Grid trigger circuit of grid-control electron gun
By designing a new gate trigger circuit in the gate-controlled electronic gun, using capacitor direct coupling and tail-cut switch tube and other components to optimize pulse formation, the problems of pulse delay and power consumption in the existing technology are solved, and the steepness is achieved and low-cost circuit design.
Patent Information
- Application Number
- CN202411199826.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2024-12-27
AI Technical Summary
The gate trigger circuit of existing gate-controlled electronic guns uses pulse transformers, resulting in pulse delay and increased power consumption, making it difficult to find a balance between cost and accuracy requirements, making it difficult to optimize pulse delay.
A new gate-controlled electronic gun gate trigger circuit was designed, using capacitor direct coupling, canceling the transformer, and through components such as tail-cut switch tubes and diodes, pulse formation is optimized, pulse delay is reduced, and power consumption is reduced.
The pulse trailing edge is steeper, the power consumption of the circuit is reduced, the accuracy requirements of the electron gun are met, the transformer is cancelled, the circuit volume is reduced, and the cost is reduced.
Smart Images
Figure CN119210406A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of grid-controlled electron guns, and in particular to a grid trigger circuit of a grid-controlled electron gun capable of reducing pulse delay. Background Art
[0002] A grid-controlled electron gun is an electron gun that uses a grid close to the cathode to control the injection current. It can achieve low power control of large injection current and is widely used in the medical and other industries. With the development of radiotherapy technology and the expansion of its application scope, the demand for grid-controlled electron guns in the field of radiotherapy is also growing. Linear accelerators play an important role in tumor treatment, and grid-controlled electron guns, as an important component of linear accelerators, can significantly improve their performance and meet different treatment needs. At the same time, grid-controlled electron guns are also widely used in industries such as industry, medicine, and irradiation. For example, in the irradiation industry, grid-controlled electron guns can provide a stable beam source for irradiation accelerators.
[0003] Each component of the gate-controlled electron gun has certain technical requirements. For example, the anode has a high operating voltage, which makes high-voltage pulse modulation difficult; the gate has a low operating voltage and requires precise control; the cathode needs to have specific performance to ensure working reliability and service life. Among them, the triggering of the gate has a greater impact on the injection current, directly affecting key indicators such as the amplitude, leading and trailing edges of the injection current. Therefore, the requirements for the gate trigger circuit of the gate-controlled gun are getting higher and higher.
[0004] The emission current of the gate-controlled electron gun directly affects the energy of its electrons. The larger the current, the higher the energy and the stronger its penetration ability. In the field of electron accelerator imaging, by switching the penetration ability of the electron gun to emit electrons, clearer penetration imaging at multiple levels can be obtained. The mode adopted is to alternately switch the emission current of the electron gun between two different amplitudes, which is called the dual-energy mode of the electron gun. In the application of gate-controlled electron guns, it is usually necessary to adjust the amplitude of the gate pulse to achieve this effect. Therefore, when designing the gate trigger circuit, it is necessary to adapt to this application of the electron gun.
[0005] At present, the traditional gate pulse trigger circuit includes a voltage-stabilized power supply and energy storage capacitor, a switch tube, a pulse transformer, and a bias circuit. Figure 1 As shown, the gate voltage module A1 provides a DC voltage to charge the energy storage capacitor C1. When the trigger and drive module receives the trigger signal, the optical fiber receiving end transmits the signal to the drive chip U2, thereby driving the switch tube SW1 to turn on. The primary of T1 forms a pulse voltage, which is boosted and adjusted in polarity to form a gate voltage of a certain amplitude and width. The bias module forms a negative bias voltage for the entire gate trigger pulse, so that when there is no trigger pulse, the gate potential is below zero voltage to prevent the gate from being falsely triggered under the influence of noise.
[0006] Under the existing scheme, since the gate load is very large, the use of a pulse transformer will cause the gate trigger front end formed by the secondary of the pulse transformer to have a large overshoot and a long trailing edge, and the injection current formed by the gate-controlled electron gun will also have the same effect, that is, the front end of its injection current will have a large overshoot and a long trailing edge. If you want to form a steeper pulse trailing edge, you need to connect the T1 secondary in parallel with the resistor R1. The smaller its resistance, the steeper the trailing edge will be, but the power consumed will increase exponentially, so it is necessary to increase the power of the gate voltage module. The power of the gate voltage module cannot be increased indefinitely. It is limited by the requirements of cost and accuracy. When the steep delay meets the design accuracy requirements, the power consumption of the resistor R1 will increase, and saving power will cause the pulse delay to be extended. The gate trigger circuit of the prior art causes an irreconcilable contradiction in the design between the resistor R1 and the gate voltage module. Summary of the invention
[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a gate trigger circuit for a gate-controlled electron gun. The gate trigger circuit for the gate-controlled electron gun is redesigned to minimize pulse delay, thereby meeting the working requirements of the gate-controlled electron gun.
[0008] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is: a gate trigger circuit of a gate-controlled electron gun, comprising a gate voltage module A1, a capacitor C1, a main switch tube SW1, a bias module A3, a capacitor C2, and a resistor R1, and the trigger circuit also comprises a truncated switch tube SW2 and a trigger and drive module A2; wherein the capacitor C1 is arranged in parallel at both ends of the gate voltage module A1, the positive electrode of the capacitor C1 is connected to the drain of the main switch tube SW1, the source of the main switch tube S1 is connected to the drain of the truncated switch tube SW2, and the source of the truncated switch tube SW2 is grounded; a lead-out terminal is connected between the main switch tube SW1 and the truncated switch tube SW2 and connected to the output end GRID of the trigger circuit; the output end GRID is grounded after being connected in series with the resistor R1 and the capacitor C2 in sequence; the positive and negative electrodes of the bias module A3 are connected in parallel at both ends of the capacitor C2; the trigger and drive module A2 is used to drive the main switch tube SW1 and the truncated switch tube SW2 to be turned on or off respectively according to the presence or absence of a trigger signal, thereby outputting a pulse voltage through the output end GRID.
[0009] The trigger circuit further includes a diode V2, the source of the main switch tube SW1 is connected to the anode of the diode V2, and the cathode of the diode V2 is connected to the drain of the truncated switch tube SW2.
[0010] The trigger circuit further includes a resistor R6, which is connected in series to a loop between the drain of the main switch tube SW1 and the positive electrode of the capacitor C1.
[0011] The trigger circuit further includes a capacitor C3, and the output terminal GRID is connected to the cathode of the diode V2 via the capacitor C3.
[0012] The trigger circuit also includes a gate voltage module A4, a main switch tube SW3, a trigger and drive module A5, a capacitor C11 and a diode V4, wherein the capacitor C11 is connected in parallel at both ends of the positive and negative electrodes of the gate voltage module, the positive electrode of the capacitor C11 is connected to the drain of the main switch tube SW3, the source of the main switch tube SW3 is connected to the anode of the diode V4, and the cathode of the diode V4 is connected to the cathode of the diode V2; the output end of the trigger and drive module A5 is connected to the gate of the main switch tube SW3 and the tail switch tube SW2.
[0013] The trigger circuit further includes a resistor R61, which is connected in series between the capacitor C11 and the main switch SW3.
[0014] The trigger and drive module A2 includes optocouplers U2, U3, an inverting driver U4, and a common-phase driver U5, wherein the positive electrode of the power supply VCC1 is connected to the first input end of the optocoupler U2 via a resistor R2, the second input end of the optocoupler U2 is connected to the first input end of the optocoupler U3, and the second input end of the optocoupler U2 inputs a trigger signal; the positive electrode of the power supply VCC1 is connected to the anode of the diode V1, and the cathode of the diode V1 is respectively connected to the power supply end of the optocoupler U2, the resistor R3, and the capacitor C4; the other end of the resistor R3 is connected to the output of the optocoupler U2 The output end of the optocoupler U4 is connected to the anode of the diode V3, and the cathode of the diode V3 is connected to the input end of the inverting driver U4; the resistor R4 is connected in parallel to both ends of the diode V3; the cathode of the diode V3 is connected to the ground end of the optocoupler U2 through the capacitor C5, and the ground end of the optocoupler U2 is connected to the power ground V1G; the other end of the capacitor C4 is connected to the ground end of the inverting driver U4, and the ground end of U4 is connected to the power ground V1G; the ground end of U4 is connected to the anode of the diode V2; the output end of U4 is connected to the gate of the main switch tube SW1;
[0015] The power supply end of the optocoupler U3 is connected to the power supply VCC2, and the ground end of the optocoupler U3 is grounded; the output end of the optocoupler U3 is connected to the power supply end of the optocoupler U3 via the resistor R5; the output end of the optocoupler U3 is connected to the input end of the in-phase driver U5, and the output end of the in-phase driver U5 is connected to the gate of the truncated switch tube SW2.
[0016] The trigger circuit also includes a photoelectric receiver, the output end of which is connected to the second input end of the optical coupler U3; the input end of the photoelectric receiver is connected to the optical fiber, for receiving the trigger signal transmitted through the optical fiber and converting the optical signal into an electrical signal.
[0017] The trigger and drive module A5 includes optocouplers U22, U33 and an inverting driver U44, wherein the positive electrode of the power supply VCC1 is connected to the first input end of the optocoupler U22 via a resistor R22, the second input end of the optocoupler U22 is connected to the first input end of the optocoupler U33, and the second input end of the optocoupler U22 inputs a trigger signal; the positive electrode of the power supply VCC1 is connected to the anode of the diode V11, the cathode of the diode V11 is respectively connected to the power supply end of the optocoupler U22, the resistor R33, and the capacitor C44; the other end of the resistor R33 is connected to the output end of the optocoupler U22; the optocoupler The output end of U44 is connected to the anode of the diode V33, and the cathode of the diode V33 is connected to the input end of the inverting driver U44; the resistor R44 is connected in parallel to both ends of the diode V33; the cathode of the diode V33 is connected to the ground end of the optocoupler U22 via the capacitor C55, and the ground end of the optocoupler U22 is connected to the power ground V1G; the other end of the capacitor C44 is connected to the ground end of the inverting driver U44, and the ground end of U44 is connected to the power ground V2G; the ground end of U44 is connected to the anode of the diode V22; the output end of U44 is connected to the gate of the main switch tube SW3;
[0018] The power supply end of the optocoupler U33 is connected to the power supply VCC2, and the ground end of the optocoupler U33 is grounded; the output end of the optocoupler U33 is connected to the power supply end of the optocoupler U33 via the resistor R55; the output end of the optocoupler U33 is connected to the input end of the in-phase driver U5 of the trigger and drive module A2, and the output end of the in-phase driver U5 is connected to the gate of the truncated switch tube SW2.
[0019] The gate voltage module A1 and the gate voltage module A4 are adjustable regulated power supplies with different output voltages, which charge and store energy for the capacitors C1 and C11 respectively.
[0020] The advantages of the present invention are: (1) it can effectively reduce the power consumed by the gate matching load that is increased due to the reduction of the gate pulse trailing edge in the traditional circuit.
[0021] (2) The gate pulse trailing edge can be effectively reduced. When applied to a gate-controlled electron gun, an electron gun pulse current with a smaller trailing edge is obtained, thus meeting the accuracy requirements of the electron gun operation.
[0022] (3) Dual-energy gate pulses can be obtained by expansion and applied in the field of dual-energy electron guns.
[0023] (4) The circuit structure is simple and the cost is low. The control signal can be transmitted through optical fiber, and the control signal transmission delay is small.
[0024] (5) Compared with the trigger circuit in the prior art, the transformer component is eliminated, so that the volume of the trigger circuit is further reduced, which facilitates the layout design. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The following is a brief description of the contents expressed in the drawings of the present specification and the marks in the drawings:
[0026] Figure 1 It is a trigger circuit schematic diagram of the prior art;
[0027] Figure 2 It is the topological diagram of the gate trigger circuit;
[0028] Figure 3 This is the circuit schematic diagram of the trigger and drive module A2;
[0029] Figure 4 This is a schematic diagram of a novel gate pulse trigger circuit of the present invention;
[0030] Figure 5 Topological diagram of gate trigger circuit with dual-energy triggering;
[0031] Figure 6 The trigger timing diagram of each module of the present invention;
[0032] Figure 7 The circuit principle diagram of the dual-energy mode of the gate trigger circuit of the present invention;
[0033] Figure 8 This is a timing diagram of the dual-energy gate empty pulse of the present invention. DETAILED DESCRIPTION
[0034] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.
[0035] This solution aims at the insurmountable contradiction between module loss and delay in the existing technology, and redesigns a gate trigger circuit suitable for the gate-controlled electron gun. The circuit minimizes the pulse delay of the voltage pulse output by the trigger circuit. Compared with the existing technology, this solution has a steep pulse light delay. At the same time, compared with the existing technology, the transformer is eliminated, which has greater advantages in cost and volume. The specific circuit structure principle of the gate trigger circuit of the gate-controlled electron gun designed in this solution is introduced as follows:
[0036] like Figure 1-8As shown, a gate trigger circuit of a gate-controlled electron gun includes a gate voltage module A1, a capacitor C1, a main switch tube SW1, a bias module A3, a capacitor C2, and a resistor R1. The trigger circuit also includes a truncated switch tube SW2 and a trigger and drive module A2; wherein the capacitor C1 is arranged in parallel at both ends of the gate voltage module A1, the positive electrode of the capacitor C1 is connected to the drain of the main switch tube SW1, the source of the main switch tube S1 is connected to the drain of the truncated switch tube SW2, and the source of the truncated switch tube SW2 is grounded; a lead-out terminal is connected between the main switch tube SW1 and the truncated switch tube SW2 to an output end GRID of the trigger circuit; the output end GRID is grounded after being connected in series with a resistor R1 and a capacitor C2 in sequence; the positive and negative electrodes of the bias module A3 are connected in parallel at both ends of the capacitor C2; the trigger and drive module A2 is used to drive the main switch tube SW1 and the truncated switch tube SW2 to be turned on or off respectively according to the presence or absence of a trigger signal, thereby outputting a pulse voltage through the output end GRID.
[0037] The trigger circuit of the present solution further includes a diode V2, the source of the main switch tube SW1 is connected to the anode of the diode V2, and the cathode of the diode V2 is connected to the drain of the truncated switch tube SW2.
[0038] The trigger circuit of the present solution further includes a resistor R6, which is connected in series to a loop between the drain of the main switch tube SW1 and the positive electrode of the capacitor C1.
[0039] The trigger circuit of the present solution further includes a capacitor C3, and the output terminal GRID is connected to the cathode of the diode V2 via the capacitor C3.
[0040] The above scheme realizes a gate trigger circuit that can reduce the gate pulse delay. When its output end is applied to the gate-controlled electron gun, an electron gun pulse current with a smaller trailing edge is obtained. When controlling, it is only necessary to drive the main switch tube SW1 and the tail switch tube SW2 to be turned on or off respectively through the trigger and drive module A2 according to the presence or absence of the trigger signal, and then the pulse voltage can be output through the output terminal GR ID.
[0041] In order to expand the dual-energy mode of the gate-controlled electron gun, the trigger circuit in the embodiment of the present application also includes a gate voltage module A4, a main switch tube SW3, a trigger and drive module A5, a capacitor C11 and a diode V4, wherein the positive and negative ends of the gate voltage module are connected in parallel with a capacitor C11, the positive electrode of the capacitor C11 is connected to the drain of the main switch tube SW3, the source of the main switch tube SW3 is connected to the anode of the diode V4, and the cathode of the diode V4 is connected to the cathode of the diode V2; the output end of the trigger and drive module A5 is connected to the gate of the main switch tube SW3 and the truncated switch tube SW2. A resistor R61 is connected in series between the capacitor C11 and the main switch tube SW3. Similarly, the trigger and drive module A5 can drive the main switch tube SW3 and the truncated switch tube SW2 to be turned on or off according to the presence or absence of the trigger signal, and the pulse voltage can be output through the output terminal GRID. By setting the voltage of gate voltage module A and gate voltage module A4 to be different, C1 and C11 can be charged differently. Then, trigger pulses are input alternately from U1 and U6 to form gate pulses of alternating amplitudes on the gate, thereby forming gun emission currents of alternating magnitudes.
[0042] The specific circuit design for the trigger and drive module A2 is as follows: the trigger and drive module A2 includes optocouplers U2 and U3, an inverting driver U4, and a non-inverting driver U5, wherein the positive electrode of the power supply +15V is connected to the first input terminal of the optocoupler U2 via a resistor R2, the second input terminal of the optocoupler U2 is connected to the first input terminal of the optocoupler U3, and the second input terminal of the optocoupler U2 inputs a trigger signal; the positive electrode of the +15V power supply is connected to the anode of the diode V1, and the cathode of the diode V1 is connected to the power supply terminal of the optocoupler U2, the resistor R3, and the capacitor C4 respectively; the other end of the resistor R3 is connected to Connected to the output end of the optocoupler U2; the output end of the optocoupler U4 is connected to the anode of the diode V3, and the cathode of the diode V3 is connected to the input end of the inverting driver U4; the resistor R4 is connected in parallel to both ends of the diode V3; the cathode of the diode V3 is connected to the ground end of the optocoupler U2 through the capacitor C5, and the ground end of the optocoupler U2 is connected to the power ground V1G; the other end of the capacitor C4 is connected to the ground end of the inverting driver U4, and the ground end of U4 is connected to the power ground V1G; the ground end of U4 is connected to the anode of the diode V2; the output end of U4 is connected to the gate of the main switch tube SW1;
[0043] The power supply terminal of the optocoupler U3 is connected to the +5V power supply, and the ground terminal of the optocoupler U3 is grounded; the output terminal of the optocoupler U3 is connected to the power supply terminal of the optocoupler U3 through the resistor R5; the output terminal of the optocoupler U3 is connected to the input terminal of the in-phase driver U5, and the output terminal of the in-phase driver U5 is connected to the gate of the truncated switch tube SW2. The power supply terminal of the in-phase driver U5 is connected to the +15V power supply, and its ground terminal is grounded; in the optocouplers U2 and U3 in this solution, the first input terminal and the second input terminal are pins 1 and 2 respectively, the ground terminal is pin 5, the power supply terminal is pin 6, and the output terminal is pin 4.
[0044] The trigger signal is input to the pin 2 of the optocoupler U3, and the conduction of the optocouplers U2 and U3 is controlled according to the trigger signal. In order to realize remote control triggering and reduce the delay of signal transmission, a photoelectric receiver U1 is provided, and the output end of the photoelectric receiver is connected to the second input end of the optocoupler U3; the input end of the photoelectric receiver is connected to the optical fiber, which is used to receive the trigger signal transmitted through the optical fiber and convert the optical signal into an electrical signal. The photoelectric receiver can use the model HFBR-531 to realize the conversion of the photoelectric signal and send it to the optocoupler U3.
[0045] The trigger and drive module A5 designed for dual-energy mode has a similar circuit structure to A2, with only some changes, such as Figure 4 As shown, the trigger and drive module A5 includes optocouplers U22, U33 and an inverting driver U44, wherein the positive electrode of the power supply +15V is connected to the first input terminal of the optocoupler U22 via a resistor R22, the second input terminal of the optocoupler U22 is connected to the first input terminal of the optocoupler U33, and the second input terminal of the optocoupler U22 inputs a trigger signal; the positive electrode of the power supply VCC1 is connected to the anode of the diode V11, and the cathode of the diode V11 is respectively connected to the power supply terminal of the optocoupler U22, the resistor R33, and the capacitor C44; the other end of the resistor R33 is connected to the output terminal of the optocoupler U22; the output terminal of the optocoupler U44 is connected to the anode of the diode V33, and the cathode of the diode V33 is connected to the input terminal of the inverting driver U44; the resistor R44 is connected in parallel to both ends of the diode V33; the cathode of the diode V33 is connected to the ground terminal of the optocoupler U22 via the capacitor C55, and the ground terminal of the optocoupler U22 is connected to the power ground V1 G; the other end of the capacitor C44 is connected to the ground terminal of the inverting driver U44, and the ground terminal of U44 is connected to the power ground V2G; the ground terminal of U44 is connected to the anode of the diode V22; the output end of U44 is connected to the gate of the main switch tube SW3;
[0046] The power supply end of the optocoupler U33 is connected to +5V, and the ground end of the optocoupler U33 is grounded; the output end of the optocoupler U33 is connected to the power supply end of the optocoupler U33 through the resistor R55; the output end of the optocoupler U33 is connected to the input end of the in-phase driver U5 of the trigger and drive module A2, and the output end of the in-phase driver U5 is connected to the gate of the tail switch tube SW2. The trigger signal is input to the pin 2 of the optocoupler U33, and the conduction of the optocouplers U22 and U33 is controlled according to the trigger signal. In order to realize remote control triggering and reduce the delay of signal transmission, a photoelectric receiver U1 is provided, and the output end of the photoelectric receiver is connected to the second input end of the optocoupler U33; the input end of the photoelectric receiver is connected to the optical fiber, which is used to receive the trigger signal transmitted through the optical fiber and convert the optical signal into an electrical signal. The photoelectric receiver can use the model HFBR-531 to realize the conversion of the photoelectric signal and send it to the optocoupler U33. The design of A5 saves the cost of a in-phase driver, reuses the in-phase driver in A2, and saves the hardware resource cost on the basis of meeting the function realization.
[0047] In order to realize the dual-energy mode, in the dual-energy mode, the gate voltage module A1 and the gate voltage module A4 are adjustable regulated power supplies with different output voltages, which respectively charge and store energy for the capacitors C1 and C11 to realize different output voltages of the capacitors C1 and C11.
[0048] The above circuit structure of the present application is explained in principle below in conjunction with the accompanying drawings:
[0049] The gate trigger circuit of the gate-controlled electron gun provided in this embodiment optimizes the topology of the gate pulse forming circuit, cancels the pulse transformer, and adopts a capacitor direct coupling method to connect with the bias part, and on this basis, adds a tail circuit to minimize the pulse trailing edge, and cancels the transformer, resulting in a smaller volume, lower cost, and lower module loss; its working principle is described as follows:
[0050] The trigger circuit principle in design Figure 1-8 middle:
[0051] The gate voltage module A1 is an adjustable voltage-stabilized power supply, which forms a stable voltage of a certain amplitude after energy storage by C1.
[0052] The gate voltage module A4 is an adjustable voltage regulator, which forms a stable voltage of a certain amplitude after energy storage in C11. It should be noted that in dual energy mode, C1 and C11 should output different voltages after energy storage.
[0053] SW1 is the main switch tube, used to form the gate pulse, and SW2 is the tail switch tube.
[0054] C3 is a DC-isolating coupling capacitor, which can ensure that the bias module will not be short-circuited to the ground when SW2 is turned on, and can achieve the coupling of the gate pulse voltage when SW1 is turned on.
[0055] A3 is the power supply of the bias module. After energy storage through C2, a negative bias is formed. The gate is pulled down to a negative potential through R1 to avoid false triggering.
[0056] The working process is described as follows:
[0057] The bias module A3 applies a negative voltage to the gate through R1, so that the gate voltage is below 0V to avoid false triggering.
[0058] When no trigger signal is sent to U1, 1 and 2 of the optical receiver U1 are not turned on, no current flows through the input terminals of the optocouplers U2 and U3, and their output terminals 4 are all high level. U4 is an inverting driver, and U5 is a non-inverting driver. Therefore, when their inputs are all high level, U5 outputs high, making SW2 turned on. The +15V voltage charges capacitor C4 through diode V1, and finally reaches the negative end of the power supply (triangle ground) through V2. Since the circuit works in a state without trigger signal input for most of the time, a stable voltage P1 of about 12V can be formed on C4. The ground of this power supply is V1G. This power supply can be used to power U2 and U4, that is, terminal P1 is drawn between the cathode of diode V1 and capacitor C4. This terminal P1 is used to power the optocoupler U2 and the inverting driver U4. Similarly, in the dual-energy mode, P11 is drawn in A5, and P11 is used to power the optocouplers U22 and U44 respectively.
[0059] When a trigger signal is sent to U1, 1 and 2 of the optical receiver U1 are turned on, current flows through the input terminals of U2 and U3, and their outputs become low. There are no other devices in the input circuit of U5, and its output will immediately become low when the trigger signal is sent, and SW2 is turned off. When the front end of U4 does not receive a trigger signal, capacitor C5 is fully charged. When the trigger signal arrives, the output pin 4 of U2 is pulled low, and the input voltage of U4 (the voltage of C5) will be discharged to the action threshold of U4 through resistor R4, and then SW1 will be triggered to turn on, forming a pulse voltage, which is coupled to the gate through capacitor C3.
[0060] When the trigger signal ends, the current at the input ends of the optocouplers U2 and U3 stops, and the outputs of the optocouplers U2 and U3 are pulled high by the power supply. At this time, the voltage diode V3 on C5 is directly charged, which can make the voltage of C5 increase faster, so that SW2 is turned on and SW1 is turned off at the same time, forming a more ideal truncation effect.
[0061] Resistor R6 can prevent the gate voltage module power supply from short-circuiting for a short period of time (tens to hundreds of nanoseconds) after SW2 is turned on and SW1 is not turned off. The timing diagram is shown in Figure 6 , 8 shown.
[0062] At the same time, the gate trigger circuit in this scheme can be expanded to form a dual-energy gate control mode, such as Figure 4 ,7 As shown. Figure 2 On the basis of the above, a gate voltage module 2 and a switch tube SW3 are newly added, and a trigger and drive module similar to A2 is added. The optocoupler output of this module used to drive the tail switch tube SW2 is connected to the corresponding optocoupler output (SG) in module A2, and the driver U5 can be used to save costs.
[0063] In order to realize the dual-energy control mode, A1 and A4 are set to different voltages respectively, and trigger pulses are input alternately from U1 and U6 to form gate pulses of alternating amplitudes on the gate, thereby forming gun emission currents of alternating magnitudes.
[0064] The gate trigger circuit of the gate-controlled electron gun using the above scheme is applied to the electron gun and has the following advantages:
[0065] (1) The power consumed by the gate matching load increased by reducing the trailing edge of the gate pulse in the traditional circuit can be effectively reduced.
[0066] (2) It can effectively reduce the trailing edge of the gate pulse. When applied to a gate-controlled electron gun, an electron gun pulse current with a smaller trailing edge is obtained.
[0067] (3) Dual-energy gate pulses can be obtained by expansion and applied in the field of dual-energy electron guns.
[0068] (4) The transformer is eliminated, saving costs and reducing the size of the trigger circuit.
[0069] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.
Claims
1. A gate trigger circuit of a gate-controlled electron gun, comprising a gate voltage module A1, a capacitor C1, a main switch tube SW1, a bias module A3, a capacitor C2, and a resistor R1, characterized in that: The trigger circuit also includes a truncated switch tube SW2 and a trigger and drive module A2; wherein a capacitor C1 is arranged in parallel at both ends of the gate voltage module A1, the positive electrode of the capacitor C1 is connected to the drain of the main switch tube SW1, the source of the main switch tube S1 is connected to the drain of the truncated switch tube SW2, and the source of the truncated switch tube SW2 is grounded; a lead-out terminal is connected between the main switch tube SW1 and the truncated switch tube SW2 and connected to the output end GRID of the trigger circuit; the output end GRID is grounded after being connected in series with a resistor R1 and a capacitor C2; the positive and negative electrodes of the bias module A3 are connected in parallel at both ends of the capacitor C2; the trigger and drive module A2 is used to drive the main switch tube SW1 and the truncated switch tube SW2 to be turned on or off respectively according to the presence or absence of a trigger signal, thereby outputting a pulse voltage through the output end GRID.
2. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 1, characterized in that: The trigger circuit further includes a diode V2, the source of the main switch tube SW1 is connected to the anode of the diode V2, and the cathode of the diode V2 is connected to the drain of the truncated switch tube SW2.
3. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 1 or 2, characterized in that: The trigger circuit further includes a resistor R6, which is connected in series to a loop between the drain of the main switch tube SW1 and the positive electrode of the capacitor C1.
4. A gate trigger circuit for a gate-controlled electron gun as claimed in any one of claims 1 to 3, characterized in that: The trigger circuit further includes a capacitor C3, and the output terminal GRID is connected to the cathode of the diode V2 via the capacitor C3.
5. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 4, characterized in that: The trigger circuit also includes a gate voltage module A4, a main switch tube SW3, a trigger and drive module A5, a capacitor C11 and a diode V4, wherein the capacitor C11 is connected in parallel at both ends of the positive and negative electrodes of the gate voltage module, the positive electrode of the capacitor C11 is connected to the drain of the main switch tube SW3, the source of the main switch tube SW3 is connected to the anode of the diode V4, and the cathode of the diode V4 is connected to the cathode of the diode V2; the output end of the trigger and drive module A5 is connected to the gate of the main switch tube SW3 and the tail switch tube SW2.
6. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 5, characterized in that: The trigger circuit further includes a resistor R61, which is connected in series between the capacitor C11 and the main switch SW3.
7. A gate trigger circuit for a gate-controlled electron gun according to any one of claims 1 to 6, characterized in that: The trigger and drive module A2 includes optocouplers U2 and U3, an inverting driver U4, and a common-phase driver U5, wherein the positive electrode of the power supply VCC1 is connected to the first input terminal of the optocoupler U2 via a resistor R2, the second input terminal of the optocoupler U2 is connected to the first input terminal of the optocoupler U3, and the second input terminal of the optocoupler U2 inputs a trigger signal; The positive electrode of the power supply VCC1 is connected to the anode of the diode V1, and the cathode of the diode V1 is connected to the power supply end of the optocoupler U2, the resistor R3, and the capacitor C4 respectively; the other end of the resistor R3 is connected to the output end of the optocoupler U2; the output end of the optocoupler U4 is connected to the anode of the diode V3, and the cathode of the diode V3 is connected to the input end of the inverting driver U4; the resistor R4 is connected in parallel to both ends of the diode V3; the cathode of the diode V3 is connected to the ground end of the optocoupler U2 through the capacitor C5, and the ground end of the optocoupler U2 is connected to the power ground V1G; the other end of the capacitor C4 is connected to the ground end of the inverting driver U4, and the ground end of U4 is connected to the power ground V1G; the ground end of U4 is connected to the anode of the diode V2; the output end of U4 is connected to the gate of the main switch tube SW1; The power supply end of the optocoupler U3 is connected to the power supply VCC2, and the ground end of the optocoupler U3 is grounded; the output end of the optocoupler U3 is connected to the power supply end of the optocoupler U3 via the resistor R5; the output end of the optocoupler U3 is connected to the input end of the in-phase driver U5, and the output end of the in-phase driver U5 is connected to the gate of the truncated switch tube SW2.
8. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 7, characterized in that: The trigger circuit also includes a photoelectric receiver, the output end of which is connected to the second input end of the optical coupler U3; the input end of the photoelectric receiver is connected to the optical fiber, for receiving the trigger signal transmitted through the optical fiber and converting the optical signal into an electrical signal.
9. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 7, characterized in that: The trigger and drive module A5 includes optocouplers U22, U33 and an inverting driver U44, wherein the positive electrode of the power supply VCC1 is connected to the first input terminal of the optocoupler U22 via a resistor R22, the second input terminal of the optocoupler U22 is connected to the first input terminal of the optocoupler U33, and the second input terminal of the optocoupler U22 inputs a trigger signal; The positive electrode of the power supply VCC1 is connected to the anode of the diode V11, and the cathode of the diode V11 is respectively connected to the power supply end of the optocoupler U22, the resistor R33, and the capacitor C44; the other end of the resistor R33 is connected to the output end of the optocoupler U22; the output end of the optocoupler U44 is connected to the anode of the diode V33, and the cathode of the diode V33 is connected to the input end of the inverting driver U44; the resistor R44 is connected in parallel to both ends of the diode V33; the cathode of the diode V33 is connected to the ground end of the optocoupler U22 through the capacitor C55, and the ground end of the optocoupler U22 is connected to the power ground V1G; the other end of the capacitor C44 is connected to the ground end of the inverting driver U44, and the ground end of U44 is connected to the power ground V2G; the ground end of U44 is connected to the anode of the diode V22; the output end of U44 is connected to the gate of the main switch tube SW3; The power supply end of the optocoupler U33 is connected to the power supply VCC2, and the ground end of the optocoupler U33 is grounded; the output end of the optocoupler U33 is connected to the power supply end of the optocoupler U33 via the resistor R55; the output end of the optocoupler U33 is connected to the input end of the in-phase driver U5 of the trigger and drive module A2, and the output end of the in-phase driver U5 is connected to the gate of the truncated switch tube SW2.
10. A gate trigger circuit for a gate-controlled electron gun as claimed in claim 5, characterized in that: The gate voltage module A1 and the gate voltage module A4 are adjustable regulated power supplies with different output voltages, which charge and store energy for the capacitors C1 and C11 respectively.