Boost unit and laminated high-voltage generator

Abstract

The invention belongs to the technical field of high-voltage electronic measurement, and provides a boosting unit and a laminated high-voltage generator. Wherein the boosting unit comprises a first circuit module and a second circuit module; the first circuit module and the second circuit module have the same structure and are reversely connected in series; each of the first circuit module and the second circuit module comprises a high-voltage power supply circuit, an MOS tube discharge circuit, a control circuit and a damping resistor; the high-voltage power supply circuit is composed of a coil and a voltage doubling rectification filter circuit connected with the coil. A positive electrode P of the high-voltage power supply circuit is connected to a positive high-voltage output end P1 through a damping resistor, a negative electrode N of the high-voltage power supply circuit is connected to a negative high-voltage output end N1 through a diode D4 of the control circuit, and the MOS tube discharge circuit is connected between the positive electrode P of the high-voltage power supply circuit and the negative high-voltage output end N1 in parallel. And under the control of the control circuit, the MOS tube discharge circuit is turned off while boosting is realized, and the MOS tube discharge circuit is turned on while voltage reduction is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of high-voltage electronic measurement, and in particular relates to a boost unit and a laminated high-voltage generator. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The ultra-low frequency high-voltage generator can generate any high-voltage waveform. It is mainly developed for the withstand voltage and dielectric loss tests of power cables and large-capacity power equipment. Compared with traditional power frequency test equipment, it greatly reduces the weight and volume of the equipment. The current ultra-low frequency high-voltage generator still has problems such as excessive weight (100kg level) and large volume. The latest laminated high-voltage generator has a predictable small weight and volume. Its simple insulation structure has clear high safety. The partial discharge of its laminated structure is extremely small, and it can also be used as a power supply without partial discharge.

[0004] The stacked high-voltage generator is composed of several stacked booster units. The design of the booster unit has a crucial impact on conversion efficiency, heat dissipation and reliability. In particular, some early solutions for the discharge circuit using MOS tubes in series are not perfect enough, resulting in a high failure rate of MOS tubes. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a boost unit and a laminated high-voltage generator, wherein the boost unit is composed of a high-voltage power supply circuit for providing energy, a MOS tube discharge circuit and a control circuit for absorbing energy, wherein the high-voltage power supply is composed of a PCB coil and a voltage doubling rectifier circuit, the MOS tube discharge circuit adopts a series connection and multiple protection structures to improve its working reliability, the control circuit can cooperate with the step-up and step-down to timely control the work of the MOS tube discharge circuit, so that the boost unit has a very high working efficiency, the boost unit is implemented by a single-board ultra-thin structure, and multiple boost units are stacked in series to form a laminated high-voltage generator, which has extremely high working safety and extremely small volume and weight as a whole.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a boost unit.

[0008] A boost unit comprises: a first circuit module and a second circuit module; the first circuit module and the second circuit module have the same structure and are reversely connected in series;

[0009] The first circuit module and the second circuit module both include a high-voltage power supply circuit, a MOS tube discharge circuit, a control circuit and a damping resistor;

[0010] The high-voltage power supply circuit is composed of a coil and a voltage-doubling rectifier filter circuit connected thereto; the positive electrode P of the high-voltage power supply circuit is connected to the positive high-voltage output terminal P1 through a damping resistor, the negative electrode N of the high-voltage power supply circuit is connected to the negative high-voltage output terminal N1 through a diode D4 of the control circuit, the MOS tube discharge circuit is connected in parallel between the positive electrode P and the negative high-voltage output terminal N1 of the high-voltage power supply circuit, and under the control of the control circuit, the MOS tube discharge circuit is closed while boosting the voltage, and the MOS tube discharge circuit is opened while reducing the voltage.

[0011] As an implementation manner, the MOS tube discharge circuit includes at least one MOS tube string, and each MOS tube string includes its own positive electrode P, low voltage electrode N, gate G and negative electrode N1.

[0012] As an implementation mode, when the MOS tube discharge circuit includes at least two MOS tube strings, the positive electrode P, low voltage electrode N, gate G and negative electrode N1 of each MOS tube string are respectively connected in parallel to form the positive electrode P, low voltage electrode N, gate G and negative electrode N1 of the MOS tube discharge circuit.

[0013] As an implementation method, each MOS tube string is composed of a plurality of identical NMOS tubes Q3, a vibration elimination capacitor C3, a bidirectional TVS tube T3, a voltage dividing resistor R3 and a varistor M3;

[0014] The source and drain of all NMOS tubes are connected in series to form a MOS tube string. The drain of the NMOS tube at the high-voltage end of the MOS tube string is the positive electrode P, and the source of the NMOS tube at the low-voltage end of the MOS tube string is connected in series with the current limiting resistor RS to form the negative electrode N1.

[0015] A vibration elimination capacitor C3 is connected in parallel between the drain and gate of each NMOS tube, a TVS tube T3 is connected in parallel between the gate and source of all NMOS tubes except the NMOS at the low voltage end, and a voltage divider resistor R3 and a varistor M3 are connected in parallel between the gates of all adjacent NMOS tubes except the NMOS at the low voltage end;

[0016] A voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gate and drain of the NMOS tube at the high-voltage end, a voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gate of the upper-level NMOS tube at the low-voltage end and the low-voltage pole N, and the gate of the NMOS tube at the low-voltage end is the gate G of the MOS tube string.

[0017] As an implementation mode, the control circuit is composed of a diode D4, a filter capacitor C4, a varistor M4, a resistor R4 and a voltage stabilizing diode Z4;

[0018] The cathode of the diode D4, one end of the filter capacitor C4, one end of the varistor M4 and one end of the resistor R4 are connected as the cathode N of the control circuit; the anode of the diode D4, the other end of the filter capacitor C4, the other end of the varistor M4 and the anode of the voltage-stabilizing diode Z4 are connected as the anode N1 of the control circuit; the other end of the resistor R4 and the cathode of the voltage-stabilizing diode Z4 are connected as the control end G of the control circuit.

[0019] When the high-voltage power supply circuit outputs energy to the outside, the voltage across P / N is higher than the voltage across P1 / N1. At this time, diode D4 is turned on, and the voltage across voltage-stabilizing diode Z4 is about -0.7V. This voltage forces the NMOS tube at the low-voltage end of the MOS tube discharge circuit to be cut off, and forces the entire MOS tube string in the MOS tube discharge circuit to be cut off, so that the P1 / N1 voltage increases synchronously with the voltage of the high-voltage power supply circuit.

[0020] When the voltage of the high-voltage power supply circuit decreases, the voltage across P / N is lower than the voltage across P1 / N1. At this time, the voltage of the negative electrode N of the control circuit is higher than the voltage of the positive electrode N1 of the control circuit, so that the diode D4 is cut off. When the voltage between N and N1 is higher than the conduction voltage of the NMOS tube at the low-voltage end in the MOS tube discharge circuit, the NMOS tube at the low-voltage end in the MOS tube discharge circuit is turned on, and at the same time, all other NMOS tubes in the MOS tube discharge circuit are turned on. The energy of the external load of P1 / N1 is absorbed by the NMOS tube, forcing the voltage of P1 / N1 to decrease synchronously with the voltage of the high-voltage power supply circuit.

[0021] As an implementation manner, the maximum operating current ID of each MOS tube string in the MOS tube discharge circuit is:

[0022] ID=(VZ-VG) / RS

[0023] Among them, VZ is the voltage across the voltage regulator tube Z4; VG is the conduction voltage of the NMOS tube at the low voltage end in the MOS tube discharge circuit; RS is the resistance value of the current limiting resistor.

[0024] As an implementation mode, the high-voltage power supply circuit includes at least one voltage-doubling rectifier filter circuit, and the voltage-doubling rectifier circuit includes a corresponding PCB coil, a rectifier diode and a capacitor.

[0025] As an implementation mode, the high-voltage power supply circuit includes at least two voltage-doubling rectifier filter circuits, and each voltage-doubling rectifier circuit includes a corresponding PCB coil, a rectifier diode and a capacitor.

[0026] In which, the high-voltage power supply circuit includes at least two four-fold voltage rectifier and filter circuits connected in series, each four-fold voltage rectifier and filter circuit includes a PCB coil, four diodes and four capacitors, the four diodes are connected in series in the same direction, two capacitors are connected in series and connected in parallel at both ends of the two middle series-connected diodes, the middle point of the series capacitors is connected to one end of the PCB coil, the other two capacitors are connected in series and connected at both ends of the four series-connected diodes, the middle point of the series capacitors is connected to the other end of the coil and the middle point of the four series-connected diodes, so as to obtain a DC voltage four times the peak voltage of the coil.

[0027] A second aspect of the present invention provides a stacked high voltage generator.

[0028] A stacked high voltage generator is formed by stacking a number of boosting units as described above, wherein the output voltages of the boosting units are in a series connection state.

[0029] The beneficial effects of the present invention are:

[0030] (1) The boost unit of the present invention automatically turns off the MOS discharge circuit when the high-voltage power supply output increases, and turns on the MOS tube discharge circuit when the high-voltage power supply output decreases, thereby realizing automatic voltage regulation for capacitive loads. Compared with the traditional resistive discharge circuit, the output voltage efficiency is very high, especially the use of MOS tube discharge, so that the discharge heat is dispersed on each MOS tube, which is conducive to heat dissipation.

[0031] (2) The voltage-dividing resistor in the MOS tube discharge circuit enables the MOS tube to evenly bear the high voltage. The varistor protects the MOS tube from overvoltage shock. The discharge current limiting function enables the MOS to work reliably.

[0032] (3) The increased damping resistance makes the external power supply more stable, eliminates the impact of high-voltage current mutation on the low-voltage drive circuit, and makes the equipment work more reliable.

[0033] (4) The boost unit of the present invention is composed of a first circuit module and a second circuit module with the same structure connected in reverse series. By driving their respective PCB coils, a boost unit can generate a maximum voltage output of + / -2kV. When several boost units are stacked in series, a higher continuously adjustable high-voltage output can be generated. The use of a voltage doubling rectifier circuit reduces the number of turns required for the coil by the high-voltage power supply. PCB coils and patch components can be used. The boost unit is a single circuit board ultra-thin and ultra-light structure, which is conducive to stacking and use, so that a laminated ultra-low frequency high-voltage generator can be realized. Compared with traditional equipment, the weight is only 1 / 3.

[0034] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 is a schematic diagram of a laminated high voltage generator according to an embodiment of the present invention;

[0037] Figure 2 is a circuit diagram of a boost unit according to an embodiment of the present invention;

[0038] Figure 3 It is a working principle diagram of the boost unit in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] according to Figure 1 and Figure 2 A boost unit according to an embodiment of the present invention comprises: a first circuit module a and a second circuit module b; the first circuit module a and the second circuit module b have the same structure and are connected in reverse series; the first circuit module a and the second circuit module b both comprise a high-voltage power supply circuit 1, a MOS tube discharge circuit 2, a control circuit 3 and a damping resistor R; the high-voltage power supply circuit 1 is composed of two voltage-doubling rectifier filter circuits including a coil; the positive electrode P of the high-voltage power supply is connected to the positive high-voltage output terminal P1 through the damping resistor R, the negative electrode N of the high-voltage power supply is connected to the negative high-voltage output terminal N1 through the diode D4 of the control circuit, the MOS tube discharge circuit 2 is connected in parallel between the positive electrode P of the high-voltage power supply and the negative high-voltage output terminal N1, and the MOS tube discharge circuit is closed while boosting the voltage under the control of the control circuit 3, and the MOS tube discharge circuit is opened while reducing the voltage.

[0043] In one embodiment, the high-voltage power supply circuit includes at least one voltage-doubling rectifier filter circuit, and the voltage-doubling rectifier circuit includes a corresponding PCB coil, a rectifier diode and a capacitor.

[0044] In another embodiment, the high-voltage power supply circuit includes at least two voltage-doubling rectifier filter circuits, and each voltage-doubling rectifier circuit includes a corresponding PCB coil, a rectifier diode, and a capacitor.

[0045] In which, the high-voltage power supply circuit includes at least two four-fold voltage rectifier and filter circuits connected in series, each four-fold voltage rectifier and filter circuit includes a PCB coil, four diodes and four capacitors, the four diodes are connected in series in the same direction, two capacitors are connected in series and connected in parallel at both ends of the two middle series-connected diodes, the middle point of the series capacitors is connected to one end of the PCB coil, the other two capacitors are connected in series and connected at both ends of the four series-connected diodes, the middle point of the series capacitors is connected to the other end of the coil and the middle point of the four series-connected diodes, so as to obtain a DC voltage four times the peak voltage of the coil.

[0046] For example, in this embodiment, the PCB coil of the high-voltage power supply circuit 1 includes two independent coils, each coil is 60T. Driven by the magnetic rod, each coil can generate a maximum peak-to-peak voltage of 250V. Through two series-connected four-fold voltage rectifier circuits, a maximum voltage of 250V*4*2=2000V can be output. The diode model used is US1M and the capacitor is 0.1uF / 1000V. Its positive pole is P and its negative pole is N. General electronic technology professionals can easily understand the role and working principle of the high-voltage power supply circuit.

[0047] In one or more embodiments, the MOS tube discharge circuit 2 includes at least one MOS tube string, each MOS tube string includes its own positive electrode P, low voltage electrode N, gate G and negative electrode N1. In order to increase the discharge current and reduce the electrical stress of the NMOS tube, the MOS tube discharge circuit 2 may include multiple MOS tube strings with the same structure. The positive electrode P, low voltage electrode N, gate G and negative electrode N1 of each MOS tube string are respectively connected in parallel to form the positive electrode P, low voltage electrode N, gate G and negative electrode N1 of the MOS tube discharge circuit.

[0048] Among them, each MOS tube string is composed of several identical NMOS tubes Q3, vibration elimination capacitor C3, bidirectional TVS tube T3, voltage divider resistor R3 and varistor M3. The source and drain of all NMOS tubes are connected in series to form a MOS tube string. The drain of the MOS tube at the high-voltage end of the NMOS tube string is the positive electrode P, and the source of the NMOS tube at the low-voltage end of the MOS tube string is connected in series with the current limiting resistor RS to become the negative electrode N1. A vibration elimination capacitor C3 is connected in parallel between the drain and gate of each NMOS tube. Except for the NMOS at the low-voltage end, A TVS tube T3 is connected in parallel between the gate and source of all NMOS tubes, a voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gates of all adjacent NMOS tubes except the NMOS at the low-voltage end, a voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gate and drain of the NMOS tube at the high-voltage end, a voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gate of the upper-level NMOS tube of the NMOS tube at the low-voltage end and the low-voltage pole N, and the gate of the NMOS tube at the low-voltage end is the gate G of the MOS tube string.

[0049] The voltage-equalizing resistor R3 of the MOS tube discharge string realizes voltage equalization of the NMOS tube, the varistor M3 protects the NMOS tube, the vibration-eliminating capacitor C3 makes the MOS tube work stably, and the TVS tube protects the gate of the NMOS; the voltage-stabilizing tube Z4 and the current-limiting resistor RS of the control circuit 3 limit the maximum working current of the NMOS tube, so that the NMOS tube works in a safe area.

[0050] like Figure 2As shown in part 2 of the embodiment, the present embodiment comprises three independent MOS tube strings X1 to X3 with the same structure, each MOS string is formed by 12 NMOS tubes Y1 to Y12 connected in series, wherein Y1 is at the low voltage end and Y12 is at the high voltage end; since the current of Y2 to Y12 is controlled by Y1, there is a delay in the current transmission process, which may cause Y2 to Y12 to oscillate, and a vibration elimination capacitor C3 is connected in parallel between the drain and the gate of Y1 to Y12 to effectively eliminate the oscillation, and C3 may be selected from 470pF to 2200pF; a bidirectional TVS tube T3 is connected in parallel between the gate and the source of Y2 to Y12 to protect the gate of the MOS tube, and its protection voltage may be selected from 5V to 10V; in particular, 12 voltage dividing resistors R3 connected between P and N divide the high voltage power supply, and the voltage dividing point is connected to the gate of each NMOS tube, The voltages at both ends of all MOS tubes are basically consistent, and the voltage of the MOS tube string is equalized, thereby preventing the uneven voltage distribution of the MOS tube string from causing the breakdown of individual NMOS tubes; taking the voltage of 3600V between P / N as an example, the voltage across R3 of each voltage-dividing resistor is 300V, which is also the voltage borne by each NMOS tube Q3. In this embodiment, the value of R3 is 300K; each voltage-dividing resistor R3 is connected in parallel with a varistor M3, which can further limit abnormal conditions, especially the voltage across the NMOS tube in the case of external high-voltage impact, and further improve reliability. In this embodiment, the voltage value range of M3 is 270V to 470V; in this embodiment, the maximum designed operating current of the MOS tube string is about 50mA, and FQD2N60C in TO252 package is used, which does not exceed its safe operating area.

[0051] In one or more embodiments, the attached Figure 2 The control circuit 3 is composed of a diode D4, a filter capacitor C4, a varistor M4, a resistor R4 and a voltage-stabilizing diode Z4, wherein the cathode of the diode D4, one end of the filter capacitor C4, one end of the varistor M4 and one end of the resistor R4 are connected as the cathode N of the control circuit, the anode of the diode D4, the other end of the filter capacitor C4, the other end of the varistor M4 and the anode of the voltage-stabilizing diode Z4 are connected as the anode N1 of the control circuit, and the other end of the resistor R4 and the cathode of the voltage-stabilizing diode Z4 are connected as the control end G of the control circuit.

[0052] The working principle of the control circuit 3 is:

[0053] When the high-voltage power supply circuit 1 outputs energy to the outside, the voltage across P / N is higher than the voltage across P1 / N1. At this time, D4 ​​is turned on, and the voltage across Z4 is about -0.7V. This voltage forces the MOS tube Y1 to be turned off and forces the entire MOS tube string to be turned off, so that the voltage of P1 / N1 increases synchronously with the voltage of the high-voltage power supply circuit 1.

[0054] When the voltage of the high-voltage power supply circuit 1 decreases, the voltage across P / N is lower than the voltage across P1 / N1. At this time, the voltage of the negative electrode N of the control circuit 3 is higher than the voltage of the positive electrode N1 of the control circuit, so that D4 is cut off. When the voltage between N and N1 is higher than the conduction voltage of Y1 (about 3V), Y1 is turned on, and Y2~Y12 are turned on at the same time. The energy of the external load (especially the capacitive load) of P1 / N1 is absorbed by the NMOS tube, forcing the voltage of P1 / N1 to decrease synchronously with the voltage of the high-voltage power supply circuit 1.

[0055] In order to limit the maximum on-current of NMOS, R4 and Z4 limit the gate voltage of Y1, and the maximum on-current of NMOS tube is limited by the current limiting resistor RS; using the voltage regulator Z4 with VZ=10V, the on-voltage VG of Y1 is 3V, and RS is 130Ω, then the maximum operating current ID of each MOS tube string is:

[0056] ID=(VZ-VG) / RS=53.8mA

[0057] When three MOS tubes are connected in series and parallel, the total maximum operating current is 53.8mA*3=161mA, which can meet the requirements of most high-voltage generators. In the embodiment, D4 adopts US1M, M4 voltage is 24V, R4 is 10K, and C4 is 10nF.

[0058] The damping resistor R has two main functions. One is to stabilize the high-voltage output current and reduce the current impact on the low-voltage and high-frequency drive circuit. The other is that when an external high voltage impacts the boost unit, the damping resistor cooperates with each varistor to protect the MOS tube and other devices. In the embodiment, the value is 600Ω.

[0059] When 40 boost units are installed in a stacked manner, an output capacity of 80kV / 50mA is achieved. Actual measurements show that under full load, the temperature rise of the boost unit is only 30° under forced air cooling. In other embodiments, only one MOS tube string can be used, and 20 boost units can be installed in a stacked manner to achieve an output capacity of 40kV / 35mA.

[0060] In order to further illustrate the working principle of the boost unit, Figure 3 A simplified circuit is used to show the process of the output voltage of the circuit increasing and decreasing when there is a capacitive load. The four-fold voltage rectifier circuit is simplified from two stages to one stage, the MOS tube string is simplified from M strings to 1 string, and the MOS tube unit in each string is simplified from N stages to 2 stages. All varistors M3, M4, all TVS protection tubes T3, vibration elimination capacitor C3 and damping resistor R are removed, and CL is added as the load capacitor, where R31=R3, Q31=Q3.

[0061] The boost unit works in two stages:

[0062] The first stage is the charging stage. When the high-frequency drive received by the coil W1 is strengthened and the voltage U generated at both ends of the rectifier circuit is greater than the voltage UL at both ends of CL, the diode D4 is forced to turn on and charges CL through D4 to generate a charging current IC. At this time, the voltage at both ends of D4 is about -0.7V, the gate voltage of Q3 is lower than the source voltage, Q3 is cut off, and Q31 is also forced to cut off due to the lack of source current. At the same time, since R31=R3, they divide the voltage of US so that Q31 and Q3 are subjected to the same voltage and are in a voltage-equalizing state.

[0063] The second stage is the discharge stage. At this time, W1 is weakened by the high-frequency drive, and the voltage U generated at both ends of the rectifier circuit is gradually lower than the voltage UL at both ends of CL. At this time, the diode D4 is cut off, and the voltage at point N, that is, the voltage of the gate G, is higher than the voltage of the negative output N1, forcing Q3 to turn on. The current flowing through Q3 also forces Q31 to turn on and form a discharge current ID, which reduces UL. At the same time, since R31=R3, they divide the voltage of UL so that Q31 and Q3 are subjected to the same voltage and are in a voltage-equalizing state.

[0064] The above two stages force UL to follow the change of U and keep U=UL, so as to obtain a linear change of UL with the strength of driving W1.

[0065] When the two circuits follow Figure 1 When the coils on both sides are connected in reverse series as shown, any voltage output can be achieved linearly and bipolarly.

[0066] In some other embodiments, a stacked high voltage generator is provided, which is formed by stacking a plurality of boosting units as described above, wherein the output voltages of the boosting units are connected in series.

[0067] It should be noted here that, except for the boost unit, other components of the stacked high-voltage generator can be realized by using existing technologies, which will not be described in detail here.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A boost unit, characterized in that: include: A first circuit module and a second circuit module; the first circuit module and the second circuit module have the same structure and are connected in reverse series; The first circuit module and the second circuit module both include a high-voltage power supply circuit, a MOS tube discharge circuit, a control circuit and a damping resistor; The high-voltage power supply circuit is composed of a coil and a voltage-doubling rectifier filter circuit connected thereto; the positive electrode P of the high-voltage power supply circuit is connected to the positive high-voltage output terminal P1 through a damping resistor, the negative electrode N of the high-voltage power supply circuit is connected to the negative high-voltage output terminal N1 through a diode D4 of the control circuit, the MOS tube discharge circuit is connected in parallel between the positive electrode P and the negative high-voltage output terminal N1 of the high-voltage power supply circuit, and under the control of the control circuit, the MOS tube discharge circuit is closed while boosting the voltage, and the MOS tube discharge circuit is opened while reducing the voltage.

2. The boost unit according to claim 1, characterized in that: The MOS tube discharge circuit includes at least one MOS tube string, and each MOS tube string includes a respective positive electrode P, a low voltage electrode N, a gate electrode G and a negative electrode N1.

3. The boost unit according to claim 2, characterized in that: When the MOS tube discharge circuit includes at least two MOS tube strings, the positive electrode P, low voltage electrode N, gate G and negative electrode N1 of each MOS tube string are respectively connected in parallel to form the positive electrode P, low voltage electrode N, gate G and negative electrode N1 of the MOS tube discharge circuit.

4. The boost unit according to claim 2, characterized in that: Each MOS tube string is composed of several identical NMOS tubes Q3, vibration elimination capacitor C3, bidirectional TVS tube T3, voltage divider resistor R3 and varistor M3; The source and drain of all NMOS tubes are connected in series to form a MOS tube string. The drain of the NMOS tube at the high-voltage end of the MOS tube string is the positive electrode P, and the source of the NMOS tube at the low-voltage end of the MOS tube string is connected in series with the current limiting resistor RS to form the negative electrode N1. A vibration elimination capacitor C3 is connected in parallel between the drain and gate of each NMOS tube, a TVS tube T3 is connected in parallel between the gate and source of all NMOS tubes except the NMOS at the low voltage end, and a voltage divider resistor R3 and a varistor M3 are connected in parallel between the gates of all adjacent NMOS tubes except the NMOS at the low voltage end; A voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gate and drain of the NMOS tube at the high-voltage end, a voltage-dividing resistor R3 and a varistor M3 are connected in parallel between the gate of the upper-level NMOS tube at the low-voltage end and the low-voltage pole N, and the gate of the NMOS tube at the low-voltage end is the gate G of the MOS tube string.

5. The boost unit according to any one of claims 1 to 4, characterized in that: The control circuit is composed of a diode D4, a filter capacitor C4, a varistor M4, a resistor R4 and a voltage stabilizing diode Z4; The cathode of the diode D4, one end of the filter capacitor C4, one end of the varistor M4 and one end of the resistor R4 are connected as the cathode N of the control circuit; the anode of the diode D4, the other end of the filter capacitor C4, the other end of the varistor M4 and the anode of the voltage-stabilizing diode Z4 are connected as the anode N1 of the control circuit; the other end of the resistor R4 and the cathode of the voltage-stabilizing diode Z4 are connected as the control end G of the control circuit.

6. The boost unit according to claim 5, characterized in that: When the high-voltage power supply circuit outputs energy to the outside, the voltage across P / N is higher than the voltage across P1 / N1. At this time, diode D4 is turned on, and the voltage across voltage-stabilizing diode Z4 is about -0.7V. This voltage forces the NMOS tube at the low-voltage end of the MOS tube discharge circuit to be cut off, and forces the entire MOS tube string in the MOS tube discharge circuit to be cut off, so that the P1 / N1 voltage increases synchronously with the voltage of the high-voltage power supply circuit.

7. The boost unit according to claim 5, characterized in that: When the voltage of the high-voltage power supply circuit decreases, the voltage across P / N is lower than the voltage across P1 / N1. At this time, the voltage of the negative electrode N of the control circuit is higher than the voltage of the positive electrode N1 of the control circuit, so that the diode D4 is cut off. When the voltage between N and N1 is higher than the conduction voltage of the NMOS tube at the low-voltage end in the MOS tube discharge circuit, the NMOS tube at the low-voltage end in the MOS tube discharge circuit is turned on, and at the same time, all other NMOS tubes in the MOS tube discharge circuit are turned on. The energy of the external load of P1 / N1 is absorbed by the NMOS tube, forcing the voltage of P1 / N1 to decrease synchronously with the voltage of the high-voltage power supply circuit.

8. The boost unit according to claim 7, characterized in that: The maximum operating current ID of each MOS tube string in the MOS tube discharge circuit is: ID=(VZ-VG) / RS Among them, VZ is the voltage across the voltage regulator tube Z4; VG is the conduction voltage of the NMOS tube at the low voltage end in the MOS tube discharge circuit; RS is the resistance value of the current limiting resistor.

9. The boost unit according to claim 1, characterized in that: The high-voltage power supply circuit includes at least one voltage-doubling rectifier filter circuit, and the voltage-doubling rectifier circuit includes a corresponding PCB coil, a rectifier diode and a capacitor; Or the high-voltage power supply circuit includes at least two voltage-doubling rectifier filter circuits, and each voltage-doubling rectifier circuit includes a corresponding PCB coil, a rectifier diode and a capacitor.

10. A laminated high voltage generator, characterized in that: The boost unit is formed by stacking a plurality of boost units as claimed in any one of claims 1 to 9, wherein the output voltages of the boost units are connected in series.

Images