Hot cathode ionization gauge and anode and cathode voltage automatic adjusting circuit thereof

Abstract

The invention discloses a thermionic cathode ionization gauge anode and cathode voltage automatic adjusting circuit, which is characterized in that a cathode stable emission control module emits electrons after a cathode reaches a red hot state, and the electrons move towards the anode under the traction of anode high voltage under a vacuum condition and flow to a cathode stable emission feedback circuit; after the first sampling voltage is compared with a preset voltage, the power of the heating cathode filament is adjusted to adjust emission electrons, and electron emission current is stabilized; and the anode voltage stabilization module adjusts the voltage output of the power supply module through the voltage division sampling circuit and compares the second sampling voltage with the standard voltage, if the anode voltage becomes large or small, the second sampling voltage is adjusted to output voltage through the voltage stabilization circuit, the output voltage is input to the high-frequency transformation primary side of the transformer, then the voltage is accompanied, a voltage loop is formed, and the anode voltage is stabilized. The circuit realizes automatic adjustment of the anode voltage and the cathode voltage of the hot cathode ionization gauge, so that the anode voltage and the cathode voltage are stable, and the vacuum test precision of the hot cathode ionization gauge is improved.

Description

Technical Field

[0001] This invention relates to the field of vacuum measurement technology, specifically to a hot cathode ionization gauge and its automatic adjustment circuit for anode and cathode voltages. Background Technology

[0002] In the typical principle of hot cathode ionization gauges, the cathode steady-state voltage and anode traction voltage are required to be stable and reliable. Especially when the load rate changes, such as the length of the ionization gauge connection cable, the switching of the emission current, and the interference of the electromagnetic environment, the anode voltage and cathode voltage become unstable, thereby reducing the acquisition accuracy of vacuum measurements. Summary of the Invention

[0003] The purpose of this invention is to provide a hot cathode ionization gauge and its automatic adjustment circuit for anode and cathode voltages, which solves the problems of unstable anode and cathode voltages and low acquisition accuracy of vacuum measurements in the prior art.

[0004] This invention is achieved through the following technical solution:

[0005] In a first aspect, the first embodiment of the present invention provides an automatic adjustment circuit for the anode and cathode voltages of a hot cathode ionization gauge, comprising a power supply module, a cathode stabilization control module, and an anode voltage stabilization module;

[0006] The power module provides power to the cathode stabilization control module;

[0007] The cathode stabilization control module is connected to the power module and the cathode of the hot cathode ionization gauge. After the cathode reaches a red-hot state, it emits electrons. Under vacuum conditions, the electrons move towards the anode under the pull of the high voltage of the anode. At the same time, the electrons flow to the cathode stabilization feedback circuit. After comparing the first sampling voltage with the preset voltage, the power of the heated cathode filament is adjusted to adjust the emitted electrons and stabilize the electron emission current of the hot cathode ionization gauge.

[0008] The anode voltage regulator module is connected to the power supply module and the cathode stabilization control module respectively. The initial anode voltage is obtained by the transformer in the cathode stabilization control module. The initial voltage anti-spying voltage modulation chip adjusts the voltage output of the power supply module through the voltage divider sampling circuit. When the anode voltage changes, the second sampling voltage is compared with the standard voltage. If the anode voltage increases or decreases, the second sampling voltage and the standard voltage will deviate. The second sampling voltage is then adjusted by the voltage regulator circuit to adjust the output voltage. The output voltage is then input to the primary side of the high-frequency transformer of the transformer and then subjected to voltage matching to form a voltage loop, thereby stabilizing the anode voltage.

[0009] Furthermore, the cathode stabilization control module includes a cathode stabilization module and a transformer module. The transformer module is a transformer. The cathode stabilization module includes a PWM modulation circuit. The PWM modulation circuit includes a voltage modulation chip, a first MOSFET, a second MOSFET, a first resistor, a second resistor, a third resistor, a fourth resistor, a seventh resistor, an eighth resistor, a tenth resistor, a first capacitor, a second capacitor, a third capacitor, a ninth capacitor, a thirteenth capacitor, an eighteenth TVS diode, and a twentieth TVS diode. The voltage modulation chip is a UC2846. The eighth pin of the voltage modulation chip is connected to one end of the ninth capacitor. The ninth pin of the voltage modulation chip is connected to one end of the eighth resistor. The other ends of the ninth capacitor and the eighth resistor are grounded. The thirteenth pin of the voltage modulation chip is connected to one end of the second capacitor. The other end of the second capacitor is grounded. The first pin of the transformer is connected to the drain of the first MOSFET and one end of the eighteenth TVS diode. The other end of the eighteenth TVS diode is connected to one end of the first capacitor and the negative terminal of the thirteenth capacitor, and then grounded. The other end of the first capacitor is connected to the positive terminal of the thirteenth capacitor. The gate of the first MOSFET is connected to one end of the fourth resistor and one end of the third resistor. The other end of the fourth resistor is grounded. The other end of the third resistor is connected to the fourteenth pin of the voltage modulation chip. The source of the first MOSFET is connected to one end of the first resistor, one end of the second resistor, and the source of the second MOSFET. The other end of the first resistor is connected to one end of the third capacitor and the fourth and sixteenth pins of the voltage modulation chip. The other end of the second resistor is connected to the other end of the third capacitor and the third pin of the voltage modulation chip, and then grounded. The gate of the second MOSFET is connected to one end of the seventh resistor and one end of the tenth resistor. The other end of the seventh resistor is connected to the eleventh pin of the voltage modulation chip. The drain of the second MOSFET is connected to one end of the twentieth TVS diode and the fourth pin of the transformer. The other end of the twentieth TVS diode is connected to the other end of the tenth resistor and then grounded.

[0010] Furthermore, the transformer is an EER28, the first and second MOSFETs are both IRF640, and the eighteenth and twentieth TVS diodes are both SMBJ150.

[0011] Furthermore, the cathode stabilization control module also includes a filtering module, which includes a first rectifier, a first inductor, a fourth capacitor, and a fifth capacitor. The ninth and twelfth pins of the transformer are respectively connected to the third and first pins of the first rectifier. The first pin of the first rectifier is connected to one end of the first inductor. The other end of the first inductor is connected to the positive terminals of the fourth and fifth capacitors, respectively. The negative terminals of the fourth and fifth capacitors are connected to the tenth and eleventh pins of the transformer, respectively. The two ends of the fifth capacitor are connected to the cathode of the hot cathode ionization gauge.

[0012] Furthermore, the first rectifier tube is an MBRF20100.

[0013] Furthermore, the cathode stabilization control module also includes a cathode stabilization feedback module, which includes 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th, 21st, 22nd, 23rd, 24th, and 25th resistors, 11th, 12th, 15th, 16th, 17th, 18th, and 19th capacitors, a third transistor, a sixth Zener diode, a first amplifier, and a second amplifier, both of which are LM amplifiers. 258, one end of the twelfth resistor is connected to an external input signal; one end of the fourteenth and seventeenth resistors, along with one end of the common-mode inductor, is connected to the terminal of the thermionic ionization gauge; the other end of the fourteenth resistor is connected to one end of the thirteenth, sixteenth, and seventeenth resistors, respectively; the other end of the sixteenth resistor is connected to the collector of the third transistor; the base of the third transistor is connected to one end of the twenty-first resistor; the emitter of the third transistor is grounded; the other end of the thirteenth resistor is connected to one end of the twentieth and twenty-fourth resistors, respectively; the other end of the twentieth resistor... One end of the 24th resistor is connected to one end of the 19th capacitor, the negative terminal of the 6th Zener diode, one end of the 23rd resistor, and the 6th pin of the 2nd amplifier. The other end of the 24th resistor is connected to the other end of the 19th capacitor and the positive terminal of the 6th Zener diode, and then grounded. The 5th pin of the 2nd amplifier is connected to one end of the 25th resistor and one end of the 18th resistor. The other end of the 25th resistor is grounded. The other end of the 18th resistor is connected to one end of the 11th capacitor, one end of the 12th capacitor, the 8th pin of the 2nd amplifier, the 2nd pin of the voltage modulation chip, the other end of the 12th resistor, the 8th pin of the 1st amplifier, and one end of the 15th resistor. The other ends of the 11th capacitor and the 12th capacitor are grounded. The 7th pin of the 2nd amplifier is connected to one end of the 17th capacitor. The other end of the 17th capacitor is connected to the 4th pin of the 2nd amplifier and then grounded. The other end of the 23rd resistor is connected to the 2nd pin of the 1st amplifier, one end of the 18th capacitor, and one end of the 22nd resistor. The other end of the 22nd resistor is connected to one end of the 16th capacitor. The 1st pin of the 1st amplifier is connected to the other ends of the 16th capacitor, the other end of the 18th capacitor, and the 5th pin of the voltage modulation chip. The third pin of the first amplifier is connected to the other end of the fifteenth resistor, one end of the nineteenth resistor, and one end of the fifteenth capacitor, respectively. The other end of the nineteenth resistor and the other end of the fifteenth capacitor are connected to ground.

[0014] Furthermore, the anode voltage regulator module includes a third diode, a fourth diode, an eighth capacitor, and a tenth capacitor. The sixth pin of the transformer is connected to one end of the eighth capacitor and one end of the tenth capacitor, respectively. The other end of the eighth capacitor is connected to the anode voltage output by the power module and the negative terminal of the third diode, respectively. The positive terminal of the third diode is connected to the negative terminal of the fourth diode and the seventh pin of the transformer, respectively. The positive terminal of the fourth diode is connected to the other end of the tenth capacitor and grounded.

[0015] Furthermore, the power module includes a power chip, a sixth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, and a seventh Zener diode. The first pin of the power chip is connected to the positive terminal of the twentieth capacitor, one end of the twenty-first capacitor, and a 24V power supply. The negative terminal of the twentieth capacitor is connected to the other end of the twenty-first capacitor, the third pin of the power chip, the fifth pin of the power chip, one end of the twenty-seventh resistor, and one end of the twenty-eighth resistor, and then grounded. The other end of the twenty-eighth resistor is connected to the other end of the twenty-seventh resistor, one end of the sixth resistor, the positive terminal of the seventh Zener diode, and the fourth pin of the power chip. The other end of the sixth resistor is connected to one end of the twenty-sixth resistor, and the other end of the twenty-sixth resistor outputs an anode voltage. The negative terminal of the seventh Zener diode is connected to the positive terminals of the twenty-second and twenty-third capacitors, the second pin of the power chip, and the power supply VCC. The negative terminals of the twenty-second and twenty-third capacitors are connected to ground.

[0016] Furthermore, the power chip is an LM2596.

[0017] Secondly, another embodiment of the present invention provides a hot cathode ionization gauge, including the automatic adjustment circuit for the anode and cathode voltages of the hot cathode ionization gauge described in the first embodiment above.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] This invention provides a hot cathode ionization gauge and its automatic anode and cathode voltage adjustment circuit. By setting a cathode emission stabilization control module to stabilize the electron emission current of the hot cathode ionization gauge, and by stabilizing the anode voltage through an anode voltage stabilization module, the anode and cathode voltages of the hot cathode ionization gauge are automatically adjusted, thereby stabilizing the anode and cathode voltages and improving the vacuum testing accuracy of the hot cathode ionization gauge. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 The schematic diagram of an automatic adjustment circuit for the anode and cathode voltages of a hot cathode ionization gauge provided in the first embodiment of the present invention;

[0022] Figure 2 This is an overall circuit diagram of an automatic voltage adjustment circuit for a thermionic cathode ionization gauge provided in the first embodiment of the present invention;

[0023] Figure 3 This is the circuit diagram of the power supply module;

[0024] Figure 4 Circuit diagram of the cathode stabilization control module;

[0025] Figure 5 The circuit diagram for the cathode stabilization feedback module;

[0026] Figure 6 This is the circuit diagram of the anode voltage regulator module. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0028] like Figure 1 As shown, the first embodiment of the present invention provides an automatic adjustment circuit for the anode and cathode voltages of a hot cathode ionization gauge, comprising: a power supply module, a cathode stabilization control module, and an anode voltage stabilization module;

[0029] The power module provides power to the cathode stabilization control module;

[0030] The cathode stabilization control module is connected to the power module and the cathode of the hot cathode ionization gauge. After the cathode reaches a red-hot state, it emits electrons. Under vacuum conditions, the electrons move towards the anode under the pull of the high voltage of the anode. At the same time, the electrons flow to the cathode stabilization feedback circuit. After comparing the first sampling voltage with the preset voltage, the power of the heated cathode filament is adjusted to adjust the emitted electrons and stabilize the electron emission current of the hot cathode ionization gauge.

[0031] The anode voltage regulator module is connected to the power supply module and the cathode stabilization control module respectively. The initial anode voltage is obtained by the transformer in the cathode stabilization control module. The initial voltage anti-spying voltage modulation chip adjusts the voltage output of the power supply module through the voltage divider sampling circuit. When the anode voltage changes, the second sampling voltage is compared with the standard voltage. If the anode voltage increases or decreases, the second sampling voltage and the standard voltage will deviate. The second sampling voltage is then adjusted by the voltage regulator circuit to adjust the output voltage. The output voltage is then input to the primary side of the high-frequency transformer of the transformer and then subjected to voltage matching to form a voltage loop, thereby stabilizing the anode voltage.

[0032] like Figure 2 The diagram shows the overall circuit diagram of an automatic adjustment circuit for the anode and cathode voltages of a hot cathode ionization gauge. This automatic adjustment circuit for the anode and cathode voltages of the hot cathode ionization gauge is applicable to ZJ27.

[0033] like Figure 3 The diagram shows the circuit diagram of a power supply module. The power supply module includes a power chip U10, a sixth resistor R6, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a twentieth capacitor C20, a twenty-first capacitor C21, a twenty-second capacitor C22, a twenty-third capacitor F23, and a seventh Zener diode D7. The first pin of the power chip is connected to the positive terminal of the twentieth capacitor C20, one end of the twenty-first capacitor C21, and a 24V power supply. The negative terminal of the twentieth capacitor C20 is connected to the other end of the twenty-first capacitor C21, the third pin of the power chip U10, the fifth pin of the power chip U10, and one end of the twenty-seventh resistor R27. One end of the 28th resistor R28 is connected to ground. The other end of the 28th resistor R28 is connected to the other end of the 27th resistor R27, one end of the 6th resistor R6, the positive terminal of the 7th Zener diode D7, and the fourth pin of the power supply chip U10. The other end of the 6th resistor R6 is connected to one end of the 26th resistor R26, which outputs the anode voltage. The negative terminal of the 7th Zener diode D7 is connected to the positive terminals of the 22nd capacitor C22 and the 23rd capacitor C23, the second pin of the power supply chip U10, and the power supply VCC. The negative terminals of the 22nd capacitor C22 and the 23rd capacitor C23 are connected to ground. The power supply chip is LM2596.

[0034] The power chip U10 is a DC / DC converter chip with an input voltage range of 4.5V~36V, capable of driving a 3A load. The 24VDC input is filtered by the circuit of the twentieth capacitor C20 and the twentieth capacitor C21 before reaching the first pin of the LM2596. The fourth pin of the LM2596 is the feedback pin, with a typical privacy voltage of 1.23V. This characteristic is used to adjust the cathode supply voltage and the anode traction voltage. Under normal circumstances, when the anode voltage is 200VDC, after passing through the twenty-sixth resistor R26, the sixth resistor R6, the twenty-seventh resistor R27, and the twenty-eighth resistor R28, a privacy voltage of 1.23V is obtained and enters the fourth pin of the LM2596, i.e., the output stable VCC voltage. When the 200VDC output fluctuates or the load changes, the voltage drop caused by the 200VDC output will increase or decrease as the voltage increases through the 26th resistor R26, the 6th resistor R6, the 27th resistor R27, and the 28th resistor R28. This will cause VCC to change accordingly, and after feedback, it will stabilize at a feedback voltage of 1.23V.

[0035] like Figure 4The diagram shows the circuit diagram of the cathode stabilization control module. The cathode stabilization control module includes a cathode stabilization module and a transformer module. The transformer module is a transformer PT1. The cathode stabilization module includes a PWM modulation circuit in push-pull mode. The PWM modulation circuit includes a voltage modulation chip U1, a first MOSFET Q1, a second MOSFET Q2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a seventh resistor R7, an eighth resistor R8, a tenth resistor R10, a first capacitor C1, a second capacitor C2, a third capacitor C3, a ninth capacitor C9, a thirteenth capacitor C13, an eighteenth TVS diode D18, and a twentieth TVS diode D20. The voltage modulation chip is a UC2846. The eighth pin of the voltage modulation chip U1 is connected to one end of the ninth capacitor, and the ninth pin of the voltage modulation chip U1 is connected to one end of the eighth resistor R8. The other ends of the ninth capacitor C9 and the eighth resistor R8 are grounded. The thirteenth pin of the voltage modulation chip U1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded. The first pin of transformer PT1 is connected to the drain (D) of the first MOSFET Q1 and one end of the eighteenth TVS diode D18. The other end of the eighteenth TVS diode D18 is connected to one end of the first capacitor C1 and the negative terminal of the thirteenth capacitor C1, and then grounded. The other end of the first capacitor C1 is connected to the positive terminal of the thirteenth capacitor C13. The gate (G) of the first MOSFET is connected to one end of the fourth resistor R4 and one end of the third resistor R3. The other end of the fourth resistor R4 is grounded. The other end of the third resistor R3 is connected to the fourteenth pin of voltage modulation chip U1. The source (S) of the first MOSFET Q1 is connected to one end of the first resistor R1, one end of the second resistor R2, and the second MOSFET Q2. The source (S) of the transistor is connected to the ground. The other end of the first resistor R1 is connected to one end of the third capacitor C3 and the fourth and sixteenth pins of the voltage modulation chip U1. The other end of the second resistor R2 is connected to the other end of the third capacitor C3 and the third pin of the voltage modulation chip U1, and then grounded. The gate of the second MOSFET Q2 is connected to one end of the seventh resistor R7 and one end of the tenth resistor R10. The other end of the seventh resistor R7 is connected to the eleventh pin of the voltage modulation chip U1. The drain (D) of the second MOSFET Q2 is connected to one end of the twentieth TVS diode D20 and the fourth pin of the transformer PT1. The other end of the twentieth TVS diode D20 is connected to the other end of the tenth resistor R10 and then grounded. The transformer PT1 is an EER28, the first MOSFET Q1 and the second MOSFET Q2 are both IRF640, and the eighteenth TVS diode D18 and the twentieth TVS diode D20 are both SMBJ150.

[0036] The cathode stabilization control module also includes a filtering module, which comprises a first rectifier diode D1, a first inductor L1, a fourth capacitor C4, and a fifth capacitor C5. The ninth pin of transformer PT1 is connected to the third pin of the first rectifier diode D1, and the twelfth pin of transformer PT1 is connected to the first pin of the first rectifier diode D1. The first pin of the first rectifier diode D1 is connected to one end of the first inductor L1, and the other end of the first inductor L1 is connected to the positive terminals of the fourth capacitor C4 and the fifth capacitor, respectively. The negative terminals of the fourth capacitor C4 and the fifth capacitor C5 are connected to the tenth and eleventh pins of transformer PT1, respectively. The two ends of the fifth capacitor C5 are connected to the cathode of the hot cathode ionization gauge. The first rectifier diode D1 is an MBRF20100.

[0037] In the cathode stabilization module, the eighth resistor R8 and the ninth capacitor C9 are voltage modulation chip U1. The RC oscillation provides a frequency of 100kHz. The third resistor R3 and the seventh resistor R7 are current-limiting and energy-absorbing resistors. When the fourteenth pin of the voltage modulation chip U1 is high, the first MOSFET Q1 is turned on. The VCC voltage generated by the power chip U10 enters from the second and third pins of the transformer PT1, flows out from the first pin of the transformer PT1, passes through the eighteenth TVS diode D18 to the source (S) and drain (G) of the first MOSFET Q1, is sampled by the second resistor R2 and filtered by the RC oscillator, and then flows from the first resistor R1 and the third capacitor C3 to the fourth pin of U1. Similarly, when the eleventh pin of the voltage modulation chip U1 outputs a high voltage, the second MOSFET Q2 is turned on, and the voltage of the transformer PT1 flows from the third pin to the fourth pin, and then flows out from the source of the second MOSFET Q2, completing the overall push-pull operation. Thus, the voltage coupled out from the primary side of the transformer PT1 is rectified by the first rectifier diode D1, and after passing through the first inductor L1, the fourth capacitor C4 and the fifth capacitor C5 for energy storage and filtering, it is sent to the cathode of the thermionic ionization gauge.

[0038] like Figure 5The diagram shows the circuit diagram of the cathode stabilization feedback module. The cathode stabilization control module also includes a cathode stabilization feedback module, which includes resistors R12 (12th), R13 (13th), R14 (14th), R15 (15th), R16 (16th), R17 (17th), R18 (18th), R19 (19th), R20 (20th), R21 (21st), R22 (22nd), R23 (23rd), R24 (24th), R25 (25th), capacitors C11 (11th), C12 (12th), C15 (15th), C16 (16th), C17 (17th), C18 (18th), C19 (19th), and a third transistor. T3, the sixth Zener diode D6, the first amplifier U2A and the second amplifier U2B, both of which are LM258 amplifiers. One end of the twelfth resistor R12 is connected to an external input signal; a high level enables the drive, and a low level disables it. One end of the fourteenth resistor R14 and the seventeenth resistor R17 is connected to one end of the common-mode inductor L2, which is connected to terminal P1 to the cathode of the hot cathode ionization gauge. The other end of the fourteenth resistor R14 is connected to one end of the thirteenth resistor R13, one end of the sixteenth resistor R16, and the other end of the seventeenth resistor R17, respectively. The other end of the sixteenth resistor R16 is connected to the collector of the third transistor T3. The base of the third transistor T3 is connected to one end of the twenty-first resistor R21. The emitter of transistor T3 is grounded. The other end of the thirteenth resistor R13 is connected to one end of the twentieth resistor R20 and one end of the twenty-fourth resistor. The other end of the twentieth resistor R20 is connected to one end of the nineteenth capacitor C19, the negative terminal of the sixth Zener diode D6, one end of the twenty-third resistor R23, and the sixth pin of the second amplifier. The other end of the twenty-fourth resistor R24 ​​is connected to the other end of the nineteenth capacitor C19 and the positive terminal of the sixth Zener diode D6, and then grounded. The fifth pin of the second amplifier U2B is connected to one end of the twenty-fifth resistor R25 and one end of the eighteenth resistor R18. The other end of the twenty-fifth resistor R25 is grounded. The other end of the eighteenth resistor R18 is connected to one end of the eleventh capacitor C11, the twelfth resistor R13, and the negative terminal of the sixth Zener diode D6, one end of the eleventh capacitor C11, and the negative terminal of the sixth Zener diode D6, one end of the twentieth resistor R23, and one end of the sixth amplifier U2B ... One end of capacitor C12, the eighth pin of the second amplifier U2B, the second pin of the voltage modulation chip U1, the other end of the twelfth resistor R12, the eighth pin of the first amplifier U2A, and one end of the fifteenth resistor are connected. The other ends of the eleventh capacitor C11 and the twelfth capacitor C12 are grounded. The seventh pin of the second amplifier U2B is connected to one end of the seventeenth capacitor C17. The other end of the seventeenth capacitor C17 is connected to the fourth pin of the second amplifier U2B and then grounded. The other end of the twenty-third resistor R23 is connected to the second pin of the first amplifier U2A, one end of the eighteenth capacitor C18, and one end of the twenty-second resistor R22. The other end of the twenty-second resistor R22 is connected to one end of the sixteenth capacitor.The first pin of the first amplifier U2A is connected to the other end of the sixteenth capacitor C16, the other end of the eighteenth capacitor C18, and the fifth pin of the voltage modulation chip U1. The third pin of the first amplifier U2A is connected to the other end of the fifteenth resistor R15, one end of the nineteenth resistor R19, and one end of the fifteenth capacitor C15. The other ends of the nineteenth resistor R19 and the fifteenth capacitor C15 are connected to ground.

[0039] The stable emission current of the hot cathode ionization gauge is 1mA and 0.1mA. When the stable emission current is 0.1mA, the voltage sampled by the thirteenth resistor R13 and the twenty-fourth resistor R24 ​​is filtered by the twentieth resistor R20 and the nineteenth capacitor C19 and then flows to the second amplifier U2B. Together with the sixteenth capacitor C16, the eighteenth capacitor C18, the twenty-second resistor R22, and the twenty-third resistor R23, they form a hardware PID regulation circuit. The output from the first pin of the first amplifier U2A is sent to the fifth pin of the voltage modulation chip U1 for error modulation. When the emission current fluctuates, the voltage fed back to the twenty-fourth resistor R24 ​​changes. The voltage is adjusted by the first amplifier U2A to the fifth pin of the voltage modulation chip U1 to cancel the error.

[0040] like Figure 6 The diagram shows the circuit diagram of the anode voltage regulator module. The anode voltage regulator module includes a third diode D3, a fourth diode D4, an eighth capacitor C8, and a tenth capacitor C10. The sixth pin of the transformer PT1 is connected to one end of the eighth capacitor C8 and one end of the tenth capacitor C10. The other end of the eighth capacitor C8 is connected to the anode voltage output by the power supply module and the negative terminal of the third diode D3. The positive terminal of the third diode D3 is connected to the negative terminal of the fourth diode D4 and the seventh pin of the transformer PT1. The positive terminal of the fourth diode D4 is connected to the other end of the tenth capacitor C10 and grounded.

[0041] The initial anode voltage is obtained through open-loop coupling of transformer PT1. While the cathode voltage is accurately adjusted, an open-loop voltage output is generated, which is proportional to the transformer's turns ratio. For example, when VCC is 15VDC, a 200VDC voltage can be output. However, this 200VDC is unstable, resulting in a 2% to 5% error when under load. To overcome this problem, the ingenious aspect of this embodiment is the inclusion of a dual voltage-matching circuit. Voltage is coupled to the sixth and seventh pins of the secondary side of transformer PT1. This voltage, through the dual voltage-matching circuit consisting of the third diode D3, the fourth diode D4, the eighth capacitor C8, and the tenth capacitor C10, yields the initial 200VDC voltage.

[0042] The 200VDC voltage is divided and sampled by resistors R26 (26th), R6 (6th), R27 (27th), and R28 (28th) before reaching pin 4 of power chip U10 to adjust the VCC output. When the load on the anode voltage changes (e.g., decreases), the sampling voltage of power chip U10 is less than 1.23V. To stabilize at 1.23V, VCC increases. As VCC increases, the initial 200V anode voltage coupled from transformer PT1 rises. Conversely, when the anode voltage 200VDC increases, the voltage across resistors R26 (26th), R6 (6th), R27 (27th), and R28 (28th) will be higher than 1.23V. Feedback from pin 4 of power chip U10 reduces the VCC voltage. This reduction in VCC, coupled through PT1, ensures a stable 200V anode output, free from interference from the load and electromagnetic environment.

[0043] This invention provides an automatic adjustment circuit for the anode and cathode voltages of a hot cathode ionization gauge. By setting a cathode emission stabilization control module to stabilize the electron emission current of the hot cathode ionization gauge, and by stabilizing the anode voltage through an anode voltage stabilization module, the circuit achieves automatic adjustment of the anode and cathode voltages of the hot cathode ionization gauge, thereby stabilizing the anode and cathode voltages and improving the vacuum testing accuracy of the hot cathode ionization gauge.

[0044] Another embodiment of the present invention provides a hot cathode ionization gauge, including an automatic adjustment circuit for the anode and cathode voltages of the hot cathode ionization gauge described in the first embodiment. By setting a cathode emission stabilization control module to stabilize the electron emission current of the hot cathode ionization gauge, and by setting an anode voltage stabilization module to stabilize the anode voltage, the automatic adjustment of the anode and cathode voltages of the hot cathode ionization gauge is realized, thereby stabilizing the anode and cathode voltages and improving the vacuum testing accuracy of the hot cathode ionization gauge.

[0045] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A circuit for automatically adjusting the anode and cathode voltages of a hot cathode ionization gauge, characterized in that, include: Power supply module, cathode stabilization control module, and anode voltage regulator module; The power module provides power to the cathode stabilization control module; The cathode stabilization control module is connected to the power module and the cathode of the hot cathode ionization gauge. After the cathode reaches a red-hot state, it emits electrons. Under vacuum conditions, the electrons move towards the anode under the pull of the high voltage of the anode. At the same time, the electrons flow to the cathode stabilization feedback circuit. After comparing the first sampling voltage with the preset voltage, the power of the heated cathode filament is adjusted to adjust the emitted electrons and stabilize the electron emission current of the hot cathode ionization gauge. The anode voltage regulator module is connected to the power supply module and the cathode stabilization control module respectively. The initial anode voltage is obtained by the transformer in the cathode stabilization control module. The initial voltage anti-spying voltage modulation chip adjusts the voltage output of the power supply module through the voltage divider sampling circuit. When the anode voltage changes, the second sampling voltage is compared with the standard voltage. If the anode voltage increases or decreases, the second sampling voltage and the standard voltage will deviate. The second sampling voltage is then adjusted by the voltage regulator circuit to adjust the output voltage. The output voltage is then input to the primary side of the high-frequency transformer of the transformer and then subjected to voltage matching to form a voltage loop, thereby stabilizing the anode voltage.

2. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 1, characterized in that, The cathode stabilization control module includes a cathode stabilization module and a transformer module. The transformer module is a transformer. The cathode stabilization module includes a PWM modulation circuit. The PWM modulation circuit includes a voltage modulation chip, a first MOSFET, a second MOSFET, a first resistor, a second resistor, a third resistor, a fourth resistor, a seventh resistor, an eighth resistor, a tenth resistor, a first capacitor, a second capacitor, a third capacitor, a ninth capacitor, a thirteenth capacitor, an eighteenth TVS diode, and a twentieth TVS diode. The voltage modulation chip is a UC2846. The eighth pin of the voltage modulation chip is connected to one end of the ninth capacitor. The ninth pin of the voltage modulation chip is connected to one end of the eighth resistor. The other ends of the ninth capacitor and the eighth resistor are grounded. The thirteenth pin of the voltage modulation chip is connected to one end of the second capacitor, and the other end of the second capacitor is grounded. The first pin of the transformer is connected to the drain of the first MOSFET and one end of the eighteenth TVS diode. The other end of the eighteenth TVS diode is connected to one end of the first capacitor and the negative terminal of the thirteenth capacitor, and then grounded. The other end of the first capacitor is connected to the positive terminal of the thirteenth capacitor. The gate of the first MOSFET is connected to one end of the fourth resistor and one end of the third resistor. The other end of the fourth resistor is grounded. The other end of the third resistor is connected to the fourteenth pin of the voltage modulation chip. The source of the first MOSFET is connected to one end of the first resistor, one end of the second resistor, and the source of the second MOSFET. The other end of the first resistor is connected to one end of the third capacitor and the fourth and sixteenth pins of the voltage modulation chip. The other end of the second resistor is connected to the other end of the third capacitor and the third pin of the voltage modulation chip, and then grounded. The gate of the second MOSFET is connected to one end of the seventh resistor and one end of the tenth resistor. The other end of the seventh resistor is connected to the eleventh pin of the voltage modulation chip. The drain of the second MOSFET is connected to one end of the twentieth TVS diode and the fourth pin of the transformer. The other end of the twentieth TVS diode is connected to the other end of the tenth resistor and then grounded.

3. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 2, characterized in that, The transformer is an EER28, the first and second MOSFETs are both IRF640, and the eighteenth and twentieth TVS diodes are both SMBJ150.

4. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 2, characterized in that, The cathode stabilization control module also includes a filtering module, which includes a first rectifier, a first inductor, a fourth capacitor, and a fifth capacitor. The ninth and twelfth pins of the transformer are respectively connected to the third and first pins of the first rectifier. The first pin of the first rectifier is connected to one end of the first inductor. The other end of the first inductor is connected to the positive terminals of the fourth and fifth capacitors. The negative terminals of the fourth and fifth capacitors are connected to the tenth and eleventh pins of the transformer, respectively. The two ends of the fifth capacitor are connected to the cathode of the hot cathode ionization gauge.

5. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 4, characterized in that, The first rectifier tube is MBRF20100.

6. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 2, characterized in that, The cathode stabilization control module further includes a cathode stabilization feedback module, which includes 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th, 21st, 22nd, 23rd, 24th, and 25th resistors, 11th, 12th, 15th, 16th, 17th, 18th, and 19th capacitors, a third transistor, a sixth Zener diode, a first amplifier, and a second amplifier. Both the first and second amplifiers are LM258 chips. One end of the twelfth resistor is connected to an external input signal. One end of the fourteenth and seventeenth resistors, along with one end of the common-mode inductor, is connected to the cathode of the thermionic ionization gauge. The other end of the fourteenth resistor is connected to one end of the thirteenth, sixteenth, and seventeenth resistors, respectively. The other end of the sixteenth resistor is connected to the collector of the third transistor. The base of the third transistor is connected to one end of the twenty-first resistor. The emitter of the third transistor is grounded. The other end of the thirteenth resistor is connected to one end of the twentieth and twenty-fourth resistors, respectively. The other end of the twentieth resistor is connected to... The following resistors are connected to the following terminals: one end of the nineteenth capacitor, the negative terminal of the sixth Zener diode, one end of the twenty-third resistor, and the sixth pin of the second amplifier; the other end of the twenty-fourth resistor is connected to the other end of the nineteenth capacitor and the positive terminal of the sixth Zener diode, and then grounded; the fifth pin of the second amplifier is connected to one end of the twenty-fifth resistor and one end of the eighteenth resistor, and the other end of the twenty-fifth resistor is grounded; the other end of the eighteenth resistor is connected to one end of the eleventh capacitor, one end of the twelfth capacitor, the eighth pin of the second amplifier, the second pin of the voltage modulation chip, the other end of the twelfth resistor, the eighth pin of the first amplifier, and one end of the fifteenth resistor, and the other ends of the eleventh and twelfth capacitors are grounded; the seventh pin of the second amplifier is connected to one end of the seventeenth capacitor, and the other end of the seventeenth capacitor is connected to the fourth pin of the second amplifier and then grounded; the other end of the twenty-third resistor is connected to the second pin of the first amplifier, one end of the eighteenth capacitor, and one end of the twenty-second resistor, and the other end of the twenty-second resistor is connected to one end of the sixteenth capacitor; the first pin of the first amplifier is connected to the other ends of the sixteenth capacitor, the other end of the eighteenth capacitor, and the fifth pin of the voltage modulation chip. The third pin of the first amplifier is connected to the other end of the fifteenth resistor, one end of the nineteenth resistor, and one end of the fifteenth capacitor, respectively. The other end of the nineteenth resistor and the other end of the fifteenth capacitor are connected to ground.

7. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 2, characterized in that, The anode voltage regulator module includes a third diode, a fourth diode, an eighth capacitor, and a tenth capacitor. The sixth pin of the transformer is connected to one end of the eighth capacitor and one end of the tenth capacitor, respectively. The other end of the eighth capacitor is connected to the anode voltage output by the power module and the negative terminal of the third diode, respectively. The positive terminal of the third diode is connected to the negative terminal of the fourth diode and the seventh pin of the transformer, respectively. The positive terminal of the fourth diode is connected to the other end of the tenth capacitor and grounded.

8. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 2, characterized in that, The power module includes a power chip, a sixth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, and a seventh Zener diode. The first pin of the power chip is connected to the positive terminal of the twentieth capacitor, one end of the twenty-first capacitor, and a 24V power supply. The negative terminal of the twentieth capacitor is connected to the other end of the twenty-first capacitor, the third pin of the power chip, the fifth pin of the power chip, one end of the twenty-seventh resistor, and one end of the twenty-eighth resistor, and then grounded. The other end of the twenty-eighth resistor is connected to the other end of the twenty-seventh resistor, one end of the sixth resistor, the positive terminal of the seventh Zener diode, and the fourth pin of the power chip. The other end of the sixth resistor is connected to one end of the twenty-sixth resistor, and the other end of the twenty-sixth resistor outputs an anode voltage. The negative terminal of the seventh Zener diode is connected to the positive terminals of the twenty-second and twenty-third capacitors, the second pin of the power chip, and the VCC power supply. The negative terminals of the twenty-second and twenty-third capacitors are connected and then grounded.

9. The automatic voltage adjustment circuit for the anode and cathode of the hot cathode ionization gauge as described in claim 8, characterized in that, The power chip is LM2596.

10. A hot cathode ionization gauge, comprising an automatic adjustment circuit for the anode and cathode voltages of the hot cathode ionization gauge as described in any one of claims 1-9.

Images