A program-controlled pulse voltage generating device based on Marx generating principle

Abstract

The embodiment of the application discloses a program-controlled pulse voltage generating device based on Marx generating principle, and relates to the technical field of voltage generating device.The program-controlled pulse voltage generating device comprises a core control unit, a program-controlled charging unit and a Marx pulse voltage generating unit, the core control unit comprises a single-chip microcomputer, the program-controlled charging unit comprises a power rectifier circuit, a high-frequency transformer circuit, a power management circuit and a voltage output circuit, and the Marx pulse voltage generating unit comprises a Marx generating circuit and a driving circuit, and the Marx generating circuit does not adopt a step-up inductor.The embodiment of the application can solve the problem that output pulse voltage cannot simultaneously control pulse voltage amplitude and width.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage generating device, in particular to a program-controlled pulse voltage generating device based on Marx generating principle. BACKGROUND

[0002] In recent years, with the development of power semiconductor technology, the gas switch in the traditional Marx circuit is gradually replaced by solid-state switch to realize high repetition frequency and high reliability pulse design. In order to improve the efficiency of the Marx generator, the charging resistor is replaced by inductor and diode, the energy storage effect of the inductor is used, and the voltage of the energy storage capacitor is boosted by controlling the on-off time and frequency of the solid-state switch. When the solid-state switch is off, the energy storage capacitor is in parallel state, the energy stored in the inductor and the power supply are charged to the energy storage capacitor through the diode at the same time, and the charging voltage is higher than the power supply voltage, so as to realize the voltage boosting of the energy storage capacitor. When the solid-state switch is turned on, the energy storage capacitor is discharged in series to the load, and the voltage amplitude is equal to n times the voltage value of the energy storage capacitor (n is the number of energy storage capacitors).

[0003] In this scheme, the solid-state switch is in the state of continuous conduction and shutdown, so that a large number of repeated pulses are applied to the two ends of the load, and therefore it cannot be applied to occasions requiring single pulse voltage. In actual operation, the on-off frequency of the solid-state switch is generally fixed, and the charging voltage of the energy storage capacitor depends on the on-off time of the solid-state switch. If different amplitude pulse voltages are required, the on-off time of the solid-state switch needs to be changed constantly, so the width of the pulse voltage applied to the two ends of the load is also changed. Therefore, if a fixed pulse voltage amplitude is required, a fixed pulse voltage width cannot be obtained, and if a fixed pulse voltage width is required, a fixed pulse voltage amplitude cannot be obtained. SUMMARY

[0004] Therefore, the embodiment of the present application provides a program-controlled pulse voltage generating device based on Marx generating principle to solve the problem that the output pulse voltage cannot control the pulse voltage amplitude and width at the same time.

[0005] A program-controlled pulse voltage generating device based on Marx generating principle, comprising a power supply unit, a core control unit, a program-controlled charging unit and a Marx pulse voltage generating unit, wherein:

[0006] The power supply unit is used to convert alternating current into stable direct current to supply power to the whole device;

[0007] The core control unit comprises a single-chip microcomputer;

[0008] The program-controlled charging unit comprises a power rectifier circuit, a high-frequency transformer circuit, a power management circuit and a voltage output circuit;

[0009] The Marx pulse voltage generating unit comprises a Marx generating circuit and a driving circuit, and the Marx generating circuit does not use a boost inductor;

[0010] The power supply rectifier circuit is used for converting alternating current into stable direct current provided to the high-frequency transformer circuit; the power management circuit comprises a pulse width modulation chip, and is used for receiving voltage data provided by the single-chip microcomputer and outputting a pulse signal to the high-frequency transformer circuit; the high-frequency transformer circuit adopts a flyback power supply principle, stores electric energy in a high-frequency transformer in the high-frequency transformer circuit according to an output frequency and a duty cycle of the pulse signal output by the power management circuit, and provides the electric energy to the Marx generating circuit through the voltage output circuit; and the driving circuit receives a control signal of the single-chip microcomputer to control the on-off time of the solid-state switch in the Marx generating circuit.

[0011] Further, the power supply unit comprises a transformer L1, a rectifier bridge D1 and a plurality of power stabilizing modules U1-U4 connected in sequence.

[0012] Further, the power supply rectifier circuit comprises a first output end and a second output end, and a first filter capacitor C 13 and a second filter capacitor C 14 are connected in series between the first output end and the second output end, and a first voltage equalizing resistor R1 and a second voltage equalizing resistor R2 are also connected in series, the first filter capacitor C 13 is connected in parallel with the first voltage equalizing resistor R1, and the second filter capacitor C 14 is connected in parallel with the second voltage equalizing resistor R2.

[0013] Further, the power supply rectifier circuit is filtered by an X safety capacitor CX1, CX3, a Y safety capacitor CY1, CY2 and a common-mode inductor L2, is rectified by a rectifier bridge D2, and finally obtains stable direct current through the first filter capacitor C 13 , the second filter capacitor C 14 , the first voltage equalizing resistor R1 and the second voltage equalizing resistor R2.

[0014] Further, the high-frequency transformer circuit comprises a first transformer L5, a second transformer L3, a first NPN transistor Q1, a second NPN transistor Q2, a third NPN transistor Q3 and a fourth NPN transistor Q4;

[0015] The pulse width modulation chip comprises a first pulse signal output end and a second pulse signal output end, the first pulse signal output end is connected to the base of the fourth NPN transistor Q4, and the second pulse signal output end is connected to the base of the third NPN transistor Q3;

[0016] The direct current power supply is connected to the resistor R 12 The third NPN transistor Q3 is connected to the fourth NPN transistor Q4, and the fourth NPN transistor Q4 is connected to the first transformer L5.

[0017] The first output end of the power supply rectifier circuit is connected to the collector of the first NPN transistor Q1, the emitter of the first NPN transistor Q1 is connected to the collector of the second NPN transistor Q2, and the emitter of the second NPN transistor Q2 is connected to the second output end of the power supply rectifier circuit.

[0018] The secondary winding of the first transformer L5 includes a first secondary winding and a second secondary winding, one end of the first primary winding is connected to the base of the second NPN transistor Q2 through a diode D4 and a protection resistor R6, and the other end is connected to the emitter of the second NPN transistor Q2. 13 The second primary winding has three terminals, one of which is connected to the primary winding of the second transformer L3 between the first filter capacitor C 14 and the second filter capacitor C

[0019] The voltage output circuit is used to rectify and filter the output of the secondary winding of the second transformer L3 and provide it to the Marx generator circuit.

[0020] Further, the first pulse signal output by the first pulse signal output end and the second pulse signal output by the second pulse signal output end are a pair of complementary pulse signals.

[0021] Further, the primary winding of the second transformer L3 is connected in parallel with a resistor R9 and a capacitor C 18 .

[0022] Further, the pulse width modulation chip includes an output voltage acquisition end for acquiring the output voltage between the two output ends of the voltage output circuit and a reference voltage receiving end for obtaining the reference voltage from the single-chip microcomputer, and the pulse width modulation chip compares the obtained output voltage with the reference voltage to adjust the duty cycle of the output pulse signal.

[0023] Further, the power management circuit further comprises a digital-to-analog conversion chip, an input end of the digital-to-analog conversion chip is connected to the single-chip microcomputer, and an output end of the digital-to-analog conversion chip is connected to the pulse width modulation chip to provide a reference voltage for the pulse width modulation chip.

[0024] Further, in the voltage output circuit, the secondary winding of the second transformer L3 sequentially passes through a rectifier bridge D7, an energy storage inductor L4, a filter capacitor C 19 ~C 22 The output is provided to the Marx generating circuit;

[0025] And / or, two output ends of the voltage output circuit are connected in series with two voltage dividing resistors R 10 , R 11 A connection point between the two voltage dividing resistors is connected to an output voltage collection end of the pulse width modulation chip.

[0026] Further, the driving circuit comprises a control switch U5, a control end of the control switch U5 is connected to a control signal output end of the single-chip microcomputer, the control switch U5 is connected with a plurality of optocouplers U6-U9 connected in series, output ends of the plurality of optocouplers U6-U9 respectively control one solid-state switch Q5-Q8 in the Marx generating circuit, the control switch U5 is an optocoupler, and the solid-state switches Q5-Q8 in the Marx generating circuit are all NPN transistors.

[0027] The program-controlled pulse voltage generating device based on the Marx generating principle provided by the embodiment of the application has the following advantages: on the one hand, the power management circuit includes a pulse width modulation chip, the power management circuit is used for receiving voltage data provided by a single-chip microcomputer and outputting a pulse signal to a high-frequency transformer circuit, the high-frequency transformer circuit adopts the flyback power principle, and the power is stored in a high-frequency transformer in the high-frequency transformer circuit according to the output frequency and the duty cycle of the pulse signal output by the power management circuit, and the power is provided to the Marx generating circuit through a voltage output circuit, so that the power management circuit can adjust the duty cycle of the output pulse signal by means of the pulse width modulation chip, thereby adjusting the energy storage time of the high-frequency transformer and further adjusting the amplitude of the output voltage, so as to achieve the purpose of controlling the pulse voltage amplitude; on the other hand, the Marx generating circuit does not use a boost inductor, so the circuit itself loses the function of boosting by controlling the on-off of the solid-state switch, and therefore the driving circuit receives the control signal of the single-chip microcomputer to control the on-off time of the solid-state switch in the Marx generating circuit, so that the output pulse width depends on the on time of the solid-state switch, thereby achieving the purpose of controlling the pulse voltage width. Therefore, the embodiment of the application is improved on the basis of the Marx generating principle, and can solve the problem that the output pulse voltage cannot control the pulse voltage amplitude and width at the same time, so as to achieve the purpose that the output pulse voltage amplitude and width can be directly controlled by the upper computer. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0029] Figure 1 The circuit diagram of the power supply unit in the application;

[0030] Figure 2 The circuit diagram of the core control unit in the application;

[0031] Figure 3 The circuit diagram of the program-controlled charging unit in the application;

[0032] Figure 4 The circuit diagram of the driving circuit of the Marx pulse voltage generating unit in the application;

[0033] Figure 5 The circuit diagram of the Marx generating circuit of the Marx pulse voltage generating unit in the application. DETAILED DESCRIPTION

[0034] The embodiments of the present application will be described in detail below with reference to the drawings.

[0035] It should be noted that the embodiments described are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] The embodiment of the present application provides a program-controlled pulse voltage generating device based on Marx generating principle, as shown in the figure, which comprises a core control unit 11, a program-controlled charging unit 12 and a Marx pulse voltage generating unit 13, wherein: Figures 1-5

[0037] The core control unit 11 comprises a single-chip microcomputer, which can be various models of single-chip microcomputers, and in the embodiment shown in the figure, it is an STM32 single-chip microcomputer; the single-chip microcomputer can perform data transmission with an upper computer through a serial communication mode, and complete data transmission with related units in SPI communication protocol;

[0038] The program-controlled charging unit 12 comprises a power rectifier circuit 121, a high-frequency transformer circuit 122, a power management circuit 123 and a voltage output circuit 124;

[0039] The Marx pulse voltage generating unit 13 comprises a Marx generating circuit 131 and a driving circuit 132, and the Marx generating circuit 131 does not use a boost inductor;

[0040] The power rectifier circuit 121 is used to convert alternating current into stable direct current to provide for the high-frequency transformer circuit 122; the power management circuit 123 comprises a pulse width modulation chip, and is used to receive voltage data provided by the single-chip microcomputer and output pulse signals to the high-frequency transformer circuit 122; the high-frequency transformer circuit 122 adopts a flyback power supply principle, stores electric energy in a high-frequency transformer in the high-frequency transformer circuit 122 according to the output frequency and duty cycle of the pulse signals output by the power management circuit 123, and provides the electric energy to the Marx generating circuit 131 through the voltage output circuit 124; the driving circuit 132 receives control signals of the single-chip microcomputer to control the on-off time of solid-state switches in the Marx generating circuit 131.

[0041] ​The program-controlled pulse voltage generating device based on the Marx generating principle in the embodiment of the application, on the one hand, the power management circuit includes a pulse width modulation chip, the power management circuit is used for receiving voltage data provided by a single-chip microcomputer and outputting a pulse signal to a high-frequency transformer circuit, the high-frequency transformer circuit adopts the flyback power principle, and the power management circuit is used for storing power in a high-frequency transformer in the high-frequency transformer circuit according to the output frequency and the duty cycle of the pulse signal output by the power management circuit, and providing the power to the Marx generating circuit through a voltage output circuit, so that the power management circuit can adjust the duty cycle of the output pulse signal by means of the pulse width modulation chip, thereby adjusting the energy storage time of the high-frequency transformer, further adjusting the amplitude of the output voltage, and achieving the purpose of controlling the pulse voltage amplitude; on the other hand, the Marx generating circuit does not use a boost inductor, so that the circuit itself loses the function of boosting by controlling the on-off of the solid-state switch, and because of this, the driving circuit receives the control signal of the single-chip microcomputer to control the on-off time of the solid-state switch in the Marx generating circuit, so that the output pulse width depends on the on time of the solid-state switch, thereby achieving the purpose of controlling the pulse voltage width. Therefore, the embodiment of the application is improved on the basis of the Marx generating principle, and can solve the problem that the output pulse voltage cannot control the pulse voltage amplitude and width at the same time, so as to achieve the purpose that the output pulse voltage amplitude and width can be directly controlled by the upper computer.

[0042] Power supply unit

[0043] In view of the fact that there are many different chips in the circuit and the supply voltages are different, a power supply unit 10 can be provided to convert alternating current into stable direct current for supplying power to the entire device.

[0044] The power supply unit 10 can adopt various designs in the art. For example, Figure 1 A circuit diagram of an embodiment of the power supply unit 10 is shown, which mainly functions to supply power to the entire system. It converts 220V mains power into the required direct current voltage through the transformer L1 and the rectifier bridge D1, and then converts it into the required voltage value through the power stabilizing modules U1, U2, U3 and U4. Among them, U1 is used to provide +12V direct current power, U2 is used to provide +5V direct current power, U3 is used to provide +3.3V direct current power, and U4 is used to provide +2.048V direct current power; the number of power stabilizing modules can be flexibly designed according to needs, and is not limited to the four shown in the figure, but can be more or less. In order to filter and stabilize, capacitors C1-C 10 .

[0045] Core control unit

[0046] Figure 2The circuit diagram of the core control unit 11 embodiment is shown. This unit is the core control part of the program-controlled pulse voltage generating device of the present application based on the principle of Marx generator, which is composed of an STM32 single-chip microcomputer and a crystal oscillator, and the main function is to process the received pulse amplitude and pulse width data, and then control the capacitor parallel charging voltage and the capacitor series discharge time. Among them, PA9 and PA10 are connected with TX and RX of the serial port respectively, which plays the function of data transmission between the upper computer (not shown); PB0, PB1 and PB2 are connected with the DIN, SCLK and CS pins of the digital-to-analog conversion chip (TLC5618 chip) of the program-controlled charging unit 12, which provides digital data for it. PB3 and PB4 are pulse width output control pins and charging voltage feedback pins.

[0047] Programmed charging unit

[0048] Figure 3 The circuit diagram of the program-controlled charging unit 12 embodiment is shown. This part is based on the basic principle of flyback power supply, combined with the voltage comparison function of the pulse width modulation chip (TL494 power management chip) 1, 2 pins, to realize voltage programming and stable output. It is mainly composed of power rectifier circuit 121, high-frequency transformer circuit 122, power management circuit 123 and voltage output circuit 124.

[0049] Working principle: when the core control unit 11 transmits the preset voltage value digital data to the program-controlled charging unit 12 through the SPI communication protocol, the digital-to-analog conversion chip (TLC5618 chip) of the program-controlled charging unit 12 converts the digital quantity into voltage value as the reference voltage of the pulse width modulation chip (TL494 chip), at the same time, the pulse width modulation chip outputs a pulse signal with dead time to control the high-frequency transformer to work, so as to output voltage on the high-frequency transformer secondary winding, then the pulse width modulation chip compares the collected output voltage value with the reference voltage to adjust the duty cycle of the output pulse signal, so as to adjust the energy storage time of the high-frequency transformer, and then adjust the amplitude of the output voltage, so that the output voltage is more stable.

[0050] (1) Power rectifier circuit

[0051] The power rectifier circuit 121 is used to convert alternating current into stable direct current to provide for the high-frequency transformer circuit 122, which can adopt various designs that can be easily thought of by those skilled in the art.

[0052] As shown in Figure 3 , in the output part, the power rectifier circuit 121 preferably includes a first output end and a second output end, and a first filter capacitor C 13 and a second filter capacitor C 14, and a first equalizing resistor R1 and a second equalizing resistor R2 are connected in series, and a first filter capacitor C 13 Connected in parallel with the first voltage balancing resistor R1, the second filter capacitor C 14 The second voltage balancing resistor R2 is connected in parallel.

[0053] In specific implementation, the power rectifier circuit 121 filters 220VAC through the X safety capacitors CX1 and CX3, the Y safety capacitors CY1 and CY2, and the common mode inductor L2, and then rectifies it through the rectifier bridge D2, and finally passes through the filter capacitor C 13 and C 14 , equalizing resistors R1 and R2 to obtain a stable DC power.

[0054] (2) High-frequency voltage circuit

[0055] The function of the high-frequency transformer circuit 122 is to store the DC power obtained by the power rectifier circuit 121 in the high-frequency transformer according to the output frequency and duty cycle of the pulse width modulation chip (TL494 chip), and then output the power in the secondary winding.

[0056] The high frequency transformer circuit 122 can adopt various designs that can be easily thought of by those skilled in the art. In one embodiment, for example, Figure 3 As shown, it preferably includes a first transformer L5, a second transformer L3, a first NPN transistor Q1, a second NPN transistor Q2, a third NPN transistor Q3 and a fourth NPN transistor Q4; here, the transformers L3 and L5 are the high-frequency transformers mentioned above;

[0057] The pulse width modulation chip (TL494 chip in the figure) includes a first pulse signal output terminal (C1, pin 8) and a second pulse signal output terminal (C2, pin 11). The first pulse signal output terminal is connected to the base of the fourth NPN transistor Q4, and the second pulse signal output terminal is connected to the base of the third NPN transistor Q3.

[0058] DC power supply +12V through the protection resistor R 12 Then it is divided into three paths, one of which is connected to the base of the fourth NPN transistor Q4, and the emitter of the fourth NPN transistor Q4 is grounded (for protection, the emitter can be connected to the base of the fourth NPN transistor Q4 through the capacitor C 23 Ground, the base of Q4 and R 12 A resistor R can be connected in series 15 ); another path is connected to the middle lead of the primary winding of the first transformer L5, and the two end leads of the primary winding of the first transformer L5 are respectively connected to the collector of the third NPN transistor Q3 and the collector of the fourth NPN transistor Q4; the last path is connected to the base of the third NPN transistor Q3, and the emitter of the third NPN transistor Q3 is grounded (for protection, the emitter can be connected to the ground through a diode D10 between the ground and the base of Q3 and R 12 between the ground and the base of Q3 and R 13 ; for protection, resistors R 14 , R 16 between the base and the emitter of Q3 and Q4, respectively, and diodes D8 and D9 between the collector and the emitter of Q3 and Q4, respectively;

[0059] The first output end of the power supply rectifier circuit 121 is connected to the collector of the first NPN transistor Q1, the emitter of the first NPN transistor Q1 is connected to the collector of the second NPN transistor Q2, and the emitter of the second NPN transistor Q2 is connected to the second output end of the power supply rectifier circuit 121; for protection, diodes D5 and D6 can be connected between the collector and the emitter of Q1 and Q2, respectively;

[0060] The secondary winding of the first transformer L5 includes a first secondary winding and a second secondary winding. One end of the first primary winding (pin 5) is connected to the base of the second NPN transistor Q2 through a diode D4 and a protective resistor R6 (for protection, a capacitor C 17 may be connected in parallel across D4 and R6, and a resistor R7 can be connected in series between R6 and the base of Q2), and the other end (pin 4) is connected to the emitter of the second NPN transistor Q2; the second primary winding has three leads, one of which (pin 3) is connected between the first filter capacitor C 13 and the second filter capacitor C 14 (for protection, a capacitor C 15 may be connected in parallel across D3 and R3, and a resistor R4 can be connected in series between R3 and the base of Q1), the middle lead (pin 2) is connected to the emitter of the first NPN transistor Q1, and the other end (pin 1) is connected to the base of the first NPN transistor Q1 through a diode D3 and a protective resistor R3 (for protection, a capacitor C 16 may be connected in parallel across D3 and R3, and a resistor R4 can be connected in series between R3 and the base of Q1); for protection, resistors R5 and R8 can be connected between the base and the emitter of Q1 and Q2, respectively.

[0061] The voltage output circuit 124 is used to rectify and filter the output of the secondary winding of the second transformer L3 and provide it to the Marx generator circuit 131.

[0062] Here, the working principle of the circuit is as follows:

[0063] When Q3 is on and Q4 is off: DC 12V voltage passes through R 12, Q3 induces electromotive force on the secondary winding of the transformer L5, which makes Q1 conduct through D3, R3, R4 and R5. At this time, the DC voltage rectified by the power supply rectifier circuit 121 flows out from the positive electrode of the capacitor C 13 , passes through Q1, the secondary winding of L5, the primary winding of L3, and returns to the negative electrode of the capacitor C 13 , and outputs electric energy through the secondary winding of L3.

[0064] When Q3 is off and Q4 is on: the DC 12V voltage passes through R 12 , Q4 induces electromotive force on the secondary winding of the transformer L5, which makes Q2 conduct through D4, R6, R7 and R8. At this time, the DC voltage rectified by the power supply rectifier circuit 121 flows out from the positive electrode of the capacitor C 14 , passes through the primary winding of L3, the secondary winding of L5, Q2, and returns to the negative electrode of the capacitor C 14 , and outputs electric energy through the secondary winding of L3.

[0065] The primary winding of the second transformer L3 is preferably connected in parallel with a resistor R9 and a capacitor C 18 , and the resistor R9 and the capacitor C 18 absorb the reverse induced electromotive force when the current of the transformer L3 commutates, so as to prevent the induced high voltage from damaging the components.

[0066] (3) Power management circuit

[0067] The pulse width modulation chip can be a fixed frequency pulse width modulation chip, and can be various models. In the figure, it is a TL494 chip. The function of the TL494 chip is to compare the voltage across the voltage dividing resistor R 11 with the reference voltage of pin 2, and then change the duty cycle of the output pulses of pin 8 and pin 11. That is, the pulse width modulation chip (TL494 chip) includes an output voltage acquisition end (1IN+, pin 1) for acquiring the output voltage between the two output ends of the voltage output circuit 124 and a reference voltage receiving end (1IN-, pin 2) for obtaining the reference voltage from the single-chip microcomputer. The pulse width modulation chip compares the obtained output voltage with the reference voltage to adjust the duty cycle of the output pulse signal.

[0068] For the convenience of acquiring the output voltage, two voltage dividing resistors R 10 and R 11 can be connected in series between the two output ends of the voltage output circuit 124, and the connection point between the two voltage dividing resistors is connected to the output voltage acquisition end (1IN+, pin 1) of the pulse width modulation chip (TL494 chip).

[0069] For the convenience of obtaining the reference voltage, the power management circuit 123 further comprises a digital-to-analog conversion chip, which can be various models, and in the figure is TLC5618 chip. The input end of the TLC5618 chip is connected to the single-chip microcomputer, and the output end is connected to the TL494 chip to provide the reference voltage for the TL494 chip. Specifically, the voltage value on the pin 2 of the TL494 chip is provided by the voltage converted from the data sent by the core control unit 11 in the form of SPI communication protocol, wherein the pins 1, 2 and 3 of the TLC5618 are connected to the DIN, SCLK and CS of the core control unit 11.

[0070] After the pin 13 of the TL494 chip is connected with the pin 14, the TL494 chip will output in the push-pull form, that is, the pins 8 and 11 will output a pair of complementary pulse signals, that is, the first pulse signal output by the first pulse signal output end (C1, pin 8) and the second pulse signal output by the second pulse signal output end (C2, pin 11) are preferably a pair of complementary pulse signals. The pulse frequency is determined by the capacitor C 26 and the resistor R 22 connected to the pins 5 and 6, respectively. The dead time is determined by the voltage connected to the pin 4, that is, the reference 5V voltage output on the pin 14 determines the voltage division on the resistor R 19 .

[0071] (4) Voltage output circuit

[0072] The voltage output circuit 124 can adopt various designs easily thought by those skilled in the art. In one embodiment, as shown in Figure 3 , the secondary winding of the second transformer L3 sequentially passes through the rectifier bridge D7, the energy storage inductor L4 and the filter capacitor C 19 ~C 22 and then outputs to provide for the Marx generating circuit 131.

[0073] Marx pulse voltage generation unit

[0074] The Marx pulse voltage generating unit 13 mainly comprises two parts of the Marx generating circuit 131 and the driving circuit 132. The parallel energy storage capacitors are charged by the program-controlled charging unit 12, and when the charging reaches the preset voltage, the driving circuit 132 receives the X signal of the core control unit 11 to control the solid-state switches Q5-Q8 to be turned on, so that the energy storage capacitors are connected in series to output pulse voltage to the load. The output pulse width depends on the conduction time of the solid-state switches.

[0075] (1) Driving circuit

[0076] The driving circuit 132 can adopt various designs easily thought by those skilled in the art. In one embodiment, as shown in Figure 4As shown, mainly consists of optical coupling isolator and current limiting resistor.

[0077] The driving circuit 132 includes a control switch U5 (preferably also an optocoupler), the control end of the control switch U5 is connected to the control signal output end (X signal) of the single-chip microcomputer, the control switch U5 is connected with a plurality of optocouplers U6-U9 in series, and the output ends of the plurality of optocouplers U6-U9 control one solid-state switch Q5-Q8 in the Marx generator circuit 131 respectively.

[0078] When the optical coupling isolator U5 receives the high-level signal of the core control unit X, the output end is turned on. 24 The voltage is applied to the optical coupling isolators U6, U7, U8 and U9, so that the output end is turned on, and a 12V direct current voltage is output.

[0079] (2) Marx generator circuit

[0080] Figure 5 The circuit diagram of the Marx generator circuit 131 is shown in the embodiment, in which n=4, n is the number of stages of the Marx generator, and can be flexibly selected according to actual needs. The solid-state switches (Q5-Q8) in the Marx generator circuit 131 can all be NPN transistors. The Marx generator circuit 131 is improved on the basis of the previous Marx generator, and the boost inductance is removed, so that the circuit itself loses the function of controlling the solid-state switch to cut off the boost. Therefore, the program-controlled charging circuit 12 is used to charge the parallel energy storage capacitors, and the function of adjustable pulse width is realized.

[0081] Before the driving circuit 132 receives the X signal of the core control unit 11, the solid-state switches of the Marx generator circuit 131 are in the off state, at this time, the program-controlled charging unit 12 charges the four groups of parallel energy storage capacitors through diodes D 12 ~D 19 When the core control unit 11 detects that the energy storage capacitors are fully charged, the control signal is sent to turn on the solid-state switches, and the four groups of energy storage capacitors are discharged to the load in series.

[0082] In summary, the technical scheme of the embodiment of the application realizes the adjustable pulse width under the premise of meeting the requirement of the pulse voltage output amplitude, and the output pulse amplitude is continuously adjustable. The pulse voltage generator is simple to use, and the pulse voltage amplitude and pulse width can be directly input through the serial port of the upper computer.

[0083] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A programmable pulse voltage generating device based on the principle of Marx generator, characterized in that, The power supply unit, the core control unit, the program-controlled charging unit and the Marx pulse voltage generating unit are included, wherein: The power supply unit is used for converting alternating current into stable direct current to supply power to the whole device; The core control unit includes a single-chip microcomputer; The program-controlled charging unit includes a power rectifier circuit, a high-frequency transformer circuit, a power management circuit and a voltage output circuit; The Marx pulse voltage generating unit includes a Marx generating circuit and a driving circuit, and the Marx generating circuit does not use a boost inductor; The power rectifier circuit is used for converting alternating current into stable direct current to provide the high-frequency transformer circuit; the power management circuit includes a pulse width modulation chip, and the power management circuit is used for receiving voltage data provided by the single-chip microcomputer and outputting a pulse signal to the high-frequency transformer circuit; the high-frequency transformer circuit uses a flyback power supply principle, and according to the output frequency and duty cycle of the pulse signal output by the power management circuit, stores electrical energy in a high-frequency transformer in the high-frequency transformer circuit, and provides the electrical energy to the Marx generating circuit through the voltage output circuit; the driving circuit receives a control signal of the single-chip microcomputer to control the on-off time of a solid-state switch in the Marx generating circuit; The power rectifier circuit comprises a first output end and a second output end, a first filter capacitor (C 13 ) and a second filter capacitor (C 14 ) are connected in series between the first output end and the second output end, and a first voltage equalization resistor (R1) and a second voltage equalization resistor (R2) are also connected in series, the first filter capacitor (C 13 ) and the first voltage equalization resistor (R1) are connected in parallel, and the second filter capacitor (C 14 ) and the second voltage equalization resistor (R2) are connected in parallel; The high-frequency transformer circuit includes a first transformer (L5), a second transformer (L3), a first NPN transistor (Q1), a second NPN transistor (Q2), a third NPN transistor (Q3) and a fourth NPN transistor (Q4); The pulse width modulation chip includes a first pulse signal output end and a second pulse signal output end, the first pulse signal output end is connected to the base of the fourth NPN transistor (Q4), and the second pulse signal output end is connected to the base of the third NPN transistor (Q3); The direct current power supply is divided into three ways through a protection resistor (R 12 ), one of which is connected to the base of the fourth NPN transistor (Q4), the emitter of which is grounded; another is connected to the middle lead of the primary winding of the first transformer (L5), the two ends of which are connected to the collector of the third NPN transistor (Q3) and the collector of the fourth NPN transistor (Q4) respectively; the last one is connected to the base of the third NPN transistor (Q3), the emitter of which is grounded; The first output end of the power rectifier circuit is connected to the collector of the first NPN transistor (Q1), the emitter of the first NPN transistor (Q1) is connected to the collector of the second NPN transistor (Q2), and the emitter of the second NPN transistor (Q2) is connected to the second output end of the power rectifier circuit; The secondary winding of the first transformer (L5) comprises a first secondary winding and a second secondary winding, one end lead of the first secondary winding is connected to the base of the second NPN transistor (Q2) through a diode (D4) and a protection resistor (R6), and the other end lead is connected to the emitter of the second NPN transistor (Q2); the second secondary winding has three end leads, one end lead is connected between the first filter capacitor (C 13 ) and the second filter capacitor (C 14 ) through the primary winding of the second transformer (L3), the other end lead is connected to the base of the first NPN transistor (Q1) through a diode (D3) and a protection resistor (R3), and the middle lead is connected to the emitter of the first NPN transistor (Q1); The voltage output circuit is used for rectifying and filtering the output of the secondary winding of the second transformer (L3) and providing the output to the Marx generating circuit; The pulse width modulation chip includes an output voltage acquisition end for acquiring the output voltage between the two output ends of the voltage output circuit and a reference voltage receiving end for acquiring the reference voltage from the single-chip microcomputer, and the pulse width modulation chip compares the obtained output voltage with the reference voltage to adjust the duty cycle of the output pulse signal; The power management circuit further includes a digital-to-analog conversion chip, the input end of the digital-to-analog conversion chip is connected to the single-chip microcomputer, and the output end of the digital-to-analog conversion chip is connected to the pulse width modulation chip to provide the reference voltage to the pulse width modulation chip.

2. The programmable pulse voltage generator based on the Marx generator principle according to claim 1, characterized in that The power supply unit includes a transformer (L1), a rectifier bridge (D1) and a plurality of power stabilizing modules (U1-U4) connected in sequence.

3. The programmable pulse voltage generator based on the Marx generator principle according to claim 1, characterized in that, The power rectifier circuit is filtered by X safety capacitors (CX1, CX3), Y safety capacitors (CY1, CY2), and common-mode inductors (L2), rectified by a rectifier bridge (D2), and finally stabilized by the first filter capacitor (C 13 ), the second filter capacitor (C 14 ), the first voltage-sharing resistor (R1), and the second voltage-sharing resistor (R2) to obtain stable direct current.

4. The programmable pulse voltage generator based on the Marx generator principle according to claim 1, characterized in that, The first pulse signal output end outputs a first pulse signal and the second pulse signal output end outputs a second pulse signal, which are a pair of complementary pulse signals; and / or the primary winding of the second transformer (L3) is connected in parallel with a resistor (R9) and a capacitor (C 18 ).

5. The programmable pulse voltage generator based on Marx generator principle according to claim 1, characterized in that, In the voltage output circuit, the secondary winding of the second transformer (L3) sequentially passes through a rectifier bridge (D7), an energy storage inductor (L4), a filter capacitor (C 19 ~C 22 ) and then outputs to provide the Marx generating circuit; and / or, two output ends of the voltage output circuit are connected in series with two voltage dividing resistors (R 10 , R 11 ), and a connection point between the two voltage dividing resistors is connected to an output voltage collection end of the pulse width modulation chip.

6. The programmable pulse voltage generator based on the Marx generator principle according to claim 1, characterized in that, The driving circuit comprises a control switch (U5), a control end of the control switch (U5) is connected with a control signal output end of the single-chip microcomputer, the control switch (U5) is connected with a plurality of optocouplers (U6-U9) in series, output ends of the plurality of optocouplers (U6-U9) respectively control one solid-state switch (Q5-Q8) in the Marx generating circuit, the control switch (U5) is an optocoupler, and the solid-state switches (Q5-Q8) in the Marx generating circuit are all NPN transistors.

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