Voltage sampling circuit of plasma equipment

Abstract

The utility model discloses a voltage sampling circuit of plasma equipment, which comprises a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cut-off circuit and a processing circuit, and the acquisition ends of the primary voltage sampling circuit and the detection power supply circuit are respectively connected with the plasma equipment. The output end of the detection power supply circuit is connected with the input end of the reverse protection circuit, the output end of the reverse protection circuit is connected with the output end of the primary voltage sampling circuit end in parallel, the output end of the primary voltage sampling circuit end is connected with the input end of the reverse cut-off circuit, and the output end of the reverse cut-off circuit is connected with the input end of the processing circuit. Therefore, the primary voltage sampling circuit is connected with the detection power supply circuit in parallel, rapid switching of plasma working voltage and measuring voltage in a non-working state is met, high-voltage signals output by plasma equipment are converted into low-voltage signals through the processing circuit, and safety and reliability of the sampling circuit are effectively maintained.

Description

Technical Field

[0001] The utility model relates to the technical field of plasma, in particular to a voltage sampling circuit of plasma equipment. Background Art

[0002] Plasma equipment is a type of equipment that uses plasma for ignition of coal-fired boiler plasma, process processing, material processing or scientific research. It has high energy and high reactivity, so it is necessary to sample the high voltage output by the plasma equipment in the working state, and to detect the electrode state of the plasma equipment when it is in the shutdown state. However, due to the high voltage and high power output by the plasma equipment, the sampling circuit is easily damaged during sampling, which seriously affects the emergency operation of the plasma equipment. Therefore, it is particularly important to sample the high voltage output by the plasma equipment.

[0003] In the prior art, the sampling of the high voltage output by the plasma device and the electrode state is switched by two independent circuits. The sampling of the electrode state is to attach the detection power supply to the plasma working output circuit through an external circuit, and then judge the electrode state through the voltage conversion of the detection circuit. The sampling of the high voltage is to cut off the external additional circuit for sampling during the startup process of the plasma device after the high and low voltage switching is completed, so that the detection power supply is disconnected from the plasma working output circuit, and then the plasma power element works, thereby outputting a high voltage and high power DC power supply for the normal operation of the plasma device.

[0004] However, when sampling the high and low voltages of plasma equipment, there is a problem that the switching sampling circuit process takes a long time, which causes the working high voltage of external circuit components to enter the sampling circuit and damage the control system, thereby affecting the stability of the plasma equipment in emergency commissioning and daily use. Utility Model Content

[0005] Based on the above-mentioned deficiencies of the prior art, the utility model provides a voltage sampling circuit for a plasma device to solve the problem of a long switching time of the sampling circuit in the prior art.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The utility model provides a voltage sampling circuit of a plasma device in a first aspect, the voltage sampling circuit comprising: a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cutoff circuit and a processing circuit;

[0008] The collection ends of the primary voltage sampling circuit and the detection power supply circuit are respectively connected to the plasma equipment, and the output end of the detection power supply circuit is connected to the input end of the reverse protection circuit;

[0009] The output end of the reverse protection circuit is connected in parallel with the output end of the primary voltage sampling circuit, and the output end of the primary voltage sampling circuit is connected to the input end of the reverse cutoff circuit;

[0010] The output end of the reverse cutoff circuit is connected to the input end of the processing circuit;

[0011] When the primary voltage sampling circuit detects that the plasma device outputs a working high voltage signal, the processing circuit preprocesses the working high voltage signal, converts the preprocessed working high voltage signal into a low voltage signal that meets a preset accuracy threshold, and outputs the low voltage signal.

[0012] Optionally, in the voltage sampling circuit of the above-mentioned plasma device, the processing circuit includes: a voltage dividing circuit, an absorption circuit, a correction circuit and an isolation conversion circuit;

[0013] The input end of the voltage divider circuit is connected to the output end of the reverse cutoff circuit, and the output end of the voltage divider circuit is connected to the input end of the absorption circuit;

[0014] The input end of the correction circuit is connected to the output end of the absorption circuit, and the output end of the correction circuit is connected to the input end of the isolation conversion circuit;

[0015] The output end of the isolation conversion circuit outputs the converted voltage signal.

[0016] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the isolation conversion circuit is composed of three isolation elements: working power isolation, input signal isolation and output signal isolation.

[0017] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the voltage divider circuit adopts a resistor voltage divider.

[0018] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the correction circuit adopts an adjustable resistor.

[0019] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the reverse protection circuit uses a voltage regulator tube.

[0020] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the reverse cutoff circuit adopts a high-voltage diode.

[0021] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the reverse peak withstand voltage of the reverse cutoff circuit has a value range greater than 1000 VDC.

[0022] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the volt direct current (VDC) voltage of the detection power supply circuit is 24V.

[0023] Optionally, in the voltage sampling circuit of the above-mentioned plasma equipment, the range of the measurement accuracy of the voltage divider circuit is between 0 and 1000 VDC.

[0024] The utility model provides a voltage sampling circuit of a plasma device, the voltage sampling circuit comprises: a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cut-off circuit and a processing circuit, the collection ends of the primary voltage sampling circuit and the detection power supply circuit are respectively connected to the plasma device, the output end of the detection power supply circuit is connected to the input end of the reverse protection circuit, the output end of the reverse protection circuit is connected in parallel with the output end of the primary voltage sampling circuit end, and the output end of the primary voltage sampling circuit end is connected to the input end of the reverse cut-off circuit, and the output end of the reverse cut-off circuit is connected to the input end of the processing circuit, wherein, when the primary voltage sampling circuit detects that the plasma device outputs a working high voltage signal, the working high voltage signal is preprocessed by the processing circuit, and the working high voltage signal after the preprocessing is converted into a low voltage signal that meets a preset accuracy threshold, and the low voltage signal is output. Thus, by connecting the primary voltage sampling circuit in parallel with the detection power supply circuit, the rapid switching of the measured voltage when the plasma working voltage and the non-working state are met, and the high voltage signal output by the plasma device is converted into a low voltage signal by the processing circuit, which can effectively maintain the safety and reliability of the sampling circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 A first structural block diagram of a voltage sampling circuit of a plasma device provided by an embodiment of the utility model;

[0027] Figure 2 A second structural block diagram of a voltage sampling circuit of a plasma device provided by an embodiment of the utility model;

[0028] Figure 3A third structural block diagram of a voltage sampling circuit of a plasma device provided by an embodiment of the utility model;

[0029] Figure 4 A fourth structural block diagram of a voltage sampling circuit of a plasma device provided by an embodiment of the utility model;

[0030] Figure 5 A flow chart of a voltage sampling method for a plasma device provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In the present invention, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0033] As can be seen from the background technology, at present, the working voltage and non-working sampling of the plasma equipment output are usually switched by two independent circuits. Therefore, at any time, there is only one voltage signal for subsequent measurement devices, which leads to the problem of voltage switching timeliness between the plasma working voltage and the non-working voltage, thereby affecting the stability of the plasma equipment in emergency commissioning and daily use.

[0034] Therefore, the embodiment of the utility model provides a voltage sampling circuit of a plasma device, and the voltage sampling circuit includes: a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cutoff circuit, and a processing circuit. Through the parallel connection of the primary voltage sampling circuit and the detection power supply circuit, the rapid switching of the plasma working voltage and the measured voltage in the non-working state is realized, thereby achieving the purpose of rapid sampling and state monitoring of the plasma device, and the high voltage is also converted into a low voltage that meets the requirements through the processing circuit, effectively improving the reliability and safety of the sampling circuit.

[0035] See also Figure 1 , shows a first structural block diagram of a voltage sampling circuit of a plasma device provided by an embodiment of the utility model, the voltage sampling circuit includes: a primary voltage sampling circuit 101, a detection power supply circuit 102, a reverse protection circuit 103, a reverse cutoff circuit 104 and a processing circuit 105.

[0036] Specifically, the collection ends of the primary voltage sampling circuit 101 and the detection power supply circuit 102 are respectively connected to the plasma equipment, and the output end of the detection power supply circuit 102 is connected to the input end of the reverse protection circuit 103 .

[0037] In some embodiments, the detection power circuit 102 is an external auxiliary detection circuit that requires a 24VDC voltage, so the volt direct current (VDC) voltage of the detection power circuit 102 is 24V to connect to the reverse protection circuit 103 .

[0038] The output end of the reverse protection circuit 103 is connected in parallel with the output end of the primary voltage sampling circuit 101 , and the output end of the primary voltage sampling circuit 101 is connected to the input end of the reverse cutoff circuit 104 .

[0039] It should be noted that the collection ends of the primary voltage sampling circuit 101 and the detection power supply circuit 102 are both connected to the DC output circuit of the plasma device, and the output end of the primary voltage sampling circuit 101 is connected in parallel with the output end of the reverse protection circuit 103. At the same time, the detection power supply circuit 102 is connected in parallel with the primary voltage sampling circuit 101 through the reverse protection circuit 103 and then connected to the input end of the reverse cutoff circuit 104. Therefore, when the plasma device is working, a DC voltage in the range of 0-1000VDC will be output and collected by the collection end of the primary voltage sampling circuit 101. When the plasma device is not working, the detection power supply circuit 102 outputs a 24VDC detection voltage and outputs it to the output end of the primary voltage sampling circuit 101, so that the primary voltage sampling circuit 101 and the detection power supply circuit 102 can be quickly switched, thereby maintaining the reliability and safety of the voltage sampling circuit.

[0040] It should also be noted that the output end of the reverse protection circuit 103 is connected in parallel with the output end of the primary voltage sampling circuit 101, which can effectively achieve the reliability of the two circuits and complete the transient switching between high and low voltages. It should also be noted that the output signal of the primary voltage sampling circuit 101 and the reverse protection circuit 103 is connected in parallel and then connected to the reverse cutoff circuit 104, so that the reverse cutoff circuit 104 is used to ensure that the circuit of the primary voltage sampling circuit 101 when collecting plasma equipment is working is normal, thereby effectively playing a reverse connection measure for the sampling signal of the primary voltage sampling circuit 101.

[0041] In some embodiments, the reverse protection circuit 103 preferably uses a voltage regulator. It should be noted that all circuits that achieve reverse protection are applicable to this claim.

[0042] In some embodiments, the reverse cutoff circuit 104 preferably uses a high voltage diode. It should be noted that all circuits that achieve the reverse cutoff function are applicable to this claim.

[0043] The output terminal of the reverse blocking circuit 104 is connected to the input terminal of the processing circuit 105 .

[0044] It should be noted that the reverse cutoff circuit 104 is used to prevent the problem of damage to components caused by the reverse positive and negative connection of the DC high-voltage signal of the primary voltage sampling circuit 101. Therefore, the key parameters of the electronic components designed for the reverse cutoff circuit 104 satisfy Vrrm≧1000VDC. That is to say, in some embodiments, the reverse peak withstand voltage range of the reverse cutoff circuit 104 must be greater than 1000VDC to effectively cut off the high voltage signal output by the reverse connection of the primary voltage sampling circuit 101 to the plasma device.

[0045] When the primary voltage sampling circuit 101 detects that the plasma device outputs a working high voltage signal, the processing circuit 105 pre-processes the working high voltage signal, converts the pre-processed working high voltage signal into a low voltage signal that meets a preset accuracy threshold, and outputs a low voltage signal. It should be noted that the plasma device operating state signal is a high level, which determines that the sampling signal is a primary high voltage input signal, and the plasma device operating state signal is a low level, which determines that the sampling signal is a 24VDC power supply detection signal, and the power supply detection signal is reduced from 24V to 0V, thereby judging the electrode contact, so as to realize the rapid switching between the primary voltage sampling circuit 101 and the detection power supply circuit 102.

[0046] Optionally, when the processing circuit 105 detects that the plasma device outputs a non-working low voltage signal, the processing circuit 105 preprocesses the non-working low voltage signal, converts the preprocessed non-working low voltage signal into a secondary low voltage signal that meets a preset accuracy threshold, and outputs the secondary low voltage signal.

[0047] Some are being implemented, such as Figure 2 In the second structural block diagram of a voltage sampling circuit of a plasma device shown in FIG. 1 , the processing circuit 105 includes: a voltage dividing circuit 201 , an absorption circuit 202 , a correction circuit 203 and an isolation conversion circuit 204 .

[0048] The input end of the voltage divider circuit 201 is connected to the output end of the reverse cutoff circuit 104 , and the output end of the voltage divider circuit 201 is connected to the input end of the absorption circuit 202 .

[0049] Specifically, the output signal of the reverse cutoff circuit 104 is transmitted to the voltage divider circuit 201, and the voltage divider circuit 201 performs voltage division processing on the output signal of the reverse cutoff circuit 104, so as to avoid damaging subsequent devices.

[0050] In some embodiments, the voltage divider circuit 201 preferably uses a resistor divider. It should be noted that all circuits that achieve voltage division are applicable to this claim.

[0051] It should be noted that since the voltage divider circuit 201 needs to meet the 0-1000VDC range accuracy requirement in order to divide the DC voltage in the range of 0-1000VDC output by the plasma equipment when it is working, in some embodiments, the range accuracy of the voltage divider circuit 201 is between 0 and 1000VDC, so as to achieve that the signal range after voltage division meets the range of the input signal of the subsequent isolation conversion circuit 204.

[0052] It should also be noted that the absorption circuit 202 adopts a bandpass filtering design, which can effectively filter out high-frequency and low-frequency signals. Therefore, after the voltage divider circuit 201 transmits the divided signal to the absorption circuit 202, the absorption circuit 202 will eliminate the signal ripple of the divided signal, thereby achieving the stability of the output signal.

[0053] The input end of the correction circuit 203 is connected to the output end of the absorption circuit 202 , and the output end of the correction circuit 203 is connected to the input end of the isolation conversion circuit 204 .

[0054] It can be understood that the signal output by the absorption circuit 202 will be transmitted to the correction circuit 203, and the correction circuit 203 will correct the signal output by the absorption circuit 202, and the corrected signal must be in linear proportion to the output signal of the primary voltage sampling circuit 101, and the error rate can be lower than 5‰. Of course, it can also be other thresholds, which can be set specifically according to needs.

[0055] For example, by sampling the plasma working voltage parameters, a voltage value of 500V is first obtained, and then the voltage divider circuit 201, the absorption circuit 202 and the correction circuit 203 are used to perform voltage division, filtering and correction respectively, and finally a voltage value of 5V is obtained, so an error of ±5×5‰=±0.025V is acceptable.

[0056] In some embodiments, the correction circuit 203 preferably uses an adjustable resistor. It should be noted that all circuits that achieve the correction function are applicable to this claim.

[0057] It should also be noted that the output signal of the correction circuit 203 will be transmitted to the isolation conversion circuit 204, which will isolate and transform the output signal of the correction circuit 203, and the signal after isolation and transformation is required to be linearly proportional to the output signal of the primary voltage sampling circuit 101.

[0058] For example, the signal input to the isolation conversion circuit 204 is 5V, and the converted output signal has a voltage value of 0.025V. The control system derives that the device operating voltage is 500V based on the 0.025V voltage value.

[0059] The output terminal of the isolation conversion circuit 204 outputs the converted voltage signal.

[0060] In some embodiments, the output end of the reverse protection circuit 103 is also connected to the input end of the isolation conversion circuit 204, which is used to directly transmit the low voltage signal collected by the detection power supply circuit 102 to the isolation conversion circuit 204 for isolation and conversion. For details, please refer to Figure 3 A third structural block diagram of a voltage sampling circuit of a plasma device is shown.

[0061] In some embodiments, the isolation conversion circuit 204 is composed of three isolation components: working power isolation, input signal isolation, and output signal isolation. It can effectively prevent the output signal of the primary voltage sampling circuit 101 from entering the post-stage processing circuit 105 and interfering with or damaging the processing circuit 105, thereby achieving the reliability and safety of the sampling circuit and the processing circuit 105.

[0062] It should be emphasized that in the present invention, a high-precision adjustable series voltage divider circuit 201 is designed based on the voltage division principle of a series circuit, and the output signal of the primary voltage sampling circuit 101 is transmitted to the voltage divider circuit 201, and the output signal of the voltage divider circuit 201 is transmitted to the absorption circuit 202, and the output signal of the absorption circuit 202 is then transmitted to the isolation conversion circuit 204 to complete the isolation and conversion of the sampling signal.

[0063] The utility model provides a voltage sampling circuit of a plasma device, the voltage sampling circuit comprises: a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cut-off circuit and a processing circuit, the collection ends of the primary voltage sampling circuit and the detection power supply circuit are respectively connected to the plasma device, the output end of the detection power supply circuit is connected to the input end of the reverse protection circuit, the output end of the reverse protection circuit is connected in parallel with the output end of the primary voltage sampling circuit, and the output end of the primary voltage sampling circuit is connected to the input end of the reverse cut-off circuit, and the output end of the reverse cut-off circuit is connected to the input end of the processing circuit, wherein, when the primary voltage sampling circuit detects that the plasma device outputs a working high voltage signal, the working high voltage signal is preprocessed by the processing circuit, and the working high voltage signal after the preprocessing is converted into a low voltage signal that meets a preset accuracy threshold, and the low voltage signal is output. Thus, by connecting the primary voltage sampling circuit in parallel with the detection power supply circuit, the rapid switching of the measured voltage when the plasma working voltage and the non-working state are met, and the high voltage signal output by the plasma device is converted into a low voltage signal by the processing circuit, which can effectively maintain the safety and reliability of the sampling circuit.

[0064] Some are being implemented, such as Figure 4 The fourth structural block diagram of a voltage sampling circuit of a plasma device is shown, the voltage sampling circuit includes: a primary voltage sampling circuit 101, a detection power supply circuit 102, a reverse protection circuit 103, a reverse cutoff circuit 104 and a processing circuit 105, the processing circuit 105 includes: a voltage divider circuit 201, an absorption circuit 202, a correction circuit 203 and an isolation conversion circuit 204.

[0065] The collection ends of the primary voltage sampling circuit 101 and the detection power supply circuit 102 are respectively connected to the plasma equipment, and the output end of the detection power supply circuit 102 is connected to the input end of the reverse protection circuit 103 .

[0066] The output end of the primary voltage sampling circuit 101 is connected to the input end of the reverse cutoff circuit 104, and the output end of the reverse cutoff circuit 104 is connected in parallel with the output end of the reverse protection circuit 103, and then connected to the input end of the processing circuit 105. Among them, the input end of the voltage divider circuit 201 is connected to the output end of the reverse cutoff circuit 104, the output end of the voltage divider circuit 201 is connected to the input end of the absorption circuit 202, the input end of the correction circuit 203 is connected to the output end of the absorption circuit 202, the input end of the isolation conversion circuit 204 is respectively connected to the output end of the reverse protection circuit 103 and the output end of the correction circuit 203, and the output end of the isolation conversion circuit 204 outputs the converted voltage signal.

[0067] It should be noted that Figure 4 The fourth structural block diagram shown is only related to Figure 1The circuits included in the first structural block diagram shown are only connected in different ways, but the implementation methods of the circuits are the same, so the specific implementation methods can refer to the detailed description of the above-mentioned circuits.

[0068] It should also be noted that according to Figure 1 The embodiments and methods described herein Figure 4 The embodiments described in detail are only two preferred embodiments of the present invention. Other connection modes are also possible and are not limited to the connection modes in the above two embodiments.

[0069] The above embodiments are related to the description of a voltage sampling circuit of a plasma device. Figure 5 The present utility model also provides a flow chart of a voltage sampling method for a plasma device, the voltage sampling method comprising:

[0070] S501, obtaining a working high voltage signal output by a plasma device.

[0071] Optionally, when a non-operating low voltage signal output by the plasma device is obtained,

[0072] S502: Preprocess the working high voltage signal.

[0073] It should be noted that the working high voltage signal is divided and filtered for correction processing to meet the subsequent processing requirements for the voltage signal.

[0074] S503: Convert the preprocessed working high voltage into a low voltage signal that meets a preset accuracy threshold.

[0075] Specifically, the working high voltage signal output by the plasma device is converted into a secondary low voltage signal that meets the accuracy requirements, that is, a processing signal, thereby effectively solving the safety and reliability of the sampling circuit.

[0076] S504: Output a low voltage signal.

[0077] It should be noted that the execution principle of steps S501 to S504 can be found in the above-mentioned description of the voltage sampling circuit of the plasma device, which will not be repeated here.

[0078] It should also be noted that a voltage sampling circuit and a voltage sampling method for a plasma device are implemented on a PCB circuit board.

[0079] In summary, the utility model provides a voltage sampling circuit for a plasma device, the voltage sampling circuit includes: a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cutoff circuit and a processing circuit, the collection ends of the primary voltage sampling circuit and the detection power supply circuit are respectively connected to the plasma device, the output end of the detection power supply circuit is connected to the input end of the reverse protection circuit, the output end of the reverse protection circuit is connected in parallel with the output end of the primary voltage sampling circuit end, and the output end of the primary voltage sampling circuit end is connected to the input end of the reverse cutoff circuit, and the output end of the reverse cutoff circuit is connected to the input end of the processing circuit. By connecting the primary voltage sampling circuit in parallel with the detection power supply circuit, the rapid switching of the measured voltage when the plasma is in the working state and the non-working state is met, and then the collected high voltage signal is divided, filtered, corrected, isolated and transformed by the processing circuit, and the high voltage signal output by the plasma device is converted into a secondary low voltage signal that meets the accuracy requirements, thereby achieving the purpose of high-speed sampling and state monitoring of the plasma device, and solving the timeliness problem of emergency use of the plasma.

[0080] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present utility model.

[0081] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A voltage sampling circuit for a plasma device, characterized in that: The voltage sampling circuit comprises: a primary voltage sampling circuit, a detection power supply circuit, a reverse protection circuit, a reverse cutoff circuit and a processing circuit; The collection ends of the primary voltage sampling circuit and the detection power supply circuit are respectively connected to the plasma equipment, and the output end of the detection power supply circuit is connected to the input end of the reverse protection circuit; The output end of the reverse protection circuit is connected in parallel with the output end of the primary voltage sampling circuit, and the output end of the primary voltage sampling circuit is connected to the input end of the reverse cutoff circuit; The output end of the reverse cutoff circuit is connected to the input end of the processing circuit; When the primary voltage sampling circuit detects that the plasma device outputs a working high voltage signal, the processing circuit preprocesses the working high voltage signal, converts the preprocessed working high voltage signal into a low voltage signal that meets a preset accuracy threshold, and outputs the low voltage signal.

2. The voltage sampling circuit according to claim 1, characterized in that: The processing circuit includes: a voltage dividing circuit, an absorption circuit, a correction circuit and an isolation conversion circuit; The input end of the voltage divider circuit is connected to the output end of the reverse cutoff circuit, and the output end of the voltage divider circuit is connected to the input end of the absorption circuit; The input end of the correction circuit is connected to the output end of the absorption circuit, and the output end of the correction circuit is connected to the input end of the isolation conversion circuit; The output end of the isolation conversion circuit outputs the converted voltage signal.

3. The voltage sampling circuit according to claim 2, characterized in that: The isolation conversion circuit is composed of three isolation components: working power isolation, input signal isolation and output signal isolation.

4. The voltage sampling circuit according to claim 2, characterized in that: The voltage divider circuit adopts a resistor voltage divider.

5. The voltage sampling circuit according to claim 2, characterized in that: The correction circuit adopts an adjustable resistor.

6. The voltage sampling circuit according to claim 1, characterized in that: The reverse protection circuit adopts a voltage regulator tube.

7. The voltage sampling circuit according to claim 1, characterized in that: The reverse cut-off circuit adopts a high-voltage diode.

8. The voltage sampling circuit according to claim 1, characterized in that: The reverse peak withstand voltage of the reverse cutoff circuit has a value range of greater than 1000 VDC.

9. The voltage sampling circuit according to claim 1, characterized in that: The VDC voltage of the detection power supply circuit is 24V.

10. The voltage sampling circuit according to claim 2, characterized in that: The range of the measuring range accuracy of the voltage divider circuit is between 0 and 1000 VDC.

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