A cone beam x-ray source filament heating circuit

Abstract

The utility model relates to cone shaped beam X ray source technical field discloses a cone shaped beam X ray source filament heating circuit, can obtain stable X ray output, have certain anti -interference ability, can guarantee under high frequency can work normally, including core control module, main control signal input circuit, enable control circuit, drive and power switch module, feedback and current sampling module, filament output and switching module, power supply circuit, relay FK2 and relay FK3, core control module is connected with main control signal input circuit, drive and power switch module respectively, power supply circuit is connected with enable control circuit, filament output and switching module, drive and power switch module respectively, drive and power switch module connect feedback and current sampling module, filament output and switching module, and enable control circuit connects control main control signal input circuit, and enable control circuit passes through relay FK2 and relay FK3 control connection main control signal input circuit.

Description

Technical Field

[0001] This utility model relates to the field of cone-beam X-ray source technology, specifically, a cone-beam X-ray source filament heating circuit. Background Technology

[0002] The cone-beam X-ray source mainly consists of a central control circuit, AC power supply, filament heating circuit, delay control circuit, AC / DC rectifier and filter circuit, X-ray tube assembly, auxiliary power supply, operating table, rotating anode drive circuit, high-pressure oil tank, Kv generation circuit, etc.

[0003] The filament heating circuit, as one of the core components of X-ray equipment (cone-beam X-ray source), determines the accuracy of mA and affects the lifespan of the X-ray tube through the stability of the filament current. Its performance directly relates to the quality of X-rays and the safety of medical applications. With the continuous advancement of medical technology, the requirements for X-ray equipment are becoming increasingly stringent, especially in improving X-ray quality, shortening exposure time, and reducing radiation damage to patients and medical staff. Because cone-beam X-ray sources use area array detectors as the X-ray receiving device, their X-ray utilization efficiency is higher.

[0004] Traditional power frequency X-ray machines generate high voltage in a relatively simple way, mainly by stepping up the voltage using a power frequency transformer. However, this method suffers from problems such as large waveform pulsation and less than ideal X-ray quality.

[0005] Traditional X-ray machine filament heating circuits typically use power frequency current for heating. This method has problems such as large tube current inertia and insignificant filament skin effect, resulting in low tube current accuracy. Utility Model Content

[0006] The purpose of this invention is to design a filament heating circuit for a cone-beam X-ray source that can obtain stable X-ray output, has a certain anti-interference capability, and can ensure normal operation at high frequencies.

[0007] This utility model is achieved through the following technical solution: a cone-beam X-ray source filament heating circuit, comprising a core control module, a main control signal input circuit, an enable control circuit, a drive and power switch module, a feedback and current sampling module, a filament output and switching module, a power supply circuit, relays FK2 and FK3. The core control module is connected to the main control signal input circuit and the drive and power switch module respectively. The power supply circuit is connected to the enable control circuit, the filament output and switching module, and the drive and power switch module respectively. The drive and power switch module is connected to the feedback and current sampling module and the filament output and switching module. The enable control circuit is connected to the main control signal input circuit, and the enable control circuit controls the main control signal input circuit through relays FK2 and FK3.

[0008] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The core control module includes a chip FU1. The IN+ and VREF pins of chip FU1 are connected to the main control signal input circuit. The IN- and COMP pins of chip FU1 are connected together and grounded through capacitor FC5. The RT pin of chip FU1 is grounded through potentiometer FRP2. The RD and CT pins of chip FU1 are connected together and connected to the GND pin of chip FU1 through capacitor FC7. The GND pin of chip FU1 is grounded. A capacitor FC11 is connected between the SS and SD pins of chip FU1, and the SS pin is also connected to the control terminal of potentiometer FRP3 through diode FD3. One fixed terminal of potentiometer FRP3 is connected to a +5.1V power supply, and the other fixed terminal is grounded and connected to the SD pin of chip FU1. The OUTA and OUTB pins of chip FU1 are connected to the drive and power switch module.

[0009] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The main control signal input circuit includes resistors FR20, FR19, and FR7, potentiometers FRP1, FR6, and FR5, capacitor FC6, contact FK2C of relay FK2, and contact FK3C of relay FK3. The VREF pin of chip FU1 is connected to the first fixed terminal of potentiometer FRP1 through resistor FR6, and the second fixed terminal of potentiometer FRP1 is grounded through resistor FR7. The control terminal of potentiometer FRP1... The first moving contact (pin 11) of contact FK2C is connected to the first moving contact (pin 11) of contact FK3C. The second moving contact (pin 9) of contact FK2C is connected to the central control circuit (MAST signal) and is connected to the second moving contact (pin 9) of contact FK3C through resistor FR20. The second moving contact (pin 9) of contact FK3C is also grounded through resistor FR19. The stationary contact (pin 13) of contact FK3C is connected to the IN+ pin of chip FU1 through resistor FR5. The IN+ pin of chip FU1 is also grounded through capacitor FC6.

[0010] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The enable control circuit includes an RReady enable control circuit, which is equipped with a resistor FR12, a resistor FR11, a capacitor FC13, a transistor FV2 (preferably a sampling transistor), a coil FK2A of a relay FK2, a diode FD2, a light-emitting diode FDS2, a contact FK2B of the relay FK2, a terminal CX7, and a resistor FR13. The diode FD2 is connected in parallel with the coil FK2A (preferably the negative terminal of the diode FD2 is connected to the coil). The positive terminal (pin 16) of coil FK2A is connected in series with LED FDS2 and resistor FR13, which are connected in parallel across coil FK2A (the positive terminal of LED FDS2 and resistor FR13 are connected together). The second terminal (pin 16) of coil FK2A is connected to the power supply circuit (the non-common terminal of resistor FR13 is connected to the power supply circuit). The first terminal (pin 1) of coil FK2A is connected to the third terminal (collector) of transistor FV2. The second terminal (base) of transistor FV2 is connected to the RReady enable signal (RReady) through resistor FR12 and diode FD5 (preferably with the negative terminal connected to the base of FV2) connected in series. The enable signal is a signal used to determine the operating mode of the system (filament heating circuit), which is generated by the central control circuit. The common terminal of resistor R12 and diode FD5 is connected to the first terminal (emitter) of transistor FV2 and grounded through resistor FR11 and capacitor FC13 connected in parallel. Terminal CX7 is connected to contact FK2B (the first moving contact (pin 3) of contact FK2B is connected to pin 3 of terminal CX7, the second moving contact (pin 8) of contact FK2B is connected to pin 1 of terminal CX7, and pin 2 of terminal CX7 is connected to the stationary contact (pin 4) of contact FK2B). Terminal CX7 is connected to the central control circuit and feeds back the switch signal to the central control circuit to indicate the machine's operating status.

[0011] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The enable control circuit further includes an FReady enable control circuit, which is equipped with resistor FR18, resistor FR17, capacitor FC15, transistor FV3 (preferably a triode), coil FK3A of relay FK3, diode FD8, light-emitting diode FDS3, contact FK3B of relay FK3, terminal CX7F, and resistor FR16. Diode FD8 is connected in parallel with coil FK3A (preferably, the negative terminal of diode FD8 is connected to...). The positive terminal (pin 16) of coil FK3A is connected in series with LED FDS3 and resistor FR16, which are connected in parallel with coil FK3A (the positive terminal of LED FDS3 and resistor FR16 are connected together). The second terminal (pin 16) of coil FK3A is connected to the power supply circuit (the non-common terminal of resistor FR16 is connected to the power supply circuit). The first terminal (pin 1) of coil FK3A is connected to the third terminal (collector) of transistor FV3. The second terminal (base) of transistor FV3 is connected to the FReady enable signal (FReady) through resistor FR18 and diode FD7 (preferably with the negative terminal connected to the base of FV3) connected in series. The enable signal is a signal used to determine the operating mode of the system (filament heating circuit), which is generated by the central control circuit. The common terminal of resistor R18 and diode FD7 is connected to the first terminal (emitter) of transistor FV5 and grounded through resistor FR17 ​​and capacitor FC15 connected in parallel. Terminal CX7F is connected to contact FK3B (the first moving contact (pin 6) of contact FK3B is connected to pin 3 of terminal CX7F, the second moving contact (pin 8) of contact FK3B is connected to pin 1 of terminal CX7F, and pin 2 of terminal CX7F is connected to the stationary contact (pin 4) of contact FK3B). Terminal CX7F is also connected to the central control circuit and feeds back the switch signal to the central control circuit to indicate the machine's operating status.

[0012] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this invention, the following structure is specifically adopted: The drive and power switch module includes resistors FR2, FR1, and FR4, a switch FR2, transistors FQ1 and FQ2, and a high-frequency transformer FT2. The first pin (source) of transistor FQ1 and the first pin (source) of transistor FQ2 are connected together and grounded. The OUTA pin of chip FU1 is connected to the second pin (gate) of transistor FQ2 through resistor FR3. The second pin (gate) of transistor FQ2 is grounded through resistor FR4. The third pin (drain) of transistor FQ2 is connected to the seventh pin (pin 7) of the primary side of high-frequency transformer FT2; the OUTB pin of chip FU1 is connected to the second pin (gate) of transistor FQ1 through resistor FR2, the second pin (gate) of transistor FQ1 is grounded through resistor FR1, and the third pin (drain) of transistor FQ1 is connected to the first pin (pin 1) of the primary side of high-frequency transformer FT2; the third pin (pin 3), fourth pin (pin 4), and fifth pin (pin 5) of the primary side of high-frequency transformer FT2 are connected together and connected to the power supply circuit; the secondary side of high-frequency transformer FT2 is connected to the feedback and current sampling module and the filament output and switching module.

[0013] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The feedback and current sampling module includes a current transformer FT1, a sampling resistor FR8, and a terminal CX6. The first end of the primary side of the current transformer FT1 is connected to the eighth pin (pin 8) of the secondary side of the high-frequency transformer FT2. The first end of the primary side of the current transformer FT1 is connected to the rotating anode drive circuit (which is fed back to the central processing circuit after electrical isolation and processing, as a sampling feedback signal of the filament current). The sampling resistor FR8 is connected in parallel on the secondary side of the current transformer FT1, and the two ends of the sampling resistor FR8 (one end forming feedback signal FIT1 and the other end forming feedback signal FIT2) are also connected to the central control circuit through the terminal CX6. The remaining pin (pin 1) of the terminal CX6 is grounded.

[0014] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The filament output and switching module includes jumper JP1 (as the output jumper of the high-frequency transformer (inverter drive transformer) FT2, providing stable current output), resistor FR10, resistor FR9, capacitor FC12, transistor FV1 (preferably a triode), relay FK1, diode FD1, light-emitting diode FDS1, terminal CX5, and resistor FR14. The input side of jumper JP1 is connected to pins 13 and 14 on the secondary side of the high-frequency transformer FT2. The output end of jumper JP1 is connected to the stationary contact (pin 13) of contact FK1C and the stationary contact (pin 14) of contact FK1B. The first moving contact (pin 11) of contact FK1C and the first moving contact (pin 6) of contact FK1B are connected together and connected to the X-ray tube assembly (LF heating output signal) through terminal CX5. The second moving contact (pin 9) and the second moving contact (pin 8) of contact FK1B are connected together and connected to the X-ray tube assembly (SF heating output signal) through terminal CX5. The remaining pin of terminal CX5 is grounded. Diode FD1 is connected in parallel to the coil FK1A of relay FK1 (preferably, the negative terminal of diode FD1 is connected to the positive terminal 16 of coil FK3A). LED FDS1 and resistor FR14, which are connected in series, are connected in parallel to coil FK1A (the positive terminal of LED FDS1 and resistor FR14 are connected together). The second end (pin 16) of coil FK1A is connected to the power supply circuit (the non-common terminal of resistor FR14 is connected to the power supply circuit). The first end (pin 1) of coil FK1A is connected to the third end (collector) of transistor FV1. The second end (base) of transistor FV1 is connected to the LF / SF signal (the LF / SF signal is used to control the switching of the large and small filaments in the X-ray tube of the X-ray tube assembly) through the series resistor FR10 and diode FD4 (preferably, the negative terminal is connected to the base of FV1). The LF / SF signal is switched manually via an external button. The input signal is sent to the central processing circuit, which then processes it and outputs it to this circuit to switch between large and small filaments. The common terminal of resistor R10 and diode FD4 is connected to the first terminal (emitter) of transistor FV1 and grounded through parallel resistor FR9 and capacitor FC12. Terminal CX7F is connected to contact FK3B (the first moving contact (pin 6) of contact FK3B is connected to pin 3 of terminal CX7F, the second moving contact (pin 8) of contact FK3B is connected to pin 1 of terminal CX7F, and pin 2 of terminal CX7F is connected to the stationary contact (pin 4) of contact FK3B).

[0015] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The power supply circuit includes terminal CX4, capacitor FC1 (preferably a sampling electrolytic capacitor), capacitor FC2, capacitor FC3 (preferably a sampling electrolytic capacitor), capacitor FC4, capacitor FC8, capacitor FC9, and inductor FL1. The first end of inductor FL1 is grounded through capacitors FC1 and FC2 connected in parallel, and the second end of inductor FL1 is grounded through capacitors FC3 and FC4 connected in parallel. The second end of inductor FL1 is connected to a +24V power supply. The first end of inductor FL1 is connected to pins 1 and 3 of terminal CX4, and pins 2 and 4 of terminal CX4 are both grounded. Terminal CX4 is connected to an auxiliary power supply (also known as a power management board, responsible for outputting the 24VDC power required in each circuit). Capacitors FC8 and FC9 are connected in parallel, with one end of the parallel capacitors FC8 and FC9 connected to a +24V power supply (this +24V power supply is used to provide +24V power to FT2), and the other end grounded.

[0016] To further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: the chip FU1 is an SG3525, the VIN and VC pins of the chip FU1 are connected together and connected to a +15V power supply, and the VIN and VC pins of the chip FU1 are also grounded through capacitor FC10; a +5.1V power supply is also connected to the VREF pin of the chip FU1.

[0017] Compared with the prior art, this utility model has the following advantages and beneficial effects: This invention can achieve stable X-ray output, has a certain anti-interference capability, and can ensure normal operation at high frequencies.

[0018] Compared to power frequency inverters, this invention provides a more stable filament current with less fluctuation.

[0019] Because medical X-ray equipment requires high component lifespan, this invention uses a PWM device to control the signal, which is more stable than existing resonant transformers. This invention also incorporates a signal feedback path, enabling real-time feedback of the filament heating current signal to the central control circuit for feedback adjustment of the PWM device input.

[0020] This invention can make mA more accurate, extend the life of the X-ray tube, and thus increase the stability of the system (filament heating circuit).

[0021] This invention utilizes high-frequency inverter technology in the filament heating circuit, significantly reducing the influence of tube current inertia and improving the skin effect of the filament. This innovation enables random compensation of the tube current, thereby greatly improving the accuracy and stability of the tube current. This is of great significance for improving the quality of X-rays and the accuracy of medical diagnosis. Attached Figure Description

[0022] Figure 1 This is the circuit schematic diagram of this utility model (excluding the power supply circuit and FReady enable control circuit).

[0023] Figure 2 This is a schematic diagram of the power supply circuit described in this utility model.

[0024] Figure 3 This is a schematic diagram of the FReady enable control circuit described in this utility model. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to represent selected embodiments of this utility model.

[0027] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by terms, etc., is based on the orientation or positional relationship shown in the drawings and is only for the convenience of describing this utility model and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," "setting," "layout," and "fixing," etc., should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections. The specific means used are not limited to conventional mechanical connection methods such as screwing, interference fit, riveting, and threaded auxiliary connections. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] Example 1: A filament heating circuit for a cone-beam X-ray source can achieve stable X-ray output, possesses a certain degree of anti-interference capability, and ensures normal operation at high frequencies. Figure 1 , Figure 2 , Figure 3 As shown, the system includes a core control module, a main control signal input circuit, an enable control circuit, a drive and power switch module, a feedback and current sampling module, a filament output and switching module, a power supply circuit, relays FK2 and FK3. The core control module is connected to the main control signal input circuit and the drive and power switch module. The power supply circuit is connected to the enable control circuit, the filament output and switching module, and the drive and power switch module. The drive and power switch module is connected to the feedback and current sampling module and the filament output and switching module. The enable control circuit is connected to the main control signal input circuit and controls the main control signal input circuit through relays FK2 and FK3.

[0032] Example 2: This embodiment is a further optimization based on the above embodiments. The parts that are the same as those in the aforementioned technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3As shown, to further better realize the cone-beam X-ray source filament heating circuit of this utility model, the following structure is specifically adopted: The core control module includes a chip FU1. The IN+ and VREF pins of chip FU1 are connected to the main control signal input circuit. The IN- and COMP pins of chip FU1 are connected together and grounded through capacitor FC5. The RT pin of chip FU1 is grounded through potentiometer FRP2. The RD and CT pins of chip FU1 are connected together and connected to the GND pin of chip FU1 through capacitor FC7. The GND pin of chip FU1 is grounded. A capacitor FC11 is connected between the SS and SD pins of chip FU1, and the SS pin is also connected to the control terminal of potentiometer FRP3 through diode FD3. One fixed terminal of potentiometer FRP3 is connected to a +5.1V power supply, and the other fixed terminal is grounded and connected to the SD pin of chip FU1. The OUTA and OUTB pins of chip FU1 are connected to the drive and power switch module.

[0033] Example 3: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3 As shown, to further improve the implementation of the cone-beam X-ray source filament heating circuit of this utility model, the following structure is specifically adopted: The main control signal input circuit includes resistors FR20, FR19, FR7, potentiometers FRP1, FR6, FR5, capacitor FC6, contact FK2C of relay FK2, and contact FK3C of relay FK3. The VREF pin of chip FU1 is connected to the first fixed terminal of potentiometer FRP1 through resistor FR6, and the second fixed terminal of potentiometer FRP1 is grounded through resistor FR7. The control signal input circuit of potentiometer FRP1... The first moving contact (pin 11) of contact FK2C is connected to the control terminal. The stationary contact (pin 13) of contact FK2C is connected to the first moving contact (pin 11) of contact FK3C. The second moving contact (pin 9) of contact FK2C is connected to the central control circuit (MAST signal) and is connected to the second moving contact (pin 9) of contact FK3C through resistor FR20. The second moving contact (pin 9) of contact FK3C is also grounded through resistor FR19. The stationary contact (pin 13) of contact FK3C is connected to the IN+ pin of chip FU1 through resistor FR5. The IN+ pin of chip FU1 is also grounded through capacitor FC6.

[0034] Example 4: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3As shown, to further improve the implementation of the cone-beam X-ray source filament heating circuit of this utility model, the following structure is specifically adopted: The enable control circuit includes an RReady enable control circuit, which is equipped with a resistor FR12, a resistor FR11, a capacitor FC13, a transistor FV2, a coil FK2A of a relay FK2, a diode FD2, a light-emitting diode FDS2, a contact FK2B of the relay FK2, a terminal CX7, and a resistor FR13. The diode FD2 is connected in parallel with the coil FK2A (preferably, the negative terminal of the diode FD2 is connected to the coil FK2A). The positive terminal (pin 16) of the 2A coil is connected in series with an LED FDS2 and a resistor FR13, which are connected in parallel with the coil FK2A (the positive terminal of the LED FDS2 and the resistor FR13 are connected together). The second terminal (pin 16) of the coil FK2A is connected to the power supply circuit (the non-common terminal of the resistor FR13 is connected to the power supply circuit). The first terminal (pin 1) of the coil FK2A is connected to the third terminal (collector) of the transistor FV2. The second terminal (base) of the transistor FV2 is connected to the RReady enable signal (RReady) through a series resistor FR12 and a diode FD5 (preferably with the negative terminal connected to the base of FV2). The enable signal is a signal used to determine the operating mode of the system (filament heating circuit), which is generated by the central control circuit. The common terminal of resistor R12 and diode FD5 is connected to the first terminal (emitter) of transistor FV2 and grounded through resistor FR11 and capacitor FC13 connected in parallel. Terminal CX7 is connected to contact FK2B (the first moving contact (pin 3) of contact FK2B is connected to pin 3 of terminal CX7, the second moving contact (pin 8) of contact FK2B is connected to pin 1 of terminal CX7, and pin 2 of terminal CX7 is connected to the stationary contact (pin 4) of contact FK2B). Terminal CX7 is connected to the central control circuit and feeds back the switch signal to the central control circuit to indicate the machine's operating status.

[0035] Example 5: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3As shown, to further better realize the filament heating circuit of the cone-beam X-ray source described in this utility model, the following structure is specifically adopted: The enable control circuit further includes an LReady enable control circuit, which is provided with resistor FR18, resistor FR17, capacitor FC15, transistor FV3, coil FK3A of relay FK3, diode FD8, light-emitting diode FDS3, contact FK3B of relay FK3, terminal CX7F and resistor FR16. Diode FD8 is connected in parallel with coil FK3A (preferably, the negative terminal of diode FD8 is connected to coil F). The positive terminal (pin 16) of coil FK3A is connected in series with LED FDS3 and resistor FR16, which are connected in parallel across coil FK3A (the positive terminal of LED FDS3 and resistor FR16 are connected together). The second terminal (pin 16) of coil FK3A is connected to the power supply circuit (the non-common terminal of resistor FR16 is connected to the power supply circuit). The first terminal (pin 1) of coil FK3A is connected to the third terminal (collector) of transistor FV3. The second terminal (base) of transistor FV3 is connected to the FReady enable signal (FReady) through a series resistor FR18 and diode FD7 (preferably with the negative terminal connected to the base of FV3). The enable signal is a signal used to determine the operating mode of the system (filament heating circuit), which is generated by the central control circuit. The common terminal of resistor R18 and diode FD7 is connected to the first terminal (emitter) of transistor FV5 and grounded through resistor FR17 ​​and capacitor FC15 connected in parallel. Terminal CX7F is connected to contact FK3B (the first moving contact (pin 6) of contact FK3B is connected to pin 3 of terminal CX7F, the second moving contact (pin 8) of contact FK3B is connected to pin 1 of terminal CX7F, and pin 2 of terminal CX7F is connected to the stationary contact (pin 4) of contact FK3B). Terminal CX7F is also connected to the central control circuit and feeds back the switch signal to the central control circuit to indicate the machine's operating status.

[0036] Example 6: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3As shown, to further better realize the cone-beam X-ray source filament heating circuit of this utility model, the following structure is specifically adopted: The drive and power switch module includes resistors FR2, FR1, FR4, FR2, transistors FQ1 and FQ2, and a high-frequency transformer FT2. The first pin (source) of transistor FQ1 and the first pin (source) of transistor FQ2 are connected together and grounded. The OUTA pin of chip FU1 is connected to the second pin (gate) of transistor FQ2 through resistor FR3. The second pin (gate) of transistor FQ2 is grounded through resistor FR4. The third pin (drain) of transistor FQ2 is connected to the seventh pin (pin 7) of the primary side of high-frequency transformer FT2; the OUTB pin of chip FU1 is connected to the second pin (gate) of transistor FQ1 through resistor FR2, the second pin (gate) of transistor FQ1 is grounded through resistor FR1, and the third pin (drain) of transistor FQ1 is connected to the first pin (pin 1) of the primary side of high-frequency transformer FT2; the third pin (pin 3), fourth pin (pin 4), and fifth pin (pin 5) of the primary side of high-frequency transformer FT2 are connected together and connected to the power supply circuit; the secondary side of high-frequency transformer FT2 is connected to the feedback and current sampling module and the filament output and switching module.

[0037] Example 7: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3 As shown, to further better realize the filament heating circuit of the cone-beam X-ray source described in this utility model, the following structure is specifically adopted: The feedback and current sampling module includes a current transformer FT1, a sampling resistor FR8, and a terminal CX6. The first end of the primary side of the current transformer FT1 is connected to the eighth pin (pin 8) of the secondary side of the high-frequency transformer FT2. The first end of the primary side of the current transformer FT1 is connected to the rotating anode drive circuit (which is fed back to the central processing circuit after electrical isolation and processing, as a sampling feedback signal of the filament current). The sampling resistor FR8 is connected in parallel on the secondary side of the current transformer FT1, and the two ends of the sampling resistor FR8 (one end forms the feedback signal FIT1, and the other end forms the feedback signal FIT2) are also connected to the central control circuit through the terminal CX6. The remaining pin (pin 1) of the terminal CX6 is grounded.

[0038] Example 8: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3As shown, to further improve the implementation of the cone-beam X-ray source filament heating circuit described in this utility model, the following structure is specifically adopted: The filament output and switching module includes jumper JP1 (as the output jumper of the high-frequency transformer (inverter drive transformer) FT2, providing a stable current output), resistor FR10, resistor FR9, capacitor FC12, transistor FV1, relay FK1, diode FD1, light-emitting diode FDS1, terminal CX5, and resistor FR14. The input side of jumper JP1 is connected to pins 13 and 14 on the secondary side of the high-frequency transformer FT2. The output end of jumper JP1 is connected to the stationary contact (pin 13) of contact FK1C and the stationary contact (pin 14) of contact FK1B. The first moving contact (pin 11) of contact FK1C and the first moving contact (pin 6) of contact FK1B are connected together and connected to the X-ray tube assembly (LF heating output signal) through terminal CX5. The second moving contact of contact FK1C... The moving contact (pin 9) and the second moving contact (pin 8) of contact FK1B are connected together and connected to the X-ray tube assembly (SF heating output signal) through terminal CX5. The remaining pin of terminal CX5 is grounded. Diode FD1 is connected in parallel to the coil FK1A of relay FK1 (preferably, the negative terminal of diode FD1 is connected to the positive terminal 16 of coil FK3A). LED FDS1 and resistor FR14, which are connected in series, are connected in parallel to coil FK1A (the positive terminal of LED FDS1 and resistor FR14 are connected together). The second end (pin 16) of coil FK1A is connected to the power supply circuit (the non-common terminal of resistor FR14 is connected to the power supply circuit). The first end (pin 1) of coil FK1A is connected to the third end (collector) of transistor FV1. The second end (base) of transistor FV1 is connected to the LF / SF signal (the LF / SF signal is used to control the switching of the large and small filaments in the X-ray tube of the X-ray tube assembly) through the series resistor FR10 and diode FD4 (preferably, the negative terminal is connected to the base of FV1). The LF / SF signal is switched manually via an external button. The input signal is sent to the central processing circuit, which then processes it and outputs it to this circuit to switch between large and small filaments. The common terminal of resistor R10 and diode FD4 is connected to the first terminal (emitter) of transistor FV1 and grounded through parallel resistor FR9 and capacitor FC12. Terminal CX7F is connected to contact FK3B (the first moving contact (pin 6) of contact FK3B is connected to pin 3 of terminal CX7F, the second moving contact (pin 8) of contact FK3B is connected to pin 1 of terminal CX7F, and pin 2 of terminal CX7F is connected to the stationary contact (pin 4) of contact FK3B).

[0039] Example 9: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3 As shown, to further better realize the cone-beam X-ray source filament heating circuit of this utility model, the following configuration structure is specifically adopted: The power supply circuit includes terminal CX4, capacitor FC1 (preferably a sampling electrolytic capacitor), capacitor FC2, capacitor FC3 (preferably a sampling electrolytic capacitor), capacitor FC4, capacitor FC8, capacitor FC9, and inductor FL1. The first end of inductor FL1 is grounded through capacitors FC1 and FC2 connected in parallel, and the second end of inductor FL1 is grounded through capacitors FC3 and FC4 connected in parallel. The second end of inductor FL1 is connected to a +24V power supply. The first end of inductor FL1 is connected to pins 1 and 3 of terminal CX4, and pins 2 and 4 of terminal CX4 are both grounded. Terminal CX4 is connected to an auxiliary power supply (also known as a power management board, responsible for outputting the 24VDC power required in each circuit). Capacitors FC8 and FC9 are connected in parallel. One point of the parallel capacitors FC8 and FC9 is connected to a +24V power supply (this +24V power supply is used to provide +24V power to FT2), and the other end is grounded.

[0040] Example 10: This embodiment is a further optimization based on any of the above embodiments. The parts that are the same as those in the foregoing technical solutions will not be repeated here. Figure 1 , Figure 2 , Figure 3 As shown, to further improve the implementation of the cone-beam X-ray source filament heating circuit of this utility model, the following configuration structure is specifically adopted: the chip FU1 adopts SG3525, the VIN and VC pins of the chip FU1 are connected together and connected to a +15V power supply, and the VIN and VC pins of the chip FU1 are also grounded through capacitor FC10; a +5.1V power supply is also connected to the VREF pin of the chip FU1.

[0041] Example 11: A cone-beam X-ray source filament heating circuit, such as Figure 1 , Figure 2 , Figure 3 As shown, its connection structure has been clearly explained in the above embodiments and will not be repeated here. This embodiment will provide a detailed explanation of the function and working principle of the circuit.

[0042] The pulse width modulation (PWM) method is employed, which compares the slowly changing DC signal sampled and amplified by the voltage error amplifier of the FU1 (SG3525) chip with the ramp of a constant-frequency triangular wave. Through PWM principles, the pulse width signal at that moment is obtained. This signal is then amplified by the driver and power switching module to obtain the switching control signal. When the input voltage suddenly decreases or the load impedance suddenly decreases, the decrease in output voltage is delayed due to the large output capacitance and inductance phase shift delay of the main circuit (the front-end input circuit composed of SG3525). The information about the decreased output voltage is further delayed by the compensation circuit of the voltage error amplifier of the FU1 (SG3525) chip before reaching the PWM comparator of the FU1 (SG3525) chip to widen the pulse width. These two delays result in a slow transient response.

[0043] The filament heating of a cone-beam X-ray source generally consists of two stages: filament preheating and exposure heating. The main function of the filament heating circuit in this cone-beam X-ray source is to excite the X-ray tube (a component of the X-ray tube assembly) to generate an electron source. Essentially, it provides a power source that, under the influence of a high-voltage electric field, generates a high-speed electron flow. The feedback signals include filament feedback signals (sampled current applied to the large and small filaments, fed back to the central control circuit; current transformer FT1 uses an EI22 for sampling, and terminal CX6 outputs filament feedback signals FIT1 and FIT2 to the rotating anode drive circuit (after electrical isolation and processing, fed back to the central processing circuit as filament current sampling feedback signals) and tube current feedback signals (i.e., mA- and mA+ on the high-voltage tank, fed back to the central control circuit). The filament current is high-frequency AC, with a low voltage but a large current. The filament needs to be preheated to allow the filament current to reach the filament current value corresponding to the set tube current. Then, high voltage is applied to the cathode and anode of the cone-beam X-ray source.

[0044] Chip FU1 (SG3525) adjusts the pulse width according to the feedback current. Pins 6 (RT) and 7 (RD) are connected to the PWM generator of chip FU1 (SG3525) via an external potentiometer (FRP2 model: 3296-10KΩ adjustable potentiometer) and capacitor (FC7 model: 103) to set the oscillation frequency and timing period of the PWM generator. Pins 11 (OUTA) and 14 (OUTB) are connected to the drive circuit of the power switch module via a driver (pins 11 and 14 are 180° out of phase). Resistors FR2 and FR3 are used as current-limiting resistors. Transistors FQ1 and FQ2 are both N-channel MOSFETs. The IR540N chip FU1's PWM generator provides gate charge to transistors FQ1 and FQ2, maintaining normal rise-off functionality. As a high-frequency inverter switch, this system (filament heating circuit) is a closed-loop system. Pin 2 (IN+) of chip FU1 is input to the central control circuit via the main control signal. The central control circuit calculates and generates the MAST signal based on the filament feedback signals FIT1 and FIT2 and the preset filament value. (The maximum value of the MAST signal is a 5V DC voltage signal; the preset value is data written into the central control circuit, such as 255 representing 5V and 250 representing 4.9V.) 245 represents 4.8V). The filament adjustment circuit (including the feedback and current sampling module, and the filament output and switching module) is a closed-loop adjustment system. It samples the filament feedback signal through the current transformer FT1, detects the output result of the control in a timely manner, and feeds the detected filament feedback signal back to the input terminal (central control circuit) through the feedback terminal (pin 3 (FIT1 signal) and pin 2 (FIT2 signal) of terminal CX6) to generate the MAST signal, adjust the input quantity, correct the control error, and improve the control accuracy.

[0045] The half-bridge high-frequency inverter power supply (i.e., the drive and power switching module, mainly composed of resistors FR1, FR2, FR3, FR4, transistors FQ1, FQ2, and high-frequency transformer FT2 (preferably model EI40-14H)) primarily supplies power to the hot cathode X-ray tube filament of the cone-beam X-ray source's X-ray assembly. Figure 1Pin 2 of terminal CX5 is connected to the large filament (LF), and pin 3 of terminal CX5 is connected to the small filament (SF). The LF / SF signal is an external filament switching signal (used to control the switching between the large and small filaments inside the X-ray tube assembly; the LF / SF signal is manually switched via an external button, the input signal is sent to the central processing circuit, and then the central processing circuit processes and outputs it to this circuit to realize the switching between the large and small filaments) to confirm whether the filament current is input to the large or small filament. At any given time, the filament current can only be supplied to either the large or small filament, and the switching is achieved through contacts FK1B and FK1C). The conditions for X-ray generation mainly include two parts: the KV generation circuit and the filament heating power supply. The KV generation circuit provides a DC high voltage, applying a high-voltage electric field between the cathode and anode of the X-ray tube assembly; the filament power supply (in this invention) is mainly used for filament heating. After heating, the thermionic electrons generated by the filament bombard the anode target surface at high speed under the action of the high-voltage electric field, thereby generating X-rays.

[0046] Half-bridge topology ( Figure 1 The OUTA and OUTB output connection sections of the FU1 chip consist of two bridge arms: one is a series voltage equalization bridge arm composed of resistors (such as resistors FR1 and FR2), and the other is a switching bridge arm composed of two power switching transistors (transistors FQ1 and FQ2). The switching transistors alternately conduct, providing an alternating voltage to the primary side of the filament transformer (high-frequency transformer FT2), thereby transferring energy to the secondary side of the high-frequency transformer FT2.

[0047] The FU1 (SG3525) chip processes and calculates the sampled tube current signal (the output MAST signal of the central control circuit) to generate a filament current PWM control signal that meets the requirements, thereby obtaining a stable X-ray output. Unlike resonant converters, PWM converters have relatively simple pulse width modulation and good steady-state performance. Compared with other industrial power supplies, medical X-ray high-voltage generators (high-voltage generators of cone-beam X-ray sources) do not have high efficiency requirements but require high system stability and device lifespan. Therefore, using a PWM device (i.e., the SG3525 chip) to control the signal is more suitable. This invention requires that the PWM control method have a shorter signal transmission delay time, a certain anti-interference capability, and be able to work normally at high frequencies. It also requires electrical isolation between the front-end input circuit composed of SG3525 and the control circuit (the control circuit (central control circuit) that receives FIT1 and FIT2 feedback signals and outputs MAST signals). At the same time, when the front-end input circuit composed of SG3525 is overcurrent or the drive circuit (FR1, FR2, FR3, FR4, FQ1 and FQ2) is undervoltage, the drive circuit can quickly cut off the positive gate voltage and turn off the device.

[0048] The SG3525 includes the following modules: a reference source, an oscillator circuit, an error comparator composed of differential amplifiers, a phase splitter circuit, a PWM signal generation circuit, and combinational logic circuitry. The PWM signal generation circuit consists of a comparator and a latch; the comparator generates the PWM signal, and the latch stores the PWM signal. The phase splitter circuit is composed of flip-flops, outputting two square waves, each with a frequency half that of the oscillator. The combinational logic circuitry consists of OR gates and NOR gates.

[0049] MOSFET is a voltage-controlled unipolar metal-oxide-semiconductor field-effect transistor. It requires very little drive power, making it easy to drive. Furthermore, because only majority carriers participate in conduction and there is no minority carrier recombination time, MOSFETs can operate at very high switching frequencies, making them ideal power devices for high-frequency, low-power converters. Considering the application scenario of this system, the performance is ideal. Therefore, both transistors FQ1 and FQ2 in this invention are MOSFETs.

[0050] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model are within the protection scope of the present utility model.

Claims

1. A filament heating circuit for a cone-beam X-ray source, characterized in that: It includes a core control module, a main control signal input circuit, an enable control circuit, a drive and power switch module, a feedback and current sampling module, a filament output and switching module, a power supply circuit, and relays FK2 and FK3. The core control module is connected to the main control signal input circuit and the drive and power switch module. The power supply circuit is connected to the enable control circuit, the filament output and switching module, and the drive and power switch module. The drive and power switch module is connected to the feedback and current sampling module and the filament output and switching module. The enable control circuit is connected to the main control signal input circuit and controls the main control signal input circuit through relays FK2 and FK3.

2. The filament heating circuit for a cone-beam X-ray source according to claim 1, characterized in that: The core control module includes chip FU1. The IN+ and VREF pins of chip FU1 are connected to the main control signal input circuit. The IN- and COMP pins of chip FU1 are shared and grounded through capacitor FC5. The RT pin of chip FU1 is grounded through potentiometer FRP2. The RD and CT pins of chip FU1 are shared and connected to the GND pin of chip FU1 through capacitor FC7. The GND pin of chip FU1 is grounded. A capacitor FC11 is connected between the SS and SD pins of chip FU1, and the SS pin is also connected to the control terminal of potentiometer FRP3 through diode FD3. One fixed terminal of potentiometer FRP3 is connected to a +5.1V power supply, and the other fixed terminal is grounded and connected to the SD pin of chip FU1. The OUTA and OUTB pins of chip FU1 are connected to the drive and power switch module.

3. The filament heating circuit for a cone-beam X-ray source according to claim 2, characterized in that: The main control signal input circuit includes resistors FR20, FR19, and FR7, potentiometers FRP1, FR6, and FR5, capacitor FC6, contact FK2C of relay FK2, and contact FK3C of relay FK3. The VREF pin of chip FU1 is connected to the first fixed terminal of potentiometer FRP1 through resistor FR6. The second fixed terminal of potentiometer FRP1 is grounded through resistor FR7. The control terminal of potentiometer FRP1 is connected to the first moving contact of contact FK2C. The stationary contact of contact FK2C is connected to the first moving contact of contact FK3C. The second moving contact of contact FK2C is connected to the central control circuit and is also connected to the second moving contact of contact FK3C through resistor FR20. The second moving contact of contact FK3C is also grounded through resistor FR19. The stationary contact pin of contact FK3C is connected to the IN+ pin of chip FU1 through resistor FR5. The IN+ pin of chip FU1 is also grounded through capacitor FC6.

4. The filament heating circuit for a cone-beam X-ray source according to claim 2, characterized in that: The enable control circuit includes an RReady enable control circuit, which is equipped with a resistor FR12, a resistor FR11, a capacitor FC13, a transistor FV2, a coil FK2A of a relay FK2, a diode FD2, a light-emitting diode FDS2, a contact FK2B of the relay FK2, a terminal CX7, and a resistor FR13. The diode FD2 is connected in parallel to the coil FK2A. The light-emitting diode FDS2 and the resistor FR13, which are connected in series, are also connected in parallel to the coil FK2A. The second end of the coil FK2A is connected to the power supply circuit. The first end of the coil FK2A is connected to the third end of the transistor FV2. The second end of the transistor FV2 is connected to the RReady enable signal through the resistor FR12 and the diode FD5, which are connected in series. The common terminal of the resistor R12 and the diode FD5 is connected to the first end of the transistor FV2 and grounded through the resistor FR11 and the capacitor FC13, which are connected in parallel. The terminal CX7 is connected to the contact FK2B and is also connected to the central control circuit.

5. The filament heating circuit for a cone-beam X-ray source according to claim 2, characterized in that: The enable control circuit also includes an FReady enable control circuit, which is equipped with resistor FR18, resistor FR17, capacitor FC15, transistor FV3, coil FK3A of relay FK3, diode FD8, light-emitting diode FDS3, contact FK3B of relay FK3, terminal CX7F, and resistor FR16. Diode FD8 is connected in parallel to coil FK3A. Light-emitting diode FDS3 and resistor FR16, which are connected in series, are also connected in parallel to coil FK3A. The second end of coil FK3A is connected to the power supply circuit. The first end of coil FK3A is connected to the third end of transistor FV3. The second end of transistor FV3 is connected to the FReady enable signal through resistor FR18 and diode FD7, which are connected in series. The common terminal of resistor R18 and diode FD7 is connected to the first end of transistor FV5 and grounded through resistor FR17 ​​and capacitor FC15, which are connected in parallel. Terminal CX7F is connected to contact FK3B and is also connected to the central control circuit.

6. The filament heating circuit for a cone-beam X-ray source according to claim 2, characterized in that: The drive and power switch module includes resistors FR2, FR1, and FR4, a setting FR2, transistors FQ1 and FQ2, and a high-frequency transformer FT2. The first pin of transistor FQ1 and the first pin of transistor FQ2 are shared and grounded. The OUTA pin of chip FU1 is connected to the second pin of transistor FQ2 via resistor FR3, and the second pin of transistor FQ2 is grounded via resistor FR4. The third pin of transistor FQ2 is connected to the seventh pin of the primary side of the high-frequency transformer FT2. The OUTB pin of chip FU1 is connected to the second pin of transistor FQ1 via resistor FR2, and the second pin of transistor FQ1 is grounded via resistor FR1. The third pin of transistor FQ1 is connected to the first pin of the primary side of the high-frequency transformer FT2. The third, fourth, and fifth pins of the primary side of the high-frequency transformer FT2 are shared and connected to the power supply circuit. The secondary side of the high-frequency transformer FT2 is connected to the feedback and current sampling module and the filament output and switching module.

7. The filament heating circuit for a cone-beam X-ray source according to claim 6, characterized in that: The feedback and current sampling module includes a current transformer FT1, a sampling resistor FR8, and a terminal CX6. The first end of the primary side of the current transformer FT1 is connected to the eighth pin of the secondary side of the high-frequency transformer FT2. The first end of the primary side of the current transformer FT1 is connected to the rotating anode drive circuit. The sampling resistor FR8 is connected in parallel on the secondary side of the current transformer FT1, and the two ends of the sampling resistor FR8 are also connected to the central control circuit through the terminal CX6. The remaining pin of the terminal CX6 is grounded.

8. The filament heating circuit for a cone-beam X-ray source according to claim 6, characterized in that: The filament output and switching module includes jumper JP1, resistors FR10 and FR9, capacitor FC12, transistor FV1, relay FK1, diode FD1, light-emitting diode FDS1, terminal CX5, and resistor FR14. The input side of jumper JP1 is connected to pins 13 and 14 of the secondary side of high-frequency transformer FT2. The output terminal of jumper JP1 is connected to the stationary contact of relay FK1C and the stationary contact of relay FK1B. The first moving contact of contact FK1C and the first moving contact of contact FK1B are shared and connected to the X-ray tube assembly through terminal CX5. The second moving contact of contact FK1C and the second moving contact of contact FK1B are shared... The X-ray tube assembly is connected via terminal CX5, with the remaining pin of terminal CX5 grounded. Diode FD1 is connected in parallel to the coil FK1A of relay FK1. LED FDS1 and resistor FR14, which are connected in series, are connected in parallel to coil FK1A. The second end of coil FK1A is connected to the power supply circuit. The first end of coil FK1A is connected to the third end of transistor FV1. The second end of transistor FV1 is connected to the LF / SF signal via resistor FR10 and diode FD4, which are connected in series. The common terminal of resistor R10 and diode FD4 is connected to the first end of transistor FV1 and grounded via resistor FR9 and capacitor FC12, which are connected in parallel. Terminal CX7F is connected to contact FK3B.

9. The filament heating circuit for a cone-beam X-ray source according to claim 2, characterized in that: The power supply circuit includes terminal CX4, capacitors FC1, FC2, FC3, FC4, FC8, FC9, and inductor FL1. The first end of inductor FL1 is grounded through capacitors FC1 and FC2 connected in parallel, and the second end of inductor FL1 is grounded through capacitors FC3 and FC4 connected in parallel. The second end of inductor FL1 is connected to a +24V power supply. The first end of inductor FL1 is connected to pins 1 and 3 of terminal CX4, and pins 2 and 4 of terminal CX4 are grounded. Terminal CX4 is connected to an auxiliary power supply. Capacitors FC8 and FC9 are connected in parallel, with one end of the parallel capacitors FC8 and FC9 connected to a +24V power supply and the other end grounded.

10. A cone-beam X-ray source filament heating circuit according to claim 2, characterized in that: The chip FU1 uses an SG3525. The VIN and VC pins of the chip FU1 are connected to a +15V power supply. The VIN and VC pins of the chip FU1 are also grounded through a capacitor FC10. A +5.1V power supply is also connected to the VREF pin of the chip FU1.

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