Ripple signal processing circuit, high-voltage power supply circuit, and high-voltage power supply device

Abstract

The embodiment of the invention provides a ripple signal processing circuit, a high-voltage power supply circuit and high-voltage power supply equipment, the ripple signal processing circuit comprises a high-pass filter and a voltage follower circuit, the high-pass filter is used for obtaining a voltage input signal and outputting a ripple signal in the voltage input signal, and the voltage follower circuit is used for outputting the ripple signal in the voltage input signal. And the impedance converter is used for receiving the ripple signal, performing impedance conversion and outputting an output signal to an oscilloscope. In the technical scheme, the equivalent resistance of the high-pass filter is equal to the resistance after the internal resistance of the high-pass filter and the resistance of the voltage follower circuit are connected in parallel. Therefore, the equivalent resistance of the high-pass filter is not affected by the internal resistance of the oscilloscope. When the capacitance of the high-pass filter is fixed, the larger the resistance value of the internal resistor of the high-pass filter is, the lower the cut-off frequency of the high-pass filter is, and the frequency of the ripple signal detected by the oscilloscope is lower.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of power supply technology, and more specifically, to a ripple signal processing circuit, a high-voltage power supply circuit, and a high-voltage power supply device. Background Art

[0002] Ripple signal (also called "ripple") is a complex noise signal, which is a periodic signal that fluctuates up and down around the output DC voltage. However, the period and amplitude of the ripple signal are not constant, but change over time, and the ripple waveforms of different power supplies are also different. The ripple signal is a non-ideal DC signal with AC components. These AC components may have a negative impact on the normal operation of the circuit, such as causing fluctuations in the output voltage or current, noise, and other problems. In severe cases, it may even affect the stability and reliability of the equipment. Therefore, in the design, manufacture and operation of power electronic devices, it is necessary to detect the ripple signal to ensure the quality and stability of the output signal, and take corresponding measures to adjust and optimize it.

[0003] The existing ripple detection technology detects low-frequency ripple signals by converting them into digital signals, and then indirectly observing them through the host computer software. This method requires the addition of an additional sampling and conditioning circuit to convert the ripple signal into a digital signal, and it is not possible to directly observe whether the ripple signal is abnormal. Therefore, how to detect low-frequency ripple signals is an urgent problem to be solved. Summary of the invention

[0004] The embodiments of the present application provide a ripple signal processing circuit, a high-voltage power supply circuit and a high-voltage power supply device, which can realize the detection of low-frequency ripple signals.

[0005] In a first aspect, an embodiment of the present application provides a ripple signal processing circuit, which includes: a high-pass filter and a voltage follower circuit, wherein the high-pass filter is used to obtain a voltage input signal and output a ripple signal in the voltage input signal, and the voltage follower circuit is used to receive the ripple signal, perform impedance transformation, and output the output signal to the oscilloscope.

[0006] If the output of the high-pass filter is directly connected to an oscilloscope, the resistance of the high-pass filter will be connected in parallel with the internal resistance of the oscilloscope, reducing the equivalent resistance of the high-pass filter, making it impossible to detect low-frequency ripple signals. If a voltage follower circuit is connected, the equivalent resistance of the high-pass filter is the resistance of the internal resistance of the high-pass filter connected in parallel with the resistance of the voltage follower circuit. Therefore, if a voltage follower circuit is connected, the equivalent resistance of the high-pass filter will not be affected by the internal resistance of the oscilloscope. When the capacitance of the high-pass filter is constant, the greater the resistance of the internal resistance of the high-pass filter, the lower the cut-off frequency of the high-pass filter. Therefore, the cut-off frequency of the high-pass filter can be reduced by a voltage follower circuit, so that the oscilloscope can detect ripple signals with lower frequencies. For example, when the above technical solution is applied to a 10kV high-voltage power supply, an oscilloscope can be used to observe that the output of the high-voltage power supply has a jitter of about 40mV.

[0007] In combination with the first aspect, in a possible implementation, the ripple signal processing circuit also includes: a protection circuit, one end of which is coupled to the high-pass filter, and the other end of which is coupled to the voltage follower circuit, and the protection circuit is used to perform overvoltage protection on the voltage follower circuit.

[0008] The above technical solution adds a protection circuit, so as to protect the voltage follower circuit, thereby preventing the voltage follower circuit from being damaged by the high voltage generated in certain scenarios (such as a short circuit of a high voltage signal).

[0009] In combination with the first aspect, in a possible implementation manner, the circuit further includes a detection circuit, and the detection circuit is used to obtain a ripple signal and determine whether a micro-discharge event occurs according to the ripple signal.

[0010] The long-term occurrence of micro-discharge events in the high-voltage power supply circuit may cause insulation damage, resulting in sparking of the high-voltage power supply circuit and damage to the circuit. Therefore, the above technical solution further adds a detection circuit capable of detecting whether a micro-discharge event has occurred, so that a micro-discharge event can be detected. In this way, corresponding processing can be performed when a micro-discharge event is detected. For example, the input of the high-voltage power supply circuit is turned off.

[0011] In combination with the first aspect, in a possible implementation, the detection circuit includes a preprocessing circuit and a comparison circuit, the preprocessing circuit is used to obtain the ripple signal, convert a first peak signal in a non-preset peak direction in the ripple signal into a second peak signal in a preset peak direction, and output the second peak signal to the comparison circuit, wherein the preset peak direction is a falling peak signal or a rising spike signal; the comparison circuit is used to compare the second peak signal with a micro-discharge reference value to determine whether the micro-discharge event occurs.

[0012] The spike signal used to detect the micro-discharge event includes a rising spike signal and a falling spike signal. The rising spike signal and the falling spike signal correspond to different micro-discharge reference values. The above technical solution converts the spike signal into a spike signal in the same direction as the micro-discharge reference value through a pre-processing circuit. For example, the falling spike is converted into a rising spike signal, and the rising spike signal is maintained unchanged. In this way, only one micro-discharge reference value is needed to determine whether a micro-discharge event occurs, thereby simplifying the design of the comparison circuit.

[0013] In combination with the first aspect, in a possible implementation, the preprocessing circuit includes: a first resistor, a second resistor and an operational amplifier, wherein the first port of the first resistor is connected to the reverse input terminal of the operational amplifier; the first port of the second resistor is connected to the reverse input terminal; the second port of the second resistor is connected to the output terminal of the operational amplifier; the second port of the first resistor is used to obtain the ripple signal, and the same-direction input terminal of the operational amplifier is used for grounding; the output terminal of the first operational amplifier is used to output the second spike signal.

[0014] In combination with the first aspect, in a possible implementation manner, the protection circuit includes at least one of the following elements: a gas discharge tube, a third resistor, or a transient voltage suppression TVS diode.

[0015] In combination with the first aspect, in a possible implementation, the protection circuit includes the gas discharge tube, the third resistor and the TVS diode, the first port of the third resistor is connected to the first port of the gas discharge tube, the second port of the third resistor is connected to the first port of the TVS diode, and the second port of the gas discharge tube is connected to the second port of the TVS diode.

[0016] In combination with the first aspect, in a possible implementation, the impedance transformation can decouple the internal resistance of the high-pass filter from the internal resistance of the oscilloscope. In this way, the equivalent resistance of the high-pass filter is related to the internal resistance of the high-pass filter, but has nothing to do with the internal resistance of the oscilloscope. The internal resistance of the oscilloscope will not affect the cutoff frequency of the high-pass filter.

[0017] In a second aspect, an embodiment of the present application provides a high-voltage power supply circuit, which includes the ripple signal processing circuit in the first aspect or any possible implementation of the first aspect.

[0018] In a third aspect, an embodiment of the present application provides a high-voltage power supply device, which includes the high-voltage power supply circuit in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural block diagram of a high-voltage power supply device provided according to an embodiment of the present application.

[0020] Figure 2 It is a schematic structural diagram of a high voltage power supply circuit.

[0021] Figure 3 It is a schematic structural block diagram of a ripple signal processing circuit provided according to an embodiment of the present application.

[0022] Figure 4 It is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application.

[0023] Figure 5 It is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application.

[0024] Figure 6 It is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application.

[0025] Figure 7 is a schematic diagram of a spike signal.

[0026] Figure 8 It is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application.

[0027] Fig. 9 is a schematic diagram of a flip spike signal.

[0028] Fig.10 is a schematic diagram of a protection circuit provided according to an embodiment of the present application.

[0029] Fig.11 is a schematic diagram of another protection circuit provided according to an embodiment of the present application.

[0030] Fig.12 is a schematic diagram of another protection circuit provided according to an embodiment of the present application.

[0031] Fig.13 is a schematic diagram of another protection circuit provided according to an embodiment of the present application.

[0032] Fig.14 It is a schematic diagram of a voltage follower circuit provided according to an embodiment of the present application.

[0033] Fig.15 is a schematic diagram of another voltage follower circuit provided according to an embodiment of the present application.

[0034] Fig.16 is a schematic diagram of another voltage follower circuit provided according to an embodiment of the present application.

[0035] Fig.17is a schematic diagram of a preprocessing circuit provided according to an embodiment of the present application.

[0036] Fig.18 is a schematic diagram of another preprocessing circuit provided according to an embodiment of the present application.

[0037] Fig.19 is a schematic diagram of another preprocessing circuit provided according to an embodiment of the present application.

[0038] Fig. 20 is a schematic diagram of a comparison circuit provided according to an embodiment of the present application.

[0039] Fig.21 is a schematic diagram of a detection circuit provided according to an embodiment of the present application.

[0040] Fig. 22 is a schematic diagram of a comparison circuit provided according to an embodiment of the present application.

[0041] Fig.23 is a schematic diagram of another ripple signal processing circuit provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0043] In the embodiments of the present application, words such as "exemplary" and "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present concepts in a concrete way.

[0044] In the embodiments of the present application, "corresponding (corresponding, relevant)" and "corresponding (corresponding)" can sometimes be used interchangeably. It should be pointed out that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0045] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art can appreciate that with the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0046] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0047] In the present application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: including the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0048] Figure 1 is a schematic structural block diagram of a high voltage power supply device provided according to an embodiment of the present application. Figure 1 The illustrated high-voltage power supply device 100 includes a high-voltage power supply circuit 110 and a control circuit 120 .

[0049] The high-voltage power supply circuit 110 is used to output high-voltage electricity to other devices.

[0050] The control circuit 120 is used to control the power output of the high-voltage power circuit 110 so that the output is stabilized at a set value.

[0051] Figure 2 Yes Figure 1 The schematic structure diagram of the high voltage power supply circuit 110 is shown in FIG. Figure 2 As shown, the high-voltage power supply circuit 110 includes: an inverter topology circuit, a boost transformer, a voltage doubling circuit, a current detection unit, a ripple detection unit and a processing unit.

[0052] The low voltage input signal can be converted into an AC signal after passing through the inverter topology circuit. The AC signal enters the step-up transformer. The turns ratio of the secondary side to the primary side of the step-up transformer is high, and the primary side and the secondary side are electrically isolated. In this way, the primary side input AC signal can be converted into a secondary side output high voltage AC signal to obtain an AC signal with a higher voltage value. For ease of description, the AC signal input to the primary side can be referred to as the first AC signal, and the AC signal output from the secondary side can be referred to as the second AC signal. The voltage value of the second AC signal is greater than the voltage value of the first AC signal.

[0053] The voltage doubling circuit obtains the second AC signal (i.e., the AC signal output by the step-up transformer) and continues to increase the voltage amplitude of the second AC signal. For ease of description, the second AC signal after the voltage amplitude is increased may be referred to as a third AC signal. The voltage doubling circuit may also convert the third AC signal into a DC signal. The DC signal is output after passing through a current detection unit and a ripple detection unit.

[0054] The current detection unit and the ripple detection unit can feed back the received signal (which can be called "received signal") to the processing unit. The processing unit determines whether to generate a control signal (which can be called an ONOFF signal) to control the on and off of the low-voltage input signal based on the acquired signal. An oscilloscope can be connected to the processing unit to observe the ripple signal.

[0055] Figure 3 is a schematic structural block diagram of a ripple signal processing circuit provided according to an embodiment of the present application. Figure 3 The ripple signal processing circuit 300 shown in FIG. 1 includes a high-pass filter 310 and a voltage follower circuit 320. Figure 3 The ripple signal processing circuit 300 shown may correspond to Figure 2 The ripple detection unit and the processing unit in the high-voltage power supply circuit 110 are shown, wherein the ripple detection unit includes a high-pass filter 310 , and the processing unit includes a voltage follower circuit 320 .

[0056] The high-pass filter 310 is used to obtain a voltage input signal and output a ripple signal in the voltage input signal.

[0057] The voltage follower circuit 320 is used to receive the ripple signal, perform impedance transformation, and output the output signal to the oscilloscope.

[0058] In an ideal state, the output signal output by the voltage follower circuit 320 is exactly the same as the ripple signal. In other words, the magnitude and phase of the output signal are the same as the ripple signal. However, in an actual circuit, since electronic components are not ideal components, the output signal is not exactly the same as the ripple signal.

[0059] In some embodiments, the high-pass filter 310 may be a CR high-pass filter. In other words, the high-pass filter 310 may include a capacitor and a resistor. If the output of the high-pass filter 310 is directly connected to an oscilloscope, the resistance of the high-pass filter 310 will be connected in parallel with the internal resistance of the oscilloscope, which will reduce the equivalent resistance of the high-pass filter 310, thereby making it impossible for the oscilloscope to detect low-frequency ripple signals. If a voltage follower circuit is connected, the resistance value of the equivalent resistance of the high-pass filter is the resistance value of the internal resistance of the high-pass filter in parallel with the resistance of the external circuit of the high-pass filter. The external circuit of the high-pass filter includes a circuit located between the high-pass filter and the oscilloscope. Figure 3 In the ripple signal processing circuit 300 shown, the external circuit of the high-pass filter 310 includes a voltage follower circuit 320. Therefore, if the voltage follower circuit 320 is connected, the equivalent resistance of the high-pass filter 310 will not be affected by the internal resistance of the oscilloscope. When the capacitance of the high-pass filter 310 is constant, the greater the resistance of the internal resistance of the high-pass filter 310, the lower the cut-off frequency of the high-pass filter 310. Therefore, the cut-off frequency of the high-pass filter 310 can be reduced by the voltage follower circuit 320, so that the oscilloscope can detect a ripple signal with a lower frequency.

[0060] In some embodiments, the voltage follower circuit referred to in the embodiments of the present application may also be referred to as an impedance conversion circuit or a resistance conversion circuit.

[0061] In some other embodiments, in addition to the CR high-pass filter, the high-pass filter 310 may also be other types of high-pass filters, such as a T-type high-pass filter, a π-type high-pass filter, and the like.

[0062] In some embodiments, in order to prevent excessive voltage from damaging the voltage follower circuit, a protection circuit may be inserted between the high pass filter and the voltage follower circuit.

[0063] Figure 4 is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application. Figure 4 The ripple signal processing circuit 400 shown in FIG. 4 includes: a high-pass filter 410, a voltage follower circuit 420 and a protection circuit 430. Figure 4 The ripple signal processing circuit 400 shown may correspond to Figure 2 The ripple detection unit and the processing unit in the high-voltage power supply circuit 110 are shown, wherein the ripple detection unit includes a high-pass filter 410 , and the processing unit includes a voltage follower circuit 420 and a protection circuit 430 .

[0064] like Figure 4As shown, one end of the protection circuit 430 is coupled to the high-pass filter 410 , and the other end of the protection circuit 430 is coupled to the voltage follower circuit 420 .

[0065] The protection circuit 430 can perform overvoltage protection on the voltage follower circuit 420 to prevent the input voltage of the voltage follower circuit 420 from exceeding a safe voltage.

[0066] The protection circuit 430 can be designed according to the requirements of overvoltage protection. For example, in some embodiments, the safety voltage can be 15V. In this case, the protection circuit 430 can prevent the input voltage of the voltage follower circuit 420 from being higher than 15V. It can be understood that 15V is just an example of a safety voltage. According to the requirements, the safety voltage can also be other values, such as 13V, 12V, 10V, or 5V.

[0067] The function of high pass filter 410 is similar to Figure 3 and Figure 4 The function of the high-pass filter in is the same as that of the voltage follower circuit 420. Figure 3 The functions of the voltage follower circuit in are the same, and for the sake of brevity, they will not be described here.

[0068] Figure 5 is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application. Figure 5 The ripple signal processing circuit 500 shown in FIG. 5 includes a high-pass filter 510, a voltage follower circuit 520, a protection circuit 530, and a detection circuit 540. Figure 5 The ripple signal processing circuit 500 shown may correspond to Figure 2 The ripple detection unit and the processing unit in the high-voltage power supply circuit 110 are shown, wherein the ripple detection unit includes a high-pass filter 510 , and the processing unit includes a voltage follower circuit 520 , a protection circuit 530 and a detection circuit 540 .

[0069] like Figure 5 The function of the high pass filter 510 in the ripple signal processing circuit 500 is similar to that of Figure 3 and Figure 4 The high-pass filter in the ripple signal processing circuit shown in FIG. Figure 5 The function of the voltage follower circuit 520 in the ripple signal processing circuit 500 is similar to that of the Figure 3 and Figure 4 The functions of the voltage follower circuit in the ripple signal processing circuit shown in FIG. 1 are the same, and for the sake of brevity, they will not be described here in detail. Figure 5 The protection circuit 530 in the ripple signal processing circuit 500 shown can be used to perform overvoltage protection on the voltage follower circuit 520 and can also perform overvoltage protection on the detection circuit 540 .

[0070] like Figure 5 The detection circuit 540 is coupled to the protection circuit 530. In this way, the detection circuit 540 can obtain the ripple signal to detect the peak signal in the ripple signal.

[0071] In some other embodiments, the ripple signal processing circuit may not include a protection circuit. In this case, the detection circuit may be directly coupled to the high-pass filter.

[0072] exist Figure 4 and Figure 5 In the ripple signal processing circuit shown, the external circuit of the high-pass filter may include a voltage follower circuit and a protection circuit.

[0073] Figure 6 is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application. Figure 6 The ripple signal processing circuit 600 shown in FIG. 6 includes a high-pass filter 610, a voltage follower circuit 620, and a detection circuit 640. Figure 6 The ripple signal processing circuit 600 shown may correspond to Figure 2 The ripple detection unit and the processing unit in the high-voltage power supply circuit 110 are shown, wherein the ripple detection unit includes a high-pass filter 610 , and the processing unit includes a voltage follower circuit 620 and a detection circuit 640 .

[0074] like Figure 6 The function of the high pass filter 610 in the ripple signal processing circuit 600 is similar to that of Figures 3 to 5 The high-pass filter in the ripple signal processing circuit shown in FIG. Figure 6 The function of the voltage follower circuit 620 in the ripple signal processing circuit 600 is similar to that of the Figures 3 to 5 The functions of the voltage follower circuit in the ripple signal processing circuit shown are the same, and for the sake of brevity, they will not be described again here.

[0075] like Figure 6 The detection circuit 640 is coupled to the high pass filter 610. In this way, the detection circuit 640 can obtain the ripple signal to detect the peak signal in the ripple signal.

[0076] Figure 7 is a schematic diagram of a spike signal.

[0077] The ripple signal may include multiple spike signals. A spike signal usually refers to a short, rapid voltage change. This change may be caused by switching action in the circuit, power supply noise, or other factors. The peak value of the spike signal can be upward or downward. This depends on the direction of the voltage change. If the voltage suddenly increases, the peak value of the spike signal will be upward; if the voltage suddenly decreases, the peak value of the spike signal will be downward. The peak value of the spike signal depends on the amplitude of the voltage change. If the amplitude of the voltage change is large, the peak value of the spike signal will also be large; conversely, if the amplitude of the voltage change is small, the peak value of the spike signal will also be small.

[0078] like Figure 7 The four spike signals shown are spike signal 701, spike signal 702, spike signal 703 and spike signal 704, wherein spike signal 701 and spike signal 703 are spike signals with downward level, and spike signal 702 and spike signal 704 are spike signals with upward level. For ease of description, the spike signal with downward level can be called a falling spike signal, and the spike signal with upward level can be called a rising spike signal. In other words, spike signal 701 and spike signal 703 are falling spike signals, and spike signal 702 and spike signal 704 are rising spike signals.

[0079] like Figure 7 As shown, there may be two micro-discharge reference values, which may be referred to as a first micro-discharge reference value and a second micro-discharge reference value. The two micro-discharge reference values ​​are preset. It is understandable that if the absolute value of the micro-discharge reference value is set to a small value, the recognition of micro-discharge events may be frequently triggered, thereby generating a shutdown signal to shut down the input end of the high-voltage power supply circuit; conversely, if the absolute value of the micro-discharge reference value is set to a high value, the micro-discharge events that damage the circuit may not be effectively detected.

[0080] In some embodiments, the first micro-discharge reference value and the second micro-discharge reference value may be opposite numbers to each other. Figure 7 In the figure, Var is used to represent the second micro-discharge reference value. Figure 7 In other embodiments, the first micro-discharge reference value is a positive number greater than 0, and the second micro-discharge reference value is a negative number less than 0, but the absolute value of the first micro-discharge reference value is different from the absolute value of the second micro-discharge reference value. For ease of description, in the following embodiments, the first micro-discharge reference value and the second micro-discharge reference value are opposite numbers.

[0081] For a rising spike signal, the first micro-discharge reference value is a positive value. Therefore, if the peak value of the rising spike signal is greater than the first micro-discharge reference value, then it can be considered that a micro-discharge event has occurred. For a falling spike signal, the second micro-discharge reference value is a negative value. Therefore, if the peak value of the spike signal is less than the second micro-discharge reference value, then it can be considered that a micro-discharge event has occurred. Correspondingly, if the peak value of the rising spike signal is less than or equal to the first micro-discharge reference value, then it can be considered that no micro-discharge event has occurred; if the peak value of the falling spike signal is less than or equal to the second micro-discharge reference value, then it can be considered that no micro-discharge event has occurred.

[0082] Microdischarge is a tip discharge phenomenon. The principle is that the curvature of the signal tip is larger. Under the same potential difference, the electric field strength is greater, which leads to the insulation medium near the signal tip being more easily broken down under the same insulation conditions, resulting in discharge. Long-term continuous microdischarge events in the high-voltage power supply circuit may cause insulation damage, resulting in sparks in the high-voltage power supply circuit and damaging the circuit. When a continuous microdischarge event is detected, the high-voltage power supply circuit input is turned off, and the high-voltage output will drop to 0V to avoid sparks caused by continuous microdischarge.

[0083] like Figure 5 and Figure 6 The function of the detection circuit in is to compare the peak value of the spike signal in the ripple signal with the micro-discharge reference value to determine whether a micro-discharge event occurs. Figure 7 The ripple signal shown is the ripple signal obtained by the detection circuit. Figure 7 The value of the spike signal 701 shown is less than the second micro-discharge reference value, so it can be determined that a micro-discharge event has occurred; the value of the spike signal 702 is greater than the first micro-discharge reference value, so it can be determined that a micro-discharge event has occurred; the value of the spike signal 703 is greater than the second micro-discharge reference value, so it can be determined that no micro-discharge event has occurred; the value of the spike signal 704 is less than the first micro-discharge reference value, so it can be determined that no micro-discharge event has occurred.

[0084] Figure 8 is a schematic structural block diagram of another ripple signal processing circuit provided according to an embodiment of the present application. Figure 8 The ripple signal processing circuit 800 shown includes a high-pass filter 810, a voltage follower circuit 820, a protection circuit 830 and a detection circuit 840, wherein the functions of the high-pass filter 810, the voltage follower circuit 820 and the protection circuit 830 are the same as those in the above embodiment, and are not described again for the sake of simplicity.

[0085] like Figure 8The detection circuit 840 shown includes a preprocessing circuit 841 and a comparison circuit 842. The function of the preprocessing circuit 841 is to invert one of the falling peak signal or the rising peak signal, and then send the inverted peak signal to the comparison circuit 842. In this way, the comparison circuit 842 can use only one micro-discharge reference value to identify whether a micro-discharge event occurs. This can make the design of the comparison circuit 842 simpler.

[0086] For the convenience of description, it is assumed in the following embodiments that the function of the pre-processing circuit 841 is to convert a falling peak signal into a rising peak signal.

[0087] Assume that the ripple signal obtained by the preprocessing circuit 841 is as follows Figure 7 As shown. The preprocessing circuit 841 obtains Figure 7 After the ripple signal shown, the peak signal 701 and the peak signal 703 are inverted. Fig. 9 is the ripple signal after the spike signal 701 and the spike signal 703 are flipped. In other words, Fig. 9 is the ripple signal output by the preprocessing circuit 841. Fig. 9 As shown, the peak signal 701 is inverted to obtain the peak signal 901, and the peak signal 703 is inverted to obtain the peak signal 903. Fig. 9 The ripple signal shown is input to the comparison circuit 842. The comparison circuit 842 can use only one micro-discharge reference value Varc to determine whether a micro-discharge event occurs. For example, the comparison circuit 842 can determine that the value of the spike signal 901 is greater than the micro-discharge reference value, so it can be determined that a micro-discharge event occurs; determine that the value of the spike signal 702 is greater than the micro-discharge reference value, so it can be determined that a micro-discharge event occurs; determine that the value of the spike signal 903 is less than the micro-discharge reference value, so it can be determined that no micro-discharge event occurs; determine that the value of the spike signal 704 is less than the micro-discharge reference value, so it can be determined that no micro-discharge event occurs.

[0088] like Figure 8 The detection circuit shown can also be applied to Figure 6 The ripple signal processing circuit shown.

[0089] Fig.10 is a schematic diagram of a protection circuit provided according to an embodiment of the present application. Fig.10 The protection circuit 1000 shown can be applied to Figure 4 , Figure 5 and Figure 8 In other words, Fig.10 The protection circuit 1000 shown may be as follows Figure 4 The protection circuit 430 shown in FIG. Figure 5 The protection circuit 530 shown and Figure 8 Protection circuit 830 is shown.

[0090] like Fig.10 As shown, the protection circuit 1000 includes a resistor 1001 , a gas discharge tube 1002 , and a transient voltage suppressor (TVS) diode 1003 .

[0091] refer to Fig.10 For the convenience of description, the port of the resistor 1001 for connecting to the gas discharge tube 1002 may be referred to as the first port of the resistor 1001, the port of the resistor 1001 for connecting to the TVS diode may be referred to as the second port of the resistor 1002, the port of the gas discharge tube 1002 for connecting to the resistor 1001 may be referred to as the first port of the gas discharge tube 1002, the port of the gas discharge tube 1002 for connecting to the TVS diode 1003 may be referred to as the second port of the gas discharge tube 1002, the port of the TVS diode 1003 for connecting to the resistor 1001 may be referred to as the first port of the TVS diode 1003, and the port of the TVS diode 1003 for connecting to the gas discharge tube 1002 may be referred to as the second port of the TVS diode 1003. That is, the first port of the resistor 1001 in the protection circuit 1000 is connected to the first port of the gas discharge tube 1002, the second port of the resistor 1001 is connected to the first port of the TVS diode 1003, and the second port of the gas discharge tube 1002 is connected to the second port of the TVS diode 1003.

[0092] Fig.10 A high pass filter 1010 is also shown. Fig.10 The high pass filter 1010 shown in FIG. 1 includes a resistor 1011 and a capacitor 1012. For ease of description, the port of the resistor 1011 for connecting to the capacitor 1012 may be referred to as the first port of the resistor 1011, and the port of the resistor 1011 for grounding may be referred to as the second port of the resistor 1011. Fig.10 As shown, the first port of the resistor 1011 is connected to the first port of the gas discharge tube 1002, and the second port of the resistor 1011 is connected to the second port of the gas discharge tube 1002. Since the second port of the resistor 1011 is grounded, and the second port of the gas discharge tube 1002 is connected to the second port of the resistor 1011, the second port of the gas discharge tube 1002 is also grounded. Similarly, the second port of the TVS diode 1003 is connected to the second port of the gas discharge tube 1002, and therefore, the second port of the TVS diode 1003 is also grounded.

[0093] Fig.11 FIG. 1 is a schematic diagram of another protection circuit provided according to an embodiment of the present application. Fig.11The protection circuit 1100 shown can be applied to Figure 4 , Figure 5 and Figure 8 In other words, Fig.10 The protection circuit 1000 shown may be as follows Figure 4 The protection circuit 430 shown in FIG. Figure 5 The protection circuit 530 shown and Figure 8 Protection circuit 830 is shown.

[0094] like Fig.11 As shown, the protection circuit 1100 includes: a resistor 1101 , a gas discharge tube 1102 , a diode 1103 and a diode 1104 .

[0095] refer to Fig.11 For the convenience of description, the end of the resistor 1101 connected to the gas discharge tube 1102 may be referred to as the first port of the resistor 1101, the end of the resistor 1101 connected to the diode 1103 and the diode 1104 may be referred to as the second port of the resistor 1102, the end of the gas discharge tube 1102 connected to the resistor 1101 may be referred to as the first port of the gas discharge tube 1102, and the other end of the gas discharge tube 1102 may be referred to as the second port of the gas discharge tube 1102. In other words, the first port of the resistor 1101 is connected to the first port of the gas discharge tube, the second port of the resistor 1102 is connected to the anode of the diode 1103, the second port of the resistor 1102 is also connected to the cathode of the diode 1104, the cathode of the diode 1103 is connected to the voltage source Vs, and the anode of the diode 1104 is connected to the negative voltage source -VS.

[0096] Fig.11 A high pass filter 1110 is also shown. Fig.11 The high pass filter 1110 shown in FIG. 1 includes a resistor 1111 and a capacitor 1112. For ease of description, the port of the resistor 1111 for connecting to the capacitor 1112 may be referred to as the first port of the resistor 1111, and the port of the resistor 1111 for grounding may be referred to as the second port of the resistor 1111. Fig.11 As shown, the first port of the resistor 1111 is connected to the first port of the gas discharge tube 1102, and the second port of the resistor 1111 is connected to the second port of the gas discharge tube 1102. Since the second port of the resistor 1111 is grounded and the second port of the gas discharge tube 1102 is connected to the second port of the resistor 1111, the second port of the gas discharge tube 1102 is also grounded.

[0097] Fig.12 FIG. 1 is a schematic diagram of another protection circuit provided according to an embodiment of the present application. Fig.12 The protection circuit 1200 shown can be applied to Figure 4 , Figure 5 and Figure 8 In other words, Fig.12 The protection circuit 1200 shown may be as follows Figure 4 The protection circuit 430 shown in FIG. Figure 5 The protection circuit 530 shown and Figure 8 Protection circuit 830 is shown.

[0098] like Fig.12 As shown, the protection circuit 1200 includes a resistor 1201 , a gas discharge tube 1202 and a TVS diode 1203 .

[0099] refer to Fig.12 For the convenience of description, the port of the resistor 1201 for connecting to the gas discharge tube 1202 may be referred to as the first port of the resistor 1201, the other port of the resistor 1201 may be referred to as the second port of the resistor 1202, the port of the gas discharge tube 1202 for connecting to the resistor 1201 may be referred to as the first port of the gas discharge tube 1202, the port of the gas discharge tube 1202 for connecting to the TVS diode 1203 may be referred to as the second port of the gas discharge tube 1202, the port of the TVS diode 1203 for connecting to the resistor 1201 may be referred to as the first port of the TVS diode 1203, and the port of the TVS diode 1203 for connecting to the gas discharge tube 1202 may be referred to as the second port of the TVS diode 1203. That is, the first port of the resistor 1201 in the protection circuit 1200 is connected to the first port of the gas discharge tube 1202 and the first port of the TVS diode, and the second port of the gas discharge tube 1202 is connected to the second port of the TVS diode 1203.

[0100] Fig.12 A high pass filter 1210 is also shown. Fig.12 The high pass filter 1210 shown in FIG. 1 includes a resistor 1211 and a capacitor 1212. For ease of description, the port of the resistor 1211 for connecting to the capacitor 1212 may be referred to as the first port of the resistor 1211, and the port of the resistor 1211 for grounding may be referred to as the second port of the resistor 1211. Fig.12 As shown, the first port of the resistor 1211 is connected to the first port of the gas discharge tube 1202, and the second port of the resistor 1211 is connected to the second port of the gas discharge tube 1202. Since the second port of the resistor 1211 is grounded, and the second port of the gas discharge tube 1202 is connected to the second port of the resistor 1211, the second port of the gas discharge tube 1202 is also grounded. Similarly, the second port of the TVS diode 1203 is connected to the second port of the gas discharge tube 1202, and therefore, the second port of the TVS diode 1203 is also grounded.

[0101] Fig.13 FIG. 1 is a schematic diagram of another protection circuit provided according to an embodiment of the present application. Fig.13 The protection circuit 1300 shown can be applied to Figure 4 , Figure 5 and Figure 8 In other words, Fig.13 The protection circuit 1300 shown may be as follows Figure 4 The protection circuit 430 shown in FIG. Figure 5 The protection circuit 530 shown and Figure 8 Protection circuit 830 is shown.

[0102] like Fig.13 As shown, the protection circuit 1300 includes: a resistor 1301 , a gas discharge tube 1302 , a diode 1303 and a diode 1304 .

[0103] refer to Fig.13 For the convenience of description, the end of the resistor 1301 connected to the diode 1303 and the diode 1304 may be referred to as the first port of the resistor 1301, the other end of the resistor 1301 may be referred to as the second port of the resistor 1302, the end of the gas discharge tube 1302 connected to the diode 1303 and the diode 1304 may be referred to as the first port of the gas discharge tube 1302, and the other end of the gas discharge tube 1302 may be referred to as the second port of the gas discharge tube 1302. In other words, the first port of the resistor 1301 is connected to the positive electrode of the diode 1303, the first port of the resistor 1302 is also connected to the negative electrode of the diode 1304, the first port of the gas discharge tube 1302 is connected to the positive electrode of the diode 1303, the first port of the gas discharge tube 1302 is also connected to the negative electrode of the diode 1304, the negative electrode of the diode 1303 is connected to the voltage source Vs, and the positive electrode of the diode 1304 is connected to the negative voltage source -VS.

[0104] Fig.13 A high pass filter 1310 is also shown. Fig.13 The high pass filter 1310 shown in FIG. 1 includes a resistor 1311 and a capacitor 1312. For ease of description, the port of the resistor 1311 for connecting to the capacitor 1312 may be referred to as the first port of the resistor 1311, and the port of the resistor 1311 for grounding may be referred to as the second port of the resistor 1311. Fig.13 As shown, the first port of the resistor 1311 is connected to the first port of the gas discharge tube 1302, and the second port of the resistor 1311 is connected to the second port of the gas discharge tube 1302. Since the second port of the resistor 1311 is grounded, and the second port of the gas discharge tube 1302 is connected to the second port of the resistor 1311, the second port of the gas discharge tube 1302 is also grounded.

[0105] Figures 10 to 13 The protection circuit shown can provide overvoltage protection for the downstream circuit to prevent excessive voltage from causing damage to the downstream circuit. Figures 10 to 13 The protection circuit shown is used for Figure 4 The ripple signal processing circuit shown in FIG. 1 , then the downstream circuit includes a voltage follower circuit; if Figures 10 to 13 The protection circuit shown is used for Figure 5 or Figure 8 The ripple signal processing circuit shown in FIG. 1 is shown in FIG. 2 , and the downstream circuit includes a voltage follower circuit and a detection circuit. It can be understood that if the oscilloscope is connected to Figure 4 , Figure 5 and Figure 8 If the ripple signal processing circuit shown in the figure is used, then the protection circuit can also protect the oscilloscope.

[0106] Figures 10 to 13 The protection circuit shown includes a gas discharge tube. A gas discharge tube is a gas discharge device. When the voltage across the gas discharge tube exceeds its breakdown voltage, the gas filled in the gas discharge tube will be ionized and the gas discharge tube will begin to discharge. At this time, the voltage across the gas discharge tube drops rapidly and the current in the tube begins to increase. The gas discharge tube can discharge the surge energy directly to the ground, thereby protecting other devices and circuits connected to it from being damaged by the surge impact.

[0107] In addition, if Fig.10 and Fig.12 The protection circuit shown also includes a TVS diode. The TVS diode is connected in parallel with the protected downstream circuit. When the transient voltage exceeds the normal operating voltage of the circuit, the TVS diode will generate an avalanche, providing an ultra-low resistance path for the transient current, resulting in the transient current being diverted through the diode, avoiding the protected component, and keeping the TVS clamping voltage in the protected downstream circuit until the voltage returns to normal.

[0108] like Fig.11 and Fig.13 The protection circuit shown also includes a diode. The diode can achieve the function of overvoltage protection, mainly because it has unidirectional conductivity and the characteristics of forward conduction and reverse blocking. Fig.11 and Fig.13As shown, the diode is connected to the input end of the downstream circuit. When a forward overvoltage appears at the input end, the diode will conduct forward, pulling the input voltage of the downstream circuit to the sum of the power supply +Vs of the subsequent circuit and the diode voltage drop VF, so that the input voltage of the downstream circuit does not exceed the device withstand voltage. In this case, the conduction state of the diode is equivalent to a low-resistance switch, which can greatly reduce the impact of overvoltage on the downstream circuit. At the same time, since the reverse breakdown voltage of the diode is relatively stable, diodes with different breakdown voltages can be selected for protection as needed.

[0109] Figures 10 to 13 The protection circuit shown includes two of the gas discharge tube, the TVS diode and the diode. In other embodiments, the protection circuit may also include only one of the gas discharge tube, the TVS diode and the diode, or any two of the gas discharge tube, the TVS diode and the diode (for example, the TVS diode and the diode) or all of them.

[0110] In some other embodiments, the protection circuit may further include one or more diodes, one end of the diode may be connected to the input end of the downstream circuit, and the other end of the diode may be grounded.

[0111] Fig.14 is a schematic diagram of a voltage follower circuit provided according to an embodiment of the present application. Fig.14 The voltage follower circuit 1400 shown can be applied to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 8 In other words, Fig.14 The voltage follower circuit 1400 shown may be as follows Figure 3 The voltage follower circuit 320 shown in FIG. Figure 4 The voltage follower circuit 420 shown in FIG. Figure 5 The voltage follower circuit 520 shown in FIG. Figure 6 The voltage follower circuit 620 shown or Figure 8 A voltage follower circuit 820 is shown.

[0112] like Fig.14 The voltage follower circuit 1400 shown is a voltage follower composed of an operational amplifier 1401. Fig.14As shown, the non-inverting input terminal of the operational amplifier 1401 is coupled to the output terminal of the high-pass filter or the protection circuit (for ease of description, this port can be called the first output port), and the reverse input terminal of the operational amplifier 1401 is coupled to the output terminal, thereby forming a voltage follower. The voltage follower does not amplify the input signal, so the voltage gain of the ideal voltage follower is 1. However, the voltage follower has a very high input impedance. The internal resistance of the high-pass filter (which can be called R FL ) and the resistor of the voltage follower (which can be called R IMP ) are connected in parallel, so when R IMP In the case of infinity, R FL and R IMP The equivalent resistance R after parallel connection (i.e., the equivalent resistance of the high-pass filter 310 mentioned above) can be approximated to R FL Therefore, a resistor with a large resistance value can be selected in the high-pass filter to reduce the cutoff frequency of the filter, hoping to obtain a low-frequency AC signal. The relationship between the cutoff frequency and the capacitor and resistor in the high-pass filter is as follows:

[0113] f c =1 / (2 π R FL C), (Formula 1)

[0114] Among them, f c is the cut-off frequency, R FL represents the resistance value of the internal resistor of the high-pass filter, and C represents the capacitance of the high-pass filter. For example, if R FL =100 megaohms (mΩ), C = 10 nanoFarads (nF), then according to Formula 1 we can determine that the cutoff frequency is 0.16 hertz (Hz).

[0115] Optionally, in some embodiments, a resistor may be inserted between the inverting input terminal and the output terminal of the operational amplifier 1401. In other words, in some embodiments, the voltage follower circuit 1400 may further include a resistor (not shown in the figure), one end of which is connected to the inverting input terminal of the operational amplifier 1401, and the other end of which is connected to the output terminal of the operational amplifier 1401.

[0116] It can be seen that since the voltage follower circuit provides a very large input impedance, the equivalent resistance of the high-pass filter can be approximated to the internal resistance of the high-pass filter. In this way, the equivalent resistance of the high-pass filter will not be limited by the internal resistance of the oscilloscope. When the capacitance of the high-pass filter is constant, the greater the resistance of the internal resistance of the high-pass filter, the lower the cut-off frequency of the high-pass filter. Therefore, the cut-off frequency of the high-pass filter can be reduced by the voltage follower circuit, so that the ripple signal with a lower frequency can be observed using an oscilloscope.

[0117] Fig.15 is a schematic diagram of another voltage follower circuit provided according to an embodiment of the present application. Fig.15 The voltage follower circuit 1500 shown can be applied to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 8 In other words, Fig.15 The voltage follower circuit 1500 shown may be as follows Figure 3 The voltage follower circuit 320 shown in FIG. Figure 4 The voltage follower circuit 420 shown in FIG. Figure 5 The voltage follower circuit 520 shown in FIG. Figure 6 The voltage follower circuit 620 shown or Figure 8 A voltage follower circuit 820 is shown.

[0118] like Fig.15 The voltage follower circuit shown is implemented by an instrumentation amplifier 1501. The two input terminals V in+ and V in- The instrument amplifier 1501 uses a dual power supply (+V s , -V s ) design, the reference voltage terminal V ref Ground, output terminal V out Used to connect the positive terminal of the oscilloscope probe. The negative terminal of the oscilloscope probe can be grounded.

[0119] Instrumentation amplifiers need to amplify weak signals, and weak signals themselves often have high internal resistance. If the input impedance of the instrumentation amplifier is too low, it will cause a significant mismatch between the input signal and the amplification circuit, which will affect the gain and accuracy of the instrumentation amplifier. Therefore, in order to ensure the high sensitivity and high stability of the amplifier to weak signals, the input impedance of the instrumentation amplifier needs to be very large. Therefore, the voltage follower circuit implemented by the instrumentation amplifier can also provide a very large resistance.

[0120] Fig.16 is a schematic diagram of another voltage follower circuit provided according to an embodiment of the present application. Fig.16 The voltage follower circuit 1600 shown can be applied to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 8 In other words, Fig.14 The voltage follower circuit 1600 shown may be as follows Figure 3 The voltage follower circuit 320 shown in FIG. Figure 4 The voltage follower circuit 420 shown in FIG. Figure 5 The voltage follower circuit 520 shown in FIG. Figure 6 The voltage follower circuit 620 shown or Figure 8 A voltage follower circuit 820 is shown.

[0121] like Fig.16 The voltage follower circuit shown is a follower circuit implemented by a triode. Fig.16 As shown, the voltage follower circuit 1600 includes a transistor 1601, a capacitor 1602, a resistor 1603, a resistor 1604, a capacitor 1605 and a resistor 1606. Fig.16 As shown, the base of transistor 1601 is connected to one end of resistor 1604 and one end of capacitor 1605, the other end of resistor 1604 is connected to the collector of transistor 1601, and the other end of capacitor 1605 is used to couple the output end of a high-pass filter or a protection circuit. One end of resistor 1606 is connected to the base of transistor 1601, and the other end is used to couple the other output end of a high-pass filter or a protection circuit. The emitter of transistor 1601 is connected to one end of resistor 1603 and one end of capacitor 1602, the other end of resistor 1603 is used to couple the other output end of a high-pass filter or a protection circuit, and the other end of capacitor 1602 is used to couple an oscilloscope. The collector of transistor 1601 is also used to couple an oscilloscope.

[0122] Fig.17 is a schematic diagram of a preprocessing circuit provided according to an embodiment of the present application. Fig.17 The pre-processing circuit 1700 shown can be applied to Figure 8 The ripple signal processing circuit shown. In other words, Fig.17 The pre-processing circuit 1700 shown may be as follows Figure 8 The pre-processing circuit 841 is shown.

[0123] like Fig.17 The pre-processing circuit 1700 shown may be an inverse proportional amplification circuit implemented by an operational amplifier. The amplification factor may be 1 or set as required.

[0124] like Fig.17 The pre-processing circuit 1700 shown in FIG. 1 includes an operational amplifier 1701, a resistor 1702, and a resistor 1703. Fig.17As shown, the inverting input terminal of the operational amplifier 1701 is connected to one end of the resistor 1702 and one end of the resistor 1703, the other end of the resistor 1702 is used to couple with the output terminal of the high-pass filter or the protection circuit, and the other end of the resistor 1703 is connected to the output terminal of the operational amplifier 1701. The same-direction input terminal of the operational amplifier 1701 is grounded, and the other output terminal of the high-pass filter or the protection circuit is also grounded. The output terminal of the operational amplifier 1701 is also used to couple with the input terminal of the comparison circuit.

[0125] like Fig.17 The inverse proportional amplifier circuit shown can set the amplification factor by adjusting the resistance values ​​of resistor 1702 and resistor 1703.

[0126] Fig.18 is a schematic diagram of another preprocessing circuit provided according to an embodiment of the present application. Fig.18 The pre-processing circuit 1800 shown can be applied to Figure 8 The ripple signal processing circuit shown. In other words, Fig.18 The pre-processing circuit 1800 shown may be as follows Figure 8 The pre-processing circuit 841 is shown.

[0127] like Fig.18 The pre-processing circuit 1800 shown can be implemented by an instrumentation amplifier 1801. The input terminal V in- is coupled to one output port of a high-pass filter or a protection circuit, and the other output terminal of the high-pass filter or the protection circuit is coupled to the input terminal V in+ Ground, the instrumentation amplifier 1801 uses a dual power supply (+V s , -V s ) design, the reference voltage terminal V ref Ground, output terminal V out Used for coupling comparison circuit. In this way, the instrumentation amplifier 1801 can also realize signal inversion.

[0128] Fig.19 is a schematic diagram of another preprocessing circuit provided according to an embodiment of the present application. Fig.19 The pre-processing circuit 1900 shown can be applied to Figure 8 The ripple signal processing circuit shown. In other words, Fig.19 The pre-processing circuit 1900 shown may be as follows Figure 8 The pre-processing circuit 841 is shown.

[0129] like Fig.19 The pre-processing circuit 1900 shown in FIG. 1 may be a negative signal flipping circuit implemented by an operational amplifier. Fig.19The pre-processing circuit 1900 shown includes an operational amplifier 1901, a resistor 1902, a resistor 1903, a resistor 1904, a diode 1905, and a diode 1906. Fig.19 As shown, the inverting input terminal of the operational amplifier 1901 is connected to one end of the resistor 1902 and one end of the resistor 1903, the other end of the resistor 1902 is connected to the positive electrode of the diode 1905, and the other end of the resistor 1903 is connected to the output terminal of the operational amplifier 1901. The non-inverting input terminal of the operational amplifier 1901 is connected to the negative electrode of the diode 1906, the positive electrode of the diode 1906 is connected to the negative electrode of the diode 1905, and the positive electrode of the diode 1906 and the negative electrode of the diode 1905 are used to couple one output terminal of the high-pass filter or the protection circuit, and the other output terminal of the high-pass filter or the protection circuit is grounded. One end of the resistor 1904 is connected to the non-inverting input terminal of the operational amplifier, and the other end of the resistor 1904 is grounded. The output terminal of the operational amplifier 1901 is used to couple the input terminal of the comparison circuit.

[0130] When the input signal is positive, the input voltage Vin of the preprocessing circuit 1900, the voltage V+ of the same-direction input terminal of the operational amplifier 1901, and the voltage V- of the reverse input terminal of the operational amplifier 1901 satisfy: Vin=V+=V-. Since the diode 1905 is reverse-cut off, no current flows through the resistor 1902, so the output voltage Vout of the operational amplifier 1901, the voltage V- of the reverse input terminal of the operational amplifier 1901, and the input voltage Vin of the preprocessing circuit 1900 satisfy: Vout=V-=Vin; when the input signal is negative, V+=V-=0, since the diode 1905 is forward-conducting, and the resistor 1902 has current flowing through, so an inverse proportional amplification circuit is formed, Vout=-Vin.

[0131] Fig. 20 is a schematic diagram of a comparison circuit provided according to an embodiment of the present application. Fig. 20 The comparison circuit 2000 shown can be applied to Figure 8 In other words, Fig. 20 The comparison circuit 2000 shown can be as follows Figure 8 The comparison circuit 842 is shown.

[0132] like Fig. 20 The comparison circuit 2000 shown in FIG. 2000 can be implemented by a voltage comparator 2001. Fig. 20As shown, one input terminal of the voltage comparator 2001 is used to input the micro-discharge reference value Varc, and the other input terminal is used to be coupled with a preprocessing circuit to obtain the input signal Vin, which is the output signal of the preprocessing circuit, i.e., the ripple signal. If Vin > Varc, then the voltage comparator 2001 outputs a high level; if Vin ≤ Varc, then the voltage comparator 2001 outputs a low level. If the voltage comparator 2001 outputs a high level, it means that a micro-discharge event has occurred; if the voltage comparator outputs a low level, it means that no micro-discharge event has occurred.

[0133] The voltage comparator 2001 can be implemented by an operational amplifier or other electronic components, such as transistors, diodes, or dedicated comparison chips, etc. The embodiments of the present application do not limit this.

[0134] Fig.21 is a schematic diagram of a detection circuit provided according to an embodiment of the present application. As Fig.21 shown, the detection circuit 2100 can be applied to the ripple signal processing circuit 500 as Figure 5 shown or the ripple signal processing circuit 600 as Figure 6 shown. In other words, the detection circuit 2100 as Fig.21 shown can be the detection circuit 540 as Figure 5 shown or the detection circuit 640 as Figure 6 shown.

[0135] As Fig.21 shown, the detection circuit 2100 includes two voltage comparators, namely the voltage comparator 2101 and the voltage comparator 2102. One input terminal of the voltage comparator 2101 is used to obtain the second micro-discharge reference value -Varc, and the other input terminal is used to be coupled with a high-pass filter or a protection circuit to obtain the input signal Vin, which is the output signal of the high-pass filter, i.e., the ripple signal. One input terminal of the voltage comparator 2102 is used to obtain the first micro-discharge reference value Varc, and the other input terminal is used to be coupled with the high-pass filter or the protection circuit to obtain the input signal Vin. If -Varc < Vin < Varc, then the detection circuit 2100 outputs a low level; otherwise, the detection circuit 2100 outputs a high level. If the detection circuit 2100 outputs a high level, it means that a micro-discharge event has occurred; if the detection circuit 2100 outputs a low level, it means that no micro-discharge event has occurred.

[0136] As Fig.21 shown, the detection circuit 2100 further includes a diode 2103, a diode 2104, and a resistor 2105.

[0137] Diode 2103 and diode 2104 can play a role in protecting the circuit. Assuming that voltage comparator 2102 outputs a high level and voltage comparator 2101 outputs a low level, if there is no diode 2103, the high level and the low level will be short-circuited. With the addition of the diode, the high level output by voltage comparator 2102 is output to resistor 2105 via diode 2104. Due to the reverse cutoff effect of diode 2103, the high level will not be sent to the output end of voltage comparator 2101.

[0138] The resistor 2105 has a current limiting function. The output of the resistor 2105 is an arc ignition (arc) signal. When the arc signal becomes high level, it means a micro-discharge event. The control unit outputs an ONOFF signal according to the number of micro-discharge events.

[0139] Fig. 22 is a schematic diagram of a comparison circuit provided according to an embodiment of the present application. Fig. 22 The comparison circuit 2200 shown can be applied to Figure 8 In other words, Fig. 22 The comparison circuit 2200 shown can be as follows Figure 8 The comparison circuit 842 is shown.

[0140] like Fig. 22 The comparison circuit 2200 shown is a hysteresis comparator. Fig. 22 The hysteresis comparator shown includes a comparator 2201, a resistor 2202, a resistor 2203 and a resistor 2204. The inverting input terminal of the comparator 2201 is used to couple with a preprocessing circuit to obtain an input signal Vin, which is an output signal of the preprocessing circuit. One end of the resistor 2202 is used to obtain a micro-discharge reference value Varc, and the other end is connected to the positive input terminal of the comparator 2201. One end of the resistor 2204 is connected to the output terminal of the comparator 2201, and the other end is connected to one end of the resistor 2203. One end of the resistor 2203 is connected to one end of the resistor 2204, and the other end is connected to the same-direction input terminal of the comparator 2201. The output signal Vout is output from the end where the resistor 2204 and the resistor 2203 are connected.

[0141] Assuming that the resistance value of the resistor 2202 is R1, the resistance value of the resistor 2203 is R2, and the resistance value of the resistor 2204 is RF, then the upper trigger threshold Vh, the lower trigger threshold Vl, the micro-discharge reference value Varc and the output voltage Uo of the hysteresis comparator satisfy the following relationship:

[0142]

[0143] As described above, the hysteresis comparator has an upper trigger threshold Vh and a lower trigger threshold Vl. When the output voltage Uo of the hysteresis comparator is at a high level, the trigger threshold is Vh. In the case where the trigger threshold is Vh, if the input voltage Vin (i.e., the output voltage of the preprocessing circuit) is greater than Vh, the output voltage of the hysteresis comparator changes from Uo to -Uo. When the output voltage Uo of the hysteresis comparator is at a low level -Uo, the trigger threshold becomes Vl. In the case where the trigger threshold is Vh, if the input voltage Vin (i.e., the output voltage of the preprocessing circuit) is less than Vl, the output voltage of the hysteresis comparator changes from -Uo to Uo; when Vl < Vin < Vh, the output of the hysteresis comparator remains unchanged. In this way, by observing whether the output voltage of the hysteresis comparator jumps (i.e., from Uo to -Uo, or from -Uo to Uo), it is possible to determine whether a micro-discharge has occurred. When Vin fluctuates around Varc, the output of the hysteresis comparator does not jump.

[0144] The ripple signal processing circuit in the embodiment of the present application may include the high-pass filter, protection circuit, voltage follower circuit, and detection circuit in the above embodiments.

[0145] Fig.23 is a schematic diagram of a ripple signal processing circuit provided according to an embodiment of the present application.

[0146] As Fig.23 shown, the ripple signal processing circuit includes the high-pass filter 1010, protection circuit 1000, voltage follower circuit 1400, preprocessing circuit 1700, and comparison circuit 1800 in the above embodiments.

[0147] The embodiment of the present application further provides a high-voltage power supply circuit, and the high-voltage power supply circuit may include the ripple signal processing circuit in the above embodiments. In other words, the high-voltage circuit may include any one of the ripple signal processing circuits such as Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 8 , or Fig.23 in the above.

[0148] For example, the high-voltage power supply circuit may be the high-voltage power supply circuit as Figure 2 shown. The ripple detection unit and processing unit in the high-voltage power supply circuit correspond to the ripple signal processing circuit in the above embodiments. In other words, the ripple signal processing circuit may include Figure 2 the ripple detection unit and processing unit in the high-voltage power supply circuit shown in the above.

[0149] It can be understood that, as Figure 2The high-voltage power supply circuit shown is only an example of a high-voltage power supply circuit. Other high-voltage power supply circuits including the ripple signal processing circuit in the above embodiment are also within the protection scope of the present application.

[0150] The present application also provides a high-voltage power supply device, which may include the high-voltage power supply circuit in the above-mentioned embodiment, and the high-voltage power supply circuit may include the ripple signal processing circuit in the above-mentioned embodiment.

[0151] For example, the high voltage power supply device may be Figure 1 The high voltage power supply device 100 shown in FIG. The high voltage power supply device 100 includes Figure 2 The high voltage power supply circuit 110 shown in FIG. The ripple detection unit and the processing unit in the high voltage power supply circuit 110 correspond to the ripple signal processing circuit in the above embodiment. In other words, the ripple signal processing circuit may include Figure 2 The ripple detection unit and the processing unit in the high voltage power supply circuit are shown.

[0152] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A ripple signal processing circuit, characterized in that: The circuit comprises: a high-pass filter and a voltage follower circuit, wherein: The high-pass filter is used to obtain a voltage input signal and output a ripple signal in the voltage input signal. The voltage follower circuit is used to receive the ripple signal, perform impedance transformation, and output the output signal to an oscilloscope.

2. The ripple signal processing circuit according to claim 1, characterized in that: The ripple signal processing circuit also includes: a protection circuit, one end of the protection circuit is coupled to the high-pass filter, and the other end of the protection circuit is coupled to the voltage follower circuit, and the protection circuit is used to perform overvoltage protection on the voltage follower circuit.

3. The circuit according to claim 1 or 2, characterized in that: The circuit further includes a detection circuit, and the detection circuit is used to obtain the ripple signal and determine whether a micro-discharge event occurs according to the ripple signal.

4. The circuit according to claim 3, characterized in that The detection circuit includes a preprocessing circuit and a comparison circuit. The preprocessing circuit is used to obtain the ripple signal, convert a first peak signal in the ripple signal that is not in a preset peak direction into a second peak signal in a preset peak direction, and output the second peak signal to the comparison circuit, wherein the preset peak direction is a falling peak or a rising peak; The comparison circuit is used to compare the second peak signal with a micro-discharge reference value to determine whether the micro-discharge event occurs.

5. The circuit according to claim 4, characterized in that The preprocessing circuit includes: a first resistor, a second resistor and an operational amplifier, wherein The first port of the first resistor is connected to the inverting input terminal of the operational amplifier; The first port of the second resistor is connected to the reverse input terminal; The second port of the second resistor is connected to the output terminal of the operational amplifier; The second port of the first resistor is used to obtain the ripple signal; The non-inverting input terminal of the operational amplifier is used for grounding; The output terminal of the first operational amplifier is used to output the second peak signal.

6. The circuit according to any one of claims 1 to 5, characterized in that The protection circuit includes at least one of the following elements: a gas discharge tube, a third resistor, or a transient voltage suppression TVS diode.

7. The circuit according to claim 6, characterized in that The protection circuit includes the gas discharge tube, the third resistor and the TVS diode, the first port of the third resistor is connected to the first port of the gas discharge tube, the second port of the third resistor is connected to the first port of the TVS diode, and the second port of the gas discharge tube is connected to the second port of the TVS diode.

8. The circuit according to any one of claims 1 to 7, characterized in that The impedance transformation can decouple the internal resistance of the high-pass filter from the internal resistance of the oscilloscope.

9. A high voltage power supply circuit, characterized in that: The high-voltage power supply circuit includes the ripple signal processing circuit according to any one of claims 1 to 8.

10. A high voltage power supply device, characterized in that: The high-voltage power supply device includes the high-voltage power supply circuit according to claim 9.

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