceeds the preset voltage range, and the comparison circuit 33 outputs a second control signal, so that the switch circuit 34 disconnects the power circuit 31 from the housing 2 to prevent the housing 2 from being charged. In the embodiment of the present invention, the switch circuit 34 does not affect the power supply circuit of the external electrical equipment, thereby ensuring the normal operation of the electrical equipment.

[0044] In some embodiments, the power supply circuit 31 includes: a common mode filter module and a voltage conversion module, the voltage conversion module is configured to convert the AC voltage connected to the input interface 1, so as to obtain the voltage actually required by each device in the device and the load 4, and the load 4 includes: a rectifier bridge 41 formed by multiple rectifier diodes, a capacitor C7, a resistor R, etc. In an embodiment of the present invention, the voltage conversion module may have a first working voltage terminal, a second working voltage terminal, a first reference ground, and a second reference ground. Among them, the signals of the first working voltage terminal and the second working voltage terminal may both be high-level signals; the voltages of the first reference ground and the second reference ground may both be low-level signals, and the two may be the same.

[0045] Figure 3 FIG. 1 is a schematic diagram of a connection between a common mode filter module and a switch circuit provided in an embodiment of the present invention. Figure 3As shown, the common-mode filter module 311 includes at least one group of Y capacitors, each group of Y capacitors includes two Y capacitors, and each group of Y capacitors is connected to at least one switch circuit 34. In a specific example, the common-mode filter module adopts a first-level common-mode filter circuit, which specifically includes a common-mode inductor L1 and two groups of Y capacitors, and the common-mode inductor L1 is connected in series in the loop of the live wire L and the neutral wire N. Each group of Y capacitors includes two Y capacitors, namely a first Y capacitor C1 / C3 and a second Y capacitor C2 / C4. Each Y capacitor is connected to the switch circuit 34.

[0046] Figure 4 is a schematic diagram of a detection circuit and a comparison circuit provided in an embodiment of the present invention, such as Figure 4 As shown, the detection circuit 32 includes: a first resistor R1, a second resistor R2 and a filter capacitor C5.

[0047] The first end of the first resistor R1 is connected to the housing 2, and the second end of the first resistor R1 and the comparison circuit 33 are connected to the first node N1, which can be regarded as the output end of the detection circuit 32. The second resistor R2 is connected between the first node N1 and the first reference ground AL1 of the power supply circuit 31. The filter capacitor C5 is connected in parallel with the second resistor R2.

[0048] The voltage of the first reference ground AL1 is different from the voltage of the ground line PE. The first resistor R1 and the second resistor R2 are used to divide the voltage between the housing 2 and the first reference ground AL1, and the filter capacitor C5 is used to filter the detection voltage of the first node N1.

[0049] In some embodiments, the detection circuit 32 also includes: a third resistor R3 and a first transistor VT1, a first end of the third resistor R3 is connected to the first node N1, a second end of the third resistor R3 is connected to the collector of the first transistor VT1, an emitter of the first transistor VT1 is connected to the first reference ground AL1, a base of the first transistor VT1 is connected to the gating control SR, and the first transistor VT1 controls the conduction and disconnection of the branch where the third resistor R3, the first transistor VT1 and the first reference ground AL1 are located according to the control signal of the gating control terminal SR. Through the setting of the first transistor VT1, a relatively consistent sampling voltage can be obtained at the first node N1 when the input mains voltage is different. For example, a control signal can be passed to the first transistor VT1 according to the actual mains power supply, so that the third resistor R3 is connected in parallel with the second resistor R2, thereby adjusting the voltage value of the first node N1 to ensure that when the housing 2 is well grounded, the detection voltage at the first node N1 is within the preset voltage range, and when the housing 2 is poorly grounded, the detection voltage at the first node N1 is outside the preset voltage range.

[0050] In some embodiments, the comparison circuit 33 includes: a second transistor, a fourth resistor R4, a fifth resistor R5 and an optocoupler device U2.

[0051] The base of the second transistor VT2 is connected to the output end of the detection circuit 32. The collector of the second transistor VT2 is connected to the first end of the optocoupler U2, the second end of the optocoupler U2 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the first working voltage terminal VCC, the third end of the optocoupler U2 is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the second working voltage terminal VDD, and the fourth end of the optocoupler U2 is connected to the second reference ground AL2. The fifth resistor R5 is used to isolate the voltage at the output end (i.e., the second node B) of the comparison circuit 33 from the voltage of the second working voltage terminal VDD, so that when the third end and the fourth end of the optocoupler U2 are turned on, a sufficiently low voltage can be output at the second node B.

[0052] Among them, the voltages of the first working voltage terminal VCC and the second working voltage terminal VDD are both high-level voltages, and the voltages of the second reference ground AL2 and the first reference ground AL1 can be the same. The above-mentioned preset voltage range is: greater than or equal to the turn-on voltage of the second transistor VT2. The first control signal is the voltage signal of the third terminal of the optocoupler device U2 when the third terminal and the fourth terminal of the optocoupler device U2 are turned on, and the second control signal is the voltage signal of the third terminal of the optocoupler device U2 when the third terminal and the fourth terminal of the optocoupler device U2 are turned off.

[0053] It should be noted that other gating devices (eg, MOS transistors) may also be used to replace the first transistor VT1 and the second transistor VT2.

[0054] In some embodiments, the comparison circuit 33 further includes: a first diode VD1, an emitter of the second transistor VT2 is connected to a first end (anode) of the first diode VD1, and a second end (cathode) of the first diode VD1 is connected to a second reference ground AL2. The setting of the first diode VD1 can adjust the conduction voltage value of the base of the second transistor VT2.

[0055] Figure 5 is a schematic diagram of a switch circuit provided in an embodiment of the present invention, such as Figure 5 As shown, in some embodiments, the switch circuit 34 includes: a loop switch device 342 and a control subcircuit 34. The control subcircuit 34 is connected to the loop switch device 342 and the first reference ground AL1 of the power supply circuit 31, and the control subcircuit 34 is configured to connect the first reference ground AL1 and the loop switch device 342 in response to a first control signal.

[0056] The loop switch device 342 connects the power circuit 31 and the housing 2. The loop switch device 342 is configured to connect the power circuit 31 and the housing 2 in response to the voltage of the first reference ground AL1, and disconnect the power circuit 31 from the housing 2 in response to the disconnection signal of the control subcircuit 34 (i.e., the signal that disconnects the first reference ground AL1 and the loop switch device 342). It should be noted that connecting the power circuit 31 and the housing 2 means that the branch connected to the power circuit 31 and the housing 2 is connected; disconnecting the power circuit 31 and the housing 2 means that no current flows between the power circuit 31 and the housing 2.

[0057] Exemplarily, the control subcircuit 34 includes a first transistor M1, a sixth resistor R6 and a seventh resistor R7, and the first transistor M1 can be a field effect transistor (MOS). The first end of the sixth resistor R6 is connected to the output end of the comparison circuit 33, the second end of the sixth resistor R6 is connected to the gate of the first transistor M1, the first electrode of the first transistor M1 is connected to the first reference ground AL1, and the second electrode of the first transistor M1 is connected to the loop switch device 342. Among them, one of the first electrode and the second electrode of the first transistor M1 is a source electrode, and the other is a drain electrode. It should be noted that the control subcircuit 34 is not limited to the structure of a transistor, for example, a triode can also be used.

[0058] In some embodiments of the present invention, when the detection circuit 32 outputs the first control signal, the first transistor M1 conducts the first reference ground AL1 and the loop switch device 342. It should be noted that: Figure 5 The switch circuit 34 in the figure is only a specific embodiment of the present invention. In practical applications, the switch circuit 34 may not include the control subcircuit 34, so that the loop switch device 342 is directly connected to the output end of the comparison circuit 33, and the loop switch device 342 is configured to connect the power circuit 31 with the housing 2 in response to the first control signal, and disconnect the power circuit 31 from the housing 2 in response to the first control signal. Alternatively, a signal conversion module is provided in the power circuit 31, and the signal conversion module generates a third control signal in response to the first control signal to control the loop switch device 342 to connect the power circuit 31 with the housing 2; and the signal conversion module generates a fourth control signal in response to the second control signal to control the loop switch device 342 to disconnect the power circuit 31 from the housing 2.

[0059] Exemplarily, the loop switch device 342 includes any one of a relay, an optocoupler device, and a transistor. Of course, the loop switch device 342 may also be other semiconductor switch devices that meet the working requirements and insulation requirements.

[0060] Figure 6 Schematic diagram of a common mode filter module and a loop switch device provided in an embodiment of the present invention, such as Figure 6As shown, in some embodiments, each group of Y capacitors is connected to at least one loop switch device 342, and different loop switch devices 342 can adopt the same structure, or, as shown in FIG. Figure 6 As shown in FIG. 1 , one group of Y capacitors connected to the loop switch device 342 uses a relay K1, and another group of Y capacitors connected to the loop switch device 342 uses an optocoupler device U1.

[0061] Each Y capacitor is connected in series with the corresponding loop switch device 342 between the power line and the ground line. The power line includes a live line L and a neutral line N, the first Y capacitor C1 / C3 and the loop switch device 342 are connected in series between the live line L and the housing 2, and the second Y capacitor C2 / C4 and the loop switch device 342 are connected in series between the neutral line N and the housing 2.

[0062] Exemplarily, the first end of the first Y capacitor C1 / C3 is connected to the live wire, the second end of the first Y capacitor C1 / C3 is connected to the first end of the loop switch device 342, and the second end of the loop switch device 342 is connected to the housing 2; the first end of the second Y capacitor C2 / C4 is connected to the neutral wire, the second end of the second Y capacitor C2 / C4 is connected to the first end of the loop switch device 342, the third end of the loop switch device 342 is connected to the control subcircuit 34, and the fourth end of the loop switch device 342 is connected to the first working voltage terminal VCC. When the third end of the loop switch device 342 receives the voltage of the first reference ground AL1, the first end of the loop switch device 342 is connected to the second end; when the control subcircuit 34 is disconnected, the first end of the loop switch device 342 is disconnected from the second end.

[0063] It should be noted that the connection method between the Y capacitor and the loop switch device 342 is not limited to Figure 6 As shown in, for example, the order of the first Y capacitor C1 / C3, the second Y capacitor C2 / C4 and the loop switch device 342 can also be swapped, that is, the first Y capacitor C1 / C3 and the second Y capacitor C2 / C4 are respectively connected to two loop switch devices 342, the loop switch device 342 connected to the first Y capacitor C1 / C3 is recorded as the first loop switch device, and the loop switch device 342 connected to the second Y capacitor C2 / C4 is recorded as the second loop switch device, then, the first end of the first Y capacitor C1 / C3 is connected to the ground line, the second end of the first Y capacitor C1 / C3 is connected to the first end of the first loop switch device 342, and the second end of the first loop switch device 342 is connected to the live wire L; the first end of the second Y capacitor is connected to the housing 2, the second end of the second Y capacitor C2 / C4 is connected to the first end of the second loop switch device 342, and the second end of the second loop switch device 342 is connected to the neutral line N.

[0064] In the embodiment of the present invention, when a leakage or poor grounding occurs between the housing 2 and the ground line PE, the voltage on the housing 2 is higher than the voltage on the ground line PE, and a current path is formed between the housing 2, the first resistor R1, the second resistor R2 and the first reference ground AL1. A detection voltage is generated at the first node N1, and the detection voltage is lower than the turn-on voltage of the second transistor VT4 and the first diode VD1 when they are connected in series. Therefore, the branch formed by the first working voltage terminal VCC, the fourth resistor R4, the optocoupler device U2, the second transistor VT2, the first diode VD1 and the first reference ground AL1 is disconnected, and the output voltage of the comparison circuit 33 is close to the voltage of the second working voltage terminal VDD (that is, the second control signal is output), and the switch circuit 34 disconnects the Y capacitor from the housing 2 in response to the second control signal, thereby achieving the purpose of disconnecting the leakage loop. For example, the second control signal is transmitted to the control subcircuit 34 to control the first transistor M1 to be disconnected, thereby automatically disconnecting the loop switch device 342; or, the second control signal is transmitted to the power supply circuit 31, and the power supply circuit 31 responds to the second control signal to control the loop switch device 342 to be disconnected; or, a suitable loop switch device 342 (such as a PMOS tube) is selected so that the second control signal can directly control the loop switch device 342 to be disconnected. In addition, an alarm circuit can also be set in the leakage protection device to report alarm information when the loop switch device 342 is disconnected.

[0065] When the contact between the housing 2 and the ground wire is good, the voltage on the housing 2 is equal to the voltage on the ground wire PE, the detection voltage at the first node N1 is greater than the turn-on voltage of the second transistor VT4, the branch formed by the first working voltage terminal VCC, the fourth resistor R4, the optocoupler device U2, the second transistor VT2, the first diode VD and the first reference ground AL1 is turned on, the output voltage of the comparison circuit 33 is close to the voltage of the second reference ground AL2 (that is, the first control signal is output), and the switch circuit 34 turns on the Y capacitor and the housing 2 in response to the first control signal.

[0066] An embodiment of the present invention further provides an electrical device, comprising a housing and the leakage protection device in the above embodiment, wherein the leakage protection device is connected to the housing.

[0067] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A leakage protection device, used in an electrical device, wherein the housing of the electrical device is connected to a ground wire, characterized in that: The leakage protection device comprises: a power supply circuit, a detection circuit, a comparison circuit and a switch circuit, wherein the power supply circuit comprises a common mode filter module; The detection circuit is configured to output a detection voltage according to the voltage on the housing; The comparison circuit is connected to the detection circuit, and is configured to compare the detection voltage with a preset voltage range, and output a first control signal when the detection voltage is within the preset voltage range; and output a second control signal when the detection voltage is outside the preset voltage range; The switch circuit connects the common mode filter module and the housing, and is configured to connect the power circuit to the housing in response to the first control signal, and disconnect the power circuit from the housing in response to the second control signal.

2. The leakage protection device according to claim 1, characterized in that: The detection circuit comprises: a first resistor, wherein a first end of the first resistor is connected to the housing, and a second end of the first resistor is connected to the comparison circuit at a first node; a second resistor, the second resistor being connected between the first node and a first reference ground; A filter capacitor is connected in parallel with the second resistor.

3. The leakage protection device according to claim 2, characterized in that: The detection circuit also includes: a third resistor and a first transistor, the first end of the third resistor is connected to the first node, the second end of the third resistor is connected to the collector of the first transistor, and the emitter of the first transistor is connected to the first reference ground.

4. The leakage protection device according to claim 1, characterized in that: The comparison circuit includes: a second transistor, a fourth resistor, a fifth resistor and an optical coupler device. The base of the second transistor is connected to the output end of the detection circuit; The collector of the second transistor is connected to the first end of the optocoupler, the second end of the optocoupler is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first working voltage terminal, the third end of the optocoupler is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the second working voltage terminal, and the fourth end of the optocoupler is connected to the second reference ground; Wherein, the preset voltage range is: greater than or equal to the turn-on voltage of the second transistor.

5. The leakage protection device according to claim 4, characterized in that: The comparison circuit further includes: a first diode connected between the emitter of the second transistor and the second reference ground.

6. The leakage protection device according to claim 1, characterized in that: The switch circuit comprises: a loop switch device and a control subcircuit, The control subcircuit is connected to the loop switch device and a first reference ground, and the control subcircuit is configured to connect the first reference ground and the loop switch device in response to the first control signal; The loop switch device connects the power supply circuit and the housing, and is configured to connect the power supply circuit and the housing in response to the voltage of the first reference ground, and to disconnect the power supply circuit from the housing in response to a disconnect signal of the control subcircuit.

7. The leakage protection device according to claim 6, characterized in that: The control subcircuit includes: a first transistor, a sixth resistor and a seventh resistor, the first end of the sixth resistor is connected to the output end of the comparison circuit, the second end of the sixth resistor is connected to the gate of the first transistor, the first electrode of the first transistor is connected to the first reference ground, and the second electrode of the first transistor is connected to the loop switch device; the two ends of the seventh resistor are respectively connected to the gate and the first electrode of the first transistor.

8. The leakage protection device according to claim 6, characterized in that: The common-mode filtering module includes at least one group of Y capacitors, each group of Y capacitors includes a first Y capacitor and a second Y capacitor, each of the first Y capacitors is connected in series with the loop switch device between the live wire and the housing, and each of the second Y capacitors is connected in series with the loop switch device between the neutral wire and the housing.

9. The leakage protection device according to claim 8, characterized in that: The first end of the first Y capacitor is connected to the live wire, the second end of the first Y capacitor is connected to the first end of the loop switch device, and the second end of the loop switch device is connected to the housing; the first end of the second Y capacitor is connected to the neutral wire, the second end of the second Y capacitor is connected to the first end of the loop switch device, and the third end of the loop switch device is connected to the control subcircuit.

10. The leakage protection device according to claim 6, characterized in that: The loop switch device includes: any one of a relay, an optocoupler device, and a transistor.

11. An electrical device, characterized in that: It comprises a housing and the leakage protection device according to any one of claims 1 to 10.

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