High-voltage power supply ripple test circuit and test method

Abstract

The invention discloses a high-voltage power supply ripple test circuit and test method, and the circuit comprises a DC signal isolation module which is connected with a power supply circuit; the peak-to-peak value detection module is connected with the direct-current signal isolation module; the voltage division and isolation module is connected with the peak-to-peak value detection module and is used for receiving the direct-current voltage signal and outputting a voltage division signal according to the direct-current voltage signal; the signal amplification module is provided with a plurality of amplification channels, the input ends of the amplification channels are connected with the voltage division and isolation module, and one of the amplification channels is in a conducting state; and the control module is connected with the output end of the amplification channel of the signal amplification module. The high-voltage power supply ripple test circuit not only can measure large alternating current ripple signals, but also can measure small alternating current ripple signals under the condition that the precision is guaranteed, and the general applicability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply testing, and particularly to a high-voltage power supply ripple testing circuit and a testing method. Background Art

[0002] Ripple is the superimposed AC fluctuation in the output of a DC stable power supply, and it is an important indicator for evaluating the performance of a DC power supply. In application fields such as electron microscopes, electron beam lithography machines, and X-ray tubes, DC power supplies of dozens of kilovolts to hundreds of kilovolts are often required to generate high-voltage acceleration electric fields. The magnitude of the ripple of the high-voltage power supply directly affects the operation effect of equipment and instruments. Therefore, it is necessary to measure the ripple of the high-voltage power supply.

[0003] Currently, the measurement of the ripple of high-voltage power supplies is mostly carried out based on the DC-blocking method using capacitors and resistors. A DC-blocking circuit formed by connecting a capacitor and a resistor in series is connected between the output terminal of the high-voltage power supply and the ground. Due to the characteristic of the capacitor blocking DC and passing AC, the DC high-voltage signal and the AC ripple signal output by the power supply are separated. When the parameters of the selected capacitor and resistor are appropriate, the voltage across the resistor is the ripple of the high-voltage power supply. The high-voltage power supply ripple measurement and analysis system in the prior art is applicable to the ripple detection scenario of precision high-voltage power supplies. When measuring with this high-voltage power supply ripple measurement and analysis system, during analog-to-digital conversion and other processing and analysis, the AC ripple signal is amplified by a large multiple, enabling the measurement and analysis of the tiny ripple of the high-voltage power supply. The high-voltage power supply ripple measurement and analysis system in the prior art has a large amplification multiple during measurement, and can only measure the ripple at the millivolt level, while it cannot measure the slightly larger ripple, and its general applicability is relatively low.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the Invention

[0005] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide a high-voltage power supply ripple testing circuit and a testing method to solve the problem that the high-voltage power supply ripple measurement and analysis system in the prior art has a large amplification multiple during measurement, can only measure the ripple at the millivolt level, while it cannot measure the slightly larger ripple, and its general applicability is relatively low.

[0006] The technical solution adopted by the present invention to solve its technical problems is: to provide a high-voltage power supply ripple testing circuit, including:

[0007] A DC signal isolation module, connected to the power supply circuit, the DC signal isolation module is used to obtain the high-voltage power supply signal output by the power supply circuit, and isolate the DC high-voltage signal in the high-voltage power supply signal and then output a first AC ripple signal;

[0008] A peak-to-peak detection module, connected to the DC signal isolation module, for receiving the first AC ripple signal and calculating and determining the ripple peak-to-peak value of the first AC ripple signal, so as to output a DC voltage signal equal to the ripple peak-to-peak value;

[0009] A voltage division and isolation module, connected to the peak-to-peak detection module, for receiving the DC voltage signal and outputting a voltage division signal according to the DC voltage signal;

[0010] A signal amplification module, having a plurality of amplification channels, the input ends of the plurality of amplification channels are connected to the voltage division and isolation module, wherein one of the plurality of amplification channels is in a conducting state, and the signal amplification module is used for receiving the voltage division signal and amplifying the voltage division signal through the conducting amplification channel and then outputting a first voltage signal;

[0011] A control module, connected to the output end of the amplification channel of the signal amplification module, for receiving the first voltage signal, performing analog-to-digital conversion on the first voltage signal to obtain a first comparison signal, and further for comparing the first comparison signal with a first preset value. When the first comparison signal is greater than the first preset value, the control module outputs a second AC ripple signal. When the first comparison signal is less than or equal to the first preset value, the control module outputs a switching signal to the signal amplification module to make the signal amplification module switch to another amplification channel to conduct until the first comparison signal is greater than the first preset value.

[0012] A further setting of the present invention further includes:

[0013] A display module, connected to the control module, for receiving and displaying the second AC ripple signal.

[0014] A further setting of the present invention, the DC signal isolation module includes:

[0015] A selection switch, which has a plurality of switch channels;

[0016] A capacitor isolation unit, having a plurality of capacitor isolation channels, the number of the capacitor isolation channels is less than or equal to the number of the switch channels, the input end of each capacitor isolation channel is connected to the power supply circuit, the output end of each capacitor isolation channel is respectively connected to the input end of a switch channel, the output end of each switch channel is connected to the peak-to-peak detection module, and the upper limit of the withstand voltage range of a plurality of the capacitor isolation channels in the capacitor isolation unit gradually increases;

[0017] An adjustable resistor, one end of which is connected to the output end of each switch channel;

[0018] A first resistor, one end of the first resistor is connected to the other end of the adjustable resistor, and the other end of the first resistor is grounded.

[0019] A further arrangement of the present invention, the peak-to-peak detection module includes:

[0020] A peak detection unit, connected to the DC signal isolation module, the peak detection unit is configured to receive the first AC ripple signal and output a peak signal of the first AC ripple signal according to the first AC ripple signal;

[0021] A trough detection unit, connected to the DC signal isolation module, the trough detection unit is configured to receive the first AC ripple signal and output a trough signal of the first AC ripple signal according to the first AC ripple signal;

[0022] A subtraction unit, connected to the peak detection unit and the trough detection unit, the subtraction unit is configured to receive the peak signal and the trough signal, and calculate and determine the ripple peak-to-peak value of the first AC ripple signal according to the peak signal and the trough signal, so as to output a DC voltage signal equal to the ripple peak-to-peak value;

[0023] A clear switch, connected to the peak detection unit and the trough detection unit.

[0024] A further arrangement of the present invention, the peak detection unit includes: a first chip, a first Schottky diode, a second Schottky diode, a first zener diode, a second zener diode, a second resistor, a third resistor, a first capacitor, a second capacitor and a third capacitor;

[0025] One end of the second resistor is connected to the DC signal isolation module, the other end of the second resistor is connected to the 3rd pin of the first chip, the positive electrode of the first Schottky diode is connected to the 2nd pin of the first chip, the negative electrode of the first Schottky diode is connected to the 1st pin of the first chip, one end of the third resistor is connected to the positive electrode of the first Schottky diode, the other end of the third resistor is connected to the 7th pin and the 6th pin of the first chip, the positive electrode of the second Schottky diode is connected to the 1st pin of the first chip, the negative electrode of the second Schottky diode is connected to the 5th pin of the first chip, the 5th pin of the first chip is connected to the subtraction unit, one end of the third capacitor is connected to the connection path between the 5th pin of the first chip and the subtraction unit, the other end of the third capacitor is grounded, the 8th pin of the first chip is connected to the first power supply terminal and one end of the second capacitor, the other end of the second capacitor is grounded, the positive electrode of the first voltage stabilizing diode is connected to the 3rd pin of the first chip, the negative electrode of the first voltage stabilizing diode is connected to the negative electrode of the second voltage stabilizing diode, the positive electrode of the second voltage stabilizing diode is grounded, the 4th pin of the first chip is connected to the second power supply terminal, one end of the first capacitor is connected to the 4th pin of the first chip, the other end of the first capacitor is grounded, and one end of the third capacitor is also connected to the clear switch.

[0026] A further arrangement of the present invention, the trough detection unit includes: a second chip, a third Schottky diode, a fourth Schottky diode, a third voltage stabilizing diode, a fourth voltage stabilizing diode, a fourth resistor, a fifth resistor, a fourth capacitor, a fifth capacitor and a sixth capacitor;

[0027] One end of the fourth resistor is connected to the DC signal isolation module, the other end of the fourth resistor is connected to the 3rd pin of the second chip, the cathode of the third Schottky diode is connected to the 2nd pin of the second chip, the anode of the third Schottky diode is connected to the 1st pin of the second chip, one end of the fifth resistor is connected to the cathode of the third Schottky diode, the other end of the fifth resistor is connected to the 7th and 6th pins of the second chip, the cathode of the fourth Schottky diode is connected to the 1st pin of the second chip, the anode of the fourth Schottky diode is connected to the 5th pin of the second chip, the 5th pin of the second chip is connected to the subtraction unit, one end of the sixth capacitor is connected to the connection path between the subtraction unit and the 5th pin of the second chip, the other end of the sixth capacitor is grounded, the 8th pin of the second chip is connected to the first power supply terminal and one end of the fifth capacitor, the other end of the fifth capacitor is grounded, the anode of the third voltage regulator diode is connected to the 3rd pin of the second chip, the cathode of the third voltage regulator diode is connected to the cathode of the fourth voltage regulator diode, the anode of the fourth voltage regulator diode is grounded, the 4th pin of the second chip is connected to the second power supply terminal, one end of the fourth capacitor is connected to the 4th pin of the second chip, the other end of the fourth capacitor is grounded, and one end of the sixth capacitor is also connected to the clear switch.

[0028] A further arrangement of the present invention, the subtraction unit includes: a third chip, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a seventh capacitor, and an eighth capacitor;

[0029] The 1st pin of the third chip is grounded, one end of the sixth resistor is connected to the 5th pin of the first chip and one end of the third capacitor, the other end of the sixth resistor is connected to the 2nd pin of the third chip, one end of the seventh resistor is connected to the 5th pin of the second chip and one end of the sixth capacitor, the other end of the seventh resistor is connected to the 3rd pin of the third chip, one end of the eighth resistor is connected to the 2nd pin of the third chip, the other end of the eighth resistor is connected to the 6th pin of the third chip, one end of the ninth resistor is connected to the 8th pin of the third chip, the other end of the ninth resistor is connected to the 7th pin of the third chip, the 7th pin of the third chip is connected to the third power supply terminal, the 6th pin of the third chip is connected to the voltage division and isolation module, one end of the seventh capacitor is connected to the 7th pin of the third chip, the other end of the seventh capacitor is grounded, one end of the tenth resistor is connected to the 3rd pin of the third chip, the other end of the tenth resistor is grounded, the 4th pin of the third chip is connected to the fourth power supply terminal, one end of the eighth capacitor is connected to the 4th pin of the third chip, and the other end of the eighth capacitor is grounded.

[0030] A further arrangement of the present invention, the voltage division and isolation module includes: a fourth chip, a fifth chip, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, and a fifteenth capacitor;

[0031] One end of the eleventh resistor is connected to the peak-to-peak detection module, the other end of the eleventh resistor is connected to the second pin of the fourth chip, one end of the twelfth resistor and one end of the ninth capacitor are commonly connected to the second pin of the fourth chip, the other end of the twelfth resistor, the other end of the ninth capacitor, and the other end of the tenth capacitor are commonly grounded, one end of the tenth capacitor is connected to the first pin of the fourth chip, the third and fourth pins of the fourth chip are grounded, the first pin of the fourth chip is connected to the fifth power supply terminal, the eighth pin of the fourth chip is connected to the fifth power supply terminal, the seventh pin of the fourth chip is connected to one end of the thirteenth resistor, the sixth pin of the fourth chip is connected to the fourteenth resistor, the fifth pin of the fourth chip is grounded, one end of the eleventh capacitor is connected to the eighth pin of the fourth chip, and the other end of the eleventh capacitor is grounded;

[0032] The other end of the thirteenth resistor is connected to the third pin of the fifth chip, the other end of the fourteenth resistor is connected to the second pin of the fifth chip, one end of the fifteenth resistor and one end of the twelfth capacitor are commonly connected to the third pin of the fifth chip, the other end of the fifteenth resistor and the other end of the twelfth capacitor are commonly grounded, the fourth pin of the fifth chip is connected to the second power supply terminal, one end of the thirteenth capacitor is connected to the fourth pin of the fifth chip, and the other end of the thirteenth capacitor is grounded, one end of the sixteenth resistor and one end of the fourteenth capacitor are commonly connected to the second pin of the fifth chip, the other end of the sixteenth resistor and the other end of the fourteenth capacitor are commonly connected to the sixth pin of the fifth chip, the sixth pin of the fifth chip is also connected to the signal amplification module, the seventh pin of the fifth chip is connected to the first power supply terminal, one end of the fifteenth capacitor is connected to the seventh pin of the fifth chip, and the other end of the fifteenth capacitor is grounded.

[0033] A further arrangement of the present invention, the signal amplification module includes: a sixth chip, a seventh chip, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a sixteenth capacitor, a seventeenth capacitor, and an eighteenth capacitor;

[0034] One end of the seventeenth resistor is connected to the voltage division and isolation module, and the other end of the seventeenth resistor is connected to the pin 3 of the sixth chip. One end of the eighteenth resistor is grounded, and the other end of the eighteenth resistor is connected to the pin 2 of the sixth chip. The pin 4 of the sixth chip is connected to the second power supply terminal. One end of the sixteenth capacitor is connected to the pin 4 of the sixth chip, and the other end of the sixteenth capacitor is grounded. The pin 7 of the sixth chip is connected to the first power supply terminal. One end of the seventeenth capacitor is connected to the pin 7 of the sixth chip, and the other end of the seventeenth capacitor is grounded. The pin 6 of the sixth chip is further connected to the pin 3 of the seventh chip;

[0035] The pins 6, 7, and 8 of the seventh chip are grounded. The pin 16 of the seventh chip is connected to the fifth power supply terminal. One end of the eighteenth capacitor is connected to the pin 16 of the seventh chip, and the other end of the eighteenth capacitor is grounded. The connection end of the pin 3 of the seventh chip and the pin 6 of the sixth chip is connected to the control module. The pins 10 and 11 of the seventh chip are connected to the control module. The pin 13 of the seventh chip, one end of the twentieth resistor, and one end of the nineteenth resistor are commonly connected to the pin 2 of the sixth chip. The other end of the twentieth resistor is connected to the pin 14 of the seventh chip. The other end of the nineteenth resistor is connected to the pin 15 of the seventh chip. The pin 9 of the seventh chip is grounded.

[0036] The present invention provides a test method applying the high-voltage power supply ripple test circuit as described above. The test method includes:

[0037] The DC signal isolation module acquires the high-voltage power supply signal output by the power supply circuit, and outputs a first AC ripple signal after isolating the DC high-voltage signal in the high-voltage power supply signal;

[0038] The peak-to-peak detection module receives the first AC ripple signal, calculates and determines the ripple peak-to-peak value of the first AC ripple signal, and outputs a DC voltage signal equal to the ripple peak-to-peak value;

[0039] The voltage division and isolation module receives the DC voltage signal and outputs a voltage division signal according to the DC voltage signal;

[0040] The signal amplification module receives the voltage division signal, and outputs a first voltage signal after amplifying the voltage division signal through the conducting amplification channel;

[0041] The control module receives the first voltage signal, and performs analog-to-digital conversion on the first voltage signal to obtain a first comparison signal;

[0042] The control module compares the first comparison signal with a first preset value. When the first comparison signal is greater than the first preset value, the control module outputs a second AC ripple signal. When the first comparison signal is less than or equal to the first preset value, the control module outputs a switching signal to the signal amplification module to cause the signal amplification module to switch to conduction of another amplification channel until the first comparison signal is greater than the first preset value.

[0043] The beneficial effects of the present invention are as follows:

[0044] When using the technical solution of the present invention to test the AC ripple signal, the control module can determine whether the selected amplification channel is appropriate according to the received first comparison signal. When the selected amplification channel is inappropriate, a switching signal is further output to the signal amplification module to cause another amplification channel to conduct until the first comparison signal is greater than the first preset value, that is, a suitable amplification channel is selected to output a second AC ripple signal, that is, the measurement of the AC ripple signal is completed. It can be seen that the high-voltage power supply ripple test circuit can not only measure large AC ripple signals but also measure small AC ripple signals while ensuring accuracy, improving the general applicability. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0046] Figure 1 is the principle block diagram of the high-voltage power supply ripple test circuit in the present invention.

[0047] Figure 2 is the circuit structure diagram of the DC signal isolation module in an embodiment of the present invention.

[0048] Figure 3 is the circuit structure diagram of the peak-to-peak detection module in an embodiment of the present invention.

[0049] Figure 4 is the output simulation waveform diagram of the peak-to-peak detection module in an embodiment of the present invention.

[0050] Figure 5 is the circuit structure diagram of the voltage division and isolation module in an embodiment of the present invention.

[0051] Figure 6 is the circuit structure diagram of the signal amplification module in an embodiment of the present invention.

[0052] Figure 7 It is a flowchart for the control module to switch the amplification channel in an embodiment of the present invention.

[0053] Figure 8 It is a circuit structure diagram of the control module in an embodiment of the present invention.

[0054] Figure 9 It is a flowchart of the high-voltage power supply ripple test method of the present invention.

[0055] Marks in the drawings: 100, power supply circuit; 200, DC signal isolation module; 201, capacitor isolation unit; 300, peak-to-peak detection module; 301, peak detection unit; 302, valley detection unit; 303, subtraction unit; 400, voltage division and isolation module; 500, signal amplification module; 600, control module; 700, display module; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; R12, twelfth resistor; R13, thirteenth resistor; R14, fourteenth resistor; R15, fifteenth resistor; R16, sixteenth resistor; R17, seventeenth resistor; R18, eighteenth resistor; R19, nineteenth resistor; R20, twentieth resistor; Rp, adjustable resistor; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor; C8, eighth capacitor; C9, ninth capacitor; C10, tenth capacitor; C11, eleventh capacitor; C12, twelfth capacitor; C13, thirteenth capacitor; C14, fourteenth capacitor; C15, fifteenth capacitor; C16, sixteenth capacitor; C17, seventeenth capacitor; C18, eighteenth capacitor; S1, selection switch; S2, clear switch; U1, first chip; U2, second chip; U3, third chip; U4, fourth chip; U5, fifth chip; U6, sixth chip; U7, seventh chip; U8, eighth chip; D1, first Schottky diode; D2, second Schottky diode; D3, first zener diode; D4, second zener diode; D5, third Schottky diode; D6, fourth Schottky diode; D7, third zener diode; D8, fourth zener diode. Detailed implementation manners

[0056] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientation or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are based on the orientation or positional relationships shown in the accompanying drawings and are constructed and operated in a specific orientation, and are only for the convenience of describing the present technical solution, rather than indicating that the indicated devices or elements must have a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0057] Ripple is the superimposed AC fluctuation amount in the output of a DC stable power supply, and it is an important indicator for evaluating the performance of a DC power supply. In application fields such as electron microscopes, electron beam lithography machines, and X-ray tubes, DC power supplies of dozens of kilovolts to hundreds of kilovolts are often required to generate high-voltage acceleration electric fields. The magnitude of the ripple of the high-voltage power supply directly affects the operation effect of the equipment and instruments. Therefore, it is necessary to measure the ripple of the high-voltage power supply.

[0058] At present, the measurement of the ripple of the high-voltage power supply is mostly carried out on the basis of the DC-blocking method of capacitors and resistors. A DC-blocking circuit composed of a series-connected capacitor and resistor is connected between the output terminal of the high-voltage power supply and the ground. Due to the characteristic of the capacitor blocking DC and passing AC, the DC high-voltage signal and the AC ripple signal output by the power supply are separated. When the parameters of the selected capacitor and resistor are appropriate, the voltage across the resistor is the ripple of the high-voltage power supply. The high-voltage power supply ripple measurement and analysis system in the prior art is applicable to the ripple detection scenario of a precision high-voltage power supply. When measuring with this high-voltage power supply ripple measurement and analysis system, during analog-to-digital conversion and other processing and analysis, the AC ripple signal is amplified by a large multiple, and the measurement and analysis of the tiny ripple of the high-voltage power supply can be realized. When measuring with the high-voltage power supply ripple measurement and analysis system in the prior art, the amplification multiple is large, and only the ripple at the millivolt level can be measured, while the ripple that is slightly larger cannot be measured, and the general applicability is low.

[0059] For example, the application document of patent CN112485697A discloses a high-voltage power supply ripple measurement and analysis system based on a lock-in amplification algorithm. This high-voltage power supply ripple measurement and analysis system is applicable to the ripple detection scenario of precision high-voltage power supplies. During specific measurement, the AC ripple signal passes through a high-voltage input circuit, a DC-blocking amplification circuit, a filtering gain compensation circuit, an analog-to-digital conversion circuit, a digital signal processing circuit, and an upper computer ripple analysis device in sequence to obtain the measurement result of the ripple. When this high-voltage power supply ripple measurement and analysis system measures, during analog-to-digital conversion and other processing and analysis, the AC ripple signal is amplified by a large multiple, enabling the measurement and analysis of tiny ripples in high-voltage power supplies. When this high-voltage power supply ripple measurement and analysis system measures, the amplification multiple is large, and it can only measure ripples at the millivolt level, while it cannot measure slightly larger ripples, resulting in relatively low general applicability.

[0060] In view of the problems existing in the prior art, the present invention provides a high-voltage power supply ripple test circuit. As Figure 1 shown, this high-voltage power supply ripple test circuit may include a DC signal isolation module 200, a peak-to-peak detection module 300, a voltage division and isolation module 400, a signal amplification module 500, and a control module 600.

[0061] Among them, the DC signal isolation module 200 is connected to the power supply circuit 100. The DC signal isolation module 200 is used to obtain the high-voltage power supply signal output by the power supply circuit 100, and output the first AC ripple signal after isolating the DC high-voltage signal in the high-voltage power supply signal; the peak-to-peak detection module 300 is connected to the DC signal isolation module 200. The peak-to-peak detection module 300 is used to receive the first AC ripple signal, and calculate and determine the ripple peak-to-peak value of the first AC ripple signal, so as to output a DC voltage signal equal to the ripple peak-to-peak value; the voltage division and isolation module 400 is connected to the peak-to-peak detection module 300. The voltage division and isolation module 400 is used to receive the DC voltage signal and output a voltage division signal according to the DC voltage signal; the signal amplification module 500 has a plurality of amplification channels. The input ends of the plurality of amplification channels are connected to the voltage division and isolation module 400. Among them, one of the plurality of amplification channels is in a conducting state. The signal amplification module 500 is used to receive the voltage division signal, and amplify the voltage division signal through the conducting amplification channel and then output the first voltage signal; the control module 600 is connected to the output end of the amplification channel of the signal amplification module 500. The control module 600 is used to receive the first voltage signal, and perform analog-to-digital conversion on the first voltage signal to obtain the first comparison signal. The control module 600 is also used to compare the first comparison signal with the first preset value. When the first comparison signal is greater than the first preset value, the control module 600 outputs the second AC ripple signal. When the first comparison signal is less than or equal to the first preset value, the control module 600 outputs a switching signal to the signal amplification module 500, so that the signal amplification module 500 switches to another amplification channel to conduct until the first comparison signal is greater than the first preset value.

[0062] Specifically, among the plurality of amplification channels of the signal amplification module 500, the amplification coefficient of each amplification channel is different, and the amplification coefficients among the plurality of amplification channels are in an increasing state. Among them, the amplification coefficient of one amplification channel can be one, and the first voltage signal is the voltage signal output by the conducting amplification channel of the voltage division signal.

[0063] When performing the AC ripple signal test, when the divided voltage signal output by the voltage division and isolation module 400 is first amplified, the amplification channel with an amplification factor of one is in the conducting state, that is, the first voltage signal is the unamplified divided voltage signal. When the first voltage signal is output to the control module 600, the control module 600 performs analog-to-digital conversion on the first voltage signal to obtain a first comparison signal, and compares the first comparison signal with a first preset value preset inside the control module 600 in advance. When the first comparison signal is greater than the first preset value, it indicates that the selected amplification channel is appropriate. At this time, the control module 600 outputs a second AC ripple signal, that is, the measured AC ripple signal. When the first comparison signal is less than the first preset value, it indicates that the selected amplification channel is not suitable. At this time, the control module 600 outputs a switching signal to the signal amplification module 500 to make another amplification channel in the signal amplification module 500 conduct, so that the divided voltage signal is amplified by the conducting amplification channel to output a first voltage signal to the control module 600. The control module 600 continues to perform analog-to-digital conversion on the first voltage signal to obtain a first comparison signal, and compares the first comparison signal with the first preset value. When the first comparison signal is greater than the first preset value, the control module 600 further outputs a second AC ripple signal. When the first comparison signal is still less than the first preset value, the control module 600 outputs a switching signal to the signal amplification module 500 again until the first comparison signal is greater than the first preset value to complete the measurement of the AC ripple signal.

[0064] In this embodiment, when the high-voltage power supply ripple test circuit performs the AC ripple signal test, the control module 600 can determine whether the selected amplification channel is appropriate according to the received first comparison signal. When the selected amplification channel is not appropriate, it further outputs a switching signal to the signal amplification module 500 to make another amplification channel conduct until the first comparison signal is greater than the first preset value, that is, a suitable amplification channel is selected. Further, the control module 600 outputs a second AC ripple signal, that is, the control module 600 outputs the ripple signal of the high-voltage DC power supply to complete the measurement of the AC ripple signal. It can be seen that the high-voltage power supply ripple test circuit can not only measure large AC ripple signals but also measure small AC ripple signals while ensuring accuracy, improving the general applicability.

[0065] Furthermore, the application document of patent document CN113960353A discloses a high-precision low-ripple test device and method for a high-voltage power supply. The high-precision low-ripple test device and method for the high-voltage power supply connect a DC-blocking circuit composed of a variable capacitor and a resistor with a fixed resistance in series between the output terminal of the high-voltage power supply and the ground, and then connect an oscilloscope probe across the resistor for ripple measurement. During the measurement, high-precision measurement of the full-band ripple can be achieved by changing the capacitance value of the variable capacitor. However, the use of an oscilloscope makes the entire measurement device have disadvantages such as large volume, high cost, and low integration.

[0066] To solve the above technical problems, as Figure 1 shown, the high-voltage power supply ripple test circuit further includes a display module 700. The display module 700 is connected to the control module 600 and is used to receive and display the second AC ripple signal.

[0067] Specifically, the display module 700 may be, but is not limited to, an OLED (Organic Light-Emitting Diode) display screen.

[0068] In this embodiment, after the control module 600 measures the second AC ripple signal, it is transmitted to the display screen for display. There is no need to externally connect an oscilloscope, which reduces the cost of the high-voltage power supply ripple test circuit. At the same time, the high-voltage power supply ripple test circuit is small in volume and high in integration.

[0069] In some embodiments, as Figure 2 shown, the DC signal isolation module 200 may include a selection switch S1, a capacitor isolation unit 201, a variable resistor Rp, and a first resistor R1. Among them, the selection switch S1 has several switch channels; the capacitor isolation unit 201 has several capacitor isolation channels, and the number of capacitor isolation channels is less than or equal to the number of switch channels. The input end of each capacitor isolation channel is connected to the power supply circuit 100, the output end of each capacitor isolation channel is respectively connected to the input end of a switch channel, the output end of each switch channel is connected to the peak-to-peak detection module 300, and the upper limit of the withstand voltage range of several capacitor isolation channels in the capacitor isolation unit 201 gradually increases; one end of the variable resistor Rp is connected to the output end of each switch channel; one end of the first resistor R1 is connected to the other end of the variable resistor Rp, and the other end of the first resistor R1 is grounded.

[0070] Specifically, the number of capacitor isolation channels of the capacitor isolation unit 201 and the withstand voltage range of each capacitor isolation channel in several capacitor isolation channels can be determined according to actual needs. Among them, the number of capacitor isolation channels needs to be less than or equal to the number of switch channels to ensure that each capacitor isolation channel can be correspondingly set with a switch channel. The selection switch S1 may be a single-pole multi-throw switch with the number of dynamic terminals of the switch equal to the number of capacitor isolation channels. When specifically connected, each dynamic terminal of the single-pole multi-throw switch is respectively connected to the output end of a capacitor isolation channel, and the static terminal of the single-pole multi-throw switch is connected to the peak-to-peak detection module 300 and one end of the variable resistor Rp; of course, the selection switch S1 may also be a single-pole multi-throw switch with the number of dynamic terminals of the switch greater than the number of capacitor isolation channels. The first resistor R1 and the variable resistor Rp are connected in series to form a ripple sampling resistor.

[0071] It can be seen that the high-voltage power supply ripple test circuit uses the capacitor-resistor DC isolation method to measure the AC ripple signal of the high-voltage power supply. During the measurement process, it requires a capacitor for isolating DC signals and a ripple sampling resistor with appropriate parameters to ensure that the AC ripple signal at both ends of the ripple sampling resistor is equal to the actual AC ripple signal at the output end of the power supply circuit 100.

[0072] Specifically, if the switching frequency of the power supply circuit 100 is f, the capacitance value of the selected capacitor for isolating DC signals is C, and the resistance value of the ripple sampling resistor is R, then the ratio of the magnitude of the first AC ripple signal to the magnitude of the actual AC ripple signal of the power supply circuit 100 can be determined by the following calculation formula:

[0073]

[0074] Among them, when 2πfCR > 100, the first AC ripple signal sampled by the ripple sampling resistor is greater than 99% of the actual ripple at the output end of the power supply circuit 100. When the parameters of both the DC isolation capacitor and the ripple sampling resistor are adjustable, it is more convenient to change the parameters of the DC signal isolation module 200, and it is more efficient to accurately measure the AC ripple signals of different models of power supply circuits 100.

[0075] When specifically connecting to the power supply circuit 100, for those skilled in the art, the DC high-voltage signal in the high-voltage power supply signal output by the power supply circuit 100 is known. According to the magnitude of this DC high-voltage signal and the switching frequency of the power supply circuit 100, those skilled in the art open one of the switch channels corresponding to the capacitor isolation channels that match this DC high-voltage signal, and adjust the adjustable resistor Rp to an appropriate resistance value to ensure the accurate sampling of the AC ripple signal in the high-voltage power supply signal.

[0076] Among them, the capacitor isolation channel that matches this high-voltage power supply signal means that the maximum withstand voltage value of this capacitor isolation channel needs to be greater than the DC high-voltage signal to prevent the capacitor in the capacitor isolation channel from being broken down. It can be seen that since the DC signal isolation module 200 has several capacitor isolation channels with gradually increasing maximum withstand voltage values, the DC signal isolation module 200 can be connected to high-voltage power supply signals with different voltage ranges.

[0077] In a specific embodiment, such as Figure 2As shown, the capacitive isolation unit 201 has four capacitive isolation channels. The capacitive isolation channel of the first path is a capacitor with a capacitance value of 10 nF and a withstand voltage of 30 kV. The capacitive isolation channel of the second path is composed of two capacitors with a capacitance value of 10 nF and a withstand voltage of 30 kV in series (equivalent to a capacitive isolation channel with a capacitance value of 5 nF and a withstand voltage of 60 kV). The capacitive isolation channel of the third path is composed of four capacitors with a capacitance value of 10 nF and a withstand voltage of 30 kV in series (equivalent to a capacitive isolation channel with a capacitance value of 2.5 nF and a withstand voltage of 120 kV). The capacitive isolation channel of the fourth path is composed of four capacitors with a capacitance value of 1 nF and a withstand voltage of 50 kV in series (equivalent to a capacitor with a capacitance value of 0.25 nF and a withstand voltage of 200 kV). The selection switch S1 is a single-pole multi-throw switch with four switch channels. The dynamic end of the single-pole multi-throw switch is the input end, and the static end of the single-pole multi-throw switch is the output end. This capacitive isolation unit 201 can be used for measuring the AC ripple signal of a high-voltage DC power supply with an output of up to 200 kV. In specific connection, the input ends of each capacitive isolation channel are commonly connected to the output end of the power supply circuit 100, and the output end of each capacitive isolation channel is respectively connected to the input end of a single-pole multi-throw switch.

[0078] The first resistor R1 and the adjustable resistor Rp are connected in series to form a ripple sampling resistor. When specifically set, the first resistor R1 can be, but is not limited to, a resistor with a resistance value of 100 KΩ, and the adjustable resistor Rp can be, but is not limited to, an adjustable resistor Rp with an adjustable resistance range of 0 - 2 MΩ. The resistance range formed by the first resistor R1 and the adjustable resistor Rp is 100 KΩ - 2.1 MΩ.

[0079] In some embodiments, such as Figure 3 As shown, the peak-to-peak detection module 300 may include a clear switch S2, a subtraction unit 303, a peak detection unit 301, and a valley detection unit 302. Among them, the peak detection unit 301 is connected to the DC signal isolation module 200. The peak detection unit 301 is used to receive the first AC ripple signal and output the peak signal of the first AC ripple signal according to the first AC ripple signal. The valley detection unit 302 is connected to the DC signal isolation module 200. The valley detection unit 302 is used to receive the first AC ripple signal and output the valley signal of the first AC ripple signal according to the first AC ripple signal. The subtraction unit 303 is connected to the peak detection unit 301 and the valley detection unit 302. The subtraction unit 303 is used to receive the peak signal and the valley signal, and calculate and determine the ripple peak-to-peak value of the first AC ripple signal to output a DC voltage signal equal to the ripple peak-to-peak value. The clear switch S2 is connected to the peak detection unit 301 and the valley detection unit 302.

[0080] Specifically, such as Figure 3As shown, the clear switch S2 can be a double - pole double - throw switch. The peak detection unit 301 can include a first chip U1, a first Schottky diode D1, a second Schottky diode D2, a first zener diode D3, a second zener diode D4, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2, and a third capacitor C3.

[0081] Among them, one end of the second resistor R2 is connected to the DC signal isolation module 200, the other end of the second resistor R2 is connected to the pin 3 of the first chip U1, the positive electrode of the first Schottky diode D1 is connected to the pin 2 of the first chip U1, the negative electrode of the first Schottky diode D1 is connected to the pin 1 of the first chip U1, one end of the third resistor R3 is connected to the positive electrode of the first Schottky diode D1, the other end of the third resistor R3 is connected to the pins 7 and 6 of the first chip U1, the positive electrode of the second Schottky diode D2 is connected to the pin 1 of the first chip U1, the negative electrode of the second Schottky diode D2 is connected to the pin 5 of the first chip U1, the pin 5 of the first chip U1 is connected to the non - inverting input terminal of the subtraction unit 303, one end of the third capacitor C3 is connected to the connection path between the non - inverting input terminal of the subtraction unit 303 and the pin 5 of the first chip U1, the other end of the third capacitor C3 is grounded, the pin 8 of the first chip U1 is connected to the first power supply terminal and one end of the second capacitor C2, the other end of the second capacitor C2 is grounded, the positive electrode of the first zener diode D3 is connected to the pin 3 of the first chip U1, the negative electrode of the first zener diode D3 is connected to the negative electrode of the second zener diode D4, the positive electrode of the second zener diode D4 is grounded, the pin 4 of the first chip U1 is connected to the second power supply terminal, one end of the first capacitor C1 is connected to the pin 4 of the first chip U1, the other end of the first capacitor C1 is grounded, and one end of the third capacitor C3 is also connected to the clear switch S2.

[0082] In this embodiment, one end of the second resistor R2 is connected to the static terminal of the selection switch S1. The model of the first chip U1 can be but is not limited to TSH4062. One end of the third capacitor C3 is grounded through a switch path of the clear switch S2. The models of the first Schottky diode D1 and the second Schottky diode D2 can be but are not limited to 1PS70SB20. The models of the first zener diode D3 and the second zener diode D4 can be but are not limited to IN4740A. The first capacitor C1 and the second capacitor C2 are decoupling capacitors respectively. The first power supply terminal is a power supply terminal that outputs + 15V DC electricity. The second power supply terminal is a power supply terminal that outputs - 15V DC electricity.

[0083] In this example, the negative electrode of the first voltage stabilizing diode D3 is connected to the negative electrode of the second voltage stabilizing diode D4. The first voltage stabilizing diode D3 and the second voltage stabilizing diode D4 form a limiting circuit at the 3rd pin of the first chip U1 to prevent the collected ripple voltage from being too high and burning out the device. When the ripple voltage signal output by the DC signal isolation module 200 is greater than the ripple peak signal output by the 7th pin of the first chip U1, the first Schottky diode D1 is cut off and the second Schottky diode D2 is turned on. At this time, the first chip U1 charges the third capacitor C3 through the second Schottky diode D2. When the ripple voltage signal output by the DC signal isolation module 200 is less than the ripple peak signal output by the 6th pin of the first chip U1, the first Schottky diode D1 is turned on and the second Schottky diode D2 is cut off. The voltage across the third capacitor C3 remains unchanged because there is no discharge loop. At the same time, a non-linear feedback amplifier is formed inside the first chip U1 to prevent the transistors inside the first chip U1 from entering a deep saturation or deep cut-off state, improving the ability to process high-frequency signals.

[0084] Further, as Figure 3 shown, the trough detection unit 302 may include a second chip U2, a third Schottky diode D5, a fourth Schottky diode D6, a third voltage stabilizing diode D7, a fourth voltage stabilizing diode D8, a fourth resistor R4, a fifth resistor R5, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6.

[0085] Among them, one end of the fourth resistor R4 is connected to the DC signal isolation module 200, and the other end of the fourth resistor R4 is connected to the 3rd pin of the second chip U2. The negative electrode of the third Schottky diode D5 is connected to the 2nd pin of the second chip U2, and the positive electrode of the third Schottky diode D5 is connected to the 1st pin of the second chip U2. One end of the fifth resistor R5 is connected to the negative electrode of the third Schottky diode D5, and the other end of the fifth resistor R5 is connected to the 7th and 6th pins of the second chip U2. The negative electrode of the fourth Schottky diode D6 is connected to the 1st pin of the second chip U2, and the positive electrode of the fourth Schottky diode D6 is connected to the 5th pin of the second chip U2. The 5th pin of the second chip U2 is connected to the inverting input terminal of the subtraction unit 303. One end of the sixth capacitor C6 is connected to the connection path between the inverting input terminal of the subtraction unit 303 and the 5th pin of the second chip U2, and the other end of the sixth capacitor C6 is grounded. The 8th pin of the second chip U2 is connected to the first power supply terminal and one end of the fifth capacitor C5, and the other end of the fifth capacitor C5 is grounded. The positive electrode of the third voltage stabilizing diode D7 is connected to the 3rd pin of the second chip U2, the negative electrode of the third voltage stabilizing diode D7 is connected to the negative electrode of the fourth voltage stabilizing diode D8, and the positive electrode of the fourth voltage stabilizing diode D8 is grounded. The 4th pin of the second chip U2 is connected to the second power supply terminal. One end of the fourth capacitor C4 is connected to the 4th pin of the second chip U2, and the other end of the fourth capacitor C4 is grounded. One end of the sixth capacitor C6 is also connected to the clear switch S2.

[0086] Specifically, the model of the second chip U2 can be but is not limited to TSH4062. One end of the sixth capacitor C6 is grounded through the other switch path of the double-pole double-throw switch. The models of the third Schottky diode D5 and the fourth Schottky diode D6 can be but are not limited to 1PS70SB20. The models of the third zener diode D7 and the fourth zener diode D8 can be but are not limited to IN4740A. The fourth capacitor C4 and the fifth capacitor C5 are decoupling capacitors respectively.

[0087] In this embodiment, the third zener diode D7 and the fourth zener diode D8 form a limiting circuit at the 3rd pin of the second chip U2 to prevent the collected ripple voltage from being too high and burning out the device. When the ripple voltage signal output by the DC signal isolation module 200 is less than the ripple valley value signal output by the 7th pin of the second chip U2, the third Schottky diode D5 is cut off and the fourth Schottky diode D6 is turned on. At this time, the second chip U2 charges the sixth capacitor C6 through the fourth Schottky diode D6; when the ripple voltage signal output by the DC signal isolation module 200 is greater than the ripple valley value signal output by the 6th pin of the second chip U2, the third Schottky diode D5 is turned on and the fourth Schottky diode D6 is cut off. The voltage across the sixth capacitor C6 remains unchanged because there is no discharge loop. At the same time, a non-linear feedback amplifier is formed inside the second chip U2 to prevent the transistors inside the second chip U2 from entering the deep saturation or deep cut-off state, improving the ability to process high-frequency signals.

[0088] Furthermore, as Figure 3 shown, the subtraction unit 303 may include a third chip U3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a seventh capacitor C7, and an eighth capacitor C8.

[0089] Among them, the first pin of the third chip U3 is grounded. One end of the sixth resistor R6 is connected to the fifth pin of the first chip U1 and one end of the third capacitor C3. The other end of the sixth resistor R6 is connected to the second pin of the third chip U3. One end of the seventh resistor R7 is connected to the fifth pin of the second chip U2 and one end of the sixth capacitor C6. The other end of the seventh resistor R7 is connected to the third pin of the third chip U3. One end of the eighth resistor R8 is connected to the second pin of the third chip U3. The other end of the eighth resistor R8 is connected to the sixth pin of the third chip U3. One end of the ninth resistor R9 is connected to the eighth pin of the third chip U3. The other end of the ninth resistor R9 is connected to the seventh pin of the third chip U3. The seventh pin of the third chip U3 is connected to the third power supply terminal. The sixth pin of the third chip U3 is connected to the voltage division and isolation module 400. One end of the seventh capacitor is connected to the seventh pin of the third chip U3. The other end of the seventh capacitor is grounded. One end of the tenth resistor R10 is connected to the third pin of the third chip U3. The other end of the tenth resistor R10 is grounded. The fourth pin of the third chip U3 is connected to the fourth power supply terminal. One end of the eighth capacitor is connected to the fourth pin of the third chip U3. The other end of the eighth capacitor is grounded.

[0090] Specifically, the model of the third chip U3 can be but is not limited to OPA454. Both the seventh capacitor C7 and the eighth capacitor C8 are decoupling capacitors.

[0091] When the peak-to-peak detection module 300 performs specific detection, the peak detection unit 301 outputs the peak signal of the first AC ripple signal to one end of the sixth resistor R6, and the trough detection unit 302 outputs the trough signal of the first AC ripple signal to one end of the seventh resistor R7. The subtraction unit 303 outputs a DC voltage signal equal to the peak-to-peak value of the first AC ripple signal after subtracting the peak signal and the trough signal. In addition, during the detection process, those skilled in the art can manually close or open the clearing switch S2. When the clearing switch S2 is closed, the third capacitor C3 and the sixth capacitor C6 are simultaneously short-circuited to ground, and the outputs of the peak detection unit 301 and the trough detection unit 302 are simultaneously cleared. When the clearing switch S2 is opened, the peak detection unit 301 and the trough detection unit 302 start working again simultaneously and output the peak signal and the trough signal after the clearing switch S2 is opened, thereby realizing the update of the measurement result.

[0092] As Figure 4 shown, it is the simulation waveform diagram output by the peak-to-peak detection module 300. In Figure 4 it, a represents the curve graph of the peak-to-peak voltage; b represents the curve graph of the peak voltage; C represents the curve graph of the peak-to-peak voltage after the clearing switch S2 is closed and then opened again; d represents the curve graph of the ripple voltage; f represents the curve graph of the trough voltage; From Figure 4It can be seen that closing and then reopening the clear switch S2 enables the peak-to-peak detection module 300 to detect the peak-to-peak voltage of the ripple after the amplitude drops.

[0093] In some embodiments, as Figure 5 shown, the voltage division and isolation module 400 may include a fourth chip U4, a fifth chip U5, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, and a fifteenth capacitor C15.

[0094] Among them, one end of the eleventh resistor R11 is connected to the peak-to-peak detection module 300, and the other end of the eleventh resistor R11 is connected to the second pin of the fourth chip U4. One end of the twelfth resistor R12 and one end of the ninth capacitor C9 are commonly connected to the second pin of the fourth chip U4. The other end of the twelfth resistor R12, the other end of the ninth capacitor C9, and the other end of the tenth capacitor C10 are commonly grounded. One end of the tenth capacitor C10 is grounded with the first pin of the fourth chip U4. The third and fourth pins of the fourth chip U4 are grounded. The first pin of the fourth chip U4 is connected to the fifth power supply terminal. The eighth pin of the fourth chip U4 is connected to the fifth power supply terminal. The seventh pin of the fourth chip U4 is connected to one end of the thirteenth resistor R13. The sixth pin of the fourth chip U4 is connected to the fourteenth resistor R14. The fifth pin of the fourth chip U4 is grounded. One end of the eleventh capacitor C11 is connected to the eighth pin of the fourth chip U4, and the other end of the eleventh capacitor C11 is grounded; the other end of the thirteenth resistor R13 is connected to the third pin of the fifth chip U5. The other end of the fourteenth resistor R14 is connected to the second pin of the fifth chip U5. One end of the fifteenth resistor R15 and one end of the twelfth capacitor C12 are commonly connected to the third pin of the fifth chip U5. The other end of the fifteenth resistor R15 and the other end of the twelfth capacitor C12 are commonly grounded. The fourth pin of the fifth chip U5 is connected to the second power supply terminal. One end of the thirteenth capacitor C13 is connected to the fourth pin of the fifth chip U5, and the other end of the thirteenth capacitor C13 is grounded. One end of the sixteenth resistor R16 and one end of the fourteenth capacitor C14 are commonly connected to the second pin of the fifth chip U5. The other end of the sixteenth resistor R16 and the other end of the fourteenth capacitor C14 are commonly connected to the sixth pin of the fifth chip U5. The sixth pin of the fifth chip U5 is also connected to the signal amplification module 500. The seventh pin of the fifth chip U5 is connected to the first power supply terminal. One end of the fifteenth capacitor C15 is connected to the seventh pin of the fifth chip U5, and the other end of the fifteenth capacitor C15 is grounded.

[0095] Specifically, one end of the eleventh resistor R11 is connected to the 6th pin of the third chip U3. The model of the fourth chip U4 can be, but is not limited to, ACPL-C87A. The model of the fifth chip U5 can be, but is not limited to, OPA228. The fifth chip U5, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, and the sixteenth resistor R16 form a differential circuit.

[0096] The specific working principle of the voltage division and isolation module 400 is as follows: The DC voltage signal equal to the peak-to-peak value of the first AC ripple signal output by the peak-to-peak detection module 300 is input to the 2nd pin of the fourth chip U4 after being divided by the eleventh resistor R11 and the twelfth resistor R12. The fourth chip U4 converts the voltage signal received at its 2nd pin into an equal-amplitude differential voltage, and this fourth chip U4 plays a role in high-voltage isolation and protecting the devices in the subsequent low-voltage circuit; thereafter, the differential voltage output by the fourth chip U4 is converted into a single-ended voltage by the differential circuit composed of the fifth chip U5, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, and the sixteenth resistor R16 and output to the signal amplification module 500.

[0097] In a specific embodiment, the resistance value of the eleventh resistor R11 is 45 KΩ, the resistance value of the twelfth resistor R12 is 5 KΩ, and the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, and the sixteenth resistor R16 are all high-precision resistors with a resistance value of 10 KΩ.

[0098] In some embodiments, as Figure 6 shown, the signal amplification module 500 may include a sixth chip U6, a seventh chip U7, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a sixteenth capacitor C16, a seventeenth capacitor C17, and an eighteenth capacitor C18.

[0099] One end of the seventeenth resistor R17 is connected to the voltage dividing and isolation module 400, and the other end of the seventeenth resistor R17 is connected to the 3rd pin of the sixth chip U6. One end of the eighteenth resistor R18 is grounded, and the other end of the eighteenth resistor R18 is connected to the 2nd pin of the sixth chip U6. The 4th pin of the sixth chip U6 is connected to the second power supply terminal. One end of the sixteenth capacitor C16 is connected to the 4th pin of the sixth chip U6, and the other end of the sixteenth capacitor C16 is grounded. The 7th pin of the sixth chip U6 is connected to the first power supply terminal. One end of the seventeenth capacitor C17 is connected to the 7th pin of the sixth chip U6, and the other end of the seventeenth capacitor C17 is grounded. The 6th pin of the sixth chip U6 is also connected to the 3rd pin of the seventh chip U7; the 6th, 7th, and 8th pins of the seventh chip U7 are grounded, the 16th pin of the seventh chip U7 is connected to the fifth power supply terminal, one end of the eighteenth capacitor C18 is connected to the 16th pin of the seventh chip U7, and the other end of the eighteenth capacitor C18 is grounded. The connection end of the 3rd pin of the seventh chip U7 and the 6th pin of the sixth chip U6 is connected to the control module 600. The 10th pin and the 11th pin of the seventh chip U7 are connected to the control module 600. The 13th pin of the seventh chip U7, one end of the nineteenth resistor R19, and one end of the twentieth resistor R20 are commonly connected to the 2nd pin of the sixth chip U6. The other end of the twentieth resistor R20 is connected to the 14th pin of the seventh chip U7, and the other end of the nineteenth resistor R19 is connected to the 15th pin of the seventh chip U7. The 9th pin of the seventh chip U7 is grounded.

[0100] Specifically, one end of the seventeenth resistor R17 is connected to the 6th pin of the fifth chip U5. The model of the sixth chip U6 can be, but is not limited to, OPA228. The seventh chip U7 is a multiplexer, and its model can be, but is not limited to, 74HC4051. The seventh chip U7 is connected in series in the feedback loop of the signal amplification module 500. Among them, the 9th pin of the seventh chip U7 is the address terminal of the seventh chip U7, and the 9th pin of the seventh chip U7 is always grounded and at a low level. The 10th and 11th pins of the seventh chip U7 are the other two address terminals of the seventh chip U7. The 10th and 11th pins of the seventh chip U7 are connected to the control module 600. The control module 600 controls the level of the address terminal of the seventh chip U7 according to the comparison result between the first comparison signal and the first preset value to switch the amplification channel.

[0101] In this embodiment, the seventeenth resistor R17 and the eighteenth resistor R18 are both high-precision resistors with a resistance value of 10K, the nineteenth resistor R19 is a high-precision resistor with a resistance value of 990K, and the twentieth resistor R20 is a high-precision resistor with a resistance value of 90K. The signal amplification module 500 has three amplification channels, and the amplification factors of the three amplification channels are ×1, ×10, and ×100 respectively (for the amplification channel corresponding to ×1, the port Y0 of the seventh chip U7 is connected to the port Z; for the amplification channel corresponding to ×10, the port Y1 of the seventh chip U7 is connected to the port Z; for the amplification channel corresponding to ×100, the port Y2 of the seventh chip U7 is connected to the port Z). When the level signals at the 9th, 10th, and 11th pins of the seventh chip U7 are 000, the port Y0 is connected to the port Z. At this time, the signal amplification module 500 constitutes a voltage follower; when the level signals at the 9th, 10th, and 11th pins of the seventh chip U7 are 001, the port Y1 is connected to the port Z. At this time, the signal amplification module 500 constitutes a non-inverting proportional amplification circuit with a gain of 10; when the level signals at the 9th, 10th, and 11th pins of the seventh chip U7 are 010, the port Y2 is connected to the port Z. At this time, the signal amplification module 500 constitutes a non-inverting proportional amplification circuit with a gain of 100.

[0102] When specifically measuring, the first-conducted amplification channel in the signal amplification module 500 has an amplification factor of ×1. When this amplification channel is conducting, the control module 600 is used to control the level signals at the 10th and 11th pins of the seventh chip U7 to be 00, that is, the level signals at the 9th, 10th, and 11th pins of the seventh chip U7 are 000, and the amplification channel of ×1 is conducting. If the first comparison signal is less than the first preset value at this time, the control module 600 is used to control the level signals at the 10th and 11th pins of the seventh chip U7 to be 01, that is, the level signals at the 9th, 10th, and 11th pins of the seventh chip U7 are 001, and the amplification channel of ×10 is conducting. If the first comparison signal is still less than the first preset value at this time, the control module 600 is used to control the level signals at the 10th and 11th pins of the seventh chip U7 to be 10, that is, the level signals at the 9th, 10th, and 11th pins of the seventh chip U7 are 010, and the amplification channel of ×100 is conducting.

[0103] In a specific embodiment, the measurement range corresponding to the amplification channel of ×1 is 2 - 20V; the measurement range corresponding to the amplification channel of ×10 is 0.2 - 2V; the measurement range corresponding to the amplification channel of ×100 is 0 - 0.2V.

[0104] In this embodiment, by setting different amplification channels and switching the amplification channels according to the comparison result between the first comparison signal and the first preset value, automatic switching of the amplification channels is achieved, the measurement accuracy of the high-voltage power supply ripple test circuit is improved, and the setting of multiple amplification channels can not only measure small AC ripple signals but also large AC ripple signals, thereby improving the general applicability of the high-voltage power supply ripple test circuit.

[0105] In some embodiments, as Figure 8 shown, the control module 600 can be a circuit built around the eighth chip U8, and the model of the eighth chip U8 can be, but is not limited to, STM32F103C8T6. As Figure 8 shown, it is the circuit diagram of the eighth chip U8 and its peripherals. Among them, the 12th pin of the eighth chip U8 is connected to the connection path between the 6th pin of the sixth chip U6 and the 3rd pin of the seventh chip U7. The first voltage signal output by the conducting amplification channel is accessed through the 12th pin of the eighth chip U8 and undergoes analog-to-digital conversion inside the eighth chip U8. The 25th pin of the eighth chip U8 is connected to the 11th pin of the seventh chip U7, and the 26th pin of the eighth chip U8 is connected to the 10th pin of the seventh chip U7. The level signals (switching signals) output through the 25th pin and the 26th pin of the eighth chip U8 are used to switch the amplification channels. The 42nd pin and the 43rd pin of the eighth chip U8 are connected to the OLED display screen, and the second AC ripple signal is output through the 42nd pin and the 43rd pin of the eighth chip U8 to the display screen for display.

[0106] Specifically, the first preset value is preset in the eighth chip U8 in advance. As Figure 7 shown, for the 12-bit analog-to-digital converter inside the eighth chip U8 and a reference voltage of 3.3V, the first preset value can be 249. That is, when the first comparison signal is greater than 249, the eighth chip U8 outputs the second ripple AC signal to the OLED display screen for display. Further, a first upper limit value is also set inside the eighth chip U8. For the 12-bit analog-to-digital converter inside the eighth chip U8 and a reference voltage of 3.3V, the first upper limit value can be 2481. When the first comparison signal is greater than the first upper limit value, the eighth chip U8 outputs an out-of-range signal to the OLED display screen for display. That is, when the first comparison signal is greater than the first upper limit value, the OLED display screen shows out of range.

[0107] In some embodiments, as Figure 9 shown, the present invention also provides a test method applying the high-voltage power supply ripple test circuit as described above. The test method includes the steps:

[0108] S100. The DC signal isolation module obtains the high-voltage power supply signal output by the power supply circuit, isolates the DC high-voltage signal in the high-voltage power supply signal, and outputs the first AC ripple signal. Specifically, as described in the embodiment of the above-mentioned high-voltage power supply ripple test circuit, details are not elaborated here.

[0109] S200. The peak-to-peak detection module receives the first AC ripple signal, calculates and determines the ripple peak-to-peak value of the first AC ripple signal, and outputs a DC voltage signal equal to the ripple peak-to-peak value. Specifically, as described in the embodiment of the above-mentioned high-voltage power supply ripple test circuit, details are not elaborated here.

[0110] S300. The voltage division and isolation module receives the DC voltage signal and outputs a voltage division signal according to the DC voltage signal. Specifically, as described in the embodiment of the above-mentioned high-voltage power supply ripple test circuit, details are not elaborated here.

[0111] S400. The signal amplification module receives the voltage division signal, amplifies the voltage division signal through the conducting amplification channel, and outputs the first voltage signal. Specifically, as described in the embodiment of the above-mentioned high-voltage power supply ripple test circuit, details are not elaborated here.

[0112] S500. The control module receives the first voltage signal, performs analog-to-digital conversion on the first voltage signal, and obtains the first comparison signal. Specifically, as described in the embodiment of the above-mentioned high-voltage power supply ripple test circuit, details are not elaborated here.

[0113] S600. The control module compares the first comparison signal with the first preset value. When the first comparison signal is greater than the first preset value, the control module outputs the second AC ripple signal. When the first comparison signal is less than or equal to the first preset value, the control module outputs a switching signal to the signal amplification module to make the signal amplification module switch to another amplification channel to conduct until the first comparison signal is greater than the first preset value. Specifically, as described in the embodiment of the above-mentioned high-voltage power supply ripple test circuit, details are not elaborated here.

[0114] In summary, the present invention provides a high-voltage power supply ripple test circuit and a test method, which have the following beneficial effects:

[0115] When the high-voltage power supply ripple test circuit performs an AC ripple signal test, the control module can determine whether the selected amplification channel is appropriate according to the received first comparison signal. When the selected amplification channel is inappropriate, the control module further outputs a switching signal to the signal amplification module to turn on another amplification channel until the first comparison signal is greater than the first preset value, that is, a suitable amplification channel is selected, and a second AC ripple signal is output to complete the measurement of the AC ripple signal. It can be seen that the high-voltage power supply ripple test circuit can not only measure large AC ripple signals but also measure small AC ripple signals while ensuring accuracy, improving the general applicability.

[0116] It can be understood that the above embodiments only represent the preferred embodiments of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention shall fall within the scope covered by the claims of the present invention.

Claims

1. A high voltage power supply ripple test circuit, characterized in that: include: A DC signal isolation module is connected to the power supply circuit, and is used to obtain the high-voltage power supply signal output by the power supply circuit, isolate the DC high-voltage signal in the high-voltage power supply signal, and then output a first AC ripple signal; a peak-to-peak value detection module, connected to the DC signal isolation module, the peak-to-peak value detection module being used to receive the first AC ripple signal, and calculate and determine the peak-to-peak value of the ripple of the first AC ripple signal, so as to output a DC voltage signal equal to the peak-to-peak value of the ripple; A voltage division and isolation module, connected to the peak-to-peak value detection module, the voltage division and isolation module is used to receive the DC voltage signal and output a voltage division signal according to the DC voltage signal; A signal amplification module, comprising a plurality of amplification channels, wherein input ends of the plurality of amplification channels are connected to the voltage division and isolation module, wherein one of the plurality of amplification channels is in a conducting state, and the signal amplification module is used to receive the voltage division signal, and output a first voltage signal after amplifying the voltage division signal through the conducting amplification channel; A control module is connected to the output end of the amplification channel of the signal amplification module. The control module is used to receive the first voltage signal, perform analog-to-digital conversion on the first voltage signal to obtain a first comparison signal, and compare the first comparison signal with a first preset value. When the first comparison signal is greater than the first preset value, the control module outputs a second AC ripple signal. When the first comparison signal is less than or equal to the first preset value, the control module outputs a switching signal to the signal amplification module to switch the signal amplification module to another amplification channel until the first comparison signal is greater than the first preset value.

2. The high voltage power supply ripple test circuit according to claim 1, characterized in that: Also includes: A display module is connected to the control module, and is used to receive and display the second AC ripple signal.

3. The high voltage power supply ripple test circuit according to claim 1 or 2, characterized in that: The DC signal isolation module comprises: A selection switch, wherein the selection switch has a plurality of switch channels; A capacitor isolation unit having a plurality of capacitor isolation channels, the number of the capacitor isolation channels being less than or equal to the number of the switch channels, the input end of each of the capacitor isolation channels being connected to the power supply circuit, the output end of each of the capacitor isolation channels being respectively connected to the input end of a switch channel, the output end of each of the switch channels being connected to the peak-to-peak value detection module, and the upper limits of the withstand voltage ranges of the plurality of capacitor isolation channels in the capacitor isolation unit being gradually increased; An adjustable resistor, one end of which is connected to the output end of each of the switch channels; A first resistor, one end of the first resistor is connected to the other end of the adjustable resistor, and the other end of the first resistor is grounded.

4. The high voltage power supply ripple test circuit according to claim 1 or 2, characterized in that: The peak-to-peak value detection module comprises: a peak detection unit connected to the DC signal isolation module, the peak detection unit being used to receive the first AC ripple signal and output a peak signal of the first AC ripple signal according to the first AC ripple signal; a valley detection unit connected to the DC signal isolation module, the valley detection unit being used to receive the first AC ripple signal and output a valley signal of the first AC ripple signal according to the first AC ripple signal; a subtraction unit connected to the peak detection unit and the trough detection unit, the subtraction unit being used to receive the peak signal and the trough signal, and to calculate and determine the ripple peak-to-peak value of the first AC ripple signal according to the peak signal and the trough signal, so as to output a DC voltage signal equal to the ripple peak-to-peak value; A zeroing switch is connected to the peak detection unit and the trough detection unit.

5. The high voltage power supply ripple test circuit according to claim 4, characterized in that: The peak detection unit includes: a first chip, a first Schottky diode, a second Schottky diode, a first voltage regulator diode, a second voltage regulator diode, a second resistor, a third resistor, a first capacitor, a second capacitor and a third capacitor; One end of the second resistor is connected to the DC signal isolation module, the other end of the second resistor is connected to the third pin of the first chip, the anode of the first Schottky diode is connected to the second pin of the first chip, the cathode of the first Schottky diode is connected to the first pin of the first chip, one end of the third resistor is connected to the anode of the first Schottky diode, the other end of the third resistor is connected to the seventh pin and the sixth pin of the first chip, the anode of the second Schottky diode is connected to the first pin of the first chip, the cathode of the second Schottky diode is connected to the fifth pin of the first chip, the fifth pin of the first chip is connected to the subtraction unit, and the One end of the third capacitor is connected to the connection path between the 5th pin of the first chip and the subtraction unit, the other end of the third capacitor is grounded, the 8th pin of the first chip is connected to the first power supply end and one end of the second capacitor, the other end of the second capacitor is grounded, the positive electrode of the first voltage regulator diode is connected to the 3rd pin of the first chip, the negative electrode of the first voltage regulator diode is connected to the negative electrode of the second voltage regulator diode, the positive electrode of the second voltage regulator diode is grounded, the 4th pin of the first chip is connected to the second power supply end, one end of the first capacitor is connected to the 4th pin of the first chip, the other end of the first capacitor is grounded, and one end of the third capacitor is also connected to the reset switch.

6. The high voltage power supply ripple test circuit according to claim 5, characterized in that: The valley detection unit includes: a second chip, a third Schottky diode, a fourth Schottky diode, a third voltage regulator diode, a fourth voltage regulator diode, a fourth resistor, a fifth resistor, a fourth capacitor, a fifth capacitor and a sixth capacitor; One end of the fourth resistor is connected to the DC signal isolation module, the other end of the fourth resistor is connected to the third pin of the second chip, the cathode of the third Schottky diode is connected to the second pin of the second chip, the anode of the third Schottky diode is connected to the first pin of the second chip, one end of the fifth resistor is connected to the cathode of the third Schottky diode, the other end of the fifth resistor is connected to the seventh pin and the sixth pin of the second chip, the cathode of the fourth Schottky diode is connected to the first pin of the second chip, the anode of the fourth Schottky diode is connected to the fifth pin of the second chip, the fifth pin of the second chip is connected to the subtraction unit, and the One end of the sixth capacitor is connected to the connection path between the subtraction unit and the 5th pin of the second chip, the other end of the sixth capacitor is grounded, the 8th pin of the second chip is connected to the first power supply end and one end of the fifth capacitor, the other end of the fifth capacitor is grounded, the positive electrode of the third voltage regulator diode is connected to the 3rd pin of the second chip, the negative electrode of the third voltage regulator diode is connected to the negative electrode of the fourth voltage regulator diode, the positive electrode of the fourth voltage regulator diode is grounded, the 4th pin of the second chip is connected to the second power supply end, one end of the fourth capacitor is connected to the 4th pin of the second chip, the other end of the fourth capacitor is grounded, and one end of the sixth capacitor is also connected to the reset switch.

7. The high voltage power supply ripple test circuit according to claim 6, characterized in that: The subtraction unit includes: a third chip, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a seventh capacitor and an eighth capacitor; The first pin of the third chip is grounded, one end of the sixth resistor is connected to the fifth pin of the first chip and one end of the third capacitor, the other end of the sixth resistor is connected to the second pin of the third chip, one end of the seventh resistor is connected to the fifth pin of the second chip and one end of the sixth capacitor, the other end of the seventh resistor is connected to the third pin of the third chip, one end of the eighth resistor is connected to the second pin of the third chip, the other end of the eighth resistor is connected to the sixth pin of the third chip, one end of the ninth resistor is connected to the eighth pin of the third chip, the other end of the ninth resistor is connected to the seventh pin of the third chip, the seventh pin of the third chip is connected to the third power supply end, the sixth pin of the third chip is connected to the voltage division and isolation module, one end of the seventh capacitor is connected to the seventh pin of the third chip, the other end of the seventh capacitor is grounded, one end of the tenth resistor is connected to the third pin of the third chip, the other end of the tenth resistor is grounded, the fourth pin of the third chip is connected to the fourth power supply end, one end of the eighth capacitor is connected to the fourth pin of the third chip, and the other end of the eighth capacitor is grounded.

8. The high voltage power supply ripple test circuit according to claim 1 or 2, characterized in that: The voltage division and isolation module includes: a fourth chip, a fifth chip, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor and a fifteenth capacitor; One end of the eleventh resistor is connected to the peak-to-peak value detection module, the other end of the eleventh resistor is connected to the second pin of the fourth chip, one end of the twelfth resistor and one end of the ninth capacitor are connected to the second pin of the fourth chip, the other end of the twelfth resistor, the other end of the ninth capacitor and the other end of the tenth capacitor are grounded, one end of the tenth capacitor is connected to the first pin of the fourth chip, the third pin and the fourth pin of the fourth chip are grounded, the first pin of the fourth chip is connected to the fifth power supply terminal, the eighth pin of the fourth chip is connected to the fifth power supply terminal, the seventh pin of the fourth chip is connected to one end of the thirteenth resistor, the sixth pin of the fourth chip is connected to the fourteenth resistor, the fifth pin of the fourth chip is grounded, one end of the eleventh capacitor is connected to the eighth pin of the fourth chip, and the other end of the eleventh capacitor is grounded; The other end of the thirteenth resistor is connected to the third pin of the fifth chip, the other end of the fourteenth resistor is connected to the second pin of the fifth chip, one end of the fifteenth resistor and one end of the twelfth capacitor are connected to the third pin of the fifth chip, the other end of the fifteenth resistor and the other end of the twelfth capacitor are grounded, the fourth pin of the fifth chip is connected to the second power supply terminal, one end of the thirteenth capacitor is connected to the fourth pin of the fifth chip, the other end of the thirteenth capacitor is grounded, one end of the sixteenth resistor and one end of the fourteenth capacitor are connected to the second pin of the fifth chip, the other end of the sixteenth resistor and the other end of the fourteenth capacitor are connected to the sixth pin of the fifth chip, the sixth pin of the fifth chip is also connected to the signal amplification module, the seventh pin of the fifth chip is connected to the first power supply terminal, one end of the fifteenth capacitor is connected to the seventh pin of the fifth chip, and the other end of the fifteenth capacitor is grounded.

9. The high voltage power supply ripple test circuit according to claim 1 or 2, characterized in that: The signal amplification module includes: a sixth chip, a seventh chip, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a sixteenth capacitor, a seventeenth capacitor and an eighteenth capacitor; One end of the seventeenth resistor is connected to the voltage division and isolation module, the other end of the seventeenth resistor is connected to the third pin of the sixth chip, one end of the eighteenth resistor is grounded, the other end of the eighteenth resistor is connected to the second pin of the sixth chip, the fourth pin of the sixth chip is connected to the second power supply terminal, one end of the sixteenth capacitor is connected to the fourth pin of the sixth chip, the other end of the sixteenth capacitor is grounded, the seventh pin of the sixth chip is connected to the first power supply terminal, one end of the seventeenth capacitor is connected to the seventh pin of the sixth chip, the other end of the seventeenth capacitor is grounded, and the sixth pin of the sixth chip is also connected to the third pin of the seventh chip; Pins 6, 7 and 8 of the seventh chip are grounded, pin 16 of the seventh chip is connected to the fifth power supply end, one end of the eighteenth capacitor is connected to the sixteenth pin of the seventh chip, the other end of the eighteenth capacitor is grounded, the connection end between pin 3 of the seventh chip and pin 6 of the sixth chip is connected to the control module, pin 10 of the seventh chip and pin 11 of the seventh chip are connected to the control module, pin 13 of the seventh chip, one end of the twentieth resistor and one end of the nineteenth resistor are connected to pin 2 of the sixth chip, the other end of the twentieth resistor is connected to pin 14 of the seventh chip, the other end of the nineteenth resistor is connected to pin 15 of the seventh chip, and pin 9 of the seventh chip is grounded.

10. A test method using the high voltage power supply ripple test circuit according to any one of claims 1 to 9, characterized in that: The test method includes: The DC signal isolation module obtains the high-voltage power signal output by the power supply circuit, isolates the DC high-voltage signal in the high-voltage power signal, and then outputs a first AC ripple signal; The peak-to-peak value detection module receives the first AC ripple signal, and calculates and determines the peak-to-peak value of the ripple of the first AC ripple signal, so as to output a DC voltage signal equal to the peak-to-peak value of the ripple; The voltage division and isolation module receives the DC voltage signal and outputs a voltage division signal according to the DC voltage signal; The signal amplification module receives the divided voltage signal, amplifies the divided voltage signal through the conducted amplification channel, and then outputs a first voltage signal; The control module receives the first voltage signal, and performs analog-to-digital conversion on the first voltage signal to obtain a first comparison signal; The control module compares the first comparison signal with a first preset value. When the first comparison signal is greater than the first preset value, the control module outputs a second AC ripple signal. When the first comparison signal is less than or equal to the first preset value, the control module outputs a switching signal to the signal amplification module to switch the signal amplification module to another amplification channel until the first comparison signal is greater than the first preset value.

Images