CN-121430910-B - Compound vacuum gauge circuit system based on module multiplexing

CN121430910BCN 121430910 BCN121430910 BCN 121430910BCN-121430910-B

Abstract

The invention discloses a composite vacuum gauge circuit system based on module multiplexing, which is configured to drive a vacuum sensor, wherein the vacuum sensor is a Pirani sensor and a hot cathode ionization sensor, the circuit system comprises a power supply circuit, a filament heating circuit, an adjustable high-voltage circuit, an ion flow measuring circuit, a voltage measuring circuit and an analog-to-digital conversion circuit, wherein a singlechip is configured to start the Pirani sensor, control the adjustable high-voltage circuit and the ion flow measuring circuit not to start, acquire the current vacuum degree based on the Pirani sensor, continuously use the Pirani sensor to measure the vacuum degree if the vacuum degree is larger than or equal to a preset threshold value, start the adjustable high-voltage circuit and the ion flow measuring circuit if the vacuum degree is smaller than the preset threshold value, and use the hot cathode ionization sensor to measure the vacuum degree. Through the switchable circuit system controlled by the singlechip, the driving and the measurement of the vacuum sensors with two different principles by means of one set of circuit system are realized.

Inventors

WANG YUWEI
YANG FAN
LIU CHENXI
WEN HAN
Zheng Runhan

Assignees

湖南大学

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (7)

1. A composite vacuum gauge circuitry based on modular multiplexing, the circuitry configured to drive a vacuum sensor, the vacuum sensor being a pirani sensor and a hot cathode ionization sensor, the circuitry comprising: The device comprises a power supply circuit, a filament heating circuit, an adjustable high-voltage circuit, an ion current measuring circuit, a voltage measuring circuit, an analog-to-digital conversion circuit and a singlechip; the voltage measuring circuit and the filament heating circuit can be selectively connected with the filament of the Pirani sensor or the filament of the hot cathode ionization sensor through a switchable connection structure; the analog-to-digital conversion circuit is connected with the filament heating circuit, the ion current measuring circuit, the voltage measuring circuit and the singlechip; the singlechip is connected with the filament heating circuit, the voltage measuring circuit, the adjustable high-voltage circuit and the ion current measuring circuit; wherein, the singlechip is configured as: Starting the Pirani sensor, and controlling the adjustable high-voltage circuit and the ion current measuring circuit not to be started; And if the vacuum degree is smaller than the preset threshold value, starting the adjustable high-voltage circuit and the ion flow measuring circuit, and measuring the vacuum degree by using the hot cathode ionization sensor.
2. The circuitry of claim 1, wherein the single-chip microcomputer is further configured to: according to the control signal of the filament heating circuit and the output signal of the voltage measuring circuit, calculating and monitoring the filament resistance value of the Pirani sensor or the hot cathode ionization sensor in real time; And when the resistance value of the filament is larger than a preset resistance threshold value, sending out an early warning signal, and closing the filament heating circuit.
3. The circuit system of claim 1 or 2, further comprising a communication circuit connected to the single-chip microcomputer and configured to receive the vacuum data sent by the single-chip microcomputer and send an early warning signal.
4. The circuitry of claim 1, wherein the single-chip microcomputer is further configured to: adjusting a PWM signal duty cycle applied to the filament heating circuit to control filament heating power; And calculating a value of current flowing through the filament based on the PWM signal duty cycle.
5. The circuitry of claim 1, wherein said measuring vacuum using said hot cathode ionization sensor comprises: Receiving the ion current voltage digital signal converted by the analog-to-digital conversion circuit; Substituting the ionic current voltage digital signal into a vacuum degree calculation function table corresponding to the hot cathode ionization sensor to obtain the vacuum degree.
6. The circuitry of claim 1, wherein the obtaining the current vacuum based on the pirani sensor comprises: Calculating a current value flowing through the filament based on the PWM signal duty ratio of the filament heating circuit, and calculating an actual resistance value of the filament by combining the filament voltage value acquired by the voltage measuring circuit; The actual resistance value is kept at a constant target value by adjusting the heating power of the filament heating circuit so as to realize constant-temperature driving; substituting the actual resistance value under the constant temperature driving into a vacuum degree calculation function table corresponding to the Pirani sensor to obtain the numerical value of the vacuum degree.
7. The circuitry of claim 1, wherein the voltage measurement circuit and the filament heating circuit establish a connection with a filament of the vacuum sensor, comprising: the voltage measuring circuit can be connected with a filament of the hot cathode ionization sensor or a filament of the Pirani sensor to acquire voltages at two ends of the corresponding filament; The filament heating circuit can establish a connection with a filament of the hot cathode ionization sensor or a filament of the pirani sensor to provide a heating drive.

Description

Compound vacuum gauge circuit system based on module multiplexing Technical Field The invention relates to the technical field of vacuum measurement, in particular to a composite vacuum gauge circuit system based on module multiplexing. Background The vacuum measurement technology plays a vital role in the fields of semiconductor industry, material science, nuclear industry, vacuum coating and the like. The hot cathode ionization vacuum gauge and the Pirani vacuum gauge are two vacuum measuring instruments which are widely applied and have complementary performances. The hot cathode ionization vacuum gauge utilizes electrons emitted by a hot cathode to ionize gas molecules under the acceleration of an electric field, and the vacuum degree is reversely pushed by measuring the generated ion flow. The vacuum gauge has the advantages of high measurement precision and good linearity, but requires a plurality of sets of circuits such as a cathode heating circuit, a high-voltage bias circuit, an ion flow measuring circuit and the like to work cooperatively, and is only suitable for a high vacuum section. The Pirani vacuum gauge uses the relation between the heat conduction characteristic of gas molecules and the vacuum degree to calculate the vacuum degree by measuring the change of filament resistance in the gas to be measured or the power required for maintaining the constant temperature of the filament. The vacuum gauge is relatively simple in structure and widely applied to the field of medium and low vacuum. Most products on the market use a constant temperature drive mode for optimum performance, which is usually achieved by a set of wheatstone bridge circuits. In practical applications, to cover a wide range of vacuum from low vacuum to high vacuum, a pirani gauge is often combined with a hot cathode ionization gauge into a composite vacuum gauge. However, existing composite vacuum gauge solutions suffer from the following significant drawbacks: The circuit system is complex and huge, and because the driving principle and the working mode of the two sensors are quite different, the traditional scheme is necessary to respectively construct two independent and complete driving and measuring circuits for the two sensors. This results in redundancy of circuit components, an increase in system complexity, and an increase in overall size, making it difficult to apply to compact scenarios where the volume of the device is severely limited. Accordingly, there is a need in the art for a circuit system that solves the above-described problems. Disclosure of Invention Based on the problems, the embodiment of the invention provides a composite vacuum gauge circuit system based on module multiplexing, and the driving and the measurement of two vacuum sensors with different principles by means of one set of circuit system are realized through a switchable circuit system controlled by a singlechip. In a first aspect, an embodiment of the present invention provides a module multiplexing-based composite vacuum gauge circuitry configured to drive a vacuum level measurement sensor, the vacuum level measurement sensor being a pirani sensor and a hot cathode ionization sensor, the circuitry comprising: The device comprises a power supply circuit, a filament heating circuit, an adjustable high-voltage circuit, an ion current measuring circuit, a voltage measuring circuit, an analog-to-digital conversion circuit and a singlechip; the voltage measuring circuit and the filament heating circuit can be connected with the filament of the hot cathode ionization sensor and the filament of the Pirani sensor; the analog-to-digital conversion circuit is connected with the filament heating circuit, the ion current measuring circuit, the voltage measuring circuit and the singlechip; The singlechip is connected with the filament heating circuit, the voltage measuring circuit, the adjustable high-voltage circuit and the ion current measuring circuit; wherein, the singlechip is configured as: The method comprises the steps of starting a Pirani sensor, controlling an adjustable high-voltage circuit and an ion flow measuring circuit to be not started, obtaining the current vacuum degree, continuously using the Pirani sensor to measure the vacuum degree if the vacuum degree is larger than or equal to a preset threshold value, starting the adjustable high-voltage circuit and the ion flow measuring circuit if the vacuum degree is smaller than the preset threshold value, and using a hot cathode ionization sensor to measure the vacuum degree. In one possible implementation, the single-chip microcomputer is further configured to: According to the control signal of the filament heating circuit and the output signal of the voltage measuring circuit, calculating and monitoring the filament resistance value of the Pirani sensor or the hot cathode ionization sensor in real time; and when the resistance value of the filament is larger than a preset resistanc