Electron beam deflection control circuit, method and high voltage generator

Abstract

The present invention provides an electron beam deflection control circuit, comprising: a first voltage source module, having a first end connected to a power supply and a second end configured to output a positive voltage; a first controllable switch, having a first end connected to the second end of the first voltage source module, the second end of the first controllable switch connected to the first end of a magnetic field generator, and the second end of the magnetic field generator connected to a reference ground; when the first voltage source module outputs a positive voltage and the first controllable switch is turned on, current flows from the first end to the second end of the magnetic field generator; a second voltage source module, having a first end connected to the power supply and a second end configured to output a negative voltage; a second controllable switch, having a first end connected to the first end of the magnetic field generator and a second end connected to the second end of the second voltage source module; when the second voltage source module outputs a negative voltage and the second controllable switch is turned on, current flows from the second end to the first end of the magnetic field generator. This control circuit has low design cost and high power density.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage generators, and in particular to an electron beam deflection control circuit, method and high-voltage generator. Background Art

[0002] High-voltage generators are mainly used to provide DC high-voltage power to external access devices and are widely used in medical equipment, such as digital direct radiography (DR) and computed tomography (CT).

[0003] A magnetic field deflection system, incorporated into a high-voltage generator, can be used to control the deflection of an electron beam within a vacuum device. The electron beam can be deflected symmetrically or asymmetrically based on the direction of the magnetic field generated by the magnetic field deflection system. Currently, most magnetic field deflection systems employ a topology in which the power supply is a current source, outputting a constant current to achieve symmetrical or asymmetrical deflection of the electron beam. However, a topology that utilizes a voltage source to achieve symmetrical or asymmetrical deflection of the electron beam is currently unavailable. Therefore, there is an urgent need for an electron beam deflection control circuit employing a voltage-based topology. Summary of the Invention

[0004] Therefore, the present invention aims to solve the technical problems existing in the circuits of the prior art that use current-type topology to control the direction of the magnetic field, thereby providing an electron beam deflection control circuit, method and high-voltage generator.

[0005] According to a first aspect, an embodiment of the present invention provides an electron beam deflection control circuit, comprising:

[0006] a first voltage source module, having a first end connected to a power supply and a second end configured to output a forward voltage, wherein the forward voltage is a voltage between the second end of the first voltage source module and a reference ground;

[0007] a first controllable switch Q1, a first end of which is connected to the second end of the first voltage source module, a second end of which is connected to the first end of a magnetic field generating device, and a second end of which is connected to the reference ground;

[0008] When the first voltage source module outputs the forward voltage and the first controllable switch Q1 is turned on, current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device;

[0009] a second voltage source module, a first end of which is connected to the power supply, and a second end of which is used to output a negative voltage, wherein the negative voltage is a voltage between the second end of the second voltage source module and the reference ground;

[0010] a second controllable switch Q2, a first end of which is connected to the first end of the magnetic field generating device, and a second end of the second controllable switch Q2 is connected to the second end of the second voltage source module;

[0011] When the second voltage source module outputs the negative voltage and the second controllable switch Q2 is turned on, the current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device;

[0012] The first controllable switch Q1 and the second controllable switch Q2 are turned on in a time-sharing manner.

[0013] Optionally, the electron beam deflection control circuit further includes:

[0014] a third controllable switch Q3, a second end of which is connected to the second end of the magnetic field generating device;

[0015] a first diode D1, having an anode connected to the first end of the third controllable switch Q3 and a cathode connected to the first end of the magnetic field generating device;

[0016] When the first controllable switch Q1 and the second controllable switch Q2 are both disconnected and current flows out of the second end of the magnetic field generating device, the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop.

[0017] Optionally, the electron beam deflection control circuit further includes:

[0018] a fourth controllable switch Q4, a second end of which is connected to the second end of the magnetic field generating device;

[0019] a second diode D2, an anode of which is connected to the first end of the magnetic field generating device, and a cathode of which is connected to the first end of the fourth controllable switch Q4;

[0020] When the first controllable switch Q1 and the second controllable switch Q2 are both disconnected and current flows out of the first end of the magnetic field generating device, the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

[0021] Optionally, the electron beam deflection control circuit further includes:

[0022] A bidirectional transient suppression diode has one end connected to the first end of the magnetic field generating device and the other end connected to the second end of the magnetic field generating device.

[0023] Optionally, the first voltage source module adopts any one of an isolated DC / DC circuit, a Buck circuit, and a Boost circuit.

[0024] Optionally, the second voltage source module adopts a Buck-Boost circuit or a flyback circuit.

[0025] Optionally, when the second voltage source module adopts the Buck-Boost circuit, it includes:

[0026] a fifth controllable switch Q5, a first end of which serves as an input end of the power supply;

[0027] a third diode D3, having a cathode connected to the second end of the fifth controllable switch Q5 and an anode connected to the second end of the second controllable switch Q2;

[0028] a first inductor L1, having a first end connected to the second end of the fifth controllable switch Q5, and a second end connected to the reference ground;

[0029] The first capacitor C1 has a first end connected to the anode of the third diode D3 and a second end connected to the reference ground.

[0030] Optionally, the electron beam deflection control circuit further includes:

[0031] a control module connected to the control ends of the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4, respectively; wherein the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all fully controllable power semiconductor devices.

[0032] According to a second aspect, an embodiment of the present invention provides an electron beam deflection control method applicable to the above-mentioned electron beam deflection control circuit, the method comprising:

[0033] When the electron beam deflection control circuit is in an initial state, the first controllable switch Q1 is controlled to be turned on, and current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device, wherein the initial state is that the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all in an off state;

[0034] Before the first controllable switch Q1 is turned off, controlling the third controllable switch Q3 to be turned on;

[0035] After the third controllable switch Q3 is turned on, the first controllable switch Q1 is turned off, and the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop;

[0036] Before the third controllable switch Q3 is turned off, controlling the second controllable switch Q2 to be turned on;

[0037] After the second controllable switch Q2 is turned on, the third controllable switch Q3 is turned off, and the current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device;

[0038] Before the second controllable switch Q2 is turned off, controlling the fourth controllable switch Q4 to be turned on;

[0039] After the fourth controllable switch Q4 is turned on, the second controllable switch Q2 is turned off, and the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

[0040] According to a third aspect, an embodiment of the present invention provides a high-voltage generator, comprising the above-mentioned electron beam deflection control circuit.

[0041] The technical solution of the present invention has the following advantages:

[0042] The present invention provides an electron beam deflection control circuit having a voltage-type topology structure for a voltage source, which changes the direction of the current flowing through a magnetic field generating device by controlling the output positive voltage and negative voltage. Symmetry or asymmetry can also be achieved by controlling the magnitude of the output positive voltage and negative voltage to be equal or different. In addition, compared with the current-type topology, on the one hand, the voltage-type topology has a wide range of devices to choose from, making selection easier; on the other hand, the voltage-type topology does not require a power inductor, which is conducive to improving power density. In summary, the electron beam deflection control circuit with a voltage-type topology structure provided in this embodiment has a low design cost and high power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 This is a composition diagram of a specific example of an electron beam deflection control circuit in Example 1 of the present application;

[0045] Figure 2 This is a circuit structure diagram of a specific example of the first voltage source module and the second voltage source module in Example 1 of the present application;

[0046] Figure 3 This is a connection diagram of a specific example of the control module and the voltage sampling module in Example 1 of the present application;

[0047] Figure 4This is a flowchart of a specific example of an electron beam deflection control method in Example 2 of the present application. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0051] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0052] Traditional magnetic field deflection systems mostly use a current-source topology suitable for current sources, outputting symmetrical or asymmetrical constant currents to achieve symmetrical or asymmetrical deflection of the magnetic field. However, the dead-zone logic of the current-source topology requires that the upper and lower bridge arms must be turned on simultaneously and cannot be turned off simultaneously, which is contrary to the dead-zone logic of the voltage-source topology in this embodiment. Furthermore, the vast majority of driver chips for controllable switches in other industries are currently designed to work with voltage-source topologies. Therefore, traditional current-source topologies require the selection of specific driver chips when selecting driver chips, which undoubtedly increases the difficulty of device selection. Furthermore, current-source topologies typically use power inductors to suppress current ripple. When current ripple requirements are very high or the target power is relatively large, the inductor needs to be larger, which is not conducive to improving power density. In contrast, voltage-source topologies do not require power inductors, which is conducive to improving power density.

[0053] Example 1

[0054] This embodiment provides an electron beam deflection control circuit, which is applied to medical equipment or industrial equipment that generates electron beams, so as to achieve symmetrical or asymmetrical deflection of the electron beam in the Z-axis direction. Figure 1 As shown, it includes a first voltage source module 11, a second voltage source module 12, a first controllable switch Q1, and a second controllable switch Q2, as detailed below.

[0055] The first voltage source module 11 has a first end connected to the positive electrode of the power supply Vin, and a second end used to output a forward voltage, where the forward voltage is the voltage between the second end of the first voltage source module and the reference ground COM; the third end of the first voltage source module 11 is connected to the negative electrode of the power supply Vin, and the fourth end is connected to the reference ground COM.

[0056] The first controllable switch Q1 has a first end connected to the second end of the first voltage source module 11, and a second end of the first controllable switch Q1 is connected to the magnetic field generating device ( Figure 1 The first end of the magnetic field generating device is connected to the first end of the magnetic field generating device, and the second end of the magnetic field generating device is connected to the reference ground COM.

[0057] When the first voltage source module 11 outputs the forward voltage and the first controllable switch Q1 is turned on, current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device.

[0058] In this embodiment, after the power supply Vin is transformed by the first voltage source module 11, a positive voltage is output through the second end of the first voltage source module 11. When the first controllable switch Q1 is turned on and the second controllable switch Q2 is turned off, the current flows from the first end to the second end of the magnetic field generating device. That is, the current flows through the coil in the magnetic field generating device. Under the action of the current, the coil generates a magnetic field in a first direction, so that the electron beam begins to be deflected.

[0059] The second voltage source module 12 has a first end connected to the positive electrode of the power supply Vin, and a second end used to output a negative voltage, where the negative voltage is the voltage between the second end of the second voltage source module and the reference ground COM; the third end of the first voltage source module 12 is connected to the negative electrode of the power supply Vin, and the fourth end is connected to the reference ground COM.

[0060] a second controllable switch Q2, a first end of which is connected to the first end of the magnetic field generating device, and a second end of the second controllable switch Q2 is connected to the second end of the second voltage source module;

[0061] When the second voltage source module 12 outputs the negative voltage and the second controllable switch Q2 is turned on, current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device.

[0062] In this embodiment, after the power supply Vin is converted by the second voltage source module 12, a negative voltage is output through the second end of the second voltage source module 12. When the second controllable switch Q2 is turned on and the first controllable switch Q1 is turned off, current flows from the second end of the magnetic field generating device to the first end. That is, the current flows through the coil within the magnetic field generating device. Under the action of the current, the coil generates a second magnetic field in a direction opposite to the first direction, thereby changing the deflection direction of the electron beam and achieving symmetrical or asymmetrical deflection of the electron beam in the Z-axis direction. By respectively changing the voltage values output by the second end of the first voltage source module 11 and the second end of the second voltage source module 12, the magnitude of the current flowing through the magnetic field generating device can be changed, thereby changing the strength of the magnetic field and achieving symmetrical or asymmetrical deflection of the electron beam in the Z-axis direction.

[0063] The first controllable switch Q1 and the second controllable switch Q2 are turned on in a time-sharing manner. This embodiment employs a voltage-source topology. A short circuit in a voltage-source topology can increase current, damaging or even burning components in the circuit. Therefore, in this embodiment, the first controllable switch Q1 and the second controllable switch Q2 cannot be turned on simultaneously.

[0064] In this embodiment, the electron beam deflection control circuit is a voltage-type topology structure for a voltage source. By controlling the output positive and negative voltages, the direction of the current flowing through the magnetic field generating device is changed. Symmetry or asymmetry can also be achieved by controlling the magnitudes of the output positive and negative voltages to be equal or unequal. Furthermore, compared to current-type topologies, voltage-type topologies offer a wider selection of components, making selection easier. Furthermore, voltage-type topologies do not require power inductors, thus facilitating improved power density. In summary, the electron beam deflection control circuit with a voltage-type topology structure provided in this embodiment has a low design cost and high power density.

[0065] As an optional implementation manner, in an embodiment of the present invention, the electron beam deflection control circuit further includes:

[0066] a third controllable switch Q3, a second end of which is connected to the second end of the magnetic field generating device;

[0067] a first diode D1, having an anode connected to the first end of the third controllable switch Q3 and a cathode connected to the first end of the magnetic field generating device;

[0068] When the first controllable switch Q1 and the second controllable switch Q2 are both disconnected and current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device, the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop.

[0069] As described above, when the second terminal of the first voltage source module 11 outputs a positive voltage, the first controllable switch Q1 is turned on, and the second controllable switch Q2 is turned off, current flows from the first terminal of the magnetic field generating device to the second terminal. Furthermore, the third controllable switch Q3 can be turned on before the first controllable switch Q1 is turned off. After the third controllable switch Q3 is turned on, the first controllable switch Q1 is turned off. At this time, the energy stored in the magnetic field generating device flows out of the second terminal of the magnetic field generating device, passes through the third controllable switch Q3 and the first diode D1, and then flows into the first terminal of the magnetic field generating device, thereby forming a freewheeling loop.

[0070] In this embodiment, after the first controllable switch Q1 and the second controllable switch Q2 are both turned off, a freewheeling circuit is used to ensure alternating switching of the first controllable switch Q1 and the second controllable switch Q2, thereby avoiding simultaneous conduction of the first controllable switch Q1 and the second controllable switch Q2.

[0071] In this embodiment, the electron beam deflection control circuit is controlled by the following method: when the electron beam deflection control circuit is in an initial state, the first controllable switch Q1 is controlled to be turned on, so that current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device, wherein the initial state is that the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all in the off state;

[0072] Before the first controllable switch Q1 is turned off, controlling the third controllable switch Q3 to be turned on;

[0073] After the third controllable switch Q3 is turned on, the first controllable switch Q1 is turned off, and the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop;

[0074] Before the third controllable switch Q3 is turned off, controlling the second controllable switch Q2 to be turned on;

[0075] After the second controllable switch Q2 is turned on, the third controllable switch Q3 is turned off, and the current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device;

[0076] Before the second controllable switch Q2 is turned off, controlling the fourth controllable switch Q4 to be turned on;

[0077] After the fourth controllable switch Q4 is turned on, the second controllable switch Q2 is turned off, and the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

[0078] Before the fourth controllable switch Q4 is turned off, controlling the first controllable switch Q1 to be turned on;

[0079] After the first controllable switch Q1 is turned on, the fourth controllable switch Q4 is turned off;

[0080] After the fourth controllable switch Q4 is turned off, the operation after the first controllable switch Q1 is turned on is repeated.

[0081] As an optional implementation manner, in an embodiment of the present invention, the electron beam deflection control circuit further includes:

[0082] a fourth controllable switch Q4, a second end of which is connected to the second end of the magnetic field generating device;

[0083] a second diode D2, an anode of which is connected to the first end of the magnetic field generating device, and a cathode of which is connected to the first end of the fourth controllable switch Q4;

[0084] When the first controllable switch Q1 and the second controllable switch Q2 are both disconnected and current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device, the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

[0085] As described above, when the second end of the second voltage source module 12 outputs a negative voltage, the second controllable switch Q2 is turned on, and the first controllable switch Q1 is turned off, current flows from the second end of the magnetic field generating device to the first end. Furthermore, the fourth controllable switch Q4 can be turned on before the second controllable switch Q2 is turned off. After the fourth controllable switch Q4 is turned on, the second controllable switch Q2 is turned off. At this time, the energy stored in the magnetic field generating device flows out of the first end of the magnetic field generating device, passes through the second diode D2 and the fourth controllable switch Q4, and then flows into the second end of the magnetic field generating device, thereby forming a freewheeling loop.

[0086] In this embodiment, after the first controllable switch Q1 and the second controllable switch Q2 are both turned off, a freewheeling circuit is used to ensure alternating switching of the first controllable switch Q1 and the second controllable switch Q2, thereby avoiding simultaneous conduction of the first controllable switch Q1 and the second controllable switch Q2.

[0087] As an optional embodiment, in an embodiment of the present invention, the electron beam deflection control circuit further includes a bidirectional transient suppression diode D7, one end of which is connected to the first end of the magnetic field generating device and the other end of which is connected to the second end of the magnetic field generating device. This diode D7 is used to suppress transient high voltage and further protect components in the electron beam deflection control circuit from damage caused by surge current.

[0088] As an optional implementation, in an embodiment of the present invention, the first voltage source module 11 adopts any one of an isolated DC / DC circuit, a Buck circuit, and a Boost circuit. The topology structure of the first voltage source module 11 is not limited to the above topology structures.

[0089] like Figure 2 As shown, as an optional implementation manner, in an embodiment of the present invention, when the first voltage source module 11 adopts the Buck circuit, it includes:

[0090] A sixth controllable switch Q6, a first end of which serves as a positive input end of the power supply Vin;

[0091] a fourth diode D4, having a cathode connected to the second end of the sixth controllable switch Q6, and an anode connected to the reference ground COM;

[0092] The second inductor L2 has a first end connected to the second end of the sixth controllable switch Q6 and a second end connected to the first end of the first controllable switch Q1 ; the second end of the second inductor L2 serves as the second end of the first voltage source module 11 to output a forward voltage.

[0093] The second capacitor C2 has a first end connected to the second end of the second inductor L2 , and a second end connected to the reference ground COM.

[0094] As an optional implementation, in an embodiment of the present invention, the second voltage source module 12 adopts a Buck-Boost circuit or a flyback circuit. The topology structure of the second voltage source module 12 is not limited to the above topology structure, but a topology structure that can generate a negative voltage needs to be adopted.

[0095] like Figure 2 As shown, as an optional implementation, in an embodiment of the present invention, when the second voltage source module 12 adopts the Buck-Boost circuit, it includes:

[0096] A fifth controllable switch Q5, a first end of which serves as a positive input end of the power supply Vin;

[0097] The cathode of the third diode D3 is connected to the second end of the fifth controllable switch Q5, and the anode is connected to the second end of the second controllable switch Q2; the anode of the third diode D3 serves as the second end of the second voltage source module 12 to output a negative voltage.

[0098] a first inductor L1, having a first end connected to the second end of the fifth controllable switch Q5, and a second end connected to the reference ground COM;

[0099] The first capacitor C1 has a first end connected to the anode of the third diode D3 and a second end connected to the reference ground COM.

[0100] As an optional implementation manner, in an embodiment of the present invention, the electron beam deflection control circuit further includes:

[0101] A control module (not shown in the figure) is connected to the control ends of the first controllable switch Q1 , the second controllable switch Q2 , the third controllable switch Q3 , and the fourth controllable switch Q4 , respectively.

[0102] Taking the first controllable switch Q1 , the second controllable switch Q2 , the third controllable switch Q3 and the fourth controllable switch Q4 as an example, the control end is the gate of the MOSFET tube.

[0103] As an optional implementation, in the embodiment of the present invention, the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all fully controllable power semiconductor devices, which can be MOSFET tubes or IGBT tubes, etc., and the connection structure is as follows: Figure 2 shown.

[0104] like Figure 3 As shown, as an optional implementation manner, in an embodiment of the present invention, the electron beam deflection control circuit further includes:

[0105] A first control module 111 connected to the first voltage source module 11;

[0106] A first voltage sampling module 112 is connected to the second end of the first voltage source module 11 and the first control module 111, and the first voltage sampling module 112 is used to collect the forward voltage value of the second end of the first voltage source module 11;

[0107] The first control module 111 is used to obtain the forward voltage value sampled by the first voltage sampling module 112 and adjust the first voltage source module 11 according to the forward voltage value. The first control module 111 enables the first voltage source module 11 to operate in a closed-loop state.

[0108] A second control module 121 connected to the second voltage source module 12;

[0109] The second voltage sampling module 122 is connected to the second end of the second voltage source module 12 and the second control module 121 respectively. The second voltage sampling module 122 is used to collect the negative voltage value of the second end of the second voltage source module 12 .

[0110] The second control module 121 is used to obtain the negative voltage value sampled by the second voltage sampling module 122 and adjust the second voltage source module 12 according to the negative voltage value. The second control module 121 enables the second voltage source module 12 to operate in a closed-loop state.

[0111] Example 2

[0112] This embodiment provides an electron beam deflection control method, which is applicable to the electron beam deflection control circuit in the above embodiment 1. Figure 4 As shown, the method includes:

[0113] When the electron beam deflection control circuit is in an initial state;

[0114] Step S101: Controlling the first controllable switch Q1 to be turned on, so that current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device, wherein the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all in the off state in the initial state;

[0115] Step S102, before the first controllable switch Q1 is turned off, controlling the third controllable switch Q3 to be turned on;

[0116] Step S103: After the third controllable switch Q3 is turned on, the first controllable switch Q1 is turned off, and the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop;

[0117] Step S104, before the third controllable switch Q3 is turned off, controlling the second controllable switch Q2 to be turned on;

[0118] Step S105: After the second controllable switch Q2 is turned on, the third controllable switch Q3 is turned off, and the current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device;

[0119] Step S106, before the second controllable switch Q2 is turned off, controlling the fourth controllable switch Q4 to be turned on;

[0120] Step S107: After the fourth controllable switch Q4 is turned on, the second controllable switch Q2 is turned off, and the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

[0121] Step S108, before the fourth controllable switch Q4 is turned off, controlling the first controllable switch Q1 to be turned on;

[0122] Step S109 , after the first controllable switch Q1 is turned on, the fourth controllable switch Q4 is turned off; after step S109 is completed, step S102 is executed.

[0123] In this embodiment, the electron beam deflection control method is applicable to an electron beam deflection control circuit that is a voltage-type topology structure for a voltage source. The direction of the current flowing through the magnetic field generating device is changed by controlling the output positive voltage and negative voltage. Symmetry or asymmetry can also be achieved by controlling the magnitude of the output positive voltage and negative voltage to be equal or different. In addition, compared with the current-type topology, on the one hand, the voltage-type topology has a wide range of devices to choose from, making selection easier; on the other hand, the voltage-type topology does not require a power inductor, which is conducive to improving power density. In summary, the electron beam deflection control circuit with a voltage-type topology structure provided in this embodiment has a low design cost and high power density.

[0124] For a detailed description of the electron beam deflection control circuit, please refer to the above method embodiment 1, which will not be repeated here.

[0125] Example 3

[0126] This embodiment provides a high-voltage generator, which may include the electron beam deflection control circuit in the above-mentioned embodiment 1.

[0127] In this embodiment, the electron beam deflection control circuit included in the high-voltage generator is a voltage-type topology structure for a voltage source. By controlling the positive and negative voltages of the output, the direction of the current flowing through the magnetic field generating device is changed. Symmetry or asymmetry can also be achieved by controlling the magnitudes of the positive and negative voltages of the output to be equal or different. In addition, compared with the current-type topology, on the one hand, the voltage-type topology has a wide range of devices to choose from, making selection easier; on the other hand, the voltage-type topology does not require a power inductor, which is conducive to improving power density. In summary, the electron beam deflection control circuit with a voltage-type topology structure provided in this embodiment has a low design cost and high power density.

[0128] For a detailed description of the electron beam deflection control circuit, please refer to the above method embodiment 1, which will not be repeated here.

[0129] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An electron beam deflection control circuit, characterized in that: include: a first voltage source module, having a first end connected to a power supply and a second end configured to output a forward voltage, wherein the forward voltage is a voltage between the second end of the first voltage source module and a reference ground; a first controllable switch Q1, a first end of which is connected to the second end of the first voltage source module, a second end of which is connected to the first end of a magnetic field generating device, and a second end of which is connected to the reference ground; When the first voltage source module outputs the forward voltage and the first controllable switch Q1 is turned on, current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device; a second voltage source module, a first end of which is connected to the power supply, and a second end of which is used to output a negative voltage, wherein the negative voltage is a voltage between the second end of the second voltage source module and the reference ground; a second controllable switch Q2, a first end of which is connected to the first end of the magnetic field generating device, and a second end of the second controllable switch Q2 is connected to the second end of the second voltage source module; When the second voltage source module outputs the negative voltage and the second controllable switch Q2 is turned on, the current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device; The first controllable switch Q1 and the second controllable switch Q2 are turned on in a time-sharing manner.

2. The electron beam deflection control circuit according to claim 1, wherein: Also includes: a third controllable switch Q3, a second end of which is connected to the second end of the magnetic field generating device; a first diode D1, having an anode connected to the first end of the third controllable switch Q3 and a cathode connected to the first end of the magnetic field generating device; When the first controllable switch Q1 and the second controllable switch Q2 are both disconnected and current flows out of the second end of the magnetic field generating device, the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop.

3. The electron beam deflection control circuit according to claim 2, wherein: Also includes: a fourth controllable switch Q4, a second end of which is connected to the second end of the magnetic field generating device; a second diode D2, an anode of which is connected to the first end of the magnetic field generating device, and a cathode of which is connected to the first end of the fourth controllable switch Q4; When the first controllable switch Q1 and the second controllable switch Q2 are both disconnected and current flows out of the first end of the magnetic field generating device, the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

4. The electron beam deflection control circuit according to any one of claims 1 to 3, characterized in that: Also includes: A bidirectional transient suppression diode has one end connected to the first end of the magnetic field generating device and the other end connected to the second end of the magnetic field generating device.

5. The electron beam deflection control circuit according to any one of claims 1 to 3, characterized in that: The first voltage source module adopts any one of an isolated DC / DC circuit, a Buck circuit, and a Boost circuit.

6. The electron beam deflection control circuit according to any one of claims 1 to 3, characterized in that: The second voltage source module adopts a Buck-Boost circuit or a flyback circuit.

7. The electron beam deflection control circuit according to claim 6, characterized in that: When the second voltage source module adopts the Buck-Boost circuit, it includes: a fifth controllable switch Q5, a first end of which serves as an input end of the power supply; a third diode D3, having a cathode connected to the second end of the fifth controllable switch Q5 and an anode connected to the second end of the second controllable switch Q2; a first inductor L1, having a first end connected to the second end of the fifth controllable switch Q5, and a second end connected to the reference ground; The first capacitor C1 has a first end connected to the anode of the third diode D3 and a second end connected to the reference ground.

8. The electron beam deflection control circuit according to claim 3, wherein: Also includes: a control module connected to the control ends of the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4, respectively; wherein the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all fully controllable power semiconductor devices.

9. A method for controlling electron beam deflection, characterized in that: Applied to the electron beam deflection control circuit of claim 3, the method comprises: When the electron beam deflection control circuit is in an initial state, the first controllable switch Q1 is controlled to be turned on, and current flows from the first end of the magnetic field generating device to the second end of the magnetic field generating device, wherein the initial state is that the first controllable switch Q1, the second controllable switch Q2, the third controllable switch Q3, and the fourth controllable switch Q4 are all in an off state; Before the first controllable switch Q1 is turned off, controlling the third controllable switch Q3 to be turned on; After the third controllable switch Q3 is turned on, the first controllable switch Q1 is turned off, and the third controllable switch Q3, the first diode D1 and the magnetic field generating device form a freewheeling loop; Before the third controllable switch Q3 is turned off, controlling the second controllable switch Q2 to be turned on; After the second controllable switch Q2 is turned on, the third controllable switch Q3 is turned off, and the current flows from the second end of the magnetic field generating device to the first end of the magnetic field generating device; Before the second controllable switch Q2 is turned off, controlling the fourth controllable switch Q4 to be turned on; After the fourth controllable switch Q4 is turned on, the second controllable switch Q2 is turned off, and the fourth controllable switch Q4, the second diode D2 and the magnetic field generating device form a freewheeling loop.

10. A high voltage generator, characterized in that: The electron beam deflection control circuit comprises the electron beam deflection control circuit according to any one of claims 1 to 8.

Images