Controllable low-noise positive high voltage generator

Abstract

The utility model relates to the field of low-noise high-voltage generators, in particular to a controllable low-noise positive high-voltage generator, which comprises a forward-flyback conversion module, an output filtering module, a sampling and phase advanced processing module, a PWM (pulse-width modulation) control module and an output voltage control module. The forward and reverse excitation type conversion module adopts double transformers to chop waves into sine-like waves and then shape the sine-like waves into high-voltage direct-current signals, the high-voltage direct-current signals are sent to the filtering module and a phase advanced processing part of the sampling and phase advanced processing module, and the filtering module filters the received signals and then outputs the signals to a sampling part of the sampling and phase advanced processing module. A driving current signal of a primary side of a first transformer and a signal output by the sampling part are sampled and then output to the phase advanced processing part, processed by the phase advanced processing part and then output to the voltage control module, processed by the voltage control module and then output to the PWM control module, and meanwhile the PWM control module introduces the driving current signal of the primary side of the first transformer and the signal output by the sampling part. And after processing, a PWM signal is output to the forward-flyback conversion module. The utility model is suitable for detectors of various models.

Description

Technical Field

[0001] The utility model relates to the field of low-noise high-voltage generators, in particular to a controllable low-noise positive high-voltage generator. Background Art

[0002] Existing high-voltage generators, such as a DC high-voltage generator for measuring the DC reference voltage of a metal oxide voltage limiter disclosed in CN204422592U, include a power supply module, a voltage measurement module, a current measurement module, and a voltage stabilizing module, a high-frequency transformer and a voltage doubler rectifier module connected in series; one output end of the voltage doubler rectifier module is connected to the current measurement module, and the other output end is connected to the voltage measurement module; the power supply module is respectively connected to the voltage measurement module, the power supply measurement module and the voltage stabilizing module. The high-voltage generator has a simple structure, low power consumption, can reduce noise, and is easy to operate on site in a series compensation device.

[0003] The voltage control method of this scheme is that the PWM generator receives the output voltage of the second filter, and sends a PWM (Pulse Width Modulation) signal to the AC (Alternating Current) / DC (Direct Current) conversion circuit based on the output voltage and the test voltage required by the manually preset DC reference voltage test, thereby adjusting the conduction and shutdown of the power electronic devices in the AC / DC conversion circuit and outputting a voltage that meets the test requirements.

[0004] However, this solution lacks advanced processing of the output voltage phase, cannot eliminate the loop control abnormality caused by the sampling feedback signal lag, and has poor safety and stability. At the same time, the noise reduction effect of this solution is not obvious. Utility Model Content

[0005] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a controllable low-noise positive high-voltage generator, which realizes the advanced processing of the phase of the output voltage and improves the safety and stability of the high-voltage generator.

[0006] The utility model adopts the following technical scheme to achieve the above-mentioned purpose. The utility model provides a controllable low-noise positive high-voltage generator, including a power supply filter module, a forward-flyback conversion module, an output filter module, a sampling and phase advance processing module, a PWM control module and an output voltage control module. The power supply filter module filters the input power supply and provides power to each module after filtering. The forward-flyback conversion module adopts a dual transformer to chop into a quasi-sine wave and then forms a high-voltage DC signal, which is then sent to the filter module and the phase advance processing part of the sampling and phase advance processing module. The output filter module filters the received signal and outputs it to the sampling part of the sampling and phase advance processing module. After sampling by the sampling part, it is output to the phase advance processing part. After processing, the phase advance processing part outputs it to the voltage control module. After processing, the voltage control module outputs it to the PWM control module. At the same time, the PWM control module introduces the driving current signal of the primary measurement of the first transformer and the signal output by the sampling part, and outputs the PWM signal to the forward-flyback conversion module after processing.

[0007] Furthermore, the forward-flyback conversion module includes a driver U2, a twelfth resistor R12, a seventeenth resistor R17, a fifteenth resistor R15, a tenth resistor R10, a third resistor R3, a fourteenth capacitor C14, a twelfth capacitor C12, a fifth capacitor C5, a sixth capacitor C6, a first diode D1, a second diode D2, a third diode D3, a first MOS tube Q1, a first transformer T1 and a second transformer T2, the fifth pin of the driver U2 is connected to the power filter module, the third pin of the driver U2 receives the input PWM signal, the fourth pin is connected to the gate of the first MOS tube Q1 through the twelfth resistor R12, the drain of the first MOS tube Q1 is grounded through the fourteenth capacitor C14 and the seventeenth resistor R17, and is grounded through the fifteenth resistor R15, and the drain of the first MOS tube Q1 is also connected to the fourth pin of the second transformer T2 The source of the first MOS tube Q1 is connected to the third pin of the second transformer T2, the first pin of the second transformer T2 is connected to the cathode of the second diode D2, the anode of the second diode D2 is connected to the first pin of the first transformer T1, the second pin of the first transformer T1 is grounded through the tenth resistor R10, the third pin of the first transformer T1 is connected to the second pin of the second transformer T2, the fifth pin of the first transformer T1 outputs a switching pulse to be shaped into a quasi-sine wave through the fifth capacitor C5 and the third resistor R3, the third resistor R3 is grounded through the sixth capacitor C6, the cathode of the third diode D3 is connected to the fifth capacitor C5, the anode of the third diode D3 is connected to the fourth pin of the first transformer T1 through the twelfth capacitor C12, the anode of the third diode D3 is also connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected to the fifth pin of the first transformer T1.

[0008] Furthermore, the output filter module includes a second inductor L2, a fourth resistor R4 and a seventh capacitor C7, one end of the second inductor L2 is connected to the output end of the forward-flyback conversion module, and the other end outputs a signal through the fourth resistor R4, and the fourth resistor R4 is grounded through the seventh capacitor C7.

[0009] Furthermore, the sampling and phase advance processing module includes a proportional resistor sampling unit U3, an eleventh resistor R11, a thirteenth resistor R13, a fourteenth resistor R14, a sixteenth resistor R16, a thirteenth capacitor C13, a fourth diode D4 and a processing chip U4B, one end of the eleventh resistor R11 is connected to the second inductor L2, the other end of the eleventh resistor R11 is connected to the fifth pin of the processing chip U4B through the fourteenth resistor R14, the fifth pin of the processing chip U4B is also connected to the cathode of the fourth diode D4, the anode of the fourth diode D4 is grounded, the thirteenth capacitor C13 is connected to both ends of the eleventh resistor R11, the third pin of the proportional resistor sampling unit U3 receives the output signal of the output filter module, the second pin of the proportional resistor sampling unit U3 is connected to the fifth pin of the processing chip U4B through the thirteenth resistor R13, the first pin of the proportional resistor sampling unit U3 is grounded, and the sixth pin of the processing chip U4B is connected to the output end of the processing chip U4B through the sixteenth resistor R16.

[0010] Furthermore, the PWM control module includes a switch controller U6, a thirty-first resistor R31, a thirty-second resistor R32, a thirty-fourth resistor R34, a thirty-sixth resistor R36 and a twentieth capacitor C20, the second pin of the switch controller U6 is grounded through the twentieth capacitor C20, the sixth pin of the switch controller U6 is grounded through the thirty-first resistor R31, the seventh pin of the switch controller U6 is grounded through the thirty-fourth resistor R34, the first pin of the switch controller U6 outputs a PWM signal, the third pin of the switch controller U6 is connected to the output voltage control module, and the fourth pin of the switch controller U6 receives the drive current signal IPre of the primary side of the first transformer T1 and the output signal VHFB of the proportional resistor sampling unit U3.

[0011] Furthermore, the output voltage control module includes a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a second MOS tube Q2, and a control chip U4A. The third pin of the control chip U4A is connected to the output voltage setting terminal Vset through the twenty-first resistor R21, and the third pin of the control chip U4A is also connected to the ground through the twenty-first resistor R21 and the nineteenth resistor R19. The third pin of the control chip U4A is also connected to the output voltage setting terminal Vset. The second pin of the control chip U4A is connected to the reference voltage terminal VRef through the twentieth resistor R20, the third pin of the control chip U4A is also connected to the source of the second MOS tube Q2, the gate of the second MOS tube Q2 is connected to the enable terminal EN through the twenty-third resistor R23, the gate of the second MOS tube Q2 is also connected to the drain of the second MOS tube Q2 through the twenty-fifth resistor R25, the drain of the second MOS tube Q2 is grounded, the second pin of the control chip U4A is connected to the output terminal Vfb of the sampling and phase advance processing module, and the first pin of the control chip U4A is connected to the PWM control module through the twenty-sixth resistor R26.

[0012] Furthermore, the power supply filter module includes a first inductor L1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4, one end of the first inductor L1 is connected to the input power supply, the other end of the first inductor L1 is grounded through the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 respectively, and the other end of the first inductor L1 serves as an output power supply end.

[0013] Beneficial effects of the utility model:

[0014] The utility model adopts an LC filter structure for input power filtering, and uses inductors and capacitors of different values ​​in combination to absorb strong interference generated by the pulse action of the switch tube and reduce noise caused by radiation conduction of the power supply line.

[0015] The forward-flyback conversion module of the utility model integrates the traditional single forward-type switching power supply and the flyback-type switching power supply, thereby realizing the switching pulse shaping into a quasi-sine wave, greatly reducing the switching pulse interference and greatly improving the noise reduction capability.

[0016] The output filter module of the utility model can effectively filter out the pulse interference of the switch tube through multi-stage RC output filtering, thereby reducing the output noise.

[0017] The utility model realizes advance acquisition of the output voltage signal through the sampling and phase advance processing module, eliminates loop control abnormality caused by hysteresis of proportional resistance sampling feedback signal, and improves the safety and stability of the high voltage generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural block diagram of a controllable low-noise positive high-voltage generator provided by an embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the circuit structure of the power filter module provided by the embodiment of the utility model;

[0020] Figure 3 This is a schematic diagram of the circuit structure of a forward-flyback conversion module provided by an embodiment of the utility model;

[0021] Figure 4 It is a schematic diagram of the circuit structure of the output filter module provided by the embodiment of the utility model;

[0022] Figure 5 It is a schematic diagram of the circuit structure of the sampling and phase advance processing module provided in the embodiment of the utility model;

[0023] Figure 6 This is a schematic diagram of the circuit structure of a PWM control module provided by an embodiment of the utility model;

[0024] Figure 7 It is a schematic diagram of the circuit structure of an output voltage control module provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present utility model clearer, the technical solution in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model.

[0026] like Figure 1 As shown, the utility model provides a controllable low-noise positive high-voltage generator, including a power supply filter module, a forward-flyback conversion module, an output filter module, a sampling and phase advance processing module, a PWM control module and an output voltage control module. The power supply filter module filters the input power supply and provides power to each module after filtering. The forward-flyback conversion module adopts a dual transformer to chop into a quasi-sine wave and then forms a high-voltage DC signal, which is then sent to the filter module and the phase advance processing part of the sampling and phase advance processing module. The output filter module filters the received signal and outputs it to the sampling part of the sampling and phase advance processing module. After sampling by the sampling part, it is output to the phase advance processing part. After processing, the phase advance processing part outputs it to the voltage control module. After processing, the voltage control module outputs it to the PWM control module. At the same time, the PWM control module introduces the driving current signal of the primary measurement of the first transformer and the signal output by the sampling part, and outputs the PWM signal to the forward-flyback conversion module after processing.

[0027] like Figure 2As shown, the power supply filter module includes a first inductor L1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4. One end of the first inductor L1 is connected to the +12V input power supply, and the other end of the first inductor L1 is grounded through the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 respectively. The other end of the first inductor L1 serves as an output power supply end to output a +12V voltage.

[0028] like Figure 3 As shown, the forward-flyback conversion module includes a driver U2, a twelfth resistor R12, a seventeenth resistor R17, a fifteenth resistor R15, a tenth resistor R10, a third resistor R3, a fourteenth capacitor C14, a twelfth capacitor C12, a fifth capacitor C5, a sixth capacitor C6, a first diode D1, a second diode D2, a third diode D3, a first MOS tube Q1, a first transformer T1 and a second transformer T2. The fifth pin of the driver U2 is connected to the power filter module, the third pin of the driver U2 receives the input PWM signal, the fourth pin is connected to the gate of the first MOS tube Q1 through the twelfth resistor R12, the drain of the first MOS tube Q1 is grounded through the fourteenth capacitor C14 and the seventeenth resistor R17, and is grounded through the fifteenth resistor R15, the drain of the first MOS tube Q1 is also connected to the fourth pin of the second transformer T2, and the A source of a MOS tube Q1 is connected to the third pin of the second transformer T2, a first pin of the second transformer T2 is connected to the cathode of the second diode D2, an anode of the second diode D2 is connected to the first pin of the first transformer T1, a second pin of the first transformer T1 is grounded through a tenth resistor R10, a third pin of the first transformer T1 is connected to the second pin of the second transformer T2, a fifth pin of the first transformer T1 outputs a switching pulse shaped into a quasi-sine wave through a fifth capacitor C5 and a third resistor R3, the third resistor R3 is grounded through a sixth capacitor C6, a cathode of the third diode D3 is connected to the fifth capacitor C5, an anode of the third diode D3 is connected to the fourth pin of the first transformer T1 through a twelfth capacitor C12, an anode of the third diode D3 is also connected to the cathode of the first diode D1, and an anode of the first diode D1 is connected to the fifth pin of the first transformer T1.

[0029] This part combines the traditional single forward switching power supply and flyback switching power supply, so as to realize the switching pulse shaping into a quasi-sine wave, which greatly reduces the switching pulse interference, which is the key to noise reduction.

[0030] When working, the PWM signal drives the PMOSFET tube Q1 through the driver U2. When Q1 is turned on, the electric energy is injected into the primary side of T2 and T1. T1 generates an induced electromotive force on the secondary side of T1 through electromagnetic coupling, and its loop is formed through C5, D3, and C12. When Q1 is turned off, the electric energy stored in T2 is released through D2, and the primary of T1 is demagnetized in the reverse direction. At this time, the secondary of T1 induces electromotive force again, and C12 is charged through the C12 and D1 loop.

[0031] The secondary of T1 adopts a similar capacitor multiplication circuit, which realizes the dual functions of forward switching power supply transmission of power and flyback switching power supply transmission of power, reduces the coil turns ratio, and is conducive to the production of T1 secondary winding.

[0032] The introduction of T2 is the essence of the entire switching power supply, which is different from the traditional forward or flyback switching power supply. When the T2 transformer is introduced, the pulse power generated by Q1 when it is turned on or off is shaped by T2 into a quasi-sine wave and sent to the two primary windings of the T1 transformer. This makes the secondary winding of T1 induce a quasi-sine wave induced electromotive force. This greatly reduces the switching pulse noise.

[0033] like Figure 4 As shown, the output filter module adopts multi-stage RC output filtering, which can effectively filter out the pulse interference of the switch tube, thereby reducing the output noise.

[0034] Specifically include inductor L2, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, capacitor C7, capacitor C8, capacitor C9, capacitor C10, capacitor C11,

[0035] One end of the inductor L2 is connected to the output end of the forward-flyback conversion module, and the other end is output after passing through resistors R4, R5, R6, R7, R8, and R9 in sequence. Capacitor C7 is connected between resistor R4 and resistor R5, capacitor C8 is connected between resistor R5 and resistor R6, capacitor C9 is connected between resistor R6 and resistor R7, capacitor C10 is connected between resistor R7 and resistor R8, and capacitor C11 is connected between resistor R8 and resistor R9.

[0036] like Figure 5As shown, the sampling and phase advance processing module includes a proportional resistor sampling unit U3, an eleventh resistor R11, a thirteenth resistor R13, a fourteenth resistor R14, a sixteenth resistor R16, a thirteenth capacitor C13, a fourth diode D4 and a processing chip U4B, one end of the eleventh resistor R11 is connected to the second inductor L2, the other end of the eleventh resistor R11 is connected to the fifth pin of the processing chip U4B through the fourteenth resistor R14, the fifth pin of the processing chip U4B is also connected to the cathode of the fourth diode D4, the anode of the fourth diode D4 is grounded, the thirteenth capacitor C13 is connected to the two ends of the eleventh resistor R11, the third pin of the proportional resistor sampling unit U3 receives the output signal of the output filter module, the second pin of the proportional resistor sampling unit U3 is connected to the fifth pin of the processing chip U4B through the thirteenth resistor R13, the first pin of the proportional resistor sampling unit U3 is grounded, and the sixth pin of the processing chip U4B is connected to the output end of the processing chip U4B through the sixteenth resistor R16.

[0037] During operation, the secondary of T1 is doubled by capacitors and diodes, and then output through LRC. The high voltage output is sampled by U3 proportional resistor. R11, C13, and R14 achieve phase advance acquisition of the output voltage, thereby shutting down Q1 tube in advance. The phase advance processing here is unique to the entire high-voltage generator, which can eliminate the hysteresis of the proportional resistor sampling feedback signal and cause loop control abnormality. D4 voltage regulation protects the U4B input to prevent excessive high voltage coupling on the high-voltage side from damaging the op amp.

[0038] like Figure 6 As shown, the PWM control module includes a switch controller U6, a thirty-first resistor R31, a thirty-second resistor R32, a thirty-fourth resistor R34, a thirty-sixth resistor R36 and a twentieth capacitor C20, the second pin of the switch controller U6 is grounded through the twentieth capacitor C20, the sixth pin of the switch controller U6 is grounded through the thirty-first resistor R31, the seventh pin of the switch controller U6 is grounded through the thirty-fourth resistor R34, the first pin of the switch controller U6 outputs a PWM signal, the third pin of the switch controller U6 is connected to the output voltage control module, and the fourth pin of the switch controller U6 receives the drive current signal IPre of the primary side of the first transformer T1 and the output signal VHFB of the proportional resistor sampling unit U3.

[0039] TI's TL5001 is used as the switch controller, and the switching frequency is set by R34. The DC feedback signal of the high-voltage output is fed into the FB port of U6, and the FB port introduces the driving current signal IPre measured by the primary of the T1 transformer.

[0040] The high voltage output AC signal passes through the phase advance processing circuit and is sent to the output voltage control module to achieve phase reversal. The output signal is filtered by R26 and C18 and then sent to the COMP pin of U6 for control.

[0041] like Figure 7 As shown, the output voltage control module includes a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a second MOS tube Q2, a control chip U4A, and a capacitor C17. The third pin of the control chip U4A is connected to the output voltage setting terminal Vset through the twenty-first resistor R21, and the third pin of the control chip U4A is also grounded through the twenty-first resistor R21 and the nineteenth resistor R19. The third pin of the control chip U4A is also connected to the reference voltage terminal VRef through the twentieth resistor R20. The control chip U The third pin of the control chip U4A is also connected to the source of the second MOS tube Q2, the gate of the second MOS tube Q2 is connected to the enable terminal EN through the twenty-third resistor R23, the gate of the second MOS tube Q2 is also connected to the drain of the second MOS tube Q2 through the twenty-fifth resistor R25, the drain of the second MOS tube Q2 is grounded, the second pin of the control chip U4A is connected to the output terminal Vfb of the output sampling and phase advance processing module through the twenty-second resistor R22, the second pin of the control chip U4A is also connected to the first pin of the control chip U4A through the capacitor C17, and the first pin of the control chip U4A is connected to the PWM control module through the twenty-sixth resistor R26.

[0042] The reference voltage VRef circuit includes resistors R39, R40, R41, and a voltage regulator chip U7. The model of U7 is LT431. The third pin of U7 is grounded, the first pin of U7 is grounded through resistor R41, the first pin of U7 is also connected to the second pin of U7 through resistor R40, and the second pin of U7 outputs the reference voltage VRef through resistor R39.

[0043] During operation, when EN is at a low level, Q2 is turned on, and U4A is at a zero level, Vfb must be at a zero level, and the sampling of the reverse output voltage must be at a zero level, so that its output is zero.

[0044] When EN is high, Q2 is turned off, and the Vfb level is determined by Vset. The output voltage is determined by the voltage divider resistor and Vset.

[0045] The output voltage is determined by Vset and the sampling ratio resistor. Assuming the ratio resistor is 200:1, the output voltage formula is:

[0046] V OUT =N*Vset

[0047] Where N is the proportional value of the proportional resistor, 200; VRef can be set by U7, R41, and R40. The current setting of VRef is 5V. Vset samples Vref and feeds it back to Vset through the center tap of the three-terminal adjustable resistor. The output

[0048] V OUT =K*1000V

[0049] Where K is the voltage division ratio of the external three-terminal adjustable resistor.

[0050] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A controllable low-noise positive high-voltage generator, characterized in that: It includes a forward-flyback conversion module, an output filtering module, a sampling and phase advance processing module, a PWM control module and an output voltage control module. The forward-flyback conversion module adopts a dual transformer to chop a quasi-sine wave and then forms a high-voltage DC signal, which is then sent to the filtering module and the phase advance processing part of the sampling and phase advance processing module. The output filtering module filters the received signal and outputs it to the sampling part of the sampling and phase advance processing module. After sampling by the sampling part, the signal is output to the phase advance processing part. After processing by the phase advance processing part, the signal is output to the voltage control module. After processing by the voltage control module, the signal is output to the PWM control module. At the same time, the PWM control module introduces the driving current signal of the primary measurement of the first transformer and the signal output by the sampling part, and outputs the PWM signal to the forward-flyback conversion module after processing. The forward-flyback conversion module comprises a driver (U2), a twelfth resistor (R12), a seventeenth resistor (R17), a fifteenth resistor (R15), a tenth resistor (R10), a third resistor (R3), a fourteenth capacitor (C14), a twelfth capacitor (C12), a fifth capacitor (C5), a sixth capacitor (C6), a first diode (D1), a second diode (D2), a third diode (D3), a first MOS tube (Q1), a first transformer (T1) and a second transformer (T2); the third pin of the driver (U2) receives an input PWM signal, the fourth pin is connected to the gate of the first MOS tube (Q1) through the twelfth resistor (R12), the drain of the first MOS tube (Q1) is grounded through the fourteenth capacitor (C14) and the seventeenth resistor (R17), and is grounded through the fifteenth resistor (R15); the drain of the first MOS tube (Q1) is also connected to the fourth pin of the second transformer (T2); the first MOS tube (Q1) The source of the first transformer (T1) is connected to the third pin of the second transformer (T2), the first pin of the second transformer (T2) is connected to the cathode of the second diode (D2), the anode of the second diode (D2) is connected to the first pin of the first transformer (T1), the second pin of the first transformer (T1) is grounded through a tenth resistor (R10), the third pin of the first transformer (T1) is connected to the second pin of the second transformer (T2), the fifth pin of the first transformer (T1) outputs a switching pulse shaped into a quasi-sine wave through a fifth capacitor (C5) and a third resistor (R3), the third resistor (R3) is grounded through a sixth capacitor (C6), the cathode of the third diode (D3) is connected to the fifth capacitor (C5), the anode of the third diode (D3) is connected to the fourth pin of the first transformer (T1) through a twelfth capacitor (C12), the anode of the third diode (D3) is also connected to the cathode of the first diode (D1), and the anode of the first diode (D1) is connected to the fifth pin of the first transformer (T1).

2. The controllable low-noise positive high-voltage generator according to claim 1, characterized in that: The output filter module comprises a second inductor (L2), a fourth resistor (R4) and a seventh capacitor (C7), one end of the second inductor (L2) is connected to the output end of the forward-flyback conversion module, and the other end outputs a signal through the fourth resistor (R4), and the fourth resistor (R4) is grounded through the seventh capacitor (C7).

3. The controllable low-noise positive high-voltage generator according to claim 2, characterized in that: The sampling and phase advance processing module comprises a proportional resistance sampling unit (U3), an eleventh resistor (R11), a thirteenth resistor (R13), a fourteenth resistor (R14), a sixteenth resistor (R16), a thirteenth capacitor (C13), a fourth diode (D4) and a processing chip (U4B), one end of the eleventh resistor (R11) is connected to the second inductor (L2), the other end of the eleventh resistor (R11) is connected to the fifth pin of the processing chip (U4B) through the fourteenth resistor (R14), and the fifth pin of the processing chip (U4B) is also connected to the fourth second The cathode of the diode (D4) is connected, the anode of the fourth diode (D4) is grounded, the thirteenth capacitor (C13) is connected to the two ends of the eleventh resistor (R11), the third pin of the proportional resistor sampling unit (U3) receives the output signal of the output filter module, the second pin of the proportional resistor sampling unit (U3) is connected to the fifth pin of the processing chip (U4B) through the thirteenth resistor (R13), the first pin of the proportional resistor sampling unit (U3) is grounded, and the sixth pin of the processing chip (U4B) is connected to the output end of the processing chip (U4B) through the sixteenth resistor (R16).

4. The controllable low-noise positive high-voltage generator according to claim 2, characterized in that: The PWM control module comprises a switch controller (U6), a thirty-first resistor (R31), a thirty-second resistor (R32), a thirty-fourth resistor (R34), a thirty-sixth resistor (R36) and a twentieth capacitor (C20); the second pin of the switch controller (U6) is grounded through the twentieth capacitor (C20); the sixth pin of the switch controller (U6) is grounded through the thirty-first resistor (R31); the seventh pin of the switch controller (U6) is grounded through the thirty-fourth resistor (R34); the first pin of the switch controller (U6) outputs a PWM signal; the third pin of the switch controller (U6) is connected to the output voltage control module; and the fourth pin of the switch controller (U6) receives a drive current signal (IPre) of the primary side of the first transformer (T1) and an output signal (VHFB) of a proportional resistor sampling unit (U3).

5. The controllable low-noise positive high-voltage generator according to claim 1, characterized in that: The output voltage control module comprises a nineteenth resistor (R19), a twentieth resistor (R20), a twenty-first resistor (R21), a twenty-second resistor (R22), a twenty-third resistor (R23), a twenty-fifth resistor (R25), a twenty-sixth resistor (R26), a second MOS tube (Q2), and a control chip (U4A). The third pin of the control chip (U4A) is connected to the output voltage setting terminal (Vset) through the twenty-first resistor (R21), the third pin of the control chip (U4A) is also grounded through the twenty-first resistor (R21) and the nineteenth resistor (R19), and the third pin of the control chip (U4A) is also connected to the output voltage setting terminal (Vset) through the twenty-first resistor (R21). 20) is connected to the reference voltage terminal (VRef), the third pin of the control chip (U4A) is also connected to the source of the second MOS tube (Q2), the gate of the second MOS tube (Q2) is connected to the enable terminal (EN) through the twenty-third resistor (R23), the gate of the second MOS tube (Q2) is also connected to the drain of the second MOS tube (Q2) through the twenty-fifth resistor (R25), the drain of the second MOS tube (Q2) is grounded, the second pin of the control chip (U4A) is connected to the output terminal (Vfb) of the sampling and phase advance processing module, and the first pin of the control chip (U4A) is connected to the PWM control module through the twenty-sixth resistor (R26).

6. The controllable low-noise positive high-voltage generator according to claim 1, characterized in that: The controllable low-noise positive high-voltage generator also includes a power supply filter module, which includes a first inductor (L1), a second capacitor (C2), a third capacitor (C3), and a fourth capacitor (C4). One end of the first inductor (L1) is connected to an input power supply, and the other end of the first inductor (L1) is grounded through the second capacitor (C2), the third capacitor (C3), and the fourth capacitor (C4), respectively. The other end of the first inductor (L1) serves as an output power supply end.

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