Leakage current switching control device and laser treatment instrument

Abstract

The application provides a leakage current switching control device and a laser treatment instrument, which comprises an electric network input unit, an electric network EMC unit, an electric network EMI unit, a sampling comparison unit, a leakage current switching unit and an electric network output unit; the electric network EMI unit comprises a common RC circuit and a standby RC circuit; the sampling comparison unit is used for outputting a first level signal to the leakage current switching unit when the electric network input unit inputs a first voltage and outputting a second level signal to the leakage current switching unit when the electric network input unit inputs a second voltage; wherein the first voltage is greater than the second voltage; the leakage current switching unit is used for controlling the standby RC circuit to be disconnected with the electric network EMI unit when the first level signal is received and controlling the standby RC circuit to be connected in parallel with the common RC circuit when the second level signal is received, so that the leakage currents generated by the electric network EMC unit and the electric network EMI unit remain unchanged. The application improves the reliability of leakage current control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply circuit, in particular to a leakage current switching control device and a laser treatment instrument. BACKGROUND

[0002] The power supply circuit in the laser treatment instrument usually includes a power grid filter circuit, and the power grid filter circuit usually includes an Electro Magnetic Compatibility (EMC) unit and an Electromagnetic Interference (EMI) unit. The EMC refers to the ability of a device or system to function in its electromagnetic environment without affecting the operation of other devices in the environment. The EMI is the electromagnetic interference caused by electromagnetic radiation. In the existing power grid filter circuit in the laser treatment instrument, the filter coefficients of the EMI unit and the EMC unit remain unchanged when the input voltage changes, thereby making the generated leakage current inconsistent, and the phenomenon of leakage current exceeding the standard is prone to occur, and the reliability of leakage current control is reduced. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a leakage current switching control device and a laser treatment instrument, which can ensure that the leakage current generated by the network composed of the power grid EMC unit and the power grid EMI unit remains unchanged when the input voltage of the power grid input unit is reduced from the first voltage to the second voltage, avoid the phenomenon of leakage current exceeding the standard, and improve the reliability of leakage current control.

[0004] In order to achieve the above purpose, the technical scheme adopted by the embodiments of the present application is as follows:

[0005] In a first aspect, the embodiments of the present application provide a leakage current switching control device, which comprises a power grid input unit, a power grid EMC unit, a power grid EMI unit, a sampling comparison unit, a leakage current switching unit and a power grid output unit.

[0006] The input end of the power grid input unit is used to be connected with a power supply, and the output end of the power grid input unit is connected with the input end of the power grid EMC unit.

[0007] The output end of the power grid EMC unit is connected with the input end of the power grid EMI unit, the output end of the power grid EMI unit is connected with the input end of the power grid output unit, and the output end of the power grid output unit is connected with a load.

[0008] The output end of the power grid EMC unit is also connected with the input end of the sampling comparison unit.

[0009] The power grid EMI unit comprises a normal RC circuit and a backup RC circuit, an output end of the sampling comparison unit is connected with an input end of the leakage current switching unit, and an output end of the leakage current switching unit is connected with the backup RC circuit;

[0010] The sampling comparison unit is configured to output a first level signal to the leakage current switching unit when the power grid input unit inputs a first voltage and output a second level signal to the leakage current switching unit when the power grid input unit inputs a second voltage, wherein the first voltage is greater than the second voltage.

[0011] The leakage current switching unit is configured to control the backup RC circuit to be disconnected with the power grid EMI unit when receiving the first level signal and control the backup RC circuit to be connected with the normal RC circuit in parallel when receiving the second level signal, so that the leakage currents generated by the power grid EMC unit and the power grid EMI unit remain unchanged.

[0012] Further, the embodiment of the present application provides a first possible implementation manner of the first aspect, and the first possible implementation manner further comprises an auxiliary power supply unit, wherein an output end of the power grid EMC unit is further connected with an input end of the auxiliary power supply unit, and an output end of the auxiliary power supply unit is connected with an input end of the sampling comparison unit.

[0013] The auxiliary power supply unit is configured to input a first voltage signal to the sampling comparison unit when the power grid input unit inputs the first voltage and input a second voltage signal to the sampling comparison unit when the power grid input unit inputs the second voltage.

[0014] The sampling comparison unit is configured to output a first level signal to the leakage current switching unit when receiving the first voltage signal and output a second level signal to the leakage current switching unit when receiving the second voltage signal.

[0015] Further, the embodiment of the present application provides a second possible implementation manner of the first aspect, and the second possible implementation manner comprises a comparator.

[0016] A positive phase input end of the comparator is connected with a reference voltage, a negative phase input end of the comparator is connected with an output end of the auxiliary power supply unit, and an output end of the comparator is connected with an input end of the leakage current switching unit.

[0017] The auxiliary power supply unit is configured to output a third voltage signal to the negative phase input end of the comparator when the power grid input unit inputs the first voltage, so that the comparator outputs a low level signal.

[0018] The auxiliary power supply unit is also configured to output a fourth voltage signal to a negative input terminal of the comparator when the grid input unit inputs the second voltage, so that the comparator outputs a high level signal.

[0019] Further, the embodiment of the present application provides a third possible implementation manner of the first aspect, wherein the leakage current switching unit comprises a switching element and an electric control device;

[0020] The control terminal of the switching element is connected with the output terminal of the sampling comparison unit, the output terminal of the switching element is connected with the control system of the electric control device, and the controlled system of the electric control device is connected in series with the standby RC circuit;

[0021] The switching element is configured to be in an off state when the comparator outputs the low level signal and to be in an on state when the comparator outputs the high level signal.

[0022] The controlled system of the electric control device is in an open state, and the control system of the electric control device is configured to trigger the controlled system to be in a closed state when the switching element is in the on state, so that the standby RC circuit is connected in parallel with the commonly used RC circuit.

[0023] Further, the embodiment of the present application provides a fourth possible implementation manner of the first aspect, wherein the commonly used RC circuit comprises a first commonly used RC circuit and a second commonly used RC circuit, the standby RC circuit comprises a first standby RC circuit and a second standby RC circuit, and the electric control device comprises a first electric control device and a second electric control device;

[0024] The controlled system of the first electric control device is connected in series with the first standby RC circuit, and the controlled system of the second electric control device is connected in series with the second standby RC circuit.

[0025] The output terminal of the switching element is connected with the control system of the first electric control device and the control system of the second electric control device respectively.

[0026] The control system of the first electric control device is configured to trigger the controlled system of the first electric control device to be in a closed state when the switching element is in the on state, so that the first standby RC circuit is connected in parallel with the first commonly used RC circuit.

[0027] The control system of the second electric control device is configured to trigger the controlled system of the second electric control device to be in a closed state when the switching element is in the on state, so that the second standby RC circuit is connected in parallel with the second commonly used RC circuit.

[0028] Further, the embodiment of the present application provides a fifth possible implementation manner of the first aspect, wherein the state detection output unit is further included.

[0029] The state detection output unit is connected with the leakage current switching unit, and is configured to output a low level when the power grid input unit inputs the first voltage and output a high level when the power grid input unit inputs the second voltage.

[0030] Further, the embodiment of the present application provides a sixth possible implementation manner of the first aspect, wherein the state detection output unit comprises a third electric control device and an output port.

[0031] The control system of the third electric control device is connected with the control system of the first electric control device and the control system of the second electric control device respectively.

[0032] The controlled system of the third electric control device comprises a fixed terminal, a first movable terminal and a second movable terminal, and the fixed terminal and the second movable terminal are in a normally closed state.

[0033] One end of the output port is connected with the fixed terminal, and the other end of the output port is connected with the first movable terminal.

[0034] The control system of the third electric control device is configured to trigger the fixed terminal and the first movable terminal to be closed and conductive when the control system of the first electric control device and the control system of the second electric control device are powered.

[0035] Further, the embodiment of the present application provides a seventh possible implementation manner of the first aspect, wherein a reference voltage source unit is further included, and the reference voltage source unit is connected with the positive input terminal of the comparator.

[0036] The reference voltage source unit is configured to provide the reference voltage for the comparator.

[0037] Further, the embodiment of the present application provides an eighth possible implementation manner of the first aspect, wherein the switching element comprises a triode, the base of the triode is connected with the output terminal of the sampling comparison unit, the collector of the triode is connected with the control system of the electric control device, and the emitter of the triode is grounded.

[0038] Further, the embodiment of the present application provides a ninth possible implementation manner of the first aspect, wherein the electric control device comprises a relay.

[0039] In the second aspect, the embodiment of the present application provides a laser treatment instrument, comprising a laser and the leakage current switching control device according to any one of the first aspect.

[0040] The embodiment of the present application provides a leakage current switching control device and a laser treatment instrument, the leakage current switching control device comprises: a power grid input unit, a power grid EMC unit, a power grid EMI unit, a sampling comparison unit, a leakage current switching unit and a power grid output unit; the input end of the power grid input unit is used for being connected with a power supply, the output end of the power grid input unit is connected with the input end of the power grid EMC unit; the output end of the power grid EMC unit is connected with the input end of the power grid EMI unit, the output end of the power grid EMI unit is connected with the input end of the power grid output unit, and the output end of the power grid output unit is connected with a load; the output end of the power grid EMC unit is also connected with the input end of the sampling comparison unit; the power grid EMI unit comprises a commonly used RC circuit and a backup RC circuit, the output end of the sampling comparison unit is connected with the input end of the leakage current switching unit, and the output end of the leakage current switching unit is connected with the backup RC circuit; the sampling comparison unit is used for outputting a first level signal to the leakage current switching unit when a first voltage is input into the power grid input unit, and outputting a second level signal to the leakage current switching unit when a second voltage is input into the power grid input unit; wherein the first voltage is greater than the second voltage; the leakage current switching unit is used for controlling the backup RC circuit to be disconnected with the power grid EMI unit when the first level signal is received, and controlling the backup RC circuit to be connected in parallel with the commonly used RC circuit when the second level signal is received, so that the leakage currents generated by the power grid EMC unit and the power grid EMI unit remain unchanged. According to the present application, the input voltage of the power grid input unit is sampled based on the sampling comparison unit, when the input voltage of the power grid input unit is reduced from the first voltage to the second voltage, the corresponding electric signal is output to the leakage current switching unit, so that the leakage current switching unit controls the backup RC circuit to be connected in parallel with the commonly used RC circuit, so that the RC circuit is increased in the power grid EMI unit, the circuit impedance is increased, and thus the generated leakage current can also be reduced, so that the leakage current generated by the network composed of the power grid EMC unit and the power grid EMI unit can remain unchanged when the input voltage of the power grid input unit is reduced from the first voltage to the second voltage, the phenomenon of excessive leakage current is avoided, and the reliability of leakage current control is improved.

[0041] Other features and advantages of the present application will be described in the following description, or can be known or determined from the description, or can be known or determined from the above-mentioned technology of the embodiment of the present application.

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0044] Figure 1 A structure diagram of a leakage current switching control device provided by an embodiment of the present application is shown.

[0045] Figure 2 A circuit diagram of a leakage current switching control device provided by an embodiment of the present application is shown. EMBODIMENT

[0046] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described below in combination with the drawings. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments.

[0047] The existing power grid filter circuit usually adopts fixed EMC and EMI filter coefficients, and only suppresses the power grid noise through the filter. Some devices select the power grid voltage through manual switch switching. However, the leakage current generated when the power grid input voltage is different is also different, and the EMI and EMC filtering effects are inconsistent. In the low power grid voltage state, the signal-to-noise ratio of the device is reduced.

[0048] In order to improve the above problems, the present application provides a leakage current switching control device and a laser treatment instrument. The embodiments of the present application will be described in detail below.

[0049] The present embodiment provides a leakage current switching control device, referring to Figure 1 The structure diagram of the leakage current switching control device, the leakage current switching control device comprises: a power grid input unit 10, a power grid EMC unit 20, a power grid EMI unit 30, a sampling comparison unit 40, a leakage current switching unit 50 and a power grid output unit 60;

[0050] The input end of the power grid input unit 10 is used to be connected with the power supply, and the output end of the power grid input unit 10 is connected with the input end of the power grid EMC unit 20;

[0051] The output end of the power grid EMC unit 20 is connected with the input end of the power grid EMI unit 30, the output end of the power grid EMI unit 30 is connected with the input end of the power grid output unit 60, and the output end of the power grid output unit 60 is connected with the load;

[0052] The output end of the power grid EMC unit 20 is also connected with the input end of the sampling comparison unit 40;

[0053] The power grid EMI unit 30 comprises a normal RC circuit and a backup RC circuit (not shown in the figure), the output end of the sampling comparison unit is connected with the input end of the leakage current switching unit, and the output end of the leakage current switching unit is connected with the backup RC circuit;

[0054] The sampling comparison unit 40 is used for outputting a first level signal to the leakage current switching unit 50 when the power grid input unit 10 inputs a first voltage, and outputting a second level signal to the leakage current switching unit 50 when the power grid input unit 10 inputs a second voltage; wherein the first voltage is greater than the second voltage.

[0055] The leakage current switching unit 50 is used for controlling the backup RC circuit to be disconnected with the power grid EMI unit 30 when receiving the first level signal, and controlling the backup RC circuit to be connected in parallel with the normal RC circuit when receiving the second level signal, so that the leakage current generated by the power grid EMC unit and the power grid EMI unit remains unchanged.

[0056] The leakage current switching unit 50 is used for switching the size of the leakage current when the power grid input voltage changes, so that it works at the optimal value of the EMI loop.

[0057] The power grid input unit 10 is a power grid power input end, and the input voltage of the power grid input unit 10 can be AC220V or AC110V. The power grid EMC unit 20 is a power grid EMC (surge absorption) loop processing, the power grid EMI unit 30 is a power grid EMI (electromagnetic compatibility absorption) loop processing. The power grid output unit 60 is a power grid output loop.

[0058] When the input voltage of the power grid input unit 10 is the first voltage, the sampling comparison unit 40 outputs the first level signal to the leakage current switching unit 50, and the leakage current switching unit 50 makes the backup RC circuit disconnected with the power grid EMI unit 30; when the input voltage of the power grid input unit 10 is reduced to the second voltage, the leakage current generated by the power grid EMI unit 30 will be larger, by making the sampling comparison unit 40 output the second level signal to the leakage current switching unit 50, the leakage current switching unit 50 controls the backup RC circuit to be connected into the power grid EMI unit 30, so that the backup RC circuit is connected in parallel with the normal RC circuit, to increase the impedance of the power grid EMI unit 30, reduce the value of the leakage current, so that the leakage current generated by the network remains unchanged when the input voltage of the power grid input unit 10 is reduced from the first voltage to the second voltage.

[0059] The leakage current switching control device provided by the embodiment can sample the input voltage of the grid input unit based on the sampling comparison unit, output corresponding electrical signals to the leakage current switching unit when the input voltage of the grid input unit decreases from the first voltage to the second voltage, and make the leakage current switching unit control the standby RC circuit and the commonly used RC circuit to be connected in parallel, so that the RC circuit is added in the grid EMI unit and the circuit impedance is increased, thereby reducing the generated leakage current, and ensuring that the leakage current generated by the network composed of the grid EMC unit and the grid EMI unit remains unchanged when the input voltage of the grid input unit decreases from the first voltage to the second voltage, avoiding the phenomenon that the leakage current exceeds the standard, and improving the reliability of leakage current control.

[0060] In one embodiment, referring to the circuit diagram of the leakage current switching control device shown in Figure 2 The leakage current switching control device provided by the embodiment further comprises an auxiliary power supply unit 70; the output end of the grid EMC unit 20 is further connected with the input end of the auxiliary power supply unit 70, and the output end of the auxiliary power supply unit 70 is connected with the input end of the sampling comparison unit 40.

[0061] The auxiliary power supply unit 70 is used for inputting a first voltage signal to the sampling comparison unit 40 when the grid input unit inputs the first voltage, and inputting a second voltage signal to the sampling comparison unit 40 when the grid input unit 10 inputs the second voltage; wherein the second voltage is less than the first voltage.

[0062] The sampling comparison unit 40 is used for outputting a first level signal to the leakage current switching unit 50 when receiving the first voltage signal, and outputting a second level signal to the leakage current switching unit 50 when receiving the second voltage signal.

[0063] As shown in Figure 2 The auxiliary power supply unit 70 comprises an isolation transformer T, a bridge circuit D, a power supply chip U1, a capacitor C1, a capacitor C2, an electrolytic capacitor E1 and an electrolytic capacitor E2. The input end of the isolation transformer T is connected with the live wire and the zero line of the output end of the grid EMC unit 20 respectively, the output end of the isolation transformer T is connected with the input end of the bridge circuit D, the output end of the bridge circuit D is connected with the input end of the power supply chip U1 and the input end of the sampling comparison unit 40. One end of the capacitor C1 is connected with the output end of the bridge circuit D and the input end of the bridge circuit D, the other end of the capacitor C1 is grounded, and the electrolytic capacitor E1 is connected with the capacitor C1 in parallel. One end of the capacitor C2 is connected with the output end of the power supply chip U1, the other end of the capacitor C2 is grounded, and the electrolytic capacitor E2 is connected with the capacitor C2 in parallel. The bridge circuit D is used for rectifying alternating current into direct current, and the power supply chip U1 is used for providing stable voltage.

[0064] In one embodiment, as Figure 2As shown, the sampling comparison unit 40 provided by the embodiment includes a comparator U2;

[0065] The positive input terminal + of the comparator U2 is connected with a reference voltage, the negative input terminal - of the comparator U2 is connected with the output terminal of the auxiliary power supply unit, and the output terminal of the comparator U2 is connected with the input terminal of the leakage current switching unit 50;

[0066] The auxiliary power supply unit 70 is configured to output a third voltage signal to the negative input terminal - of the comparator U2 when the grid input unit 10 inputs the first voltage, so that the comparator U2 outputs a low level signal;

[0067] The auxiliary power supply unit 70 is further configured to output a fourth voltage signal to the negative input terminal - of the comparator U2 when the grid input unit 10 inputs the second voltage, so that the comparator U2 outputs a high level signal.

[0068] As shown, Figure 2 The sampling comparison unit 40 further includes resistors R1-R4, the positive input terminal + of the comparator U2 is connected with the reference voltage through the resistor R1, the negative input terminal - of the comparator U2 is connected with the output terminal of the bridge circuit D through the resistor R2 and the resistor R3, the negative input terminal - of the comparator U2 is further connected with the ground terminal through the resistor R2 and the resistor R4, and the output terminal of the comparator U2 is further connected with an external power supply VCC through the resistor R6.

[0069] In an embodiment, the leakage current switching unit provided by the embodiment includes a switching element and an electric control device;

[0070] The control terminal of the switching element is connected with the output terminal of the sampling comparison unit, the output terminal of the switching element is connected with the control system of the electric control device, and the controlled system of the electric control device is connected in series with the standby RC circuit;

[0071] The switching element is configured to be in an off state when the comparator outputs a low level signal, and to be in a conductive state when the comparator outputs a high level signal;

[0072] The controlled system of the electric control device is in a normally open state, and the control system of the electric control device is configured to trigger the controlled system to be closed and conductive when the switching element is conductive, so that the standby RC circuit is connected in parallel with the commonly used RC circuit.

[0073] In an embodiment, the commonly used RC circuit provided by the embodiment includes a first commonly used RC circuit and a second commonly used RC circuit, and the standby RC circuit includes a first standby RC circuit and a second standby RC circuit;

[0074] As shown, Figure 2As shown, the leakage current switching unit 50 includes a switching element Q1, an electrical control device, a resistor R7, a resistor R8, and a diode D1. The electrical control device includes a first electrical control device K1 and a second electrical control device K2. The output terminal of the comparator U2 is connected to the base of the switching element Q1 through the resistor R7, and one end of the resistor R8 is connected to the base of the switching element Q1 while the other end is grounded.

[0075] The controlled system of the first electrical control device is connected in series in the first backup RC circuit, and the controlled system of the second electrical control device is connected in series in the second backup RC circuit.

[0076] The output terminals of the switching element are respectively connected to the control system of the first electrical controller and the control system of the second electrical controller;

[0077] The control system of the first electrical control device is used to energize and trigger the closed control system of the first electrical control device to conduct when the switching element is turned on, so that the first backup RC circuit is connected in parallel with the first common RC circuit.

[0078] The control system of the second electrical control device is used to energize and trigger the closed control system of the second electrical control device when the switching element is turned on, so that the second backup RC circuit is connected in parallel with the second regular RC circuit.

[0079] In one embodiment, the switching element provided in this embodiment includes a transistor, the base of which is connected to the output terminal of the sampling comparison unit, the collector of which is connected to the control system of the electrical control device, and the emitter of which is grounded.

[0080] The aforementioned electrical control device can be a relay, such as... Figure 2 As shown, the base of the switching element Q1 is connected to the coils of the first electrical control device K1 and the second electrical control device K2, respectively.

[0081] The first commonly used RC circuit includes resistor R9 and capacitor C3. The second commonly used RC circuit includes resistor R10 and capacitor C4. Resistor R9 and capacitor C3 are both connected between the neutral wire N and the ground wire PEA. Resistor R10 and capacitor C4 are both connected between the live wire L and the ground wire PEA.

[0082] like Figure 2 As shown, the first backup RC circuit includes a resistor R11 and a capacitor C5. One end of both resistor R11 and capacitor C5 is connected to the neutral line N, and the other end of both resistor R11 and capacitor C5 is connected to the first moving terminal 4 of the first electrical control device K1. The second moving terminal 5 of the first electrical control device K1 is connected to the grounding line PEA, and the stationary terminal 3 of the first electrical control device K1 is connected to the grounding line PEA. The connection between the stationary terminal 3 and the second moving terminal 5 of the first electrical control device K1 is normally closed, and the connection between the stationary terminal 3 and the first moving terminal 4 is normally open.

[0083] As shown in Figure 2 , the second backup RC circuit includes a resistor R12 and a capacitor C6. One end of the resistor R12 and the capacitor C6 is connected with the live wire L, and the other end of the resistor R12 and the capacitor C6 is connected with the first movable terminal 4 of the second electric control device K2. The second movable terminal 5 of the second electric control device K2 is connected with the ground wire PEA. The stationary terminal 3 of the second electric control device K2 is connected with the ground wire PEA. The connection state between the stationary terminal 3 and the second movable terminal 5 is a normally closed state. The connection state between the stationary terminal 3 and the first movable terminal 4 is a normally open state.

[0084] The above-mentioned sampling comparison unit 40 is used to identify the working mode of the power grid voltage. When the input voltage of the power grid input unit is AC220V, the comparator U2 outputs a low level to the leakage current switching unit 50, and the switching element Q1 is cut off. When the input voltage of the power grid input unit is AC110V, the comparator U2 outputs a high level to the leakage current switching unit 50, and the switching element Q1 is turned on. The coils of the first electric control device K1 and the second electric control device K2 are powered, so that the first backup RC circuit is connected between the neutral wire and the ground wire, and the second backup RC circuit is connected between the live wire and the ground wire.

[0085] In an embodiment, as shown in Figure 2 , the leakage current switching control device provided by the embodiment further includes a state detection output unit 80.

[0086] The state detection output unit 80 is connected with the leakage current switching unit 50. The state detection output unit 80 is used to output a low level when the power grid input unit 10 inputs the first voltage, and output a high level when the power grid input unit 10 inputs the second voltage.

[0087] In an embodiment, the state detection output unit 80 provided by the embodiment includes a third electric control device K3 and an output port J1.

[0088] The control system of the third electric control device is connected with the control system of the first electric control device and the control system of the second electric control device respectively.

[0089] The above-mentioned third electric control device can be a relay, as shown in Figure 2 , the state detection output unit 80 includes a third electric control device K3 and an output port J1. The coils of the third electric control device K3 are connected with the coils of the first electric control device K1 and the second electric control device K2 respectively.

[0090] The controlled system of the third electric control device K3 includes a stationary terminal 3, a first movable terminal 4 and a second movable terminal 5. The stationary terminal 3 and the second movable terminal 5 are in a normally closed state.

[0091] One end of the output port J1 is connected with the fixed terminal 3, and the other end of the output port J1 is connected with the first movable terminal 4.

[0092] The control system of the third electric control device K3 is used to trigger the fixed terminal 3 and the first movable terminal 4 of the third electric control device K3 to be closed and conductive when the control system of the first electric control device K1 and the control system of the second electric control device K2 are powered, so as to make the output port J1 output a high level signal.

[0093] When the output port J1 outputs a high level signal, it indicates that the control system of the first electric control device K1 and the control system of the second electric control device K2 are powered, that is, the input voltage of the power grid input unit 10 is the second voltage; when the output port J1 outputs a low level signal, the input voltage of the power grid input unit 10 is the first voltage.

[0094] In an embodiment, as shown in Figure 2 The leakage current switching control device provided by the embodiment further includes a reference voltage source unit 90, the reference voltage source unit 90 is connected with the positive input end + of the comparator U2; the reference voltage source unit 90 is used to provide a reference voltage for the comparator U2.

[0095] As shown in Figure 2 The reference voltage source unit 90 further includes a resistor R13, a resistor R14, a capacitor C7, an electrolytic capacitor E3 and a TVS diode D2, the output end of the power supply chip U1 is grounded through the resistor R5, the resistor R13 and the resistor R14, one end of the capacitor C7 is connected with the resistor R13 and the resistor R1, the other end of the capacitor C7 is grounded, the electrolytic capacitor E3 is connected in parallel with the capacitor C7, the positive electrode of the TVS diode D2 is grounded, and the negative electrode is connected with the resistor R5 and the resistor R13.

[0096] As shown in Figure 2 The power grid input unit 10 includes a live wire input port L-INA, a zero line input port N-INA and a ground port PEA, and the power grid output unit 60 includes a live wire output port L-OUTA, a zero line output port N-OUTA and a ground port PEA.

[0097] The power grid EMC unit 20 provided by the embodiment includes a voltage-dependent resistor VR1, a voltage-dependent resistor VR2, a voltage-dependent resistor VR3, a capacitor C8 and a lightning protection device S1, the voltage-dependent resistor VR2 is connected between the live wire L and the zero line N, one end of the voltage-dependent resistor VR1 is connected with the live wire L, the other end of the voltage-dependent resistor VR1 is connected with the lightning protection device S1 and the voltage-dependent resistor VR3, the other end of the voltage-dependent resistor VR3 is connected with the zero line N and the capacitor C8, and the capacitor C8 is connected between the live wire and the zero line. The power grid EMI unit further includes a common mode inductor CM, and the common mode inductor CM is connected with the live wire L and the zero line N.

[0098] For example, when the input voltage of the grid input unit is the first voltage AC220V, the input power passes through the grid EMC unit composed of the voltage-dependent resistor VR1, the voltage-dependent resistor VR2, the voltage-dependent resistor VR3, the capacitor C8 and the lightning protection device S1 (the grid EMC unit is used to absorb part of the surge on the grid), and then is output to the EMI absorption network composed of the common-mode inductor CM, the capacitor C3 and the capacitor C4. At this time, the auxiliary power supply unit 70, the reference voltage source unit 90 and the sampling comparison unit 40 constitute the power voltage detection circuit. When the grid voltage is detected to be 220V, the comparator U2 in the sampling comparison unit 40 outputs a low level, the switching element Q1 in the leakage current switching unit 50 is in the off state, the coil of the first electric control device K1 and the second electric control device K2 is not electrified, the first movable terminal 4 is in the off state, the first backup RC circuit composed of R11 and C5 and the second backup RC circuit composed of R12 and C6 are both in the off state with the grid EMI unit, the grid EMC unit composed of the voltage-dependent resistor VR1, the voltage-dependent resistor VR2, the voltage-dependent resistor VR3, the capacitor C8, the lightning protection device S1, the resistor R9, the capacitor C3, the resistor R10 and the capacitor C4 generates a leakage current of 300-400UA with the grid EMI unit (based on the optimal filtering coefficient of EMI), and finally the grid voltage state is output by the state detection output unit (i.e. when the coil of the third electric control device K3 is not electrified and the output port J1 outputs a low level, the input voltage of the grid input unit is 220V).

[0099] When the input voltage of the grid input unit is the first voltage AC110V, the input power supply passes through the grid EMC unit composed of the voltage-dependent resistor VR1, the voltage-dependent resistor VR2, the voltage-dependent resistor VR3, the capacitor C8 and the lightning protection device S1, and then is output to the grid EMI unit. At this time, the power supply voltage detection circuit composed of the auxiliary power supply unit 70, the reference voltage source unit 90 and the sampling comparison unit 40 detects that the grid voltage is 110V, the comparator U2 in the sampling comparison unit 40 outputs a high level, the switching element Q1 in the leakage current switching unit 50 is turned on, the coils of the first electric control device K1 and the second electric control device K2 are attracted, the first movable terminal 4 becomes a closed state, the first standby RC circuit composed of R11 and C5 and the second standby RC circuit composed of R12 and C6 are in a connected state with the grid EMI unit, the impedance in the grid EMI unit is increased, the grid EMC unit composed of the voltage-dependent resistor VR1, the voltage-dependent resistor VR2, the voltage-dependent resistor VR3, the capacitor C8, the lightning protection device S1, the resistor R9, the capacitor C3, the resistor R10, the capacitor C4, the capacitor C5, the resistor R11, the capacitor C6 and the resistor R12 generates a leakage current of 300-400UA with the grid EMI unit at the same time, and finally the grid main circuit is output by the grid output unit 60, and the grid voltage state is output by the state detection output unit (i.e. when the coil of the third electric control device K3 is electrified and the output port J1 outputs a high level, the input voltage of the grid input unit is 110V).

[0100] The leakage current switching control device provided in the embodiment can ensure that the generated leakage current is consistent when the input voltage of the grid input unit is inconsistent, and under different grid voltage conditions, different noise filtering coefficients can be switched by controlling the connection or disconnection of the standby RC circuit and the grid EMI unit, so that the grid noise can be effectively controlled in the optimal range.

[0101] Corresponding to the leakage current switching control circuit provided in the above embodiment, the embodiment provides a laser treatment instrument, which comprises a laser and the leakage current switching control device provided in the above embodiment. The grid output load unit of the leakage current switching control device is connected with the input ends of the laser and other electric components in the laser treatment instrument, so that the leakage current generated in the network can be automatically controlled to remain unchanged when the input voltage of the laser treatment instrument is reduced, the reliability of the leakage current control is improved, and the intelligence of the equipment control is improved.

[0102] In addition, in the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0103] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0104] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present application, used to illustrate the technical solutions of the present application, and are not limited thereto, the protection scope of the present application is not limited thereto, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art within the technical scope disclosed by the present application can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A leakage current switching control device, characterized in that, include: The system includes a power grid input unit, a power grid EMC unit, a power grid EMI unit, a sampling and comparison unit, a leakage current switching unit, and a power grid output unit. The input terminal of the power grid input unit is used to connect to the power supply, and the output terminal of the power grid input unit is connected to the input terminal of the power grid EMC unit. The output terminal of the power grid EMC unit is connected to the input terminal of the power grid EMI unit, the output terminal of the power grid EMI unit is connected to the input terminal of the power grid output unit, and the output terminal of the power grid output unit is connected to the load. The output terminal of the power grid EMC unit is also connected to the input terminal of the sampling comparison unit; The power grid EMI unit includes a common RC circuit and a backup RC circuit. The output terminal of the sampling comparison unit is connected to the input terminal of the leakage current switching unit, and the output terminal of the leakage current switching unit is connected to the backup RC circuit. The sampling comparison unit is used to output a first level signal to the leakage current switching unit when the power grid input unit inputs a first voltage, and to output a second level signal to the leakage current switching unit when the power grid input unit inputs a second voltage; wherein, the first voltage is greater than the second voltage; The leakage current switching unit is used to control the backup RC circuit to disconnect from the power grid EMI unit when receiving the first level signal, and to control the backup RC circuit to connect in parallel with the commonly used RC circuit when receiving the second level signal, so that the leakage current generated by the power grid EMC unit and the power grid EMI unit remains unchanged.

2. The apparatus according to claim 1, characterized in that, Also includes: Auxiliary power supply unit; the output terminal of the power grid EMC unit is also connected to the input terminal of the auxiliary power supply unit, and the output terminal of the auxiliary power supply unit is connected to the input terminal of the sampling comparison unit; The auxiliary power supply unit is used to input a first voltage signal to the sampling comparison unit when the grid input unit inputs a first voltage, and to input a second voltage signal to the sampling comparison unit when the grid input unit inputs a second voltage; The sampling comparison unit is used to output a first level signal to the leakage current switching unit when it receives the first voltage signal, and to output a second level signal to the leakage current switching unit when it receives the second voltage signal.

3. The apparatus according to claim 2, characterized in that, The sampling comparison unit includes a comparator; The positive input terminal of the comparator is connected to the reference voltage, the negative input terminal of the comparator is connected to the output terminal of the auxiliary power supply unit, and the output terminal of the comparator is connected to the input terminal of the leakage current switching unit. The auxiliary power supply unit is used to output a third voltage signal to the negative phase input terminal of the comparator when the first voltage is input to the power grid input unit, so that the comparator outputs a low level signal; The auxiliary power supply unit is also used to output a fourth voltage signal to the negative phase input terminal of the comparator when the second voltage is input to the power grid input unit, so that the comparator outputs a high-level signal.

4. The apparatus according to claim 3, characterized in that, The leakage current switching unit includes a switching element and an electrical control device; The control terminal of the switching element is connected to the output terminal of the sampling comparison unit, the output terminal of the switching element is connected to the control system of the electrical control device, and the controlled system of the electrical control device is connected in series in the backup RC circuit. The switching element is configured to be in a closed state when the comparator outputs the low-level signal, and to be in a closed state when the comparator outputs the high-level signal; The controlled system of the electrical control device is normally open. The control system of the electrical control device is used to trigger the controlled system to close and conduct when the switching element is turned on, so that the backup RC circuit and the commonly used RC circuit are connected in parallel.

5. The apparatus according to claim 4, characterized in that, The commonly used RC circuit includes a first commonly used RC circuit and a second commonly used RC circuit; the spare RC circuit includes a first spare RC circuit and a second spare RC circuit; and the electrical control device includes a first electrical control device and a second electrical control device. The controlled system of the first electronic control device is connected in series in the first backup RC circuit, and the controlled system of the second electronic control device is connected in series in the second backup RC circuit. The output terminal of the switching element is connected to the control system of the first electrical control device and the control system of the second electrical control device, respectively. The control system of the first electrical control device is used to energize and trigger the controlled system of the first electrical control device to close and conduct when the switching element is turned on, so that the first backup RC circuit is connected in parallel with the first common RC circuit. The control system of the second electrical control device is used to energize and trigger the controlled system of the second electrical control device to close and conduct when the switching element is turned on, so that the second backup RC circuit and the second common RC circuit are connected in parallel.

6. The apparatus according to claim 5, characterized in that, It also includes: a status detection output unit; The status detection output unit is connected to the leakage current switching unit. The status detection output unit is used to output a low level when the first voltage is input to the power grid input unit and to output a high level when the second voltage is input to the power grid input unit.

7. The apparatus according to claim 6, characterized in that, The status detection output unit includes a third electrical control device and an output port; The control system of the third electric control device is connected at both ends to the control system of the first electric control device and the control system of the second electric control device, respectively. The controlled system of the third electrical control device includes a stationary terminal, a first moving terminal, and a second moving terminal, wherein the stationary terminal and the second moving terminal are normally closed. One end of the output port is connected to the stationary end, and the other end of the output port is connected to the first moving end; The control system of the third electrical control device is used to trigger the stationary terminal to close and conduct with the first moving terminal when the control systems of the first electrical control device and the second electrical control device are energized.

8. The apparatus according to claim 3, characterized in that, Also includes: A reference voltage source unit, wherein the reference voltage source unit is connected to the non-inverting input terminal of the comparator; The reference voltage source unit is used to provide the reference voltage for the comparator.

9. The apparatus according to claim 4, characterized in that, The switching element includes a transistor, the base of which is connected to the output terminal of the sampling comparison unit, the collector of which is connected to the control system of the electrical control device, and the emitter of which is grounded.

10. A laser therapy instrument, characterized in that, include: The laser and the leakage current switching control device as described in any one of claims 1-9.

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