Warm air blower control circuit

Abstract

A fan heater control circuit relates to the technical field of dehumidifiers and comprises a load circuit used for driving a load; the control circuit is connected with the load circuit and is used for sending a control signal to the load circuit; the feedback circuit is connected with the control circuit and used for monitoring the working state of the load circuit and feeding back the working state to the control circuit; and the power supply circuit is respectively connected with the control circuit and the feedback circuit and is used for providing a first direct-current power supply for the load circuit and providing a second direct-current power supply for the control circuit. The embodiment of the utility model adopts an independent power supply design, the first direct-current power supply is provided for the load circuit, and the second direct-current power supply is provided for the control circuit; in addition, the feedback circuit can feed back the working state of the load to the control circuit in time, accurate adjustment and abnormal protection are achieved, and therefore the using effect and reliability of the warm air blower are improved.

Description

Technical Field

[0001] This utility model relates to the field of heater technology, specifically to a heater control circuit. Background Technology

[0002] As an integrated fan device, the warm air heater is widely used in winter heating through the combination of fan and heating element. With the improvement of living standards, people's demand for warm air heaters is constantly increasing, and their types and functions are gradually becoming more diverse.

[0003] However, existing warm air heaters typically use a single control method, which cannot adjust the status of the fan and heating element, affecting the performance. At the same time, the lack of monitoring and feedback on the working status can easily lead to overheating or abnormal operation, reducing the reliability of the equipment. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings and deficiencies of the existing technology by providing a heater control circuit, including:

[0005] Load circuit, used to drive the load;

[0006] A control circuit, connected to the load circuit, is used to send control signals to the load circuit;

[0007] A feedback circuit, connected to the control circuit, is used to monitor the operating state of the load circuit and feed back the operating state to the control circuit; and

[0008] The power supply circuit is connected to the control circuit and the feedback circuit respectively, and is used to provide a first DC power supply (+12V) to the load circuit and a second DC power supply (5V) to the control circuit.

[0009] Furthermore, the load circuit includes a first heating circuit, a second heating circuit, and a fan drive circuit. The control terminal of the control circuit is connected to the controlled terminal of the first heating circuit, the controlled terminal of the second heating circuit, and the controlled terminal of the fan drive circuit, respectively. The circuit structures of the first heating circuit and the second heating circuit are the same.

[0010] Furthermore, the first heating circuit includes a first resistor R16, a second resistor R17, a first switching transistor Q2, a second switching transistor D4, and a relay REL1. The first switching transistor Q2 is an NPN transistor, and the second switching transistor D4 is a diode. The base of the first switching transistor Q2 is connected to the control terminal of the control circuit through the first resistor R16, and is connected to the emitter and ground terminal of the first switching transistor Q2 through the second resistor R17. The collector of the first switching transistor Q2 is connected to the third terminal of the relay REL1, and is connected to the fourth terminal of the relay REL1 and the first DC power supply (+12V) through the second switching transistor D4. The collector of the first switching transistor Q2 is connected to the anode of the second switching transistor D4. The first terminal of the relay REL1 is connected to the live wire, and the second terminal of the relay REL1 is connected to the heating device.

[0011] Furthermore, the fan drive circuit includes a third resistor R14, a fourth resistor R15, a third switch Q1, and a fourth switch D3. The third switch Q1 is an NPN transistor, and the fourth switch D3 is a diode. The base of the third switch Q1 is connected to the control terminal of the control circuit through the third resistor R14, and is connected to the emitter and ground terminal of the third switch Q1 through the fourth resistor R15. The collector of the third switch Q1 is connected to the first DC power supply (+12V) through the fourth switch D3. The anode of the fourth switch D3 is connected to the collector of the third switch Q1. The fan interface is connected in parallel with the fourth switch D3.

[0012] Furthermore, the feedback circuit includes a thermistor interface NTC, a fifth resistor R13, and a first capacitor C5. The control terminal of the control circuit is connected to the second DC power supply (5V) through the fifth resistor R13, and is connected to the first terminal and the ground terminal of the thermistor interface NTC through the first capacitor C5. The second terminal of the thermistor interface NTC is connected to the control terminal of the control circuit.

[0013] Furthermore, it also includes a display circuit, which includes at least a fifth resistor R4 and a first light-emitting switch LED1. The control terminal of the control circuit is connected to the anode of the first light-emitting switch LED1 through the fifth resistor R4, and the cathode of the first light-emitting switch LED1 is grounded.

[0014] Furthermore, the power supply circuit includes an input protection module, a rectification module, a control module, a voltage regulator module, a first output module, and a second output module, which are connected sequentially.

[0015] Furthermore, it also includes a switching circuit and a timing circuit. The control terminal of the control circuit is connected to the switching circuit and the timing circuit respectively. The switching circuit is used to send a start / stop signal to the control circuit, and the timing circuit is used to send a timing signal to the control circuit.

[0016] On the other hand, this utility model also provides a heating fan, including a heating fan control circuit as described above.

[0017] This utility model embodiment adopts an independent power supply design, providing a first DC power supply (+12V) for the load circuit and a second DC power supply (5V) for the control circuit, avoiding control failure caused by unstable power supply. In addition, the feedback circuit can promptly feed back the working status of the load to the control circuit, realizing precise adjustment and abnormal protection, thereby improving the use effect and reliability of the heater. Attached Figure Description

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 This is a structural block diagram of the first embodiment of the present utility model;

[0020] Figure 2 This is a structural block diagram of the second embodiment of the present utility model;

[0021] Figure 3 This is the circuit diagram of the power supply circuit;

[0022] Figure 4 It is a circuit diagram of the control circuit;

[0023] Figure 5 This is a circuit diagram of the first heating circuit and the second heating circuit;

[0024] Figure 6 It is a circuit diagram of a switching circuit, a timing circuit, and a buzzer circuit;

[0025] Figure 7 This is the circuit diagram of the feedback circuit;

[0026] Figure 8 This is a circuit diagram of a fan drive circuit.

[0027] Figure 9 This is the circuit diagram of the display circuit.

[0028] Figure label:

[0029] 100. Control circuit; 200. Power supply circuit; 210. Input protection module; 220. Rectifier module; 230. Control module; 240. Voltage regulator module; 250. First output module; 300. Load circuit; 310. First heating circuit; 320. Second heating circuit; 330. Fan drive circuit; 400. Feedback circuit; 500. Display circuit; 600. Timing circuit; 700. Switching circuit. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings.

[0031] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive element, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to indicate that selected embodiments of the present invention are based on the embodiments of the present invention, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0034] First embodiment:

[0035] Reference Figure 1 This utility model provides a heater control circuit, including a load circuit 300 for driving the load;

[0036] The control circuit 100 is connected to the load circuit 300 and is used to send control signals to the load circuit 300.

[0037] A feedback circuit 400, connected to the control circuit 100, is used to monitor the operating status of the load circuit 300 and feed back the operating status to the control circuit 100; and

[0038] The power supply circuit 200 is connected to the control circuit 100 and the feedback circuit 400 respectively, and is used to provide a first DC power supply (+12V) to the load circuit 300 and a second DC power supply (5V) to the control circuit 100.

[0039] This utility model embodiment adopts an independent power supply design, providing a first DC power supply (+12V) for the load circuit and a second DC power supply (5V) for the control circuit, avoiding control failure caused by unstable power supply. In addition, the feedback circuit can promptly feed back the working status of the load to the control circuit, realizing precise adjustment and abnormal protection, thereby improving the use effect and reliability of the heater.

[0040] Second embodiment:

[0041] Reference Figure 2-9 Optionally, the load circuit 300 includes a first heating circuit 310, a second heating circuit 320, and a fan drive circuit 330. The control terminal of the control circuit 100 is respectively connected to the controlled terminal of the first heating circuit 310, the controlled terminal of the second heating circuit 320, and the controlled terminal of the fan drive circuit 330.

[0042] Furthermore, the first heating circuit 310 includes a first resistor R16, a second resistor R17, a first switching transistor Q2, a second switching transistor D4, and a relay REL1. The first switching transistor Q2 is an NPN transistor, and the second switching transistor D4 is a diode. The base of the first switching transistor Q2 is connected to the control terminal of the control circuit 100 through the first resistor R16, and is connected to the emitter and ground terminal of the first switching transistor Q2 through the second resistor R17. The collector of the first switching transistor Q2 is connected to the third terminal of the relay REL1, and is connected to the fourth terminal of the relay REL1 and the first DC power supply (+12V) through the second switching transistor D4. The collector of the first switching transistor Q2 is connected to the anode of the second switching transistor D4. The first terminal of the relay REL1 is connected to the live wire, and the second terminal of the relay REL1 is connected to the heating device.

[0043] It should be noted that, referring to Figure 5 The circuit structures of the first heating circuit 310 and the second heating circuit 320 are the same. Relevant practitioners can refer to the first heating circuit 310 to complete the second heating circuit 320, so it will not be described in detail.

[0044] Specifically, in the first heating circuit 310, the control circuit applies a control signal to the base of the first switching transistor Q2 through the first resistor R16 and the second resistor R17, causing it to turn on or off. When Q2 is on, the relay REL1 in its collector circuit is energized, and the live wire connected to the relay is connected to the heating device, thereby realizing the heating function. Diode D4 is used to prevent damage to transistor Q2 when the relay coil releases the induced electromotive force.

[0045] It should also be noted that, referring to Figure 5 In the first heating circuit 310, the base of the first switching transistor Q2 is connected to the control terminal of the control circuit 100 through the first resistor R16. This control terminal is the HEAT1 pin in the figure. Similarly, the second heating circuit 320 is connected to the control circuit 100, and its control terminal is the HEAT2 pin in the figure.

[0046] This embodiment employs independent first and second heating circuits, and utilizes a control circuit to precisely regulate each heating module, ensuring the flexibility and reliability of the heater's heating function. At the same time, the coordination between the relay and the protection circuit significantly improves the circuit's safety.

[0047] Furthermore, refer to Figure 8 The fan drive circuit 330 includes a third resistor R14, a fourth resistor R15, a third switch Q1, and a fourth switch D3. The third switch Q1 is an NPN transistor, and the fourth switch D3 is a diode. The base of the third switch Q1 is connected to the control terminal of the control circuit 100 through the third resistor R14, and is connected to the emitter and ground terminal of the third switch Q1 through the fourth resistor R15. The collector of the third switch Q1 is connected to the first DC power supply (+12V) through the fourth switch D3. The anode of the fourth switch D3 is connected to the collector of the third switch Q1. The fan interface is connected in parallel with the fourth switch D3.

[0048] Specifically, the control terminal of the control circuit 100 applies a control signal to the base of the third switch Q1 through the third resistor R14. When the base current of Q1 is sufficient, Q1 is turned on, and its collector forms a path, connecting to the parallel fan interface and the load circuit of the fourth switch D3, thereby driving the fan to run. D3 acts as a protective element to absorb the reverse current generated during fan operation, preventing damage to transistor Q1 due to current transients. The fourth resistor R15 is used to stabilize the base current of Q1 and reduce circuit noise.

[0049] This embodiment ensures the stability and safety of the fan drive by using an independent fan drive circuit, combined with the protection design of transistors and diodes, avoiding damage from overcurrent or reverse current, while improving the reliability and lifespan of the heater fan.

[0050] In some embodiments, reference Figure 7 The feedback circuit 400 includes a thermistor interface NTC, a fifth resistor R13, and a first capacitor C5. The control terminal of the control circuit 100 is connected to the second DC power supply (5V) through the fifth resistor R13, and is connected to the first terminal and the ground terminal of the thermistor interface NTC through the first capacitor C5. The second terminal of the thermistor interface NTC is connected to the control terminal of the control circuit 100.

[0051] Specifically, the resistance of the thermistor NTC changes with temperature, forming a temperature-dependent voltage signal. This signal is transmitted to the control terminal of the control circuit through the fifth resistor R13 for analysis and processing. The first capacitor C5 is used to filter out high-frequency interference in the circuit, ensuring the stability and accuracy of the signal. In addition, the fifth resistor R13 acts as a current limiter and a voltage divider, protecting the control circuit from overcurrent.

[0052] This embodiment combines a thermistor (NTC) with a capacitor and a resistor, enabling real-time monitoring of the heater's operating temperature via a feedback circuit. This ensures the equipment's safety and operational stability, while also improving temperature control accuracy, which helps extend the equipment's lifespan and enhance the user experience.

[0053] In some embodiments, a display circuit 500 is also included, which includes at least a fifth resistor R4 and a first light-emitting switch LED1. The control terminal of the control circuit 100 is connected to the anode of the first light-emitting switch LED1 through the fifth resistor R4, and the cathode of the first light-emitting switch LED1 is grounded.

[0054] Specifically, the display circuit 500 implements the status indication function through the control terminal of the control circuit 100. The control circuit provides current to the anode of the first light-emitting switch LED1 through the fifth resistor R4. When the control signal is activated, LED1 is turned on and emits light, providing a visual indication of the device's operating status. The fifth resistor R4 is used to limit the current and prevent LED1 from being damaged due to overcurrent.

[0055] It should be noted that, referring to Figure 9 The display circuit 500 also includes four circuits with the same structure as the circuit described above. Those skilled in the art can refer to the appendix for further information. Figure 9 The remaining circuits are completed, so they will not be described in detail.

[0056] In some embodiments, the L1 pin is used to indicate the power status. When the heater is powered on and in operation, the LED controlled by the L1 pin will light up, indicating that the device is turned on.

[0057] The L2 pin is used to indicate the heating function status. When the heating circuit 310 or 320 is activated, the LED controlled by the L2 pin will light up, indicating that the heater is heating.

[0058] The L3 pin is used to indicate the fan's operating status. When the fan drive circuit 330 is started, the LED controlled by the L3 pin will light up, indicating that the fan is running.

[0059] The L4 pin is used to indicate the status of the timing function. When the user sets the working time through the timing circuit 600, the LED controlled by the L4 pin will light up, indicating that the timing function has been activated.

[0060] The L5 pin is used to indicate a fault or abnormal state. If the feedback circuit 400 detects an abnormal temperature or other fault, the LED controlled by the L5 pin will flash or remain lit to indicate that there is a problem with the user equipment.

[0061] This embodiment's display circuit provides a clear, real-time indication of the heater's operating status, facilitating user operation and monitoring. A well-designed current limiting system ensures stable LED operation, enhancing circuit reliability and user experience.

[0062] In some embodiments, reference Figure 3 The power supply circuit 200 includes an input protection module 210, a rectifier module 220, a control module 230, a voltage regulator module 240, a first output module 250, and a second output module 260, which are connected in sequence.

[0063] This embodiment includes an input protection module, a rectifier module, a control module, a voltage regulator module, a first output module, and a second output module. The input protection module is used to prevent abnormal input voltage conditions and protect subsequent circuits. The rectifier module converts the input AC power into DC power. The control module is responsible for managing the power supply's on / off state and stabilizing the output. The voltage regulator module adjusts the unstable DC voltage to a stable output voltage. Finally, the first output module and the second output module output different voltages to power different loads.

[0064] Specifically, the protection module includes an input fuse F1, a transient suppression diode ZDR1, a filter capacitor CX1, and resistors RX1 and RX2.

[0065] Specifically, the input fuse F1 is first connected to the power input terminal to prevent overcurrent. The transient suppression diode ZDR1 is connected in parallel with the power input to absorb high-voltage transient pulses on the power line. The filter capacitor CX1 is connected in parallel in the circuit to eliminate high-frequency noise in the power input. Resistors RX1 and RX2 are connected in series on the input power line to limit current and attenuate noise.

[0066] Specifically, the rectifier module includes a bridge rectifier DB1 and capacitors EC2 and EC3.

[0067] Specifically, the input terminal of the bridge rectifier DB1 is connected to the AC power supply, and the output terminal is connected to capacitors EC2 and EC3. The capacitors are connected in parallel at the output terminal of the rectifier and are responsible for smoothing the DC power after rectification, providing a more stable DC voltage to the next stage circuit.

[0068] Specifically, the control module includes a switch controller U1 (model BPA8506D SOP7), an inductor L1, and feedback circuit components.

[0069] Specifically, the input terminal of the switch controller U1 is connected to the output DC voltage of the rectifier module. The controller U1 adjusts the stability of the output voltage according to the voltage feedback signal provided by the feedback circuit element. The inductor L1 is connected to the output terminal of U1 and is used for energy storage and voltage conversion to help efficiently convert the input DC voltage into the required stable output voltage.

[0070] Specifically, the voltage regulator module includes diodes D4 and D5, capacitors EC4 and EC5, and inductor L2.

[0071] Specifically, diodes D4 and D5 are connected to the voltage input terminal for rectification or freewheeling. Capacitors EC4 and EC5 are connected in parallel in the circuit for filtering, eliminating noise and fluctuations in the voltage. Inductor L2 is connected in series in the output circuit, forming an LC filter network with the capacitors to further smooth the output voltage and ensure voltage stability.

[0072] Specifically, the first output module 450 is used to output 12V power, and the second output module is used to output 5V power.

[0073] Specifically, the input protection module protects the circuit with fuse F1 and transient suppression diode ZDR1, and performs preliminary filtering with resistors and filter capacitors. The rectifier module 420 rectifies the AC power into DC power through bridge rectifier DB1, and smooths the output voltage with capacitors EC2 and EC3. Then, the switch controller U1 in the control module 430, together with inductor L1 and feedback circuit, adjusts and maintains the stability of the output voltage. The voltage regulator module uses diodes D4 and D5 and capacitors EC4 and EC5 to further filter and regulate the voltage. Inductor L2 further smooths the output voltage to ensure stable voltage and no noise. Finally, the fixed output voltage regulator module stabilizes the voltage at 5V through voltage regulator U3 to provide stable power supply for subsequent circuits.

[0074] This embodiment achieves multi-voltage output through modular design to meet different load requirements, while providing input protection and stable power management, effectively improving the system's reliability and anti-interference capability.

[0075] In some embodiments, the system further includes a switching circuit 700 and a timing circuit 600. The control terminal of the control circuit 100 is connected to the switching circuit 700 and the timing circuit 600, respectively. The switching circuit 700 is used to send a start / stop signal to the control circuit 100, and the timing circuit 600 is used to send a timing signal to the control circuit 100.

[0076] Specifically, refer to Figure 6 The timing circuit 600 includes a resistor R12 and a standard tactile push-button switch TIMER of model 667. The first pin of the switch is connected to ground (GND), and the third pin of the switch is internally connected to the first pin. When the switch is closed, the first and third pins are conductive. The second pin of the switch is connected to one end of the resistor R12, and the fourth pin of the switch is internally connected to the second pin. When the switch is closed, the second and fourth pins are conductive. One end of the resistor R12 is connected to the second and fourth pins of the switch, and the other end of the resistor is connected to the TIMER port of the control circuit. The ground (GND) is connected to the first pin of the switch.

[0077] When the switch is closed during operation, pins 1 and 3 are connected, and pins 2 and 4 are also connected, forming a complete current loop. The current flows from GND to R12, and then transmits the signal through the TIMER interface. The function of resistor R12 is to limit the current, prevent overcurrent in the circuit, and protect the input terminal of the subsequent circuit.

[0078] Specifically, refer to Figure 6The switching circuit 700 includes a resistor R11 and a standard tactile push-button switch (model 667) for ON / OFF operation. Pin 1 of the tactile switch (667) is connected to ground (GND), and pin 3 is internally connected to pin 1. When the switch is closed, pins 1 and 3 are conductive. Pin 2 is connected to one end of resistor R11, and pin 4 is internally connected to pin 2. When the switch is closed, pins 2 and 4 are conductive. One end of resistor R11 is connected to pin 2 of the tactile switch, and the other end is connected to the "ON / OFF" signal interface of the control circuit. The ground wire is directly connected to pin 1 of the tactile switch, forming a reference voltage.

[0079] When the switch is closed during operation:

[0080] Pin 1 and pin 3 are connected.

[0081] Pins 2 and 4 are connected, forming a current path: ground (GND) → switch → R11 → "ON / OFF" signal interface. The function of resistor R11 is to limit the current and prevent the signal interface from being subjected to excessive current when the switch is closed.

[0082] In some embodiments, a buzzer circuit is also included, which includes a buzzer BUZ and a resistor R10, connected to the control terminal of the control circuit.

[0083] It should be noted that, referring to Figure 4 The control circuit in this embodiment is illustrated using a chip from Shenzhen Chipbond Technology Co., Ltd. that integrates a capacitive touch button detection module and a microcontroller.

[0084] Specifically, VCC is the power input pin, which is connected to a +5V power supply to power the chip.

[0085] GND: Ground pin, connected to the ground wire of the circuit to form a current loop.

[0086] ON / OFF: Control pin, used to receive external switch signals to control the heater to turn on and off.

[0087] L2: General purpose input / output pin, used to control the display circuit 500.

[0088] NTC: The pin that connects to the thermistor (NTC) is used to detect temperature changes and provide temperature feedback.

[0089] L1: General purpose input / output pin, used to control the display circuit 500.

[0090] L5: General purpose input / output pin, used to control the display circuit 500.

[0091] L4: General purpose input / output pin, used to control the display circuit 500.

[0092] BUZ: Buzzer control pin, used to drive the buzzer and provide audible cues.

[0093] TIMER: Timing function control pin, used to receive timing control signals and manage the timing operation of the heater.

[0094] L3: General purpose input / output pin, used to control the display circuit 500.

[0095] P00: General purpose input / output pin.

[0096] P01: General purpose input / output pin.

[0097] SW: Switch input pin, used to receive user key input and control the function switching of the heater.

[0098] FAN: Fan control pin, outputs control signals to adjust the fan's start / stop or speed.

[0099] HEAT: Heating element control pin, outputs control signals to adjust the working state of the heating element.

[0100] In summary, the power supply circuit 200 first prevents overcurrent and high-voltage pulses through the input protection module 210, converts AC to DC using a bridge rectifier DB1, and smooths the output through filter capacitors EC2 and EC3. Then, the control module 230 and voltage regulator module 240 adjust and stabilize the voltage, outputting +12V and 5V DC power respectively to supply the load circuit 260 and the control circuit 100. The control circuit 100, as the core of the system, receives start / stop signals (via the switching circuit 700) and timing signals (via the timing circuit 600) from the user, and transmits these signals through the feedback circuit 400. The NTC thermistor monitors the operating temperature in real time. The second output module 300 of the load circuit 260 includes two independent heating circuits 310 and 320, as well as a fan drive circuit 330. The control circuit 100 controls the heating circuits to turn on and off through the HEAT1 and HEAT2 pins, respectively, and controls the fan operation through the FAN pin. The feedback circuit 400 feeds back the temperature information to the control circuit 100. The control circuit adjusts the working status of the heating and fan according to the actual temperature. The display circuit 500 displays the operating status of the device through LED indicators. The buzzer circuit provides operation feedback and warning sound.

[0101] The above is only used to illustrate the technical solution of this utility model and not to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A control circuit for a heater, characterized in that, include: Load circuit (300) is used to drive the load; A control circuit (100) is connected to the load circuit (300) and is used to send control signals to the load circuit (300); A feedback circuit (400), connected to the control circuit (100), is used to monitor the operating status of the load circuit (300) and feed back the operating status to the control circuit (100); and The power supply circuit (200) is connected to the control circuit (100) and the feedback circuit (400) respectively, and is used to provide a first DC power supply to the load circuit (300) and a second DC power supply (5V) to the control circuit (100).

2. The heater control circuit according to claim 1, characterized in that, The load circuit (300) includes a first heating circuit (310), a second heating circuit (320), and a fan drive circuit (330). The control terminal of the control circuit (100) is connected to the controlled terminal of the first heating circuit (310), the controlled terminal of the second heating circuit (320), and the controlled terminal of the fan drive circuit (330), respectively. The circuit structures of the first heating circuit (310) and the second heating circuit (320) are the same.

3. The heater control circuit according to claim 2, characterized in that, The first heating circuit (310) includes a first resistor R16, a second resistor R17, a first switching transistor Q2, a second switching transistor D4, and a relay REL1. The first switching transistor Q2 is an NPN transistor, and the second switching transistor D4 is a diode. The base of the first switching transistor Q2 is connected to the control terminal of the control circuit (100) through the first resistor R16, and is connected to the emitter and ground terminal of the first switching transistor Q2 through the second resistor R17. The collector of the first switching transistor Q2 is connected to the third terminal of the relay REL1, and is connected to the fourth terminal of the relay REL1 and the first DC power supply through the second switching transistor D4. The collector of the first switching transistor Q2 is connected to the anode of the second switching transistor D4. The first terminal of the relay REL1 is connected to the live wire, and the second terminal of the relay REL1 is connected to the heating device.

4. The heater control circuit according to claim 2, characterized in that, The fan drive circuit (330) includes a third resistor R14, a fourth resistor R15, a third switch Q1, and a fourth switch D3. The third switch Q1 is an NPN transistor, and the fourth switch D3 is a diode. The base of the third switch Q1 is connected to the control terminal of the control circuit (100) through the third resistor R14, and is connected to the emitter and ground terminal of the third switch Q1 through the fourth resistor R15. The collector of the third switch Q1 is connected to the first DC power supply through the fourth switch D3. The anode of the fourth switch D3 is connected to the collector of the third switch Q1. The fan interface is connected in parallel with the fourth switch D3.

5. A heater control circuit according to claim 1, characterized in that, The feedback circuit (400) includes a thermistor interface NTC, a fifth resistor R13 and a first capacitor C5. The control terminal of the control circuit (100) is connected to the second DC power supply (5V) through the fifth resistor R13 and to the first terminal and ground terminal of the thermistor interface NTC through the first capacitor C5. The second terminal of the thermistor interface NTC is connected to the control terminal of the control circuit (100).

6. A heater control circuit according to claim 1, characterized in that, It also includes a display circuit (500), which includes at least a fifth resistor R4 and a first light-emitting switch LED1. The control terminal of the control circuit (100) is connected to the anode of the first light-emitting switch LED1 through the fifth resistor R4, and the cathode of the first light-emitting switch LED1 is grounded.

7. A heater control circuit according to claim 1, characterized in that, The power supply circuit (200) includes an input protection module (210), a rectifier module (220), a control module (230), a voltage regulator module (240), a first output module (250), and a second output module (260), which are connected in sequence.

8. A heater control circuit according to claim 1, characterized in that, It also includes a switching circuit (700) and a timing circuit (600). The control terminal of the control circuit (100) is connected to the switching circuit (700) and the timing circuit (600) respectively. The switching circuit (700) is used to send a start / stop signal to the control circuit (100), and the timing circuit (600) is used to send a timing signal to the control circuit (100).

9. A space heater, characterized in that, Includes a heater control circuit as described in any one of claims 1-8.

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