Control circuit applied to gas furnace

Abstract

The utility model relates to a control circuit applied to a gas furnace, which comprises a main control module, a knob angle sensing module and a terminal output module, and is characterized in that the knob angle sensing module is used for acquiring a knob angle signal of a knob on the gas furnace; the signal output end of the rotary knob angle sensing module is connected with the first signal input end of the main control module so that the main control module can receive the rotary knob angle signal, and the main control module is used for generating a corresponding fan control signal according to the rotary knob angle signal. The PWM signal output end of the main control module is connected with the signal input end of the terminal output module so as to control the fan control module to adjust the rotating speed and / or the air volume of the corresponding fan according to the fan control signal; the system has the advantages of being rapid in response, high in control precision and high in durability, supports flexible adjustment, remarkably improves the adaptability and expansion capacity of the system, and meets the actual requirements of rapid adjustment and fine adjustment.

Description

Technical Field

[0001] The utility model relates to the technical field of gas furnace valve control circuits, in particular to a control circuit applied to gas furnaces. Background Art

[0002] Currently, traditional gas furnace control systems rely primarily on mechanical knobs and physical adjustments. This mechanical control method suffers from slow response and low precision, making precise control particularly difficult during rapid or subtle adjustments. Mechanical component wear during use further reduces control accuracy, and looseness or lag caused by mechanical wear can easily lead to unstable adjustments and misoperation. Furthermore, the mechanical control design struggles to adapt to different operating modes and lacks flexible adjustment options, limiting the system's adaptability and scalability. Consequently, it exhibits significant limitations under changing usage requirements. Utility Model Content

[0003] In order to solve the problems of slow response, low precision, easy wear and lack of flexibility of mechanical adjustment methods in traditional gas furnace control systems, the present application provides a control circuit for a gas furnace.

[0004] A control circuit for a gas furnace, comprising a main control module, a knob angle sensing module and a terminal output module, wherein the knob angle sensing module is used to collect a knob angle signal of a knob on the gas furnace, the signal output end of the knob angle sensing module is connected to the first signal input end of the main control module so that the main control module receives the knob angle signal, the main control module is used to generate a corresponding fan control signal according to the knob angle signal, the PWM signal output end of the main control module is connected to the signal input end of the terminal output module to control the fan control module to adjust the speed and / or air volume of the corresponding fan according to the fan control signal.

[0005] By adopting this technical solution, the knob angle sensing module can collect knob angle signals in real time and accurately transmit them to the main control module. The main control module generates corresponding fan control signals based on the received signals. Through the PWM signal output terminal connected to the terminal output module, precise control of fan speed and air volume is achieved. This circuit design abandons the limitations of traditional mechanical components and offers the advantages of fast response, high control accuracy, and strong durability. It also supports flexible adjustment and can adapt to changing operating modes, significantly improving the system's adaptability and scalability, meeting the actual needs of rapid adjustment and subtle adjustments.

[0006] Preferably, the knob angle sensing module includes six sensing units, each of which includes at least one sensing chip and a pull-up resistor. The sensing chip is used to sense the knob angle signal. The signal output end of the sensing chip is connected to the first signal input end of the main control module, the power input end of the sensing chip is connected to the power supply, and the pull-up resistor is connected between the common node between the signal output end of the sensing chip and the first signal input end of the main control module and the power supply.

[0007] By adopting the above technical solution, the six sensing units in the knob angle sensing module can be used to collaborate, and the knob angle signal can be accurately collected by utilizing the cooperation of the sensing chip and the pull-up resistor. The anti-interference ability and stability of the signal can be enhanced by configuring the pull-up resistor, thereby improving the reliability and accuracy of the knob angle collection and ensuring the accuracy of the system control.

[0008] Preferably, the terminal output module includes a connection terminal CN1 and a resistor R4, the PWM signal input end of the connection terminal CN1 is connected to the first end of the resistor R4, and the second end of the resistor R4 is connected to the PWM signal output end of the main control module.

[0009] By adopting the above technical solution, the PWM signal generated by the main control module can be stably transmitted through the terminal CN1 and resistor R4 in the terminal output module, and the current can be limited by resistor R4 to prevent overload or current fluctuations during signal transmission from affecting system operation, thereby improving the stability of control signal transmission and the reliability of fan regulation.

[0010] Preferably, a resistor R2 is connected between the switch signal output end of the connection terminal CN1 and the switch signal input end of the main control module, and a capacitor C6 is connected between the common node between the resistor R2 and the switch signal input end of the main control module and the ground.

[0011] By adopting the above technical solution, resistor R2 and capacitor C6 can be set between the switch signal output end of terminal CN1 and the switch signal input end of the main control module, effectively suppressing noise and high-frequency interference in the circuit, while improving the stability and accuracy of the switch signal, thereby ensuring the precise execution of the gas furnace control logic and the reliability of the system.

[0012] Preferably, the main control module includes a main control chip, and the chip model of the main control chip is SOP16.

[0013] By adopting the above technical solution, it is possible to provide more interfaces and higher integration by using the SOP16 model main control module chip, facilitate system expansion and modular design, and thus improve the functional richness and reliability of the gas furnace valve control circuit.

[0014] Preferably, the control circuit applied to the gas furnace further includes a read-write module, the read-write module includes a read-write terminal SL, and a data communication end of the read-write terminal SL is connected to a data communication end of the main control module.

[0015] By adopting the above technical solution, the read-write terminal SL in the read-write module can be connected to the data communication terminal of the main control module to realize two-way transmission and storage management of control data, thereby improving the system's programmability and flexible data processing capabilities, and enhancing the intelligence level of the gas furnace control circuit.

[0016] Preferably, the control circuit further includes a switching power supply module, which includes a power supply element VCC and a three-terminal voltage regulator U1. The first end of the power supply element VCC outputs a 12V voltage for power supply and is connected to the first end of the resistor R1. The second end of the resistor R1 is connected to the power input end of the three-terminal voltage regulator U1. The power output end of the three-terminal voltage regulator U1 outputs a 5V voltage for power supply. The third end of the three-terminal voltage regulator U1 is grounded.

[0017] By adopting the above technical solution, the 12V voltage can be stably converted into 5V power supply through the combination of the power supply element VCC and the three-terminal voltage regulator U1 in the switching power supply module, ensuring that the main control module and other sub-modules operate in a stable voltage environment, thereby improving the stability of system operation and the compatibility of various modules.

[0018] Preferably, a resistor R1 and a resistor R3 are connected between the power supply element VCC and the three-terminal regulator U1 respectively.

[0019] By adopting the above technical solution, current fluctuations are effectively limited and voltage is divided, avoiding the impact on the voltage regulator and subsequent circuits caused by excessive current at the power input end, thereby improving the safety and reliability of the system power supply.

[0020] Preferably, a capacitor C1 and a capacitor C2 are connected between a common node between the resistor R1 and the resistor R3 and the ground, respectively.

[0021] By adopting the above technical solution, high-frequency interference at the power input end is filtered out and the power supply voltage is smoothed, thereby improving the stability of the system power supply and ensuring the reliability of subsequent circuit operation.

[0022] Preferably, there are capacitors C3 and C4 between the power output terminal of the three-terminal voltage regulator U1 and the ground respectively.

[0023] By adopting the above technical solution, high-frequency interference at the power input end is filtered out and the power supply voltage is smoothed, thereby improving the stability of the system power supply and ensuring the reliability of subsequent circuit operation.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. The gas furnace valve control circuit effectively solves the problems of slow response, low precision, unstable adjustment and misoperation caused by mechanical wear in traditional mechanical control methods through the coordinated cooperation of the main control module, the knob angle sensing module and the terminal output module. The knob angle sensing module can collect the knob angle signal in real time and accurately transmit it to the main control module. The main control module generates the corresponding fan control signal according to the received signal, and connects the terminal output module through the PWM signal output end to achieve precise control of the fan speed and air volume. This circuit design abandons the limitations of traditional mechanical components and has the advantages of fast response, high control accuracy and strong durability. At the same time, it supports flexible adjustment and can adapt to changing working modes, significantly improving the adaptability and scalability of the system and meeting the actual needs of fast adjustment and fine adjustment.

[0026] 2. The gas furnace valve control circuit uses a new fan, whose built-in MOS tube design greatly simplifies the complexity of the control circuit. Compared with the traditional method that requires the MOS tube in the circuit to directly drive the fan, the new fan only needs to provide a PWM signal to achieve control. The knob angle signal is collected by the knob angle sensing module, and the PWM signal generated by the main control module can directly drive the fan's built-in MOS tube, thereby adjusting the fan's speed and air volume. This design not only reduces the number of components in the circuit and the complexity of circuit design and manufacturing, but also improves the reliability of the system. At the same time, by directly transmitting the PWM signal, more efficient and precise control is achieved, further optimizing the operation of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of a control circuit applied to a gas furnace in one embodiment of the present application.

[0028] Figure 2 This is a schematic diagram of a partial circuit structure of one sensing unit of a knob angle sensing module in a control circuit of a gas stove in one embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of a partial circuit structure of a main control module in a control circuit applied to a gas furnace in one embodiment of the present application;

[0030] Figure 4 This is a schematic diagram of a partial circuit structure of a terminal output module in a control circuit applied to a gas furnace in one embodiment of the present application;

[0031] Figure 5 This is a schematic diagram of a partial circuit structure of a read-write module in a control circuit applied to a gas furnace in one embodiment of the present application;

[0032] Figure 6 This is a schematic diagram of a partial circuit structure of a switching power supply module in a control circuit applied to a gas furnace in one embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application is further described in detail below with reference to the accompanying drawings.

[0034] like Figure 1 As shown, a control circuit for a gas furnace includes a main control module, a knob angle sensing module, and a terminal output module. The knob angle sensing module is used to collect a knob angle signal of a knob on the gas furnace. The signal output end of the knob angle sensing module is connected to the first signal input end of the main control module so that the main control module receives the knob angle signal. The main control module is used to generate a corresponding fan control signal according to the knob angle signal. The PWM signal output end of the main control module is connected to the signal input end of the terminal output module to control the fan control module to adjust the speed and / or air volume of the corresponding fan according to the fan control signal.

[0035] In this embodiment, the connection logic and control logic of each module in the gas furnace valve control circuit are clear and specific. The knob angle sensing module is responsible for collecting the knob angle signal of the gas furnace knob and connects its signal output terminal to the first signal input terminal of the main control module, thereby transmitting the collected angle signal to the main control module. After receiving the knob angle signal, the main control module generates a corresponding fan control signal based on this signal. The generated control signal is transmitted to the signal input terminal of the terminal output module via the main control module's PWM signal output terminal, and the terminal output module ultimately transmits the fan control signal to the fan control module. The fan control module adjusts the fan speed and air volume based on the received fan control signal to achieve a dynamic control effect that matches the knob angle signal. In the entire logic, the knob angle signal serves as the initial trigger information, passing through the knob angle sensing module to the main control module for signal processing, and then output to the terminal output module in PWM form, ultimately adjusting the fan speed and air volume of the fan control module.

[0036] To sum up, the knob angle signal can be transmitted to the main control module through the knob angle sensing module. The main control module generates a PWM fan control signal according to the received signal and transmits it to the fan control module through the terminal output module, thereby realizing intelligent adjustment of the fan speed and air volume, ensuring that the gas furnace firepower matches the air volume, and improving the system's response speed and adjustment accuracy.

[0037] Further, such as Figure 2As shown, the knob angle sensing module includes six sensing units, each of which includes at least one sensing chip and a pull-up resistor. The sensing chip is used to sense the knob angle signal. The signal output end of the sensing chip is connected to the first signal input end of the main control module, the power input end of the sensing chip is connected to the power supply, and the pull-up resistor is connected between the common node between the signal output end of the sensing chip and the first signal input end of the main control module and the power supply.

[0038] In this embodiment, the knob angle sensing module contains six sensing units, each of which is composed of at least one sensing chip and a pull-up resistor, and their connection relationship and logic are very clear. The main function of the sensing chip is to sense the knob angle signal, which is transmitted to the first signal input terminal of the main control module through the signal output terminal of the sensing chip to realize signal transmission. The power input terminal of the sensing chip is directly connected to the power supply to ensure its normal operation. A pull-up resistor is connected to the common node between the signal output terminal of the sensing chip and the first signal input terminal of the main control module. One end of the pull-up resistor is connected to the common node and the other end is connected to the power supply. The function of the pull-up resistor is to provide a stable high-level state when the signal line is not driven, preventing the signal line from floating and causing uncertainty, thereby ensuring the stability of the output signal of the sensing chip. The entire module accurately obtains the angle signal of the knob through the sensing chip, and transmits the signal to the main control module after being stabilized by the pull-up resistor, thereby providing a reliable input signal for the subsequent control logic.

[0039] In summary, through the collaboration of the six sensing units in the knob angle sensing module, the knob angle signal can be accurately collected by utilizing the cooperation of the sensing chip and the pull-up resistor, and the anti-interference ability and stability of the signal can be enhanced through the configuration of the pull-up resistor, thereby improving the reliability and accuracy of the knob angle acquisition and ensuring the accuracy of the system control.

[0040] Further, such as Figure 3-4 As shown, the terminal output module includes a connection terminal CN1 and a resistor R4, the PWM signal input end of the connection terminal CN1 is connected to the first end of the resistor R4, and the second end of the resistor R4 is connected to the PWM signal output end of the main control module.

[0041] In this embodiment, in the internal connection of the terminal output module, the wiring terminal CN1 and the resistor R4 together constitute the core path of signal transmission, and the logic is clear. The PWM signal input end of the wiring terminal CN1 is connected to the first end of the resistor R4, forming an interface for the PWM signal to enter the terminal output module. The second end of the resistor R4 is connected to the PWM signal output end of the main control module, and is used to receive the PWM signal generated by the main control module. In this connection, the resistor R4 plays the role of limiting the current and signal matching, ensuring that the signal remains stable during the transmission process and matches the input requirements of the wiring terminal CN1. Through this connection, the PWM signal generated by the main control module can be stably transmitted through the resistor R4 and smoothly enter the wiring terminal CN1, ultimately realizing the drive control of the downstream load and ensuring the integrity and reliability of the control logic.

[0042] In summary, the PWM signal generated by the main control module can be stably transmitted through the terminal CN1 and resistor R4 in the terminal output module, and the current is limited by resistor R4 to prevent overload or current fluctuations during signal transmission from affecting system operation, thereby improving the stability of control signal transmission and the reliability of fan regulation.

[0043] Further, such as Figure 3-4 As shown, a resistor R2 is connected between the switch signal output end of the connection terminal CN1 and the switch signal input end of the main control module, and a capacitor C6 is connected between the common node between the resistor R2 and the switch signal input end of the main control module and the ground.

[0044] In this embodiment, in this connection logic, the switch signal output end of the terminal CN1 is connected to the switch signal input end of the main control module through the resistor R2, forming the main path for the switch signal transmission. The function of the resistor R2 is to limit the signal current to prevent excessive current from affecting the subsequent main control module input end, and at the same time play a certain protective role in the stability of the signal. At the common node between the resistor R2 and the switch signal input end of the main control module, a capacitor C6 is connected to the ground. The function of the capacitor C6 is to decouple and filter the signal node, effectively suppressing high-frequency noise in the signal, and ensuring that the signal received by the switch signal input end is clean and stable. This connection method enables the switch signal of the terminal CN1 to be stably transmitted to the switch signal input end of the main control module after being adjusted by the resistor R2 and filtered by the capacitor C6, thereby improving the reliability and anti-interference ability of the signal transmission and providing a guarantee for the stable control of the system.

[0045] In summary, resistor R2 and capacitor C6 can be set between the switch signal output end of terminal CN1 and the switch signal input end of the main control module to effectively suppress noise and high-frequency interference in the circuit, while improving the stability and accuracy of the switch signal, thereby ensuring the precise execution of the gas furnace control logic and the reliability of the system.

[0046] Further, such as Figure 3 As shown, the main control module includes a main control chip, and the chip model of the main control chip is SOP16.

[0047] In the present embodiment, in this system, the core chip model of main control module is SOP16, provides multi-pin interface to support complicated signal processing and control tasks.The switch signal output end of terminal block CN1 is connected with the switch signal input end of main control module by resistance R2, and resistance R2 bears the limiting effect of signal current in this connection, protects the input end of main control module from the impact of excessive current, and simultaneously carries out preliminary stable regulation to signal.At the common node between resistance R2 and main control module switch signal input end, capacitor C6 is connected between ground, capacitor C6 realizes the suppression of high-frequency noise and the decoupling of signal at this node, so as to further improve signal quality, ensure that main control module can receive clean switch signal.Main control module carries out accurate parsing to the switch signal received by its internal SOP16 chip, and completes the generation of logical operation and control instruction in conjunction with other input signals, finally drives the operation of other modules in system, ensures the efficiency and stability of whole circuit logic.

[0048] In summary, by adopting the SOP16 model main control module chip, more interfaces and higher integration can be provided, which facilitates system expansion and modular design, thereby improving the functional richness and reliability of the gas furnace valve control circuit.

[0049] Further, such as Figure 5 As shown, the control circuit applied to the gas furnace further includes a read-write module, and the read-write module includes a read-write terminal SL, and a data communication end of the read-write terminal SL is connected to a data communication end of the main control module.

[0050] In this embodiment, a read-write module is also introduced into the control circuit of the gas furnace valve, further expanding the data interaction capability of the system. The core component of the read-write module is the read-write terminal SL, whose data communication terminal is directly connected to the data communication terminal of the main control module. This connection method provides a high-speed channel for data interaction between the two. In actual operation, the read-write module implements read and write operations on external data through the read-write terminal SL, and transmits this data to the main control module through the data communication terminal. The main control module uses its internal logical processing capabilities and storage functions to parse, store, or further process the received data to meet the dynamic control requirements of the system. This connection relationship between modules enhances the control circuit's ability to obtain and adjust dynamic parameters in real time, provides the system with flexible control logic and expansion support, and ensures that the gas furnace can operate efficiently and safely in different operating modes.

[0051] To sum up, the read-write terminal SL in the read-write module can be connected to the data communication terminal of the main control module to realize two-way transmission and storage management of control data, thereby improving the system's programmability and flexible data processing capabilities, and enhancing the intelligence level of the gas furnace control circuit.

[0052] Further, such as Figure 6 As shown, the control circuit also includes a switching power supply module, which includes a power supply element VCC and a three-terminal voltage regulator U1. The first end of the power supply element VCC outputs a 12V voltage for power supply and is connected to the first end of the resistor R1. The second end of the resistor R1 is connected to the power input end of the three-terminal voltage regulator U1. The power output end of the three-terminal voltage regulator U1 outputs a 5V voltage for power supply. The third end of the three-terminal voltage regulator U1 is grounded.

[0053] In this embodiment, a switching power supply module is incorporated into the control circuit to provide stable power supply support for the system. The switching power supply module primarily comprises a power supply element VCC and a three-terminal voltage regulator U1. The first terminal of the power supply element VCC is responsible for outputting a 12V voltage, which is connected to the first terminal of resistor R1 to power downstream circuits. The second terminal of resistor R1 is connected to the power input terminal of the three-terminal voltage regulator U1. Resistor R1 functions here to initially limit and regulate the current, protecting the input terminal of the three-terminal voltage regulator U1 from excessive current surges. The three-terminal voltage regulator U1, through its internal voltage stabilization circuit, stably converts the input 12V voltage to 5V and outputs it from its power output terminal, providing a reliable 5V voltage for components in the system that require low-voltage power. Furthermore, the third terminal of the three-terminal voltage regulator U1 is grounded, forming a complete current loop and stabilizing the potential. Through this circuit connection logic, the high-voltage output of the power supply element VCC, after being regulated by the three-terminal voltage regulator U1, can provide multi-level voltage support for the system, meeting the voltage requirements of different components while ensuring the safety and stability of the power supply.

[0054] In summary, the combination of the power supply element VCC in the switching power supply module and the three-terminal voltage regulator U1 can stably convert the 12V voltage into a 5V power supply, ensuring that the main control module and other sub-modules operate in a stable voltage environment, thereby improving the stability of system operation and the compatibility of various modules.

[0055] Further, such as Figure 6 As shown, a resistor R1 and a resistor R3 are connected between the power supply element VCC and the three-terminal regulator U1 respectively.

[0056] In this embodiment, in the switching power supply module of the control circuit, resistors R1 and R3 are connected in series between the power supply element VCC and the three-terminal voltage regulator U1, respectively. This design further optimizes the circuit's current regulation and signal stabilization functions. The first terminal of the power supply element VCC outputs a 12V voltage, and through the series connection of resistors R1 and R3, the input current flowing to the three-terminal voltage regulator U1 is regulated and limited, respectively. This effectively protects the power input terminal of the three-terminal voltage regulator U1 from current surges while providing distributed management of the power supply current. The first terminal of resistor R1 is directly connected to the first terminal of the power supply element VCC, and its second terminal is connected to the first terminal of resistor R3. The second terminal of resistor R3 is directly connected to the power input terminal of the three-terminal voltage regulator U1. In this series configuration, resistors R1 and R3 together form a current divider network, which ensures the smooth transmission of the power input current by refining the current regulation. The power output terminal of three-terminal voltage regulator U1 regulates the input 12V voltage to a 5V output, providing power support for modules requiring low-voltage power. Its third terminal is grounded to ensure a stable potential across the entire circuit. This distributed current regulation and voltage stabilization design protects the input terminal of three-terminal voltage regulator U1 while improving the stability and safety of the entire circuit.

[0057] In summary, effectively limiting current fluctuations and dividing the voltage can prevent the voltage regulator and subsequent circuits from being impacted by excessive current at the power input, thereby improving the safety and reliability of the system power supply.

[0058] Further, such as Figure 6 As shown, capacitors C1 and C2 are connected between the common node between the resistor R1 and the resistor R3 and the ground, respectively.

[0059] In this embodiment, in the switching power supply module of the control circuit, capacitors C1 and C2 are connected between the common node between resistors R1 and R3 and ground, respectively. This connection structure further enhances the circuit's anti-interference capability and signal stability. The first end of resistor R1 is connected to the first end of the power supply element VCC, and the second end of resistor R1 is connected to the first end of resistor R3, forming a series connection. The second end of resistor R3 is connected to the power input of the three-terminal voltage regulator U1. The common node in this structure is connected to ground via capacitors C1 and C2, respectively. Capacitors C1 and C2 filter and decouple the voltage signal at this node, effectively suppressing high-frequency noise transmitted from the power supply element VCC to this node while stabilizing the voltage value of the input signal. This filtering design eliminates fluctuations and spikes in the input voltage, providing a smoother input signal for the three-terminal voltage regulator U1, improving the accuracy of the regulated output and the reliability of the system. Through this optimized configuration, the circuit not only has stronger anti-interference capabilities, but also ensures the stable operation of the power supply system in complex electromagnetic environments, providing high-quality power support for subsequent modules.

[0060] In summary, it is used to filter out high-frequency interference at the power input end and smooth the power supply voltage, thereby improving the stability of the system power supply and ensuring the reliability of subsequent circuit operation.

[0061] Further, such as Figure 6 As shown, there are capacitors C3 and C4 between the power output terminal of the three-terminal regulator U1 and the ground respectively.

[0062] In this embodiment, in the switching power supply module of the control circuit, capacitors C3 and C4 are connected between the power output terminal of the three-terminal voltage regulator U1 and the ground, respectively. This design further enhances the stability and anti-interference capability of the output voltage. The power input terminal of the three-terminal voltage regulator U1 receives a 12V voltage from the power supply element VCC through resistors R1 and R3 connected in series, converts the voltage to 5V, and then outputs it from the power output terminal. Capacitors C3 and C4 between the power output terminal and the ground serve as filtering and decoupling. Capacitor C3 is used to quickly respond to voltage fluctuations and filter out high-frequency noise, while capacitor C4 further smoothes the output voltage, reduces ripple interference, and ensures the stability and reliability of the regulated output. This dual-capacitor configuration not only improves the adaptability of the regulated output to dynamic loads, but also effectively suppresses electromagnetic interference in complex operating environments, thereby providing a purer and more stable power supply for subsequent modules requiring 5V power, further enhancing the performance and reliability of the entire control circuit.

[0063] In summary, it is used to filter out high-frequency interference at the power input end and smooth the power supply voltage, thereby improving the stability of the system power supply and ensuring the reliability of subsequent circuit operation.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A control circuit for a gas furnace, characterized in that: The control circuit applied to a gas furnace includes a main control module, a knob angle sensing module and a terminal output module. The knob angle sensing module is used to collect the knob angle signal of the knob on the gas furnace. The signal output end of the knob angle sensing module is connected to the first signal input end of the main control module so that the main control module receives the knob angle signal. The main control module is used to generate a corresponding fan control signal according to the knob angle signal. The PWM signal output end of the main control module is connected to the signal input end of the terminal output module to control the fan control module to adjust the speed and / or air volume of the corresponding fan according to the fan control signal.

2. The control circuit for a gas furnace according to claim 1, characterized in that: The knob angle sensing module includes a maximum of six sensing units, each of which includes at least one sensing chip and a pull-up resistor. The sensing chip is used to sense the knob angle signal. The signal output end of the sensing chip is connected to the first signal input end of the main control module, and the power input end of the sensing chip is connected to the power supply. The pull-up resistor is connected between the common node between the signal output end of the sensing chip and the first signal input end of the main control module and the power supply.

3. The control circuit for a gas furnace according to claim 1, characterized in that: The terminal output module includes a connection terminal CN1 and a resistor R4 , a PWM signal input end of the connection terminal CN1 is connected to a first end of the resistor R4 , and a second end of the resistor R4 is connected to a PWM signal output end of the main control module.

4. The control circuit for a gas furnace according to claim 3, characterized in that: A resistor R2 is connected between the switch signal output end of the connection terminal CN1 and the switch signal input end of the main control module. A capacitor C6 is connected between a common node between the resistor R2 and the switch signal input end of the main control module and the ground.

5. The control circuit for a gas furnace according to claim 1, characterized in that: The main control module includes a main control chip, and the chip model of the main control chip is SOP16.

6. The control circuit for a gas furnace according to claim 5, characterized in that: The control circuit applied to the gas furnace further includes a read-write module, and the read-write module includes a read-write terminal SL. The data communication end of the read-write terminal SL is connected to the data communication end of the main control module.

7. The control circuit for a gas furnace according to claim 1, characterized in that: The control circuit also includes a switching power supply module, which includes a power supply element VCC and a three-terminal voltage regulator U1. The first end of the power supply element VCC outputs a 12V voltage for power supply and is connected to the first end of the resistor R1. The second end of the resistor R1 is connected to the power input end of the three-terminal voltage regulator U1. The power output end of the three-terminal voltage regulator U1 outputs a 5V voltage for power supply. The third end of the three-terminal voltage regulator U1 is grounded.

8. The control circuit for a gas furnace according to claim 7, characterized in that: Resistors R1 and R3 are connected between the power supply element VCC and the three-terminal voltage regulator U1 respectively.

9. The control circuit for a gas furnace according to claim 7, characterized in that: A capacitor C1 and a capacitor C2 are connected between a common node between the resistor R1 and the resistor R3 and the ground, respectively.

10. The control circuit for a gas furnace according to claim 7, characterized in that: There are capacitors C3 and C4 between the power output terminal of the three-terminal voltage regulator U1 and the ground respectively.

Images