Process gas flow self-adaptive pressure stabilizing circuit for vacuum furnace

Abstract

The utility model relates to vacuum furnace technical field, concretely relates to a process gas flow self -adaptation voltage stabilizing circuit for vacuum furnace. The circuit includes flow control valve, pressure sensor, controller, proportional valve and power module. Pressure sensor detects the pressure in vacuum furnace and exports signal to controller, and the controller contains signal comparison unit and signal amplification unit, is used for carrying out hardware comparison and amplification to pressure signal and preset pressure reference signal, exports control signal to proportional valve, and proportional valve passes through the pressure of adjusting connection flow control valve or directly drives the valve, thereby changes the process gas flow of entering vacuum furnace, forms a closed loop control loop not depending on software program. The utility model discloses through the connecting relation of pure hardware realizes the quick, self -adaptation, high reliable voltage stabilization to the pressure in vacuum furnace, simple structure, responds quickly, and the anti -interference ability is strong.

Description

Technical Field

[0001] This utility model relates to the field of vacuum furnace technology, and specifically to an adaptive voltage regulation circuit for process gas flow in a vacuum furnace. Background Technology

[0002] Vacuum furnaces are critical equipment in material heat treatment, sintering, brazing, and other processes. The stability of their internal process environment, especially the stability of process gas pressure, directly affects product quality and process repeatability. During vacuum furnace operation, the internal pressure continuously fluctuates dynamically due to factors such as workpiece venting, potential minor leaks within the furnace body, and gas volume changes caused by temperature variations. Traditional gas flow control methods often rely on operators manually adjusting valves based on experience or on preset programs with fixed time-flow curves. These methods cannot detect actual pressure changes within the furnace in real time and make rapid and accurate compensation adjustments, exhibiting significant lag and rigidity. When the furnace pressure deviates from the set value due to disturbances, traditional methods struggle to correct it promptly, leading to unstable process gas flow. This can cause uneven atmosphere within the furnace, affecting key process parameters such as diffusion layer thickness and sintering density, and in severe cases, even resulting in batch scrapping. Therefore, there is an urgent need for a pressure stabilization technology that can automatically and rapidly respond to changes in furnace pressure and adaptively adjust the process gas flow in real time to improve process control accuracy and automation levels. Although some existing electronic control solutions have introduced sensors and controllers, their control logic often relies on software algorithms, which has problems such as high program complexity, response speed limited by the scan cycle, and high reliability risk in harsh industrial electromagnetic environments.

[0003] Therefore, the existing technology still needs further development. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide an adaptive voltage regulation circuit for process gas flow in a vacuum furnace, so as to solve the problems existing in the prior art.

[0005] To achieve the above technical objectives, this utility model provides an adaptive voltage regulation circuit for process gas flow in a vacuum furnace, comprising: Includes flow control valves, pressure sensors, controllers, proportional valves, and power modules; The inlet of the flow control valve is connected to the process gas source, and the outlet is connected to the inlet of the vacuum furnace. The detection end of the pressure sensor is located inside the vacuum furnace cavity, and its signal output end is connected to the pressure signal input end of the controller. The control signal output terminal of the controller is connected to the control terminal of the proportional valve. The proportional valve is connected in series in the control air path of the flow control valve, or is integrated with the flow control valve. The power module supplies power to the controller, pressure sensor, and proportional valve.

[0006] Specifically, the proportional valve is an electro-proportional valve, and its electrical control terminal is connected to the control signal output terminal of the controller.

[0007] Specifically, the controller includes a signal comparison unit and a signal amplification unit; the signal comparison unit is used to receive the signal from the pressure sensor and a preset pressure reference signal; the output terminal of the signal comparison unit is connected to the input terminal of the signal amplification unit, and the output terminal of the signal amplification unit constitutes the control signal output terminal of the controller.

[0008] Specifically, the circuit also includes an alarm module; the trigger terminal of the alarm module is connected to the alarm signal output terminal of the controller.

[0009] Specifically, the circuit also includes a communication module; the communication module is bidirectionally connected to the controller.

[0010] Specifically, the power supply module includes a first voltage-regulating branch that powers the signal comparison unit and a second voltage-regulating branch that powers the signal amplification unit, wherein the output voltages of the first voltage-regulating branch and the second voltage-regulating branch are different.

[0011] Specifically, the alarm module includes an indicator light and a buzzer connected in series.

[0012] Specifically, the circuit also includes a display module, the input of which is connected to the display data output of the controller.

[0013] Specifically, the circuit includes at least two control loops consisting of the pressure sensor, controller, and proportional valve, which are used to control the flow rate of process gas to different areas inside the vacuum furnace.

[0014] Specifically, a manual reset switch is connected in series in the power supply circuit of the alarm module.

[0015] Beneficial effects: This invention provides an adaptive pressure stabilizing circuit for process gas flow in a vacuum furnace. By constructing a closed-loop control circuit based on pure hardware connections, it brings significant benefits. Firstly, the core benefit lies in achieving rapid, adaptive real-time pressure stabilization. Through direct signal connections between the pressure sensor, hardware signal comparison and amplification unit, proportional valve, and flow control valve, a continuous physical feedback loop independent of any software program is formed. Any minute change in furnace pressure is instantaneously detected, compared, and converted into an adjustment signal, driving the valve to adjust the gas flow. The entire response process is simulated as continuous and aperiodic, thus greatly improving the system's response speed and real-time control, and effectively suppressing pressure fluctuations within the furnace. Secondly, this solution has high reliability and strong anti-interference capabilities. Because it avoids complex program judgment processes, its function is entirely implemented through analog circuits and hardware connections, minimizing the impact of electromagnetic interference and eliminating the risk of program crashes or freezes. It is particularly suitable for long-term stable operation in industrial environments with strong electromagnetic interference, such as vacuum furnaces. Furthermore, the system has a clear structure and a high degree of modularity. Each functional module (sensing, control, execution, alarm, display, etc.) is connected through a clearly defined signal flow, facilitating production, debugging, and maintenance. For example, multi-loop expansion only requires copying the hardware module, increasing the system's flexibility and scalability. Finally, the added pure hardware alarm module and manual reset switch provide direct and effective audible and visual warnings in case of system abnormalities and force manual intervention for confirmation, further ensuring the safety and controllability of equipment operation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system composition of the adaptive voltage regulation circuit for process gas flow in a vacuum furnace provided in a specific embodiment of this utility model. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, the directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the creation of this utility model.

[0018] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0019] Please see Figure 1This utility model provides an adaptive pressure stabilizing circuit for process gas flow in a vacuum furnace, comprising: a flow control valve 100, a pressure sensor 200, a controller 300, a proportional valve 400, and a power module 500; the inlet of the flow control valve 100 is connected to a process gas source, and the outlet is connected to the inlet of the vacuum furnace; the detection end of the pressure sensor 200 is disposed inside the furnace cavity of the vacuum furnace, and its signal output end is connected to the pressure signal input end of the controller 300; the control signal output end of the controller 300 is connected to the control end of the proportional valve 400; the proportional valve 400 is connected in series in the control gas path of the flow control valve 100, or integrated with the flow control valve 100; the power module 500 supplies power to the controller 300, the pressure sensor 200, and the proportional valve 400.

[0020] It should be further noted that, in this specific embodiment, the flow control valve 100 can be a pneumatic diaphragm regulating valve, a pneumatic piston valve, etc., and its function is to regulate the flow rate of process gas (such as nitrogen, argon, etc.) entering the vacuum furnace from an external process gas source. The pressure sensor 200 is preferably an absolute pressure sensor, which exposes its pressure-sensing diaphragm or probe inside the furnace cavity through a flange interface mounted on the furnace wall. It is used to continuously detect the absolute pressure value inside the furnace in real time and convert it into an electrical signal (such as a 4-20mA current signal or a 0-10V voltage signal) for output. The controller 300 receives this pressure signal. The proportional valve 400 is a device that enables its output pressure to be linearly proportional to the input electrical signal, such as an electro-proportional valve. When the proportional valve 400 is separated from the flow control valve 100, the proportional valve 400 outputs a controlled pressure signal, which is connected through a pipe to the pneumatic actuator (such as a diaphragm or cylinder) of the flow control valve 100 as its driving pressure, thereby controlling the valve opening. When the proportional valve 400 is integrated with the flow control valve 100, it can be a regulating valve with a built-in electric positioner, whose electronic control terminal directly receives electrical signals from the controller 300. The power module 500 converts external AC power (such as 220VAC) into various DC voltages required by the system, such as providing 24VDC excitation power to the pressure sensor 200, ±15VDC and 5VDC operating power to the controller 300, and 24VDC coil power to the proportional valve 400.

[0021] It is understood that, through the connection of the above modules, this invention forms a complete hardware closed-loop control circuit: the actual pressure inside the furnace is sensed by the pressure sensor 200 and converted into an electrical signal, which is sent to the controller 300; after processing this signal, the controller 300 outputs a control electrical signal to drive the proportional valve 400; the proportional valve 400 adjusts the opening of the flow control valve 100 by changing the output gas pressure, thereby changing the intake air flow and ultimately making the pressure inside the furnace tend to stabilize. This purely hardware connection relationship achieves adaptive pressure regulation without the intervention of software programs, has a fast response speed, and the system is stable and reliable.

[0022] Specifically, the proportional valve 400 is an electro-proportional valve, and its electrical control terminal is connected to the control signal output terminal of the controller 300.

[0023] It should be further explained that, in this specific embodiment, the proportional valve 400 is specifically an electro-proportional valve. Its electrical control terminal typically accepts analog control signals, such as a 0-10V voltage signal or a 4-20mA current signal. The control signal output terminal of the controller 300 correspondingly outputs such analog signals and connects directly to the corresponding signal input terminals of the electro-proportional valve 400 (such as the positive and negative terminals of voltage input, or the "+" and "-" terminals of current input) via a pair of shielded wires. When the voltage or current value output by the controller 300 increases, the internal pilot valve of the electro-proportional valve 400 opens, causing the air pressure output to the actuator of the flow control valve 100 to increase proportionally, thereby increasing the valve opening and the intake air flow; conversely, when the control signal decreases, the output air pressure decreases, and the valve opening decreases.

[0024] Understandably, this direct electrical connection between the electro-proportional valve and the controller 300 eliminates the need for an additional electro-pneumatic converter, simplifies the system structure, reduces costs, and provides fast signal transmission and strong anti-interference capabilities, which helps improve the response speed and accuracy of the entire control loop.

[0025] Specifically, the controller 300 includes a signal comparison unit and a signal amplification unit; the signal comparison unit is used to receive the signal from the pressure sensor 200 and a preset pressure reference signal; the output terminal of the signal comparison unit is connected to the input terminal of the signal amplification unit, and the output terminal of the signal amplification unit constitutes the control signal output terminal of the controller 300.

[0026] It should be further explained that, in this specific embodiment, the core of the controller 300 consists of two specific hardware circuit units. The signal comparison unit can be implemented by a differential amplifier composed of an operational amplifier or a dedicated instrumentation amplifier chip. The real-time pressure signal (denoted as V_feedback) output by the pressure sensor 200 is connected to one input terminal (in-phase or inverting input terminal) of this unit via a wire. The preset pressure reference signal (denoted as V_setpoint) represents the target pressure value. It can be generated by a high-precision, adjustable multi-turn potentiometer. The two ends of this potentiometer are connected to a stable reference voltage (such as +5V and ground). The output voltage of the sliding end is V_setpoint, which is connected to the other input terminal of the signal comparison unit via a wire. The signal comparison unit performs analog subtraction on V_feedback and V_setpoint, outputting a difference voltage signal (V_error) representing the deviation between the two. This V_error signal is directly connected to the input terminal of the signal amplification unit via a wire. The signal amplification unit can be implemented using a non-inverting or inverting proportional amplifier circuit composed of another operational amplifier. Its amplification factor is determined by the hardware-defined ratio of the feedback resistor and the input resistor external to the operational amplifier. The signal amplification unit linearly amplifies the V_error signal by a fixed factor to obtain a control signal V_control sufficient to drive the subsequent proportional valve 400. This signal is then led out from the output pin of the operational amplifier via a wire, serving as the output of the entire controller 300.

[0027] Understandably, this purely hardware-based connection and processing method does not contain any programs or algorithms. It directly realizes the detection and amplification of pressure deviation signals through the physical connection of components such as resistors and operational amplifiers. The structure is simple, the response is instantaneous and continuous, and there is no delay caused by software scanning cycles, which greatly improves the real-time performance of the system.

[0028] Specifically, the circuit also includes an alarm module; the trigger terminal of the alarm module is connected to the alarm signal output terminal of the controller 300.

[0029] It should be further explained that, in this specific embodiment, a purely hardware alarm module is added to provide warnings when system anomalies occur (such as severely excessive pressure or sensor malfunction causing signal abnormalities). The controller 300 can internally house a voltage comparator, one input of which is connected to a fixed reference voltage (generated by a resistor divider network) representing the alarm threshold, and the other input is connected to a processed pressure signal or power monitoring signal. When an anomaly occurs, the output state of this voltage comparator will flip. The output of this voltage comparator is the alarm signal output of the controller 300, which is connected to the trigger terminal of the alarm module via a wire. The trigger terminal of the alarm module can be an input of an optocoupler or one end of a relay coil. When the trigger terminal receives a high-level or low-level alarm signal from the controller 300, it will drive the internal or subsequent audio-visual devices of the alarm module to activate.

[0030] Understandably, adding an alarm module can promptly alert operators when the system malfunctions, preventing product scrapping or equipment damage due to abnormal pressure, thus improving the safety and reliability of the entire system.

[0031] Specifically, the circuit also includes a communication module; the communication module is bidirectionally connected to the controller 300.

[0032] It should be further explained that, in this specific embodiment, a communication module is added to enable remote monitoring of the furnace pressure status or remote setting of the target pressure value. The communication module can be an RS-485 communication chip, a CAN bus transceiver, or an Ethernet physical layer chip, etc. Its bidirectional data connection with the controller 300 means that the controller 300's transmit data line (TX) is connected to the communication module's receive data pin (RX), and the controller 300's receive data line (RX) is connected to the communication module's transmit data pin (TX). Furthermore, the ground lines (GND) of both must also be connected together. The controller 300 can send the real-time pressure value it collects (analog signal converted by an internal ADC) to the communication module via the TX line. The communication module converts this into a corresponding bus signal and uploads it to the host computer or touchscreen. Simultaneously, the target pressure setting value digital command sent by the host computer or touchscreen is transmitted to the communication module via the bus. The communication module converts this into a TTL level signal and transmits it to the controller 300 via the RX line. The controller 300 internally converts this into an analog V_setpoint voltage signal via a digital-to-analog converter (DAC).

[0033] Understandably, this hardware connection allows the voltage regulator circuit to be easily integrated into a more advanced workshop control system, enabling remote data transmission and remote modification of settings, thus improving the intelligence and integration level of the equipment. Meanwhile, the core, software-independent, fast closed-loop voltage regulation function is still independently completed by the aforementioned hardware circuit.

[0034] Specifically, the power module 500 includes a first voltage-regulating branch that supplies power to the signal comparison unit and a second voltage-regulating branch that supplies power to the signal amplification unit, wherein the output voltages of the first voltage-regulating branch and the second voltage-regulating branch are different.

[0035] It should be further explained that, in this specific embodiment, the power supply module 500 is specifically designed to meet the different power quality and voltage level requirements of different circuit units within the controller 300. The power supply module 500 receives an external AC input (e.g., 220VAC), which undergoes initial DC-DC conversion via a transformer, rectifier bridge, and filter capacitor to obtain an unstable DC voltage. For the signal comparison unit, which typically includes a precision operational amplifier and a reference voltage source, it is highly sensitive to power supply noise and ripple; therefore, a first voltage regulation branch is provided. This branch can employ a low-dropout linear regulator (LDO) to stabilize the unstable DC voltage at ±5V, powering the operational amplifier in the signal comparison unit and the multi-turn potentiometer serving as the V_setpoint source. This provides a very clean and stable power supply, ensuring the reference accuracy of the pressure signal comparison. For the signal amplification unit, which requires a sufficiently powerful drive signal and may demand a higher output voltage swing, a separate second voltage regulation branch is provided. This branch can use another voltage regulator, outputting, for example, ±12V or ±15V, specifically to power the power operational amplifier in the signal amplification unit, enabling it to output a full control signal range of 0-10V. The first and second voltage regulation branches are physically separate power supply lines on the circuit board, each with its own independent voltage regulator chip, input / output filter capacitors, and decoupling capacitors.

[0036] Understandably, this hardware connection method, which provides independent and compatible power supplies for different functional modules, can effectively prevent digital noise or power circuit noise from coupling into the precision analog comparator circuit through the power lines, greatly improving the accuracy, stability, and anti-interference capability of the entire control circuit.

[0037] Specifically, the alarm module includes an indicator light and a buzzer connected in series.

[0038] It should be further explained that the specific configuration of the alarm module is further defined in this specific embodiment. The indicator light (such as a red LED) and the buzzer (active or passive) are connected in series. More specifically, the positive terminal (anode) of the indicator light is connected to the trigger terminal of the alarm module (e.g., one end of a normally open contact of a relay from the alarm signal output terminal of the controller 300) via a wire, the negative terminal (cathode) of the indicator light is connected to one power supply pin of the buzzer, and the other power supply pin of the buzzer is connected to ground. When the alarm signal output terminal of the controller 300 is active (e.g., the relay contact closes), an operating voltage (e.g., 24VDC) is applied to this series circuit consisting of the indicator light and the buzzer. At this time, the indicator light illuminates, the buzzer sounds, and an audible and visual alarm is generated simultaneously. This series connection method allows one trigger signal to drive two alarm devices simultaneously, and the circuit is very simple and reliable. Compared to the parallel connection method, the series connection will cause the entire alarm circuit to fail in the event of a circuit fault (such as an open circuit in one device), which can itself be regarded as a simple fault indication. If necessary, a current-limiting resistor can also be connected in series in this series circuit.

[0039] Understandably, this type of hardware alarm circuit has an extremely simple structure, low cost, and intuitive and reliable operation, requiring no programming or configuration.

[0040] Specifically, the circuit also includes a display module, the input of which is connected to the display data output of the controller 300.

[0041] It should be further explained that, in this specific embodiment, a display module is added to allow for intuitive reading of key parameters on-site. The display module can be a digital panel meter, an LCD display with a driver chip, or an LED digital tube module. The display data output terminal of the controller 300 depends on the type of display module: if it is an analog meter, the output terminal is an analog voltage proportional to the furnace pressure (e.g., 0-10V corresponds to 0-100Pa); if it is a digital display module, the output terminal is a parallel data line (D0-D7) or a serial communication line (such as the TX line of a UART). The input terminals of the display module correspondingly receive these signals. For example, using a three-and-a-half-digit digital voltmeter as the display module, its voltage input terminals (VIN+ and VIN-) are connected via wires to the output terminal of a buffer operational amplifier inside the controller 300. The input of this buffer operational amplifier is a scaled real-time pressure signal V_feedback. In this way, the number displayed on the meter directly represents the real-time pressure value inside the furnace. The addition of a display module provides direct status feedback to on-site operators, facilitating local operation and initial fault diagnosis of the equipment, and enhancing the convenience of human-machine interaction.

[0042] Understandably, the addition of the display module is a separate hardware connection and does not affect the core voltage regulation closed-loop function.

[0043] Specifically, the circuit includes at least two control loops consisting of the pressure sensor 200, the controller 300, and the proportional valve 400, which are used to control the flow rate of process gas to different areas inside the vacuum furnace.

[0044] It should be further explained that, in this specific embodiment, the solution of this utility model can be extended to complex vacuum furnaces that require zoned control of gas flow. For example, in large or specially structured vacuum furnaces, it may be necessary to introduce process gas into multiple locations in the furnace chamber (such as the front zone, rear zone, upper part, and lower part), and pressure equalization is required in each zone. In this case, multiple sets of the core control loop described above can be replicated. Specifically, independent pressure sensors (B1, B2…) are installed in different zones of the vacuum furnace, and each sensor is connected to its own independent controller (C1, C2…). Each controller (C1, C2…) independently controls a corresponding proportional valve (D1, D2…) according to the above connection relationship, and each proportional valve (D1, D2…) controls a flow control valve (A1, A2…) installed on different gas inlet pipes. In this way, multiple completely independent parallel control loops with identical hardware structures are formed. Each loop independently adjusts the gas flow to the zone it is responsible for based solely on the pressure sensor signal, thereby achieving adaptive and independent pressure stabilization of different zones within the furnace.

[0045] Understandably, this modular hardware connection method makes system expansion very convenient. There is no complex signal coupling between the loops, avoiding the interference and complexity that may be caused by multi-loop control by a single controller, and greatly improving the flexibility of system control and the uniformity of zone pressure.

[0046] Specifically, a manual reset switch is connected in series in the power supply circuit of the alarm module.

[0047] It should be further explained that the circuitry of the alarm module has been further optimized in this specific embodiment. A manual reset switch (usually a normally open push-button switch) is connected in series in the power supply circuit of the alarm module, either between the positive power supply terminal and the trigger terminal of the alarm module (the series branch of the indicator light and buzzer), or between the trigger terminal and the positive terminal of the indicator light. When the system triggers an alarm, the alarm module will continuously emit an audible and visual alarm. After the operator discovers and handles the fault, they need to manually press this reset switch to cut off the power supply circuit of the alarm module, thereby turning off the indicator light, stopping the buzzer, and confirming and clearing the alarm status. After this, the alarm will only be triggered again when the controller 300 outputs an alarm signal again. It is understood that... This hardware-based manual reset switch connection provides the most direct and reliable alarm confirmation mechanism. It mandates that operators perform on-site confirmation and manual reset after an alarm, preventing potential problems from being masked by unnoticed activity or automatic reset, thus further enhancing equipment operational safety. Furthermore, as a physical component, the switch's connection is simple and clear, making it easy to implement in circuit diagrams or physical installations.

[0048] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0049] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A process gas flow adaptive voltage regulator circuit for a vacuum furnace, characterized in that, It includes a flow control valve (100), a pressure sensor (200), a controller (300), a proportional valve (400), and a power module (500). The inlet end of the flow control valve (100) is connected to the process gas source, and the outlet end is connected to the inlet of the vacuum furnace. The detection end of the pressure sensor (200) is located inside the vacuum furnace cavity, and its signal output end is connected to the pressure signal input end of the controller (300). The control signal output terminal of the controller (300) is connected to the control terminal of the proportional valve (400); The proportional valve (400) is connected in series in the control air path of the flow control valve (100), or is integrated with the flow control valve (100); The power module (500) supplies power to the controller (300), pressure sensor (200) and proportional valve (400).

2. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 1, characterized in that, The proportional valve (400) is an electric proportional valve, and its electric control terminal is connected to the control signal output terminal of the controller (300).

3. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 1, characterized in that, The controller (300) includes a signal comparison unit and a signal amplification unit; the signal comparison unit is used to receive the signal from the pressure sensor (200) and a preset pressure reference signal; the output terminal of the signal comparison unit is connected to the input terminal of the signal amplification unit, and the output terminal of the signal amplification unit constitutes the control signal output terminal of the controller (300).

4. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 1, characterized in that, The circuit also includes an alarm module; the trigger terminal of the alarm module is connected to the alarm signal output terminal of the controller (300).

5. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 2, characterized in that, The circuit also includes a communication module; the communication module is bidirectionally connected to the controller (300).

6. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 3, characterized in that, The power supply module (500) includes a first regulated branch that powers the signal comparison unit and a second regulated branch that powers the signal amplification unit. The output voltages of the first regulated branch and the second regulated branch are different.

7. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 4, characterized in that, The alarm module includes an indicator light and a buzzer connected in series.

8. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 5, characterized in that, The circuit also includes a display module, the input of which is connected to the display data output of the controller (300).

9. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 6, characterized in that, The circuit includes at least two control loops consisting of the pressure sensor (200), controller (300), and proportional valve (400), which are used to control the flow rate of process gas to different areas inside the vacuum furnace.

10. The adaptive voltage regulator circuit for process gas flow in a vacuum furnace according to claim 7, characterized in that, A manual reset switch is connected in series in the power supply circuit of the alarm module.

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