Constant temperature control circuit for electric blanket
By combining the drive module and the PTC constant temperature module, sensorless constant temperature control of electric blankets is achieved, solving the problem of poor local temperature response in existing technologies, improving user experience and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO BAILUOWEI ELECTRIC APPLIANCE CO LTD
- Filing Date
- 2025-05-09
- Publication Date
- 2026-04-21
AI Technical Summary
Existing electric blanket temperature control devices can only reflect local temperature signals, resulting in a poor user experience and requiring additional temperature sensors, which increases costs.
It employs a drive module, a PTC constant temperature module, and a control module. The PTC constant temperature module feeds back the current temperature of the heating wire to the control module, achieving constant temperature control without the need for additional sensors.
It achieves constant temperature control for electric blankets, reducing costs and improving user experience.
Smart Images
Figure CN224154364U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of household electric blanket technology, specifically a constant temperature control circuit for electric blankets. Background Technology
[0002] Electric blankets, electric heating pads, pet mats, heated boots, massage heating pads, localized human body heating products, heated tire pads, heated plate pads, outdoor snow melting products, and other heat preservation and heating products (hereinafter collectively referred to as electric blankets) are widely used in the international and domestic markets and are also a commonly used heating device.
[0003] Electric blankets with temperature control functions on the market detect temperature by installing sensors with matching processors inside the blanket, and then control the output power to maintain the temperature so that the electric blanket reaches the set or program-calculated temperature. However, control devices with temperature sensors can usually only reflect the local temperature signal of the electric blanket, resulting in a poor user experience. Utility Model Content
[0004] To address the aforementioned problems, this utility model provides a constant temperature control circuit for electric blankets, which is low in cost and does not require an additional temperature sensor to achieve the purpose of constant temperature control for electric blankets.
[0005] The present invention adopts the following technical solution: a constant temperature control circuit for an electric blanket, comprising a drive module, a PTC constant temperature module, a control module, and a heating wire, wherein the heating wire is disposed in the blanket body of the electric blanket, and the drive module is connected to the control module and the heating wire, and is used to drive the heating wire to generate heat;
[0006] The PTC constant temperature module is connected to both the control module and the heating wire, and is used to feed back the current temperature of the heating layer of the heating wire to the control module so that the control module can control the operation of the drive module.
[0007] Furthermore, the electric blanket body is provided with a connecting female, which has four interfaces, namely interface H1, interface H2, interface H3 and interface D. Interfaces H1 and H3 are respectively connected to the two ends of the heating layer of the heating wire, and interface H2 is connected to the detection end of the heating wire.
[0008] Furthermore, the control circuit also includes a resistor-capacitor step-down rectifier module, an NTC over-temperature protection module, a board temperature protection module, a thyristor short-circuit protection module, a main display module, and a main communication module; wherein,
[0009] The resistor-capacitor step-down rectifier module is connected between the power line and the interface D, and is connected to the control module to generate a 5V DC power supply to the control module.
[0010] The NTC over-temperature protection module is connected to the control module and is used to realize over-temperature protection of the heating wire;
[0011] The plate temperature protection module is connected to the control module and is used to control the drive module to stop heating the heating wire when the control module experiences an abnormally high temperature.
[0012] The thyristor short-circuit protection module is connected to the control module and is used to realize short-circuit protection of the drive module;
[0013] The main display module is connected to the control module and is used to display power and fault information.
[0014] The main communication module is connected to the control module and is used to receive data.
[0015] Furthermore, the control module includes a main controller U1, which uses an OS8F2232 microcontroller.
[0016] The resistor-capacitor step-down rectifier module includes resistors R1 to R3, capacitors C1 to C4, diodes D1 and D2, Zener diode DZ1, resistor R23, Zener diode DZ2, capacitors C12 and C13, and diodes D4 and D5.
[0017] The PTC constant temperature module includes resistors R4, R5, R7, R8, R9, capacitors C5 and C6;
[0018] The drive module includes resistor R6, resistor R24, capacitor C7, and silicon controlled rectifier VT2;
[0019] The NTC over-temperature protection module includes resistors R13 to R17, capacitor C8, capacitor C9, and thermal fuse F2.
[0020] The thyristor short-circuit protection module includes resistors R10, R11, R12, varistor RV1, thyristor VT1, and thermal fuse F2;
[0021] The control circuit also includes a current fuse F1, a varistor RV2, an X2 capacitor C11, and a temperature fuse F2; the resistors R10 and R17 are both mounted in close contact with the temperature fuse F2.
[0022] One end of the current fuse F1 is connected to the neutral terminal N of the power supply line. The other end of the current fuse F1 is connected to one end of the varistor RV2, capacitor C11 (X2), and resistors R8, R9, R10, and R13, and then connected to interface H1. The other ends of the varistor RV2 and capacitor C11 are connected to one end of the thermal fuse F2, and then connected to the live terminal L of the power supply line. The other end of the thermal fuse F2 is connected to one end of the varistor RV1, capacitors C2, C3, C5, C6, C9, resistors R3, R4, R7, R12, R16, and R17, the positive terminal of diode D1, the positive terminal of Zener diode DZ1, and the first anode of the silicon controlled rectifier VT1. After all terminals are connected, the circuit is grounded. The other end of resistor R10 is connected to the other end of varistor RV1 and the second anode of SCR VT1. The other end of resistor R9 is connected to pin 10 of main controller U1. The control terminal of SCR VT1 is connected to the other end of resistor R12 and one end of resistor R11. The other end of resistor R11 is connected to pin 13 of main controller U1. The other end of resistor R8 is connected to resistor R7 and the other end of capacitor C5, and then connected to pin 9 of main controller U1. The other end of capacitor C9, the other end of resistor R16, and one end of resistor R15 are connected to pin 5 of main controller U1. Resistor R14... One end of the capacitor C7 is connected to one end of the capacitor C8 and then connected to pin 6 of the main controller U1. The other end of the capacitor C8 is grounded. The other end of the resistor R13 is connected to the other ends of resistors R14, R15, and R17 and then connected to interface H2. One end of the capacitor C7 is connected to pin 8 of the main controller U1. The other end of the capacitor C7 is connected to one end of the resistor R24. The other end of the resistor R24 is connected to one end of the resistor R6 and the control electrode of the thyristor VT2. The second anode of the thyristor VT2 is connected to interface H3. The first anode of the thyristor VT2 is connected to one end of the resistor R5 and the other ends of resistors R4 and R6. The other end of capacitor C6 is connected to the other end of resistor R5 and then connected to pin 7 of the main controller U1. The other end of resistor R3 is connected to the other ends of capacitors C2 and C3, the negative terminal of Zener diode DZ1, and the negative terminal of diode D2 and then connected to pin 1 of the main controller U1. The positive terminal of diode D2 is connected to the negative terminal of diode D1 and one end of resistor R1. The other end of resistor R1 is connected to one end of capacitor C1 and one end of resistor R2. The other ends of capacitor C1 and resistor R2 are connected and then connected to interface D. One end of capacitor C4 is connected to pin 1 of the main controller U1, and the other end of capacitor C4 is connected to pin 16 of the main controller U1 and then grounded.The positive terminal of diode D4 is connected to the positive terminal of Zener diode DZ2, one end of capacitors C12 and C13, and one end of resistor R23, and then connected to interface H1. The negative terminal of diode D4 is connected to the positive terminal of diode D5 and then connected to interface D. The negative terminal of diode D5 is connected to the negative terminal of Zener diode DZ2, the other end of capacitors C12 and C13, and resistor R23.
[0023] Furthermore, the board temperature protection module includes a thermistor R18, a resistor R19, and a capacitor C10; one end of the thermistor R18 is connected to one end of both the resistor R19 and the capacitor C10 and then connected to pin 4 of the main controller U1; the other ends of the resistor R19 and the capacitor C10 are connected to ground; and the other end of the thermistor R18 is connected to pin 1 of the main controller U1.
[0024] Further, the main display module includes a resistor R20 and a light-emitting diode LED1; the main communication module includes resistors R21-R22, an optocoupler U2, and a diode D3; the negative terminal of the light-emitting diode LED1 is connected to pin 12 of the main controller U1, the positive terminal of the light-emitting diode LED1 is connected to one end of the resistor R20, the other end of the resistor R20 is connected to pin 1 of the main controller U1, one end of the resistor R21 is connected to pin 1 of the main controller U1, the other end of the resistor R21 is connected to pin 6 of the optocoupler U2 and then to pin 11 of the main controller U1, pin 1 of the optocoupler U2 is connected to one end of the resistor R22, the other end of the resistor R22 is connected to the negative terminal of the diode D3, the positive terminal of the diode D3 is connected to the interface D, and pins 2 and 4 of the optocoupler U2 are connected to ground.
[0025] The beneficial effect of this utility model is that by setting up a drive module, a PTC constant temperature module, and a control module, the current temperature of the heating layer of the heating wire is fed back to the control module through the PTC constant temperature module, so that the control module controls the operation of the drive module, thereby achieving the purpose of constant temperature control of the electric blanket, which has good economic value. Attached Figure Description
[0026] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation
[0027] like Figure 1 As shown, a constant temperature control circuit for an electric blanket according to this utility model includes a drive module, a PTC constant temperature module, a control module, and a heating wire. The heating wire is disposed in the blanket body (not shown in the figure). The drive module is connected to both the control module and the heating wire and is used to drive the heating wire to generate heat.
[0028] The PTC constant temperature module is connected to both the control module and the heating wire. It is used to feed back the current temperature of the heating layer of the heating wire to the control module, so that the control module can control the drive module to operate.
[0029] The electric blanket body is provided with a connecting female socket, which has four interfaces, namely interface H1, interface H2, interface H3 and interface D. Interfaces H1 and H3 are respectively connected to the two ends of the heating layer 5a of the heating wire, and interface H2 is connected to the detection end 5b of the heating wire.
[0030] The control circuit also includes a resistor-capacitor step-down rectifier module, an NTC over-temperature protection module, a board temperature protection module, a thyristor short-circuit protection module, a main display module, and a main communication module; among which,
[0031] The RC step-down rectifier module is connected between the power line and interface D, and is connected to the control module to generate a 5V DC power supply to the control module.
[0032] The NTC over-temperature protection module is connected to the control module and is used to protect the heating wire from over-temperature.
[0033] The board temperature protection module is connected to the control module and is used to stop the heating of the heating wire when the control module has an abnormally high temperature.
[0034] The thyristor short-circuit protection module is connected to the control module and is used to realize short-circuit protection of the drive module;
[0035] The main display module, connected to the control module, is used to display power and fault information.
[0036] The main communication module, connected to the control module, is used to receive data.
[0037] The control module includes a main controller U1, which uses an OS8F2232 microcontroller.
[0038] The RC step-down rectifier module includes resistors R1 to R3, capacitors C1 to C4, diodes D1 and D2, Zener diode DZ1, resistor R23, Zener diode DZ2, capacitors C12 and C13, and diodes D4 and D5.
[0039] The PTC constant temperature module includes resistors R4, R5, R7, R8, R9, capacitors C5 and C6;
[0040] The drive module includes resistor R6, resistor R24, capacitor C7, and silicon controlled rectifier VT2;
[0041] The NTC over-temperature protection module includes resistors R13 to R17, capacitor C8, capacitor C9, and thermal fuse F2.
[0042] The thyristor short-circuit protection module includes resistors R10, R11, R12, varistor RV1, thyristor VT1, and thermal fuse F2;
[0043] The control circuit also includes a current fuse F1, a varistor RV2, an X2 capacitor C11, and a temperature fuse F2; wherein, the current fuse F1 serves as an overcurrent and short-circuit protection component; the varistor RV2 serves as an overvoltage protection and surge suppression component; the X2 capacitor C11 serves as an EMC component; the heating layer 5a of the heating wire 5 has a positive temperature coefficient (PTC) change characteristic of 0.0045Ω / ℃; resistors R10 and R17 are both mounted in close contact with the temperature fuse F2;
[0044] One end of the current fuse F1 is connected to the neutral terminal N of the power supply line. The other end of the current fuse F1 is connected to one end of the varistor RV2, capacitor C11 (X2), and resistors R8, R9, R10, and R13, and then connected to interface H1. The other end of the varistor RV2 and capacitor C11 (X2) is connected to one end of the thermal fuse F2, and then connected to the live terminal L of the power supply line. The other end of the thermal fuse F2 is connected to one end of the varistor RV1, capacitors C2, C3, C5, C6, and C9, resistors R3, R4, R7, R12, R16, and R17, the positive terminal of diode D1, the positive terminal of Zener diode DZ1, and the first anode of thyristor VT1, and then grounded. The other end of resistor R10 is connected to the varistor... The other end of resistor RV1 is connected to the second anode of SCR VT1. The other end of resistor R9 is connected to pin 10 of main controller U1. The control electrode of SCR VT1 is connected to the other end of resistor R12 and one end of resistor R11. The other end of resistor R11 is connected to pin 13 of main controller U1. The other end of resistor R8 is connected to the other end of resistor R7 and capacitor C5, and then connected to pin 9 of main controller U1. The other end of capacitor C9, the other end of resistor R16, and one end of resistor R15 are connected to pin 5 of main controller U1. One end of resistor R14 is connected to one end of capacitor C8, and then connected to pin 6 of main controller U1. The other end of capacitor C8 is grounded. The other end of resistor R13 is connected to resistor R1... 4. The other ends of R15 and R17 are connected to interface H2. One end of capacitor C7 is connected to pin 8 of the main controller U1. The other end of capacitor C7 is connected to one end of resistor R24. The other end of resistor R24 is connected to one end of resistor R6 and the control electrode of SCR VT2. The second anode of SCR VT2 is connected to interface H3. The first anode of SCR VT2 is connected to one end of resistor R5 and the other ends of resistors R4 and R6. The other end of capacitor C6 is connected to the other end of resistor R5 and then to pin 7 of the main controller U1. The other end of resistor R3 is connected to the other ends of capacitors C2 and C3, the negative terminal of Zener diode DZ1, and the negative terminal of diode D2 and then to pin 1 of the main controller U1. The anode of diode D2 is connected to the cathode of diode D1 and one end of resistor R1. The other end of resistor R1 is connected to one end of capacitor C1 and resistor R2. The other ends of capacitor C1 and resistor R2 are connected to interface D. One end of capacitor C4 is connected to pin 1 of main controller U1. The other end of capacitor C4 is connected to pin 16 of main controller U1 and then grounded. The anode of diode D4 is connected to the anode of Zener diode DZ2, one end of capacitors C12 and C13, and one end of resistor R23 and then connected to interface H1. The cathode of diode D4 is connected to the anode of diode D5 and then connected to interface D. The cathode of diode D5 is connected to the cathode of Zener diode DZ2, one end of capacitors C12 and C13, and the other end of resistor R23.
[0045] The board temperature protection module includes a thermistor R18, a resistor R19, and a capacitor C10. One end of the thermistor R18 is connected to one end of both the resistor R19 and the capacitor C10, and then connected to pin 4 of the main controller U1. The other ends of the resistor R19 and the capacitor C10 are connected to ground, and the other end of the thermistor R18 is connected to pin 1 of the main controller U1. Specifically, the voltage of the resistor R19 increases as the temperature of the circuit board installed inside the casing of the main controller U1 rises. When the set temperature is exceeded, the main controller U1 immediately shuts off the trigger signal of the thyristor VT2, stops heating, and displays an alarm through the main display module.
[0046] The main display module includes resistor R20 and LED1; the main communication module includes resistors R21-R22, optocoupler U2, and diode D3; the negative terminal of LED1 is connected to pin 12 of the main controller U1, the positive terminal of LED1 is connected to one end of resistor R20, the other end of resistor R20 is connected to pin 1 of the main controller U1, one end of resistor R21 is connected to pin 1 of the main controller U1, the other end of resistor R21 is connected to pin 6 of optocoupler U2 and then to pin 11 of the main controller U1, pin 1 of optocoupler U2 is connected to one end of resistor R22, the other end of resistor R22 is connected to the negative terminal of diode D3, the positive terminal of diode D3 is connected to interface D, and pins 2 and 4 of optocoupler U2 are connected to ground.
[0047] In this invention, the working principle of driving the heating wire is as follows: After the SYN pin (pin 10) of the main controller U1 detects the zero-crossing signal of the AC power supply through the resistor R9, the main controller U1 outputs a trigger pulse synchronized with the zero-crossing signal of the AC power supply from the SYN pin (pin 8) of the main controller U1. Through the capacitor C7 and the resistor R24, the thyristor VT2 is triggered, and the thyristor VT2 is turned on. Then, the AC power supply is applied to the heating layer 5a of the heating wire through the circuit of the thermal fuse F2, the thyristor VT2, the heating layer 5a of the heating wire, and the current fuse F1, so that the heating layer 5a heats up.
[0048] The working principle of generating 5V DC voltage is as follows: AC power flows through the neutral terminal N, current fuse F1, diode D4, capacitor C1, resistor R2 connected in parallel with capacitor C1, resistor R1, diode D2, Zener diode DZ1, capacitors C2 and C3 connected in parallel with Zener diode DZ1, resistor R3, thermal fuse F2, and live terminal L. Then, a 5V DC voltage Vm is obtained across capacitors C2 and C3, which powers the main controller U1.
[0049] The control circuit is equipped with a current fuse F1. When the entire circuit experiences a short circuit or other abnormal situation, and the total current flowing through the current fuse F1 exceeds the rated current of the current fuse F1, the current fuse F1 will blow, cutting off the AC power supply and the connection between the circuit, thus achieving the ultimate purpose of overcurrent protection.
[0050] The working principle of PTC constant temperature control is:
[0051] The AC power supply passes through the current fuse F1, heating wire, thyristor VT2, resistor R4, and temperature fuse F2 in sequence to form a heating circuit. A circuit current Iptc is generated in the heating circuit. The current Iptc is inversely proportional to the resistance of the heating layer 5a (i.e., temperature). A voltage proportional to the current Iptc is generated across resistor R4. The voltage Vptc is obtained by filtering through resistor R5 and capacitor C6 in the PTC constant temperature module and then sent to the main controller U1 for A / D conversion.
[0052] Subsequently, when the AC power flows through the current fuse F1, the series voltage divider of resistors R8 and R7, the filter of capacitor C5, and the temperature fuse F2, a voltage Vref proportional to the AC power is generated across capacitor C5 and sent to the main controller U1 for A / D conversion.
[0053] In the main controller U1, dividing the voltage Vref by the voltage Vptc is equivalent to dividing the voltage Vref by the current Iptc to obtain the resistance Rptc of the heating layer 5a of the heating wire 5 at the current temperature, which also gives the current temperature of the heating layer 5a of the heating wire 5.
[0054] If the current temperature of the heating layer 5a of the heating wire is lower than the set temperature, turn on the thyristor VT2 to start heating;
[0055] If the current temperature of the heating layer 5a of the heating wire is higher than the set temperature, the thyristor VT2 will be turned off to stop heating.
[0056] Furthermore, if the heating circuit current Iptc can still be detected during the heating stop period, it indicates that the thyristor VT2 has short-circuited. The main controller U1 immediately outputs a high level (5V) through the PROT pin, and then the voltage is divided by resistors R11 and R12 to turn on the thyristor VT1. The AC power will be fully applied to resistor R10, causing resistor R10 to heat up rapidly. Since resistor R10 is closely mounted with the thermal fuse F2, the thermal fuse F2 reaches its operating temperature in a short time and melts, cutting off the connection between the AC power and the heating circuit, thus achieving the final protection purpose.
[0057] If the heating circuit current Iptc cannot be detected during the heating start-up period, it indicates that the thyristor VT2 has an open circuit or the heating layer 5a of the heating wire is open, and the heating circuit cannot be established, so there will be no safety issues. However, for the sake of production convenience and user-friendliness, the main controller U1 immediately shuts off the trigger signal of the thyristor VT2 and displays an alarm through the main display module.
[0058] When an electric blanket is used improperly, localized or single-point overheating may occur. Because the insulation layer 5c in the middle of the heating wire exhibits a negative temperature coefficient (NTC) characteristic, high temperatures will cause a decrease in the insulation resistance of the insulation layer 5c. Therefore, detecting the leakage current generated by the AC power supply in the insulation layer 5c of the heating wire can determine whether the heating wire is overheating. Thus, this invention also includes NTC over-temperature protection control to protect the heating wire from high temperatures. The working principle of the NTC over-temperature protection control is as follows:
[0059] First, turn off the thyristor VT2 to avoid other interference signals or shunt circuits affecting the test results, forming the following NTC over-temperature protection circuit: neutral terminal N, current fuse F1, resistor R13, heating wire, resistor R15, resistor R16, resistor R17, temperature fuse F2, live wire L. A leakage voltage Vntc is generated on resistor R17, and the leakage voltage Vntc is converted by A / D through the main controller U1.
[0060] If the leakage voltage Vntc is greater than the over-temperature protection setting value, the thyristor VT2 will be turned off to stop heating until the leakage voltage Vntc is within the setting value range, at which point heating will be allowed to resume, thus achieving the purpose of over-temperature protection.
[0061] Furthermore, if the electric blanket is used improperly, causing a short circuit between the heating layer 5a and the detection end 5b of the heating wire, the total resistance of resistors R15 and R16 connected in series is relatively large. The AC power will be entirely applied to resistor R17, causing resistor R17 to heat up rapidly. Since resistor R17 is tightly assembled with the thermal fuse F2, the thermal fuse F2 will reach its operating temperature and melt within a short time, cutting off the connection between the AC power and the heating circuit, thus achieving the final protection purpose.
[0062] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A constant temperature control circuit for an electric blanket, characterized in that: It includes a drive module, a PTC constant temperature module, a control module, and a heating wire. The heating wire is disposed in the electric blanket body. The drive module is connected to both the control module and the heating wire and is used to drive the heating wire to generate heat. The PTC constant temperature module is connected to both the control module and the heating wire, and is used to feed back the current temperature of the heating layer of the heating wire to the control module so that the control module can control the operation of the drive module.
2. A thermostat control circuit for an electric blanket as defined in claim 1, wherein: The electric blanket body is provided with a connecting female socket, which has four interfaces, namely interface H1, interface H2, interface H3 and interface D. Interfaces H1 and H3 are respectively connected to the two ends of the heating layer of the heating wire, and interface H2 is connected to the detection end of the heating wire.
3. A thermostat control circuit for an electric blanket as defined in claim 2, wherein: The control circuit also includes a resistor-capacitor step-down rectifier module, an NTC over-temperature protection module, a board temperature protection module, a thyristor short-circuit protection module, a main display module, and a main communication module; wherein... The resistor-capacitor step-down rectifier module is connected between the power line and the interface D, and is connected to the control module to generate a 5V DC power supply to the control module. The NTC over-temperature protection module is connected to the control module and is used to realize over-temperature protection of the heating wire; The plate temperature protection module is connected to the control module and is used to control the drive module to stop heating the heating wire when the control module experiences an abnormally high temperature. The thyristor short-circuit protection module is connected to the control module and is used to realize short-circuit protection of the drive module; The main display module is connected to the control module and is used to display power and fault information. The main communication module is connected to the control module and is used to receive data.
4. A thermostat control circuit for an electric blanket according to claim 3, wherein: The control module includes a main controller U1, which uses an OS8F2232 microcontroller. The resistor-capacitor step-down rectifier module includes resistors R1 to R3, capacitors C1 to C4, diodes D1 and D2, Zener diode DZ1, resistor R23, Zener diode DZ2, capacitors C12 and C13, and diodes D4 and D5. The PTC constant temperature module includes resistors R4, R5, R7, R8, R9, capacitors C5 and C6; The drive module includes resistor R6, resistor R24, capacitor C7, and silicon controlled rectifier VT2; The NTC over-temperature protection module includes resistors R13 to R17, capacitor C8, capacitor C9, and thermal fuse F2. The thyristor short-circuit protection module includes resistors R10, R11, R12, varistor RV1, thyristor VT1, and thermal fuse F2; The control circuit also includes a current fuse F1, a varistor RV2, an X2 capacitor C11, and a temperature fuse F2; the resistors R10 and R17 are both mounted in close contact with the temperature fuse F2. One end of the current fuse F1 is connected to the neutral terminal N of the power supply line. The other end of the current fuse F1 is connected to one end of the varistor RV2, capacitor C11 (X2), and resistors R8, R9, R10, and R13, and then connected to interface H1. The other ends of the varistor RV2 and capacitor C11 are connected to one end of the thermal fuse F2, and then connected to the live terminal L of the power supply line. The other end of the thermal fuse F2 is connected to one end of the varistor RV1, capacitors C2, C3, C5, C6, C9, resistors R3, R4, R7, R12, R16, and R17, the positive terminal of diode D1, the positive terminal of Zener diode DZ1, and the first anode of the silicon controlled rectifier VT1. After all terminals are connected, the circuit is grounded. The other end of resistor R10 is connected to the other end of varistor RV1 and the second anode of SCR VT1. The other end of resistor R9 is connected to pin 10 of main controller U1. The control terminal of SCR VT1 is connected to the other end of resistor R12 and one end of resistor R11. The other end of resistor R11 is connected to pin 13 of main controller U1. The other end of resistor R8 is connected to resistor R7 and the other end of capacitor C5, and then connected to pin 9 of main controller U1. The other end of capacitor C9, the other end of resistor R16, and one end of resistor R15 are connected to pin 5 of main controller U1. Resistor R14... One end of the capacitor C7 is connected to one end of the capacitor C8 and then connected to pin 6 of the main controller U1. The other end of the capacitor C8 is grounded. The other end of the resistor R13 is connected to the other ends of resistors R14, R15, and R17 and then connected to interface H2. One end of the capacitor C7 is connected to pin 8 of the main controller U1. The other end of the capacitor C7 is connected to one end of the resistor R24. The other end of the resistor R24 is connected to one end of the resistor R6 and the control electrode of the thyristor VT2. The second anode of the thyristor VT2 is connected to interface H3. The first anode of the thyristor VT2 is connected to one end of the resistor R5 and the other ends of resistors R4 and R6. The other end of capacitor C6 is connected to the other end of resistor R5 and then connected to pin 7 of the main controller U1. The other end of resistor R3 is connected to the other ends of capacitors C2 and C3, the negative terminal of Zener diode DZ1, and the negative terminal of diode D2 and then connected to pin 1 of the main controller U1. The positive terminal of diode D2 is connected to the negative terminal of diode D1 and one end of resistor R1. The other end of resistor R1 is connected to one end of capacitor C1 and one end of resistor R2. The other ends of capacitor C1 and resistor R2 are connected and then connected to interface D. One end of capacitor C4 is connected to pin 1 of the main controller U1, and the other end of capacitor C4 is connected to pin 16 of the main controller U1 and then grounded.The anode of diode D4 is connected to the anode of Zener diode DZ2, one end of capacitors C12 and C13, and one end of resistor R23, and then connected to interface H1. The cathode of diode D4 is connected to the anode of diode D5 and then connected to interface D. The cathode of diode D5 is connected to the cathode of Zener diode DZ2, the other end of capacitors C12 and C13, and resistor R23.
5. A thermostat control circuit for an electric blanket as defined in claim 4, wherein: The board temperature protection module includes a thermistor R18, a resistor R19, and a capacitor C10; one end of the thermistor R18 is connected to one end of both the resistor R19 and the capacitor C10 and then connected to pin 4 of the main controller U1; the other ends of the resistor R19 and the capacitor C10 are connected to ground; and the other end of the thermistor R18 is connected to pin 1 of the main controller U1.
6. A thermostat control circuit for an electric blanket according to claim 4, wherein: The main display module includes a resistor R20 and a light-emitting diode LED1; the main communication module includes resistors R21-R22, an optocoupler U2, and a diode D3; the negative terminal of the light-emitting diode LED1 is connected to pin 12 of the main controller U1, the positive terminal of the light-emitting diode LED1 is connected to one end of the resistor R20, the other end of the resistor R20 is connected to pin 1 of the main controller U1, one end of the resistor R21 is connected to pin 1 of the main controller U1, the other end of the resistor R21 is connected to pin 6 of the optocoupler U2 and then to pin 11 of the main controller U1, pin 1 of the optocoupler U2 is connected to one end of the resistor R22, the other end of the resistor R22 is connected to the negative terminal of the diode D3, the positive terminal of the diode D3 is connected to the interface D, and pins 2 and 4 of the optocoupler U2 are connected to ground.