Marx generator

Abstract

The utility model belongs to the technical field of pulse power, and particularly discloses a Marx generator. The generator comprises a multi-stage charging and discharging unit; except the first-stage charging and discharging unit, the other stages of charging and discharging units comprise auxiliary trigger circuits; the auxiliary trigger circuit is used for applying a trigger pulse to the base electrode of the bipolar transistor in the charge-discharge unit when the charge-discharge unit at the previous stage discharges, so that the charge-discharge unit is conducted and discharges; wherein the first-stage charge and discharge unit is used for driving the generator to perform avalanche discharge under the condition that each stage of charge and discharge unit completes charging and receives a trigger signal; the last-stage charging and discharging unit is used for connecting a load resistor so as to generate target pulse signals at the two ends of the load resistor. According to the Marx generator, the thermal damage phenomenon of a bipolar transistor in a traditional Marx generator can be avoided, and reliable operation of the Marx generator under the repetition frequency pulse working condition is effectively achieved.

Description

Technical Field

[0001] The present application belongs to the field of pulse power technology, and more specifically, relates to a Marx generator. Background Art

[0002] High-power bipolar junction transistor (BJT) is a high-speed, fast-edge semiconductor pulse power device that can be used in nanosecond pulse power systems. Due to the small overall size and fast switching speed of BJT devices, the Marx generator based on BJT has good integration and is easy to trigger and control, and can generate pulses with amplitudes far higher than the power supply voltage. Therefore, Marx generators based on BJT have been widely used in the industry.

[0003] However, in the actual application of traditional BJT-based Marx generators under repetitive pulse conditions, after the base of BJT1 in the first-stage charge and discharge unit is triggered, due to its slow turn-on speed, it will cause BJT2 in the second-stage charge and discharge unit to be triggered by a slow voltage ramp. During repeated pulses, since BJT2 is repeatedly triggered by the slow voltage ramp, it will cause the device to partially turn on, forming a destructive current filament. Since there is not enough time for natural heat dissipation, BJT2 is extremely susceptible to thermal damage. After BJT2 is thermally damaged and becomes a short-circuit point, due to the special circuit structure of the Marx generator, the thermal damage phenomenon will continue to spread from the second-stage BJT2 to the BJTs in subsequent stages, eventually causing the entire Marx generator to fail to work properly.

[0004] Therefore, how to achieve reliable operation of the Marx generator under high-frequency pulse conditions has become a technical problem that needs to be solved urgently in the industry. Utility Model Content

[0005] In view of the defects of the prior art, the purpose of this application is to achieve reliable operation of the Marx generator under heavy-frequency pulse conditions.

[0006] To achieve the above objectives, in a first aspect, the present application provides a Marx generator, comprising:

[0007] Multi-stage charge and discharge unit; except for the first-stage charge and discharge unit, all other stages of the charge and discharge unit include auxiliary trigger circuits;

[0008] The auxiliary trigger circuit is used to apply a trigger pulse to the base of the bipolar transistor in the charge and discharge unit when the previous charge and discharge unit is discharging, so as to turn on and discharge the charge and discharge unit;

[0009] Among them, the first-level charging and discharging unit is used to drive the generator to perform avalanche discharge when the charging and discharging units of each level are charged and receive a trigger signal; the last-level charging and discharging unit is used to connect the load resistor to generate a target pulse signal at both ends of the load resistor.

[0010] Optionally, each of the charge and discharge units at each stage includes a first capacitor; except for the charge and discharge unit at the last stage, each of the charge and discharge units at each stage is connected to the emitter of the bipolar transistor in the charge and discharge unit at the next stage via its own first capacitor; the first capacitor in the charge and discharge unit at the last stage is connected to the load resistor;

[0011] Each level of the auxiliary trigger circuit is connected between the base and emitter of the corresponding bipolar transistor.

[0012] Optionally, the auxiliary trigger circuit includes a second capacitor, a first diode and a second diode;

[0013] The anode of the first diode and the anode of the second diode are connected to the emitter of the corresponding bipolar transistor, the cathode of the first diode and one end of the second capacitor are connected to the base of the corresponding bipolar transistor, and the cathode of the second diode and the other end of the second capacitor are connected to the ground.

[0014] Optionally, each level of the charging and discharging unit further includes a current limiting resistor;

[0015] One end of the current-limiting resistors in the charge and discharge units of each stage is connected in common as a DC power supply input end; the other end of the current-limiting resistors in the charge and discharge units of each stage is connected in common with the collector of each bipolar transistor and one end of each first capacitor; the other end of the first capacitor in the charge and discharge units of each stage is connected to the emitter of the bipolar transistor in the charge and discharge unit of the corresponding next stage; the other end of the first capacitor in the charge and discharge unit of the last stage is connected to the load resistor.

[0016] Optionally, a DC voltage source is further included; the positive pole of the DC voltage source is connected to the DC power input terminal, and the negative pole of the DC voltage source is grounded.

[0017] Optionally, it also includes:

[0018] Trigger signal circuit;

[0019] The trigger signal circuit is used to receive an external square wave signal when the generator completes charging, and convert the external square wave signal into a narrow pulse signal and transmit it to the first-level charging and discharging unit; the trigger signal is the narrow pulse signal.

[0020] Optionally, the trigger signal circuit includes a third capacitor and a resistor;

[0021] One end of the third capacitor is used to receive the external square wave signal; the other end of the third capacitor and one end of the resistor are connected to the base of the bipolar transistor in the first-level charging and discharging unit, and the other end of the resistor is connected to the emitter of the bipolar transistor in the first-level charging and discharging unit and is grounded.

[0022] Optionally, the first diode and the second diode in the auxiliary trigger circuit both include a high-voltage rectifier diode SM3000 or a high-voltage rectifier diode SM4000.

[0023] Optionally, the bipolar transistors in each stage of the charge and discharge unit include MMBT5401 series bipolar transistors or BCX series bipolar transistors.

[0024] Optionally, the number of stages of the multi-stage charge and discharge unit ranges from 10 to 20.

[0025] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0026] The present application provides a Marx generator that introduces an auxiliary trigger circuit into each stage of the charge-discharge unit after the second stage. This allows, under repetitive pulse conditions, when the previous stage of the charge-discharge unit is turned on for discharge, the subsequent stage of the charge-discharge unit can, through the trigger pulse applied by its auxiliary trigger circuit, turn on the internal bipolar transistor to achieve cascade discharge without being affected by the slow voltage ramp triggering of the previous stage of the bipolar transistor. This converts the bipolar transistors in the circuit from a traditional voltage ramp triggering turn-on method to a base triggering turn-on method, thereby improving the reliability of the transistor devices, ensuring uniform turn-on of the bipolar transistors in each stage of the charge-discharge unit, and avoiding the occurrence of thermal damage to the bipolar transistors in the traditional Marx generator. This effectively achieves reliable operation of the Marx generator under repetitive pulse conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the circuit structure of an existing traditional Marx generator;

[0028] Figure 2 This is one of the circuit structure diagrams of the Marx generator provided in the embodiment of the present application;

[0029] Figure 3 This is the second circuit structure diagram of the Marx generator provided in the embodiment of the present application;

[0030] Figure 4 This is the third circuit structure diagram of the Marx generator provided in the embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0032] The terms "first," "second," and the like in the specification and claims herein are used to distinguish between different objects, rather than to describe a specific order of objects. For example, a first diode and a second diode are used to distinguish between diodes having different functions, rather than to describe a specific order of diodes.

[0033] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0034] First, the technical terms involved in the embodiments of this application are introduced.

[0035] (1) Marx generator

[0036] A Marx generator is a high-voltage device that generates high-voltage pulses from a low-voltage DC power supply, charges capacitors in parallel, and then discharges them in series. It can simulate processes such as lightning and switching overvoltages. Therefore, it is often used in high-energy physical tests such as insulation impulse withstand voltage, dielectric impulse breakdown, and discharge.

[0037] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0038] Figure 1 This is a schematic diagram of the circuit structure of the existing traditional Marx generator, such as Figure 1As shown in the figure, during the charging process of a traditional Marx generator, a high-voltage DC voltage source (DC) charges the pulse discharge capacitors C1 to Cn through current-limiting resistors Rx1 to Rxn, causing the bipolar transistors BJT1 to BJT1n in each stage of the charge and discharge unit to operate in the critical avalanche region. During the discharge process, the trigger circuit QD first triggers the first-stage BJT1 to turn on. Capacitor C1 discharges through BJT1, forming a loop C1-BJT1-Rs2-C1, generating a negative pulse on Rs2, which causes a slow dV / dt voltage ramp on BJT2. When the voltage across BJT2 exceeds a certain withstand voltage, the overvoltage trip is triggered, causing C2 and C1 to discharge in series, forming a loop C2-BJT2-C1-BJT1-Rs3-C2, generating a negative pulse on Rs3, which causes a fast dV / dt voltage ramp on BJT3. When the voltage across BJT3 exceeds a certain withstand voltage, the overvoltage trip is triggered. Similarly, the remaining bipolar transistors BJT4 to BJTn are turned on in sequence, causing the capacitors C1 to Cn to discharge in series, ultimately generating a high-frequency voltage pulse on the load resistor RL, completing a pulse discharge.

[0039] However, when repeated pulse discharge is performed under repetitive pulse conditions, the BJT1 in the first-stage charge and discharge unit of the Marx circuit is turned on slowly after the base is triggered, causing the second-stage BJT2 to be triggered by a slow voltage ramp (dV / dt). Since BJT2 is repeatedly triggered by the slow dV / dt, the area where the device is turned on is small, the current filament effect is obvious, and the device is thermally damaged. Due to the particularity of the Marx generator structure, the dV / dt for triggering the third-stage BJT3 is reduced, and the thermal damage phenomenon will continue to spread from the second stage to the subsequent stages. Therefore, in the process of generating repetitive pulses by the Marx generator, how to fundamentally solve the problem of BJT2 to BJTn being easily damaged and having low reliability due to the subsequent stages being triggered by voltage ramps with different slopes is a difficult problem that needs to be solved urgently in this field.

[0040] In order to solve the above-mentioned defects in the prior art, the present application provides the following Marx generator.

[0041] Figure 2 This is one of the structural diagrams of the Marx generator provided in the embodiment of the present application, such as Figure 2 As shown, the Marx generator includes:

[0042] Multi-stage charge and discharge unit 1; except for the first-stage charge and discharge unit 11, the other stages of the charge and discharge units 12 all include an auxiliary trigger circuit 121;

[0043] The auxiliary trigger circuit 121 is used to apply a trigger pulse to the base of the bipolar transistor in the charge-discharge unit when the previous charge-discharge unit is discharging, so as to turn on the charge-discharge unit and discharge;

[0044] Among them, the first-level charge and discharge unit 11 is used to drive the generator to perform avalanche discharge when the charging of each level of charge and discharge units is completed and a trigger signal is received; the last-level charge and discharge unit 12 is used to connect the load resistor to generate a target pulse signal at both ends of the load resistor.

[0045] Specifically, the target pulse signal described in the embodiments of the present application refers to the pulse signal generated at the load connected to the last-stage unit after the charge-discharge units discharge one by one, forming an avalanche discharge. It is usually manifested as a pulse output with a higher amplitude and a shorter rise time.

[0046] In the embodiment of the present application, the Marx generator includes a multi-stage charge and discharge unit 1. Except for the first-stage charge and discharge unit 11, all other stages of the charge and discharge units 12 include an auxiliary trigger circuit 121. That is, starting from the second-stage charge and discharge unit, all subsequent stages of the charge and discharge units 12 introduce an auxiliary trigger circuit 121.

[0047] In an embodiment of the present application, after each level of charge and discharge unit completes charging, the trigger circuit sends a trigger signal to the first-level charge and discharge unit 11. Upon receiving the trigger signal, the first-level charge and discharge unit 11 drives the generator to perform avalanche discharge. That is, under the action of the trigger signal, the BJTs in each level of charge and discharge unit of the Marx generator are turned on one by one, and the charge and discharge units at each level are turned on and discharged in turn until the last level of charge and discharge unit 12 is turned on and discharged, generating a target pulse signal at both ends of the connected load resistor.

[0048] During the discharge process, starting with the second-stage charge-discharge unit 12, an auxiliary trigger circuit 121 is introduced. Each auxiliary trigger circuit 121 applies a trigger pulse to the base of the BJT in its corresponding charge-discharge unit 12 when the previous-stage charge-discharge unit is discharging, triggering the BJT to conduct, thereby turning on the corresponding charge-discharge unit and discharging. Specifically, during the triggering phase, the auxiliary trigger circuit 121 applies a trigger pulse to the base of BJT2-BJTn, converting BJT2-BJTn, which was previously turned on by a traditional voltage ramp trigger, to a base-triggered turn-on, ensuring uniform turn-on and improving the reliability of transistor device operation.

[0049] Based on the content of the above embodiment, as an optional embodiment, the number of stages of the multi-stage charge and discharge unit 1 ranges from 10 to 20.

[0050] Specifically, in the embodiment of the present application, the multi-stage charge and discharge unit 1 includes a first-stage charge and discharge unit 11, a second-stage charge and discharge unit 12, ..., an n-th-stage charge and discharge unit 12. The first-stage charge and discharge unit is the first charge and discharge unit to be cascaded, and the last-stage unit is the last charge and discharge unit to be cascaded.

[0051] In the embodiment of the present application, the value range of n is 10 to 20. Such a design can ensure the safety of the Marx generator circuit and realize reliable operation under the repetitive pulse condition.

[0052] That is to say, in the embodiment of the present application, the Marx generator may include 10-stage charge and discharge units, or 11-stage charge and discharge units, ..., or 20-stage charge and discharge units.

[0053] The Marx generator of the embodiment of the present application introduces an auxiliary trigger circuit in each stage of the unit after the second stage charge and discharge unit. Therefore, under the condition of repeated pulses, when the previous stage charge and discharge unit is turned on for discharge, the subsequent stage charge and discharge unit can turn on the internal bipolar transistor through the trigger pulse applied by its auxiliary trigger circuit to achieve cascade discharge without being affected by the slow voltage ramp triggering of the previous stage bipolar transistor. In this way, the bipolar transistors in the circuit are converted from the traditional voltage ramp triggering turn-on method to the base triggering turn-on method, which can improve the reliability of the transistor device, make the bipolar transistors in each stage of the charge and discharge unit turn on evenly, avoid the occurrence of thermal damage to the bipolar transistors in the traditional Marx generator, and effectively achieve reliable operation of the Marx generator under repeated pulse conditions.

[0054] Figure 3 This is the second structural diagram of the Marx generator provided in the embodiment of the present application, as shown in FIG. Figure 3 As shown, each level of charge and discharge unit includes not only BJT devices, namely BJT1 to BJTn, but also first capacitors, namely C1 to Cn; except for the last level charge and discharge unit 12, each level of charge and discharge unit is connected to the emitter of the BJT in the next level of charge and discharge unit through its own first capacitor; the first capacitor Cn in the last level of charge and discharge unit 12 is connected to the load resistor R L connect;

[0055] Each level of auxiliary trigger circuit 121 is connected between the base and emitter of the corresponding BJT.

[0056] Specifically, in an embodiment of the present application, the first-stage charge and discharge unit 11 in the Marx generator is composed of a base trigger device BJT1 and a first capacitor C1, the second-stage charge and discharge unit 12 is composed of an auxiliary trigger device BJT2 and a first capacitor C2, ..., and the n-th stage charge and discharge unit is composed of an auxiliary trigger device BJTn and a first capacitor Cn.

[0057] Except for the last-stage charge-discharge unit 12, each stage of the charge-discharge unit is connected to the emitter of the BJT in the next-stage charge-discharge unit via its own first capacitor. Specifically, the first-stage charge-discharge unit 11 is connected to the emitter of the BJT2 in the second-stage charge-discharge unit 12 via its first capacitor C1. The second-stage charge-discharge unit 12 is connected to the emitter of the BJT3 in the third-stage charge-discharge unit 12 via its first capacitor C2. The third-stage charge-discharge unit 12 is connected to the emitter of the BJT4 in the fourth-stage charge-discharge unit 12 via its first capacitor C3, and so on.

[0058] Among them, the auxiliary trigger circuit 121 of each stage is connected between the base and emitter of the corresponding BJT. Specifically, the auxiliary trigger circuit 121 in the second-stage charge and discharge unit 12 is connected between the base and emitter of BJT2, the auxiliary trigger circuit 121 in the third-stage charge and discharge unit 12 is connected between the base and emitter of BJT3,..., the auxiliary trigger circuit 121 in the n-th stage charge and discharge unit 12 is connected between the base and emitter of BJTn.

[0059] Figure 4 This is the third structural diagram of the Marx generator provided in the embodiment of the present application, as shown in FIG. Figure 4 As shown, in the embodiment of the present application, the auxiliary trigger circuit 121 includes a second capacitor Csi, a first diode Dsi and a second diode Dxi;

[0060] The anode of the first diode Dsi and the anode of the second diode Dxi are connected to the emitter of the corresponding BJT, the cathode of the first diode Dsi and one end of the second capacitor Csi are connected to the base of the corresponding BJT, and the cathode of the second diode Dxi and the other end of the second capacitor Csi are connected to ground.

[0061] Where i = 2, 3,…, n.

[0062] Specifically, in an embodiment of the present application, the auxiliary trigger circuit 121 in the second-stage charge and discharge unit 12 includes a second capacitor Cs2, a first diode Ds2, and a second diode Dx2. The positive electrode of the first diode Ds2 and the positive electrode of the second diode Dx2 are connected to the emitter of BJT2, the negative electrode of the first diode Ds2 and one end of the second capacitor Cs2 are connected to the base of BJT2, and the negative electrode of the second diode Dx2 and the other end of the second capacitor Cs2 are connected to the ground, so that the first diodes Ds2~Dsn are anti-parallel between the base and emitter of BJT2.

[0063] Similarly, the auxiliary trigger circuit 121 in the third-stage charge and discharge unit 12 includes a second capacitor Cs3, a first diode Ds3, and a second diode Dx3. The anode of the first diode Ds3 and the anode of the second diode Dx3 are connected to the emitter of the BJT3, the cathode of the first diode Ds3 and one end of the second capacitor Cs3 are connected to the base of the BJT3, and the cathode of the second diode Dx3 and the other end of the second capacitor Cs3 are connected to the ground. ...; the auxiliary trigger circuit 121 in the n-th stage charge and discharge unit 12 includes a second capacitor Csn, a first diode Dsn, and a second diode Dxn. The anode of the first diode Dsn, the anode of the second diode Dxn, and the emitter of the BJTn are connected to the ground. The cathode of the first diode Dsn and one end of the second capacitor Csn are connected to the base of the BJTn, and the cathode of the second diode Dxn and the other end of the second capacitor Csn are connected to the ground.

[0064] The Marx generator of the embodiment of the present application can reduce the energy loss of the auxiliary trigger capacitors Cs2 to Csn during the trigger phase by connecting the diodes Ds2 to Dsn in anti-parallel between the base and emitter of BJT2 to BJTn. In addition, by connecting the emitters of BJT2 to BJTn to the diodes Dx2 to Dxn, the energy loss of the capacitors C1 to Cn during the trigger phase can also be reduced, which is beneficial to improving the quality of the pulse signal output by the Marx generator.

[0065] Continue to refer to Figure 4 Based on the above embodiment, as an optional embodiment, each level of the charge and discharge unit further includes a current limiting resistor, namely Rx1 to Rxn;

[0066] One end of the current limiting resistors in each level of charge and discharge unit is connected in common as the DC power supply input end; the other end of the current limiting resistors in each level of charge and discharge unit is connected in common with the collector of each BJT and one end of each first capacitor; the other end of the first capacitor in each level of charge and discharge unit is connected to the emitter of the BJT in the corresponding next level of charge and discharge unit; the other end of the first capacitor Cn in the last level of charge and discharge unit 12 is connected to the load resistor R L connect.

[0067] In addition, in an embodiment of the present application, the generator further includes a DC voltage source DC; the positive pole of the DC voltage source is connected to the DC power input terminal, and the negative pole of the DC voltage source is grounded.

[0068] Specifically, in the embodiment of the present application, the base of BJT1 in the first-stage charge and discharge unit 11 is used to connect to an external drive source, the emitter is grounded, the collector is connected in series with a current-limiting resistor Rx1 and then connected to a high-voltage DC voltage source DC, and is connected to the second-stage charge and discharge unit 12 through a first capacitor C1. The remaining auxiliary trigger-stage devices BJT2~BJTn are located in the 2nd to nth-stage charge and discharge units 12 in the circuit. The emitters of BJT2~BJTn are respectively connected in series with second diodes Dx2~Dxn and then grounded. The collectors of BJT2~BJTn are respectively connected in series with current-limiting resistors Rx2~Rxn and then connected to a DC voltage source DC, and are connected to subsequent stages through their respective first capacitors C2~Cn. The bases of BJT2~BJTn are respectively connected to second capacitors Cs2~Csn and then grounded, and first diodes Ds2~Dsn are connected in anti-parallel between the base and the emitter. The first capacitor Cn in the last-stage charge and discharge unit 12 is connected to the load resistor R L Series connection.

[0069] Continue to refer to Figure 4 During the charging process, a DC voltage source DC is used to charge the first capacitor C1 in the first-stage charge and discharge unit 11 through the current limiting resistor Rx1, and the first capacitors C2 to Cn in the remaining charge and discharge units 12 are charged through the current limiting resistors Rx2 to Rxn.

[0070] Furthermore, the entire Marx generator operates under a repetitive pulse discharge condition, with normal DC power supply. The trigger signal circuit turns on BJT1 by applying a trigger signal to the base of BJT1 in the first-stage charge and discharge unit 11. After BJT1 is turned on, the first capacitor C1 discharges through BJT1 to form a loop C1-BJT1-Dx2-C1, and forms a negative voltage ramp on the second diode Dx2, causing the emitter potential of BJT2 to change from ground potential to negative potential. At the same time, due to the reverse withstand voltage effect of the first diode Ds2, the second capacitor Cs2 discharges to form a loop Cs2-Ds2-Dx2-Cs2, forming a potential difference between the base and emitter of BJT2, thereby making the base potential of BJT2 higher than the emitter potential, causing emitter electron injection to turn on BJT2, and the first capacitor C1 and the first capacitor C2 discharge in series, forming a loop C1-BJT1-Dxn-C2-BJT2-C1.

[0071] Furthermore, a negative voltage slope is formed on the second diode Dx3, and BJT3 is triggered to turn on in the same manner as described above. Similarly, due to the reverse withstand voltage effect of the first diode Ds3, the second capacitor Cs3 discharges to form a loop Cs3-Ds3-Dx3-Cs3, forming a potential difference between the base and emitter of BJT3, causing BJT3 to be triggered to turn on by the base. Similarly, in the same manner as described above, the BJT3~BJTn in the subsequent charge and discharge units of each level are turned on one by one, and finally the first capacitors C1~Cn are discharged in series, forming a loop C1-BJT1-RL-Cn-BJTn-C(n-1)-BJT(n-1)-…-C2-BJT2-C1, and finally the load resistor R L A voltage pulse is generated on the output, that is, the target pulse signal is output.

[0072] The Marx generator of the embodiment of the present application utilizes capacitors Cs2 to Csn and anti-parallel diodes Ds2 to Dsn to apply a trigger pulse to the base of BJT2 to BJTn during the triggering phase, thereby converting the BJT2 to BJTn, which were previously turned on by voltage ramp triggering, into a base-triggered turn-on, so that the turn-on is uniform, thereby improving the reliability of the device. This solves the problem of frequent thermal damage to the BJT2 to BJTn caused by uneven turn-on in conventional voltage ramp triggering, effectively solves the problem of a large number of device damages under high-frequency operation of conventional Marx generators, and improves the reliability of BJT2 to BJTn in the Marx generator.

[0073] Based on the content of the above embodiment, as an optional embodiment, the first diode and the second diode in the auxiliary trigger circuit 121 both include a high-voltage rectifier diode SM3000 or a high-voltage rectifier diode SM4000.

[0074] Specifically, in the embodiments of the present application, the first diodes Ds2-Dsn and the second diodes Dx2-Dxn in each level of the auxiliary trigger circuit 121 can each employ a high-voltage rectifier diode SM3000 or a high-voltage rectifier diode SM4000. The diode SM3000 or the diode SM4000 is an SMD diode with high-voltage rectification characteristics, suitable for circuits requiring high voltage processing, such as the Marx generator of the present application. The reverse voltage of the diode SM3000 is up to 3000V, and the reverse voltage of the diode SM4000 is up to 4000V.

[0075] The Marx generator of the embodiment of the present application and the auxiliary trigger circuit can adapt to different types of high-voltage rectifier diodes to meet the needs of different application scenarios, which is conducive to improving the flexibility and circuit performance of circuit manufacturing and reducing circuit design costs and power consumption.

[0076] Continue to refer to Figure 4Based on the above embodiment, as an optional embodiment, the generator further includes:

[0077] trigger signal circuit 13;

[0078] The trigger signal circuit 13 is used to receive an external square wave signal when the generator completes charging, and convert the external square wave signal into a narrow pulse signal and transmit it to the first-stage charge and discharge unit; the trigger signal is a narrow pulse signal.

[0079] Specifically, in the embodiment of the present application, the Marx generator further includes a trigger signal circuit 13, which can specifically adopt a differential circuit to effectively convert the input square wave signal into a narrow pulse signal by performing differential processing on the input square wave signal.

[0080] Based on the content of the above embodiment, as an optional embodiment, the trigger signal circuit 13 includes a third capacitor C0 and a resistor R0;

[0081] One end of the third capacitor C0 is used to receive an external square wave signal; the other end of the third capacitor C0 and one end of the resistor R0 are connected to the base of the BJT in the first-stage charge and discharge unit 11, and the other end of the resistor R0 is connected to the emitter of the BJT in the first-stage charge and discharge unit 11 and grounded.

[0082] Specifically, in the embodiment of the present application, a differential circuit composed of an RC circuit is introduced to process the square wave signal generated by the external trigger. The third capacitor C0 and the resistor R0 are the trigger signal input capacitor and input resistor respectively.

[0083] In an embodiment of the present application, after each level of the charge and discharge cascade unit is charged, an external trigger triggers a square wave signal. The square wave signal is processed by the third capacitor C0 and the resistor R0 to convert it into a narrow pulse signal and transmit it to the first-level charge and discharge unit 11 in the n-level charge and discharge unit. The overvoltage conduction mode is used to trigger the BJT in the first-level charge and discharge unit 11 to turn on, forming a discharge loop, and then the charge and discharge units of each level are turned on in turn to form an avalanche discharge until the load resistor R connected to the last-level charge and discharge unit 12 is turned on. L Generate the required high voltage pulse signal.

[0084] In the embodiment of the present application, by using only one resistor and one capacitor to construct a trigger signal circuit, it is possible to achieve a fast response while also having the advantages of simple structure, clear function, strong adjustability and low cost.

[0085] The Marx generator of the embodiment of the present application, by introducing an RC differential circuit, can transform an external rectangular pulse trigger signal into a narrow pulse signal, effectively extract the leading edge or trailing edge of the pulse signal, and can more efficiently trigger and control the conduction of the BJT in the charge and discharge unit, which is conducive to further improving the quality of the pulse signal output by the Marx generator.

[0086] Based on the content of the above embodiment, as an optional embodiment, the BJT in each level of the charge and discharge unit includes a BJT of the MMBT5401 series or a BJT of the BCX series.

[0087] In the Marx generator of the embodiment of the present application, the BJTs in each level of charge and discharge units can be adapted to a variety of different series and models of bipolar transistors to meet the needs of different application scenarios, which is conducive to further improving the flexibility and circuit performance of circuit manufacturing and reducing circuit design costs and power consumption.

[0088] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0089] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A Marx generator, characterized in that: include: Multi-stage charge and discharge unit; except for the first-stage charge and discharge unit, all other stages of the charge and discharge unit include auxiliary trigger circuits; The auxiliary trigger circuit is used to apply a trigger pulse to the base of the bipolar transistor in the charge and discharge unit when the previous charge and discharge unit is discharging, so as to turn on and discharge the charge and discharge unit; Among them, the first-level charging and discharging unit is used to drive the generator to perform avalanche discharge when the charging and discharging units of each level are charged and receive a trigger signal; the last-level charging and discharging unit is used to connect the load resistor to generate a target pulse signal at both ends of the load resistor.

2. The Marx generator according to claim 1, characterized in that Each level of the charge and discharge unit includes a first capacitor; except for the last level of the charge and discharge unit, each level of the charge and discharge unit is connected to the emitter of the bipolar transistor in the next level of the charge and discharge unit through its own first capacitor; the first capacitor in the last level of the charge and discharge unit is connected to the load resistor; Each level of the auxiliary trigger circuit is connected between the base and emitter of the corresponding bipolar transistor.

3. The Marx generator according to claim 2, characterized in that The auxiliary trigger circuit includes a second capacitor, a first diode and a second diode; The anode of the first diode and the anode of the second diode are connected to the emitter of the corresponding bipolar transistor, the cathode of the first diode and one end of the second capacitor are connected to the base of the corresponding bipolar transistor, and the cathode of the second diode and the other end of the second capacitor are connected to the ground.

4. The Marx generator according to claim 2, characterized in that Each level of the charging and discharging unit also includes a current limiting resistor; One end of the current-limiting resistors in the charge and discharge units of each stage is connected in common as a DC power supply input end; the other end of the current-limiting resistors in the charge and discharge units of each stage is connected in common with the collector of each bipolar transistor and one end of each first capacitor; the other end of the first capacitor in the charge and discharge units of each stage is connected to the emitter of the bipolar transistor in the charge and discharge unit of the corresponding next stage; the other end of the first capacitor in the charge and discharge unit of the last stage is connected to the load resistor.

5. The Marx generator according to claim 4, characterized in that It also includes a DC voltage source; the positive pole of the DC voltage source is connected to the DC power input terminal, and the negative pole of the DC voltage source is grounded.

6. The Marx generator according to claim 2, characterized in that Also includes: Trigger signal circuit; The trigger signal circuit is used to receive an external square wave signal when the generator completes charging, and convert the external square wave signal into a narrow pulse signal and transmit it to the first-level charging and discharging unit; the trigger signal is the narrow pulse signal.

7. The Marx generator according to claim 6, characterized in that The trigger signal circuit includes a third capacitor and a resistor; One end of the third capacitor is used to receive the external square wave signal; the other end of the third capacitor and one end of the resistor are connected to the base of the bipolar transistor in the first-level charging and discharging unit, and the other end of the resistor is connected to the emitter of the bipolar transistor in the first-level charging and discharging unit and is grounded.

8. The Marx generator according to claim 3, characterized in that The first diode and the second diode in the auxiliary trigger circuit both include a high-voltage rectifier diode SM3000 or a high-voltage rectifier diode SM4000.

9. The Marx generator according to any one of claims 2 to 8, characterized in that: The bipolar transistors in each stage of the charge and discharge unit include bipolar transistors of the MMBT5401 series or bipolar transistors of the BCX series.

10. The Marx generator according to any one of claims 1 to 8, characterized in that: The number of stages of the multi-stage charge and discharge unit ranges from 10 to 20.

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