A composite vacuum gauge circuit system based on module reuse

Abstract

The application discloses a kind of composite vacuum gauge circuit systems based on module multiplexing, the circuit system is configured as drivable vacuum sensor, vacuum sensor is Pirani sensor and hot cathode ionization sensor, circuit system includes: power supply circuit, filament heating circuit, adjustable high voltage circuit, ion current measurement circuit, voltage measurement circuit, analog-digital conversion circuit, wherein, single-chip microcomputer is configured as: starting Pirani sensor, control adjustable high voltage circuit and ion current measurement circuit are not enabled;Current vacuum degree is obtained based on Pirani sensor, if vacuum degree is greater than or equal to preset threshold, then continue to use Pirani sensor to measure vacuum degree;If vacuum degree is less than preset threshold, then enable adjustable high voltage circuit and ion current measurement circuit, and use hot cathode ionization sensor to measure vacuum degree.By the switchable circuit system controlled by single-chip microcomputer, the driving and measurement of two kinds of principle different vacuum sensors by a set of circuit system are realized.

Description

Technical Field

[0001] This invention relates to the field of vacuum measurement technology, and in particular to a composite vacuum gauge circuit system based on module reuse. Background Technology

[0002] Vacuum measurement technology plays a crucial role in fields such as the semiconductor industry, materials science, nuclear industry, and vacuum coating. Among them, thermionic vacuum gauges and Pirani vacuum gauges are two widely used and complementary vacuum measurement instruments.

[0003] Thermionic vacuum gauges utilize the ionization of gas molecules by electrons emitted from a thermionic cathode under the acceleration of an electric field, and infer the vacuum level by measuring the resulting ion flow. This type of vacuum gauge has the advantages of high measurement accuracy and good linearity, but it requires multiple circuits, such as a cathode heating circuit, a high-voltage bias circuit, and an ion flow measurement circuit, to work together, and it is only suitable for the high vacuum range.

[0004] Pirani vacuum gauges utilize the relationship between the thermal conductivity of gas molecules and the vacuum level. They calculate the vacuum level by measuring the change in filament resistance within the gas being tested or the power required to maintain a constant filament temperature. This type of vacuum gauge has a relatively simple structure and is widely used in low to medium vacuum applications. To achieve optimal performance, most products on the market employ a temperature-controlled drive mode, which typically requires a Wheatstone bridge circuit.

[0005] In practical applications, to cover a wide measurement range from low to high vacuum, a Pirani gauge and a thermionic ionization gauge are often combined into a composite vacuum gauge. However, existing composite vacuum gauge solutions have the following significant drawbacks:

[0006] The circuit system is complex and bulky: Because the two sensors have completely different driving principles and operating modes, traditional solutions must build two independent and complete driving and measurement circuits for them. This leads to redundancy of circuit components, increased system complexity, and increased overall size, making it difficult to apply to compact scenarios with strict limitations on device size.

[0007] Therefore, there is an urgent need in this field for a circuit system that can solve the above problems. Summary of the Invention

[0008] To address the aforementioned issues, this invention provides a composite vacuum gauge circuit system based on module reuse. Through a switchable circuit system controlled by a microcontroller, it enables the driving and measurement of two vacuum sensors based on different principles using a single circuit system.

[0009] In a first aspect, embodiments of the present invention provide a composite vacuum gauge circuit system based on module reuse. This circuit system is configured to drive a vacuum degree measurement sensor, which is a Pirani sensor and a thermionic cathode ionization sensor. The circuit system includes:

[0010] Power supply circuit, filament heating circuit, adjustable high voltage circuit, ion current measurement circuit, voltage measurement circuit, analog-to-digital conversion circuit, microcontroller;

[0011] The voltage measurement circuit and filament heating circuit can be connected to the filament of the thermionic ionization sensor and the filament of the Pirani sensor;

[0012] The analog-to-digital conversion circuit connects the filament heating circuit, the ion current measurement circuit, the voltage measurement circuit, and the microcontroller;

[0013] The microcontroller is connected to the filament heating circuit, voltage measurement circuit, adjustable high voltage circuit, and ion current measurement circuit.

[0014] The microcontroller is configured as follows:

[0015] Activate the Pirani sensor and disable the adjustable high-voltage circuit and ion flow measurement circuit; obtain the current vacuum level. If the vacuum level is greater than or equal to the preset threshold, continue to use the Pirani sensor to measure the vacuum level; if the vacuum level is less than the preset threshold, activate the adjustable high-voltage circuit and ion flow measurement circuit, and use the thermionic ionization sensor to measure the vacuum level.

[0016] In one possible implementation, the microcontroller is further configured as follows:

[0017] Based on the control signal of the filament heating circuit and the output signal of the voltage measurement circuit, the filament resistance value of the Pirani sensor or thermionic cathode ionization sensor is calculated and monitored in real time.

[0018] When the filament resistance value exceeds the preset resistance threshold, a warning signal is issued and the filament heating circuit is shut down.

[0019] In one possible implementation, the circuit system further includes a communication circuit connected to the microcontroller and configured to receive vacuum level data sent by the microcontroller and send a warning signal.

[0020] In one possible implementation, the microcontroller is further configured as follows:

[0021] The filament heating power is controlled by adjusting the duty cycle of the PWM signal applied to the filament heating circuit.

[0022] The current flowing through the filament is calculated based on the duty cycle of the PWM signal.

[0023] In one possible implementation, measuring the vacuum level using the hot cathode ionization sensor includes:

[0024] Receives the digital signal of ion current voltage after conversion by the analog-to-digital converter circuit;

[0025] The vacuum degree is obtained by substituting the digital signal of the ion current voltage into the vacuum degree calculation function table corresponding to the thermionic cathode ionization sensor.

[0026] In one possible implementation, obtaining the current vacuum level based on the Pirani sensor includes:

[0027] The current flowing through the filament is calculated based on the duty cycle of the PWM signal of the filament heating circuit, and the actual resistance of the filament is calculated by combining the filament voltage value collected by the voltage measurement circuit.

[0028] By adjusting the heating power of the filament heating circuit, the actual resistance value is kept at a constant target value to achieve constant temperature drive.

[0029] Based on the actual resistance value under constant temperature drive, the vacuum degree value is obtained by substituting it into the vacuum degree calculation function table corresponding to the Pirani sensor.

[0030] In one possible implementation, the voltage measurement circuit and the filament heating circuit are connected to the filament of the vacuum degree measurement sensor, including:

[0031] The voltage measurement circuit can be connected to the filament of the thermionic ionization sensor or the filament of the Pirani sensor to collect the voltage across the corresponding filament.

[0032] The filament heating circuit can be connected to the filament of the thermionic ionization sensor or the filament of the Pirani sensor to provide heating drive.

[0033] The beneficial effects of the technical solutions provided by some embodiments of the present invention include at least the following: integrating two traditionally independent systems into a single integrated circuit system, wherein the filament heating circuit and voltage measurement circuit are designed as shared general resources, capable of serving the filaments of the two sensors as needed; while the adjustable high-voltage circuit and ion flow measurement circuit specifically designed for the thermionic sensor can be controlled to shut down when not needed. This circuit structure is uniformly coordinated and controlled by a microcontroller, which dynamically configures the operating state of each circuit module by activating the Pirani sensor to measure and determine the current vacuum range: when driving the thermionic sensor, the high-voltage and ion flow measurement functions are enabled; when driving the Pirani sensor, these dedicated modules are shut down, and only the shared heating and voltage measurement circuits are used to achieve constant temperature drive. This innovative system architecture not only fundamentally solves the problems of circuit redundancy and large size in traditional solutions, but also achieves intelligent early warning of filament status by real-time monitoring of filament resistance changes, thereby simplifying the system structure, reducing equipment size, and improving the reliability and continuity of vacuum measurement. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 An exemplary system architecture diagram of a composite vacuum gauge circuit system based on module reuse is provided for an embodiment of the present invention;

[0036] Figure 2 A block diagram of a microcontroller circuit protection and monitoring logic provided in an embodiment of the present invention;

[0037] Figure 3 An exemplary schematic diagram of a composite vacuum gauge circuit system based on module reuse connected to a thermionic cathode ionization sensor is provided in an embodiment of the present invention;

[0038] Figure 4 This is an exemplary schematic diagram of a composite vacuum gauge circuit system based on module reuse connected to a Pirani sensor, provided in an embodiment of the present invention.

[0039] Figure 5 This is an exemplary schematic diagram of a composite vacuum gauge circuit system based on module reuse connecting a composite sensor, provided as an embodiment of the present invention. Detailed Implementation

[0040] To make the features and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0042] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0043] As mentioned earlier, vacuum measurement is a key technology in fields such as semiconductor manufacturing, materials science research, and the nuclear industry. Among these, thermionic vacuum gauges and Pirani vacuum gauges are two typical measuring instruments, each with unique advantages and application scenarios. Thermionic vacuum gauges emit electrons by heating the cathode, ionizing gas molecules under high voltage at the grid. The pressure of the high-vacuum environment is accurately calculated by measuring the ion current obtained at the collecting electrode. It boasts high measurement accuracy and good linearity, but its normal operation requires the coordinated operation of multiple dedicated circuits, including a cathode heating circuit, a high-voltage bias circuit, and an ion current measurement circuit. Pirani vacuum gauges, on the other hand, are based on the principle of gas thermal conduction. They infer the pressure of medium and low-vacuum environments by measuring changes in filament resistance or the power required to maintain a constant filament temperature. The isothermal drive mode is widely favored due to its wide measurement range and strong anti-interference capability, and is typically achieved using a Wheatstone bridge circuit for temperature control. In practical applications, to cover a wide range of measurements from low to high vacuum, it is often necessary to use these two types of vacuum gauges in combination. However, traditional combined solutions have significant limitations: because the driving principles and circuit requirements of the two sensors are completely different, two independent driving and measurement systems must be built for them. This not only leads to complex circuit structures, an increased number of components, and higher costs, but more importantly, it results in bulky equipment that is difficult to adapt to the trend of miniaturization and integration in modern industrial equipment. Furthermore, the filaments of both vacuum gauges are consumable parts, posing a risk of burnout during long-term use. Traditional solutions lack effective condition monitoring mechanisms and cannot provide early warnings before filament failure, which could cause serious production accidents and quality problems in processes requiring continuous monitoring of the vacuum environment.

[0044] In view of this, the present invention provides a composite vacuum gauge circuit system based on modular reuse. Through a switchable circuit architecture, two traditionally independent systems are integrated into a single integrated circuit system. The filament heating circuit and voltage measurement circuit are designed as shared, universal resources, capable of serving the filaments of both sensors as needed. The adjustable high-voltage circuit and ion flow measurement circuit, specifically designed for the thermionic ionization sensor, can be controlled to shut down when not needed. This circuit structure is uniformly coordinated and controlled by a microcontroller. By first activating the Pirani sensor to measure and determine the current vacuum range, the operating state of each circuit module is dynamically configured: when the thermionic ionization sensor is connected, the high-voltage and ion flow measurement functions are enabled; when the Pirani sensor is connected, these dedicated modules are shut down, and only the shared heating and voltage measurement circuits are used to achieve constant temperature drive. This innovative system architecture not only fundamentally solves the problems of circuit redundancy and large size in traditional solutions, but also achieves intelligent early warning of filament status by real-time monitoring of filament resistance changes. This simplifies the system structure, reduces equipment size, and improves the reliability and continuity of vacuum measurement.

[0045] Please see Figure 1 , Figure 1 This is an exemplary system architecture diagram of a composite vacuum gauge circuit system based on module reuse, provided as an embodiment of the present invention. Figure 1 As shown, the composite circuit system for vacuum measurement is configured to switchably connect to and drive vacuum degree measuring sensors, which are a Pirani sensor and a thermionic cathode ionization sensor. The composite circuit system includes: a power supply circuit, a filament heating circuit, an adjustable high-voltage circuit, an ion current measurement circuit, a voltage measurement circuit, an analog-to-digital converter circuit, and a microcontroller. The power supply circuit provides a stable operating voltage for all other functional circuits in the system. The voltage measurement circuit and the filament heating circuit can be connected to the filament of either the thermionic cathode ionization sensor or the Pirani sensor, sharing a common sensor interface. Specifically, regardless of the sensor type (Pirani sensor or thermionic cathode ionization sensor), its filament can be connected to both the filament heating circuit and the voltage measurement circuit. The adjustable high-voltage circuit and the ion current measurement circuit are functional modules specifically designed for the thermionic cathode ionization sensor, and their on / off state is controlled by the microcontroller. The output of the adjustable high-voltage circuit is fixedly connected to the grid of the thermionic cathode ionization sensor to provide a high-voltage bias for accelerating electrons. The input of the ion current measurement circuit is fixedly connected to the ion collecting electrode of the thermionic cathode ionization sensor, used to amplify the weak ion current signal and convert it into a voltage signal. The analog-to-digital converter (ADC) converts the received analog signals from the filament heating circuit, ion current measurement circuit, and voltage measurement circuit into digital signals for the microcontroller. Specifically, the voltage measurement circuit acquires the voltage across the corresponding filament, and the filament heating circuit provides the heating drive.

[0046] In one possible implementation, the circuit system also includes a communication circuit, which is connected to the microcontroller. During normal system operation, the microcontroller periodically encapsulates calculated key data, including the current vacuum level and the real-time calculated filament resistance, according to a predetermined data frame format. This data frame is sent to the communication circuit via a serial communication interface (such as UART, I2C, etc.). The communication circuit then converts the data frame into a corresponding physical signal based on its hardware type and transmits it to an external display device or host computer system, enabling intuitive display and recording of the measurement results. When the system detects an abnormal filament resistance, the process enters the warning stage: the microcontroller generates a specific warning signal data packet or sets an abnormal status flag in a regular data frame at the moment it determines that a warning needs to be issued. This warning information is sent to the communication circuit with the highest priority and immediately transmitted to external devices, thereby triggering audible and visual alarms, interface pop-ups, and other warning actions to promptly notify the operator.

[0047] The microcontroller is connected to the filament heating circuit, voltage measurement circuit, adjustable high-voltage circuit, and ion current measurement circuit. The microcontroller is configured to: activate the Pirani sensor, deactivate the adjustable high-voltage circuit and ion current measurement circuit; obtain the current vacuum level based on the Pirani sensor; if the vacuum level is greater than or equal to a preset threshold, continue measuring the vacuum level using the Pirani sensor; if the vacuum level is less than the preset threshold, activate the adjustable high-voltage circuit and ion current measurement circuit, and use a thermionic ionization sensor to measure the vacuum level. It should be noted that the preset threshold is used to determine if the current vacuum level falls within a specific range. When the vacuum level is greater than or equal to the preset threshold, it indicates that the current vacuum is in the medium or rough vacuum range; if the vacuum level is less than the preset threshold, it indicates that the current vacuum is in the high vacuum range.

[0048] Specifically, after the system is powered on, the microcontroller first activates the Pirani sensor. At this time, the adjustable high-voltage circuit and ion current measurement circuit are turned off, and the sensor is driven in a constant-temperature mode to measure the current vacuum level. If the current vacuum level is greater than or equal to a preset threshold, it can be determined that the vacuum level is in the medium vacuum to rough vacuum range, and the Pirani sensor continues to be activated. If the current vacuum level is less than the preset threshold, it can be determined that the vacuum level is in the high vacuum range, and the adjustable high-voltage circuit and ion current measurement circuit are activated to measure the vacuum level. It should be noted that the preset threshold is generally used to distinguish the range of the current vacuum level. When the vacuum level is greater than or equal to the preset threshold, it can be determined that the vacuum level is in the medium vacuum to rough vacuum range; while when the vacuum level is less than the preset threshold, it can be determined that the vacuum level is in the high vacuum range.

[0049] Furthermore, while measuring the vacuum level normally, the system can monitor changes in filament resistance in real time to predict its health status and take protective measures in case of abnormalities. In one possible implementation, please refer to... Figure 2 , Figure 2 A logic block diagram for protection and monitoring of a single-chip microcomputer circuit is provided as an embodiment of the present invention, such as... Figure 2As shown, the microcontroller first continuously acquires real-time voltage samples from the voltage measurement circuit across the filament. Simultaneously, based on the control signals sent to the filament heating circuit, the microcontroller accurately calculates the current flowing through the filament, thereby calculating the instantaneous resistance of the filament based on Ohm's law. When the filament resistance exceeds a preset resistance threshold, it is determined that the filament is severely aged or in an abnormal state about to burn out. Once this condition is met, the microcontroller immediately sends a clear warning signal to external devices via the communication circuit, prompting the user to replace the sensor. Simultaneously, as a safety protection mechanism, it automatically shuts off the output of the filament heating circuit, cutting off the power supply to the filament, thus proactively preventing the filament from burning out completely due to overheating and providing a window of opportunity for maintenance. Conversely, when the filament resistance is less than the preset resistance threshold, it is determined that the current circuit can operate normally, while continuing to monitor the actual resistance of the filament to prevent safety issues. It should be noted that the preset resistance threshold is a safe upper limit for filament resistance determined based on extensive experimental data, and is typically significantly higher than its average resistance value during normal operation.

[0050] Specifically, when the vacuum level is lower than a preset threshold, the adjustable high-voltage circuit and the ion flow measurement circuit are activated when the vacuum level is measured using a thermionic cathode ionization sensor. The vacuum level is then calculated based on the output signal of the ion flow measurement circuit. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is an exemplary schematic diagram of a composite vacuum gauge circuit system based on module reuse connected to a thermionic cathode ionization sensor, provided as an embodiment of the present invention. Figure 3As shown, an adjustable high-voltage circuit is configured to connect to the grid of the thermionic ionization sensor, and an ion current measurement circuit is configured to connect to the ion collecting electrode of the thermionic ionization sensor. Specifically, the microcontroller controls the filament heating circuit to provide precise heating power to the sensor filament, ensuring it reaches and maintains a stable operating temperature, thereby emitting a constant electron flow. Simultaneously, the microcontroller activates the adjustable high-voltage circuit to apply a positive voltage of several hundred volts to the sensor grid, accelerating the electrons emitted by the filament. These high-speed electrons collide with gas molecules in the vacuum chamber as they fly towards the grid, ionizing them and generating positive ions and secondary electrons. Subsequently, the microcontroller activates the ion current measurement circuit, which is connected to the ion collecting electrode with the lowest potential, to collect the positive ions generated during the ionization process. This circuit amplifies and converts the weak ion current signal, outputting a measurable voltage signal. The system then analyzes the emission current signal sampled from the filament heating circuit, the filament voltage signal obtained from the voltage measurement circuit, and the ion current voltage signal output from the ion current measurement circuit. The analog-to-digital converter (ADC) converts these signals into digital quantities and transmits them to the microcontroller in real time. The microcontroller first dynamically adjusts the PWM duty cycle based on the digitized emission current signal to ensure high stability of the emission current. Simultaneously, the microcontroller automatically adjusts the gain of the ion current measurement circuit based on the magnitude of the ion current voltage signal to ensure that the signal remains within the optimal range of the ADC, thus achieving accurate measurement over a wide range. After the system stabilizes, the microcontroller uses the processed ion current value as the core input parameter, substituting it into a pre-stored vacuum degree calculation function or lookup table corresponding to the characteristics of the thermionic ionization sensor. Finally, the calculated vacuum degree value, along with auxiliary information such as the filament resistance value used for status monitoring, is sent to an external display device via the communication circuit.

[0051] Specifically, when the microcontroller determines that the Pirani sensor is connected, it controls the adjustable high-voltage circuit and the ion current measurement circuit to shut down, and calculates the second vacuum level based on the output signals of the filament heating circuit and the voltage measurement circuit. Please refer to [link / reference]. Figure 4 , Figure 4This is an exemplary schematic diagram of a composite vacuum gauge circuit system based on module reuse connected to a Pirani sensor, provided by an embodiment of the present invention. When the microcontroller determines that it is driving the Pirani sensor, it controls the shut-off of the adjustable high-voltage circuit and the ion current measurement circuit, because the operation of the Pirani sensor does not require high-voltage ionization and ion current measurement functions. This not only reduces system power consumption but also avoids potential electrical interference from these circuits. At this time, only the filament heating circuit and the voltage measurement circuit are activated in the system and establish a connection with the filament of the Pirani sensor through a switchable connection structure. Then, the microcontroller continuously collects the voltage value across the filament through the voltage measurement circuit and converts it into a digital signal through the analog-to-digital converter circuit. Simultaneously, the microcontroller calculates the current value flowing through the filament based on the duty cycle of the PWM control signal output to the filament heating circuit and the known circuit characteristics. Using the real-time collected voltage value and the calculated current value, the microcontroller calculates the current resistance value of the filament in real time according to Ohm's law. This resistance value directly reflects the temperature of the filament. The control objective of the microcontroller is to maintain this resistance value constant, that is, to achieve constant temperature drive. It dynamically adjusts the duty cycle of the PWM signal through a closed-loop control algorithm (such as PID control): if the real-time resistance value is lower than the preset target resistance value, the duty cycle is reduced to decrease the heating power; if the real-time resistance value is higher than the target value, the duty cycle is increased to increase the heating power. After the constant temperature drive stabilizes, there is a definite correspondence between the ambient vacuum level and the heating power required to maintain the filament constant temperature. Since the heating power is proportional to the square of the heating current (or voltage), the microcontroller uses the heating current value under constant temperature conditions (or the equivalent voltage / power value corresponding to the PWM duty cycle) as the core input parameter, and substitutes it into the vacuum level calculation function or lookup table pre-stored internally, which corresponds to the characteristics of the Pirani sensor, for calculation. Finally, the calculated vacuum level value, along with the real-time monitored filament resistance value, is sent to the external display device through the communication circuit.

[0052] In one possible implementation, the vacuum level sensor can be a composite vacuum level sensor. For some thermionic vacuum sensors, their filaments exhibit a significant Pirani effect; therefore, such thermionic vacuum sensors can also be used for vacuum measurements in Pirani mode, hence the name composite vacuum level sensor. Connecting this composite vacuum level sensor to this circuit system allows it to operate in two modes, achieving composite vacuum measurement: low to medium vacuum measurements in Pirani mode and high vacuum measurements in the thermionic mode, thus broadening its measurement range. Please refer to [link to relevant documentation]. Figure 5 , Figure 5 This is an exemplary schematic diagram of a composite vacuum gauge circuit system based on module reuse connecting a composite sensor, as provided in an embodiment of the present invention. Figure 5As shown, when the circuit system is used to drive this composite vacuum sensor, its connection and control logic are the same as described above. The microcontroller is configured to execute the following measurement process: After the system is powered on and initialized, the circuit system is controlled to operate in Pirani drive mode by default, that is, the adjustable high voltage circuit and the ion current measurement circuit are turned off, and the composite vacuum sensor is driven to operate in Pirani mode based on the output signals of the filament heating circuit and the voltage measurement circuit, and the initial vacuum measurement value is calculated. Subsequently, the microcontroller compares the initial vacuum measurement value with a preset threshold. If the initial vacuum measurement value is greater than or equal to the preset threshold, it can be determined that the vacuum level is in the medium vacuum range to the rough vacuum range, and the circuit system is maintained to operate in Pirani drive mode. If the initial vacuum measurement value is less than the preset threshold, it indicates that the current vacuum level is in the high vacuum range. At this time, the microcontroller controls the circuit system to switch to the hot cathode ionization drive mode, enables the adjustable high voltage circuit and the ion current measurement circuit, drives the composite vacuum sensor to operate in the hot cathode ionization mode, and measures the vacuum level based on the output signal of the ion current measurement circuit.

[0053] The circuit system provided by this invention is applicable not only to driving discrete single-principle sensors, but also to driving integrated composite vacuum sensors. Through the judgment and control of the microcontroller, the sensor can be automatically selected and switched to the corresponding operating mode, achieving accurate measurement from low vacuum to high vacuum, further demonstrating the versatility and flexibility of the circuit system.

[0054] This invention provides a modular, multi-functional vacuum gauge circuit system that integrates two traditionally separate systems into a single integrated circuit. The filament heating circuit and voltage measurement circuit are designed as switchable, shared general-purpose resources, capable of serving the filaments of two different sensors as needed. The adjustable high-voltage circuit and ion flow measurement circuit, specifically designed for the thermionic ionization sensor, can be shut down when not in use. This circuit structure is uniformly coordinated and controlled by a microcontroller. By activating the Pirani sensor to measure and determine the current vacuum range, the operating state of each circuit module is dynamically configured. When driving the thermionic ionization sensor, the high-voltage and ion flow measurement functions are enabled; when driving the Pirani sensor, these dedicated modules are disabled, and only the shared heating and voltage measurement circuits are used for constant-temperature operation. This innovative system architecture not only fundamentally solves the problems of circuit redundancy and bulkiness in traditional solutions but also achieves intelligent early warning of filament status by real-time monitoring of filament resistance changes. This simplifies the system structure, reduces equipment size, and improves the reliability and continuity of vacuum measurements.

[0055] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite vacuum gauge circuit system based on module reuse, characterized in that, The circuit system is configured to drive a vacuum sensor, which is a Pirani sensor and a thermionic ionization sensor. The circuit system includes: Power supply circuit, filament heating circuit, adjustable high voltage circuit, ion current measurement circuit, voltage measurement circuit, analog-to-digital conversion circuit, microcontroller; The voltage measurement circuit and the filament heating circuit can be selectively connected to the filament of the Pirani sensor or the filament of the thermionic ionization sensor through a switchable connection structure. The analog-to-digital conversion circuit is connected to the filament heating circuit, the ion current measurement circuit, the voltage measurement circuit, and the microcontroller; The microcontroller is connected to the filament heating circuit, voltage measurement circuit, adjustable high voltage circuit and ion current measurement circuit. The microcontroller is configured as follows: Activate the Pirani sensor and disable the adjustable high-voltage circuit and the ion flow measurement circuit; The current vacuum level is obtained based on the Pirani sensor. If the vacuum level is greater than or equal to a preset threshold, the Pirani sensor is used to continue measuring the vacuum level. If the vacuum level is less than the preset threshold, the adjustable high voltage circuit and the ion flow measurement circuit are activated, and the thermionic ionization sensor is used to measure the vacuum level.

2. The circuit system as described in claim 1, characterized in that, The microcontroller is also configured to: Based on the control signal of the filament heating circuit and the output signal of the voltage measurement circuit, the filament resistance value of the Pirani sensor or thermionic cathode ionization sensor is calculated and monitored in real time. When the filament resistance value exceeds a preset resistance threshold, a warning signal is issued and the filament heating circuit is shut down.

3. The circuit system as described in claim 1 or 2, characterized in that, The circuit system also includes a communication circuit, which is connected to the microcontroller and configured to receive vacuum level data sent by the microcontroller and send a warning signal.

4. The circuit system as described in claim 1, characterized in that, The microcontroller is also configured to: The filament heating power is controlled by adjusting the duty cycle of the PWM signal applied to the filament heating circuit. The current flowing through the filament is calculated based on the duty cycle of the PWM signal.

5. The circuit system as described in claim 1, characterized in that, The measurement of vacuum using the hot cathode ionization sensor includes: Receive the digital signal of ion current voltage after conversion by the analog-to-digital conversion circuit; The vacuum degree is obtained by substituting the digital signal of the ion current voltage into the vacuum degree calculation function table corresponding to the thermionic cathode ionization sensor.

6. The circuit system as described in claim 1, characterized in that, The process of obtaining the current vacuum level based on the Pirani sensor includes: The current flowing through the filament is calculated based on the duty cycle of the PWM signal of the filament heating circuit, and the actual resistance of the filament is calculated by combining the filament voltage value collected by the voltage measurement circuit. By adjusting the heating power of the filament heating circuit, the actual resistance value is kept at a constant target value to achieve constant temperature drive. Based on the actual resistance value under the constant temperature drive, the vacuum degree value is obtained by substituting it into the vacuum degree calculation function table corresponding to the Pirani sensor.

7. The circuit system as claimed in claim 1, characterized in that, The voltage measurement circuit and the filament heating circuit are connected to the filament of the vacuum sensor, including: The voltage measurement circuit can be connected to the filament of the hot cathode ionization sensor or the filament of the Pirani sensor to collect the voltage across the corresponding filament. The filament heating circuit can be connected to the filament of the thermionic ionization sensor or the filament of the Pirani sensor to provide heating drive.

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