Electric blanket and control circuit thereof

Abstract

The invention discloses an electric blanket and a control circuit thereof, and belongs to the technical field of electric blankets, the electric blanket comprises a conversion module, a control module and a switch module; wherein the conversion module is used for converting an alternating current power supply into a direct current power supply; the control module is connected with the conversion module and used for receiving the direct-current power supply and controlling the heating temperature of the electric blanket; the switch module is connected with the control module and used for being connected or disconnected according to an instruction of the control module so as to control the heating state of the electric blanket; wherein the control module detects the current temperature by collecting the resistance value change of the heat sensitive resistance heating wire, and compares the current temperature with a preset temperature interval, so that the conduction time of the switch module is adjusted, and the electric blanket is maintained to work in the preset temperature interval. By automatically detecting and controlling the temperature of the electric blanket, accurate temperature regulation is realized, manual temperature regulation is not needed, and the electric blanket is convenient to use.

Description

Technical Field

[0001] The present invention relates to the technical field of electric blankets, in particular to an electric blanket and a control circuit thereof. Background Art

[0002] In the cold winter, electric blankets have become an indispensable heating companion for many families with their warm and comfortable characteristics. As a widely used winter heating device, the main function of electric blankets is to provide users with a warm and comfortable sleeping environment through electric heating.

[0003] At present, traditional electric blankets require manual temperature adjustment. Most traditional electric blankets only provide two-speed control, on and off, and users need to manually adjust the heating status of the electric blanket; this is not only cumbersome to operate, but also difficult to achieve precise temperature control; when the temperature of the electric blanket is too high, the user may face the risk of burns; and when the temperature is too low, the ideal heating effect cannot be achieved; traditional electric blankets often lack effective safety protection measures, such as overheating protection, short circuit protection, etc.; when the heating wire of the electric blanket is damaged or the circuit fails, it may cause serious safety accidents such as fire; in addition, the control systems of some electric blankets may lose control when components are damaged, further increasing safety risks; in addition to basic heating functions, traditional electric blankets usually lack intelligent functions such as timing and temperature display, and cannot meet users' higher demands for convenience and comfort; while pursuing low cost, how to ensure the performance and reliability of the electric blanket control system is an urgent problem to be solved. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an electric blanket and a control circuit thereof, which can automatically detect and control the temperature of the electric blanket, realize accurate temperature adjustment, and ensure the safety of the use of the electric blanket through a variety of safety protection measures. At the same time, the present invention also adds intelligent functions such as timing and temperature display, which improves the convenience of use of the electric blanket and the user experience.

[0005] The above objectives can be achieved through the following solutions: An electric blanket comprises a conversion module, a control module and a switch module; wherein the conversion module is used to convert an AC power supply into a DC power supply; the control module is connected to the conversion module and is used to receive the DC power supply and control the heating temperature of the electric blanket; the switch module is connected to the control module and is used to turn on or off according to the instruction of the control module to control the heating state of the electric blanket; wherein the control module detects the current temperature of a thermistor heating wire by collecting the resistance change of the thermistor heating wire and compares it with a preset temperature range, thereby adjusting the conduction time of the switch module to maintain the electric blanket working within the preset temperature range.

[0006] Furthermore, the conversion module includes: a chip KP3310, a fuse F1, a diode D1, a diode D2, a capacitor C1, a capacitor C2, a capacitor C3, a resistor R1, a varistor VR, a resistor R2, a resistor R3, and a resistor R4; wherein one end of the fuse F1 is connected to the live wire AC1, the other end of the fuse F1 is respectively connected to one end of the varistor VR, one end of the capacitor C1, one end of the resistor R1, and one end of the resistor R2, the other end of the resistor R1 is connected to one end of the resistor R3, and the neutral wire AC2, the other end of the varistor VR, the other end of the capacitor C1, and the other end of the resistor R3 are all connected to the ground terminal. The other end of the resistor R2 is connected to the input end of the diode D1, the output end of the diode D1 is connected to the input end of the diode D2, the output end of the diode D2 is respectively connected to the four Drain pins of the chip KP3310, the VOUT pin of the chip KP3310 is respectively connected to the control module and one end of the capacitor C3, the SEL pin of the chip KP3310 is connected to one end of the resistor R4, the VDD pin of the chip KP3310 is connected to one end of the capacitor C2, the GND pin of the chip KP3310, the other end of the capacitor C2, the other end of the capacitor C3, and the other end of the resistor R4 are respectively connected to the ground end.

[0007] Furthermore, the control module includes: a chip FT61F145-RB and a capacitor C4; wherein the VDD pin of the chip FT61F145-RB is respectively connected to one end of the capacitor C4 and one end of the capacitor C3, the other end of the capacitor C4 is connected to the ground, the AN3 pin of the chip FT61F145-RB, the AN5 pin of the chip FT61F145-RB, and the PB5 pin of the chip FT61F145-RB are respectively connected to the switch module, and the GND pin of the chip FT61F145-RB is connected to the ground.

[0008] Furthermore, the switch module includes: bidirectional thyristor T1, bidirectional thyristor T2, diode D3, voltage regulator D4, diode D5, capacitor C5, capacitor C6, capacitor C7, capacitor C87, capacitor C9, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, and resistor R16; wherein one end of the thermistor heating wire is connected to the live wire AC1, and the other end of the thermistor heating wire is connected to the input of the diode D3, respectively. The output end of the diode D3 is connected to one end of the resistor R5, the other end of the resistor R5 is respectively connected to one end of the resistor R6, one end of the resistor R7, and one end of the capacitor C5, the other end of the resistor R6 and the other end of the capacitor C5 are both connected to the ground, the other end of the resistor R7 is respectively connected to one end of the resistor R8, one end of the resistor R9, the first anode of the bidirectional thyristor T1, and the second anode of the bidirectional thyristor T2, the other end of the resistor R8 is respectively connected to one end of the capacitor C6, the chip FT61F145- The other end of the resistor R9 is connected to the control electrode of the bidirectional thyristor T1 and one end of the resistor R10 respectively, the other end of the resistor R10 is connected to one end of the resistor R11, the other end of the resistor R11 is connected to one end of the capacitor C7, the other end of the capacitor C7 is connected to one end of the resistor R12 and the output end of the voltage regulator D4 respectively, the input end of the voltage regulator D4 is grounded, the other end of the resistor R12 is connected to the capacitor C8 and the PB5 pin of the chip FT61F145-RB respectively, the capacitor C8 is connected to the PB6 pin of the chip FT61F145-RB respectively, the capacitor C8 is connected to the PB7 pin of the chip FT61F145-RB respectively, the capacitor C8 is connected to the PB6 ... The other end of is connected to one end of resistor R13, the other end of resistor R13 is respectively connected to the control electrode of bidirectional thyristor T2 and one end of resistor R14; the other end of resistor R14 is respectively connected to one end of resistor R15, one end of resistor R16, and the first anode of bidirectional thyristor T2, the other end of resistor R16 is respectively connected to one end of capacitor C9, the output end of diode D5, and AN5 pin of chip FT61F145-RB, the other end of resistor R15 is respectively connected to the other end of capacitor C9, the other end of diode D5, and ground.

[0009] Furthermore, the electric blanket also includes: a burn-through detection module, which is connected to the switch module and the control module, and is used to detect whether the heating wire in the electric blanket is burned through, and cut off the power supply when the burn-through is detected; wherein the burn-through detection module includes an auxiliary heating wire, a diode D6, a diode D7, a capacitor C10, a resistor R17, a resistor R18, and a resistor R19; one end of the auxiliary heating wire is connected to the second anode of the bidirectional thyristor T1, and the other end of the auxiliary heating wire is respectively connected to the input end of the diode D6 and the output end of the diode D7, the output end of the diode D6 is connected to one end of the resistor R17, the other end of the resistor R17 is respectively connected to one end of the capacitor C10, one end of the resistor R19, and the AN4 pin of the chip FT61F145-RB, the other end of the resistor R19 is respectively connected to the other end of the capacitor C10, one end of the resistor R18, and the ground end, and the other end of the resistor R18 is connected to the input end of the diode D7.

[0010] Furthermore, the electric blanket also includes: a zero-crossing detection and voltage reference module, which is connected to the control module and is used to detect the zero-crossing point of the alternating current and provide a voltage reference for the control module; wherein the zero-crossing detection and voltage reference module includes a capacitor C11, a diode D8, a resistor R20, a resistor R21, and a resistor R22; the input end of the diode D8 is connected to the live wire AC1, the output end of the diode D8 is respectively connected to one end of the resistor R20 and one end of the resistor R21, the other end of the resistor R20 is connected to the PA5 pin of the chip FT61F145-RB, the other end of the resistor R21 is respectively connected to one end of the resistor R22, one end of the capacitor C11, and the VREEP pin of the chip FT61F145-RB, and the other end of the capacitor C11 is respectively connected to the other end of the resistor R22 and the ground end.

[0011] Furthermore, the electric blanket also includes: a button module, connected to the control module, and used to set the working state of the electric blanket; wherein the button module includes a button W1, a button W2, and a button W3; one end of the button W1 is respectively connected to one end of the button W2, one end of the button W3, and the ground end, the other end of the button W1 is connected to the AN0 / CLKO pin of the chip FT61F145-RB, the other end of the button W2 is connected to the ISPCLK / USART-RX pin of the chip FT61F145-RB, and the other end of the button W3 is connected to the ISPDAT / AN6 pin of the chip FT61F145-RB.

[0012] Furthermore, the electric blanket also includes: a program burning interface module, which is connected to the control module and is used to burn or update the program in the control module; the program burning interface module is also used for using external buttons when the buttons are damaged; wherein the program burning interface module includes an interface Link1, a first pin of the interface Link1 is connected to the VDD pin of the chip FT61F145-RB, a second pin of the interface Link1 is connected to the ground terminal, a third pin of the interface Link1 is connected to the ISPDAT / AN6 pin of the chip FT61F145-RB, a fourth pin of the interface Link1 is connected to the AN0 / CLKO pin of the chip FT61F145-RB, and a fourth pin of the interface Link1 is connected to the ISPCLK / USART-RX pin of the chip FT61F145-RB.

[0013] Furthermore, the electric blanket also includes: a display module, which is connected to the control module and is used to display the current temperature or working status of the electric blanket; wherein the display module includes a resistor R23, a resistor R24, a light-emitting diode L1, a light-emitting diode L2, a light-emitting diode L3, a light-emitting diode L4, a light-emitting diode L5, a light-emitting diode L6, a light-emitting diode L7, a light-emitting diode L8, a light-emitting diode L9, a light-emitting diode L10, a light-emitting diode L11, a light-emitting diode L12, a light-emitting diode L13, and a light-emitting diode L14; one end of the resistor R23 is connected to the control module, and the other end of the resistor R23 is respectively connected to the output end of the light-emitting diode L1, the output end of the light-emitting diode L2, the output end of the light-emitting diode L3, the output end of the light-emitting diode L4, the output end of the light-emitting diode L5, the output end of the light-emitting diode L6, and the output end of the light-emitting diode L7; and the light-emitting diode L1 The input end of the light emitting diode L2, the input end of the light emitting diode L3, the input end of the light emitting diode L4, the input end of the light emitting diode L5, the input end of the light emitting diode L6, and the input end of the light emitting diode L7 are respectively connected to the control module; one end of the resistor R24 ​​is connected to the control module, and the other end of the resistor R24 ​​is respectively connected to the output end of the light emitting diode L8, the output end of the light emitting diode L9, the output end of the light emitting diode L10, the output end of the light emitting diode L11, the output end of the light emitting diode L12, the output end of the light emitting diode L13, and the output end of the light emitting diode L14, and the input end of the light emitting diode L8, the input end of the light emitting diode L9, the input end of the light emitting diode L10, the input end of the light emitting diode L11, the input end of the light emitting diode L12, the input end of the light emitting diode L13, and the input end of the light emitting diode L14 are respectively connected to the control module.

[0014] Based on the same inventive concept, the present invention also includes an electric blanket control circuit, and the electric blanket includes all the modules in any of the above electric blankets.

[0015] Compared with the prior art, the present invention has the following advantages: 1. The present invention can automatically control the temperature of the electric blanket within a preset range without manual adjustment by the user; by collecting the resistance change of the thermal sensitive resistor heating wire and converting it into a digital signal for processing, accurate temperature control is achieved, avoiding the problem of burns caused by too high temperature or poor heating effect caused by too low temperature; 2. The present invention has designed a variety of safety protection measures, such as thyristor self-test protection, zero-crossing detection and triggering, bidirectional thyristor drive, etc., to ensure the safety of the electric blanket during operation; in particular, the thyristor self-test protection can immediately stop working when any thyristor is damaged (such as open circuit, short circuit, poor conduction) to prevent the circuit from getting out of control; the present invention also includes heating wire burn-through protection, by detecting the coupling voltage change between the heating wire and the protection winding, timely discovering and cutting off the power supply, to prevent the heating wire from burning and causing safety hazards; 3. The present invention adopts an offline, inductor-free AC input linear regulator, namely, the chip KP3310, to achieve low-cost and high-performance power conversion. This design not only reduces the cost, but also reduces the volume and size of the circuit; the control module is implemented by the chip FT61F145-RB, which integrates the ADC module and EEPROM memory, has a reduced instruction set and hardware stack, improves processing efficiency and reliability, and reduces costs; 4. The present invention is equipped with a key module, including a power key, a heating key and a timing key. The user can set the heating time as needed to realize the timing off function, thereby improving the convenience of use; the present invention also includes a program burning interface, which can be used as a key backup interface. When the key is damaged, the function can be realized through an external key, thereby enhancing the flexibility and maintainability of the circuit; 5. The present invention realizes precise control of the heating power of the electric blanket through precise temperature control and PWM signal regulation, thus avoiding unnecessary energy waste and improving energy efficiency.

[0016] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a framework diagram of an electric blanket according to an embodiment of the present invention.

[0019] Figure 2 It is a schematic structural diagram of an electric blanket according to an embodiment of the present invention.

[0020] Figure 3 is a circuit diagram of a conversion module according to an embodiment of the present invention.

[0021] Figure 4 is a circuit diagram of a control module according to an embodiment of the present invention.

[0022] Figure 5 is a circuit diagram of a switch module according to an embodiment of the present invention.

[0023] Figure 6 4 is a circuit diagram of a burn-through detection module according to an embodiment of the present invention.

[0024] Figure 7 4 is a circuit diagram of a zero-crossing detection and voltage reference module according to an embodiment of the present invention.

[0025] Figure 8 4 is a circuit diagram of a key module according to an embodiment of the present invention.

[0026] Fig. 9 It is a circuit diagram of a program burning interface module according to an embodiment of the present invention.

[0027] Fig.10 is a circuit diagram of a display module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Reference Figure 1 One embodiment of the present invention provides an electric blanket that can automatically detect and control the temperature of the electric blanket, achieve accurate temperature adjustment, and ensure the safety of the use of the electric blanket through a variety of safety protection measures. At the same time, the present invention also adds intelligent functions such as timing and temperature display, which improves the convenience of use of the electric blanket and user experience.

[0030] The electric blanket of this embodiment specifically includes: a conversion module, a control module and a switch module; wherein, A conversion module, used for converting AC power into DC power; A control module, connected to the conversion module, for receiving a DC power supply and controlling the heating temperature of the electric blanket; A switch module, connected to the control module, used to switch on or off according to the instruction of the control module to control the heating state of the electric blanket; Among them, the control module detects the current temperature of the thermistor heating wire by collecting the resistance change of the thermistor heating wire, and compares it with the preset temperature range, thereby adjusting the conduction time of the switch module to maintain the electric blanket working within the preset temperature range.

[0031] Specifically, the electric blanket may use a thermosensitive resistor heating wire as a heating device to achieve a heating function, wherein the thermosensitive resistor heating wire may be a positive temperature coefficient thermistor heating wire, whose resistance increases with increasing temperature.

[0032] For example, Figure 2 As shown, the input end of the conversion module is connected to the AC power supply, the output end of the conversion module is connected to the control module, and the control module is connected to the switch module for controlling the switch module to be turned on or off. When the switch module is turned on or off, the AC power supply supplies power or does not supply power to the thermistor heating wire accordingly. The control module also obtains the current temperature of the thermistor heating wire through the switch module, and when the current temperature is not within the preset range, controls the on-time of the switch module so that the current temperature of the thermistor heating wire is within the preset range. Therefore, through the above method, the temperature of the thermistor heating wire can be controlled within the preset range to avoid burns caused by excessively high temperature or poor heating effect caused by excessively low temperature, and there is no need for manual temperature adjustment, which is convenient to use.

[0033] Furthermore, if Figure 3 As shown, the conversion module includes: chip KP3310, fuse F1, diode D1, diode D2, capacitor C1, capacitor C2, capacitor C3, resistor R1, varistor VR, resistor R2, resistor R3, resistor R4; wherein, One end of the fuse F1 is connected to the live wire AC1, the other end of the fuse F1 is respectively connected to one end of the varistor VR, one end of the capacitor C1, one end of the resistor R1, and one end of the resistor R2, the other end of the resistor R1 is connected to one end of the resistor R3, the neutral wire AC2, the other end of the varistor VR, the other end of the capacitor C1, and the other end of the resistor R3 are all connected to the ground terminal; The other end of the resistor R2 is connected to the input end of the diode D1, the output end of the diode D1 is connected to the input end of the diode D2, the output end of the diode D2 is respectively connected to the four Drain pins of the chip KP3310, the VOUT pin of the chip KP3310 is respectively connected to the control module and one end of the capacitor C3, the SEL pin of the chip KP3310 is connected to one end of the resistor R4, the VDD pin of the chip KP3310 is connected to one end of the capacitor C2, and the GND pin of the chip KP3310, the other end of the capacitor C2, the other end of the capacitor C3, and the other end of the resistor R4 are respectively connected to the ground end.

[0034] Specifically, in order to ensure the reliability of the circuit, the live wire AC1 of the AC power supply is also connected to a fuse F1; capacitors C2 and C3 can be electrolytic capacitors; the conversion module can be used to convert the AC power into a 5V DC voltage, that is, the voltage output by the VOUT pin of the chip KP3310 is 5V, which provides a working voltage for the control module; the chip KP3310 is an offline linear regulator with a non-inductor design, which has integrated protection functions with self-recovery functions, including VDD undervoltage protection, VDD overvoltage protection, output overload protection, output undervoltage protection, lightning surge protection and built-in over-temperature protection; by adopting an offline, non-inductor AC input linear regulator, low-cost and high-performance power conversion is achieved. This design not only reduces the cost, but also reduces the volume and size of the circuit.

[0035] Furthermore, if Figure 4 As shown, the control module includes: chip FT61F145-RB, capacitor C4; wherein, The VDD pin of the chip FT61F145-RB is connected to one end of capacitor C4 and one end of capacitor C3 respectively, the other end of capacitor C4 is connected to the ground, the AN3 pin of the chip FT61F145-RB, the AN5 pin of the chip FT61F145-RB, and the PB5 pin of the chip FT61F145-RB are connected to the switch module respectively, and the GND pin of the chip FT61F145-RB is connected to the ground.

[0036] Specifically, the control module includes the chip FT61F145-RB, which is implemented by a single-chip microcomputer, adopts a RISC reduced instruction set, a 16-layer hardware stack, integrates a 7-channel 12-resolution ADC module, and an 8-bit EEPROM storage, and a 20-pin TSSOP package; wherein, the control module also includes a capacitor C4, and the VDD pin of the chip FT61F145-RB is grounded through the capacitor C4; the VDD pin of the chip U1 is connected to the VOUT pin of the chip KP3310; by integrating the ADC module and the EEPROM storage, it has a reduced instruction set and hardware stack, which improves processing efficiency and reliability while reducing costs.

[0037] Furthermore, if Figure 5 As shown, the switch module includes: bidirectional thyristor T1, bidirectional thyristor T2, diode D3, voltage regulator D4, diode D5, capacitor C5, capacitor C6, capacitor C7, capacitor C87, capacitor C9, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16; wherein, One end of the thermistor heating wire is connected to the live wire AC1, the other end of the thermistor heating wire is respectively connected to the input end of the diode D3 and the second anode of the bidirectional thyristor T1, the output end of the diode D3 is connected to one end of the resistor R5, the other end of the resistor R5 is respectively connected to one end of the resistor R6, one end of the resistor R7, and one end of the capacitor C5, the other end of the resistor R6 and the other end of the capacitor C5 are both connected to the ground end, the other end of the resistor R7 is respectively connected to one end of the resistor R8, one end of the resistor R9, the first anode of the bidirectional thyristor T1, and the second anode of the bidirectional thyristor T2, the other end of the resistor R8 is respectively connected to one end of the capacitor C6 and the AN3 pin of the chip FT61F145-RB, and the other end of the capacitor C6 is grounded; The other end of the resistor R9 is connected to the control electrode of the bidirectional thyristor T1 and one end of the resistor R10 respectively, the other end of the resistor R10 is connected to one end of the resistor R11, the other end of the resistor R11 is connected to one end of the capacitor C7, the other end of the capacitor C7 is connected to one end of the resistor R12 and the output end of the voltage regulator D4 respectively, the input end of the voltage regulator D4 is grounded, the other end of the resistor R12 is connected to the capacitor C8 and the PB5 pin of the chip FT61F145-RB respectively, the other end of the capacitor C8 is connected to one end of the resistor R13, the other end of the resistor R13 is connected to the control electrode of the bidirectional thyristor T2 and one end of the resistor R14 respectively; The other end of the resistor R14 is respectively connected to one end of the resistor R15, one end of the resistor R16, and the first anode of the bidirectional thyristor T2. The other end of the resistor R16 is respectively connected to one end of the capacitor C9, the output end of the diode D5, and the AN5 pin of the chip FT61F145-RB. The other end of the resistor R15 is respectively connected to the other end of the capacitor C9, the other end of the diode D5, and the ground end.

[0038] Exemplarily, by adopting the driving mode of bidirectional thyristor T1 and bidirectional thyristor T2, when one of the bidirectional thyristors is short-circuited, the other bidirectional thyristor can work normally within the normal use cycle, and the chip FT61F145-RB can control the temperature of the thermistor heating wire through the normal bidirectional thyristor. When the normal use cycle is exceeded, the chip FT61F145-RB will report an error to prevent the bidirectional thyristor from being damaged and causing the circuit to be uncontrolled, thereby burning the thermistor heating wire and causing safety hazards; in addition, the AC and DC in the embodiment of the present invention are grounded, and voltage sampling is achieved through resistors R15 and R16. The chip FT61F145-RB collects the voltage signal across the resistor R15 through the AN5 pin. The voltage signal is an analog signal. By converting the analog voltage signal into a temperature digital value, the current temperature of the thermistor heating wire can be obtained.

[0039] Furthermore, if Figure 6 As shown, the electric blanket also includes: a burn-through detection module, which is connected to the switch module and the control module, and is used to detect whether the heating wire in the electric blanket is burnt through, and cut off the power supply when the burn-through is detected; wherein, The burn-through detection module includes an auxiliary heating wire, a diode D6, a diode D7, a capacitor C10, a resistor R17, a resistor R18, and a resistor R19; One end of the auxiliary heating wire is connected to the second anode of the bidirectional thyristor T1, and the other end of the auxiliary heating wire is respectively connected to the input end of the diode D6 and the output end of the diode D7, the output end of the diode D6 is connected to one end of the resistor R17, the other end of the resistor R17 is respectively connected to one end of the capacitor C10, one end of the resistor R19, and the AN4 pin of the chip FT61F145-RB, the other end of the resistor R19 is respectively connected to the other end of the capacitor C10, one end of the resistor R18, and the ground end, and the other end of the resistor R18 is connected to the input end of the diode D7.

[0040] Specifically, the thermistor heating wire includes a middle layer of heating wire, the outside of which is covered with a polyvinyl chloride layer with NTC characteristics, and the auxiliary heating wire is wound on the outer surface of the polyvinyl chloride layer of the thermistor heating wire. The material of the auxiliary heating wire can be copper, which has no temperature characteristics, and a layer of polyvinyl chloride rubber is covered on the outside of the auxiliary heating wire.

[0041] Exemplarily, when the thermistor heating wire is not heated, the polyvinyl chloride layer between the auxiliary heating wire and the heating wire in the thermistor heating wire is evenly distributed, and there is a coupling effect between the auxiliary heating wire and the heating wire, generating a weak AC voltage, and the voltage is collected through a first network composed of a diode D6, a resistor R17, a capacitor C10 and a resistor R19, wherein the diode D6 is a rectifier diode, which rectifies the AC into DC, the resistor R17 and the resistor R19 form a voltage divider network, and the capacitor C10 is a filter capacitor. The first network collects the voltage of the upper half cycle of the AC power, and the collected voltage is transmitted to the chip FT61F145-RB through the NTC pin. The diode D7 and the resistor R18 short-circuit the lower half cycle of the AC power to form a loop to release the voltage of the NTC pin to prevent the voltage of the NTC pin from being abnormal. When the thermistor heating wire is energized and heated, the polyvinyl chloride layer will The heating wire changes its characteristics due to heating, and the polyvinyl chloride layer gradually softens, resulting in a slight change in the spacing between the auxiliary heating wire and the heating wire in the thermistor heating wire. In addition, the temperature effect of the polyvinyl chloride layer is superimposed, so that the coupling voltage generated between the auxiliary heating wire and the heating wire in the thermistor heating wire becomes higher and higher. When the temperature reaches a certain value, or other abnormal reasons occur, the heating wire in the thermistor heating wire and the auxiliary heating wire are in direct contact. The chip FT61F145-RB can detect the abnormality of the heating wire in the thermistor heating wire according to the voltage collected by the first network, thereby controlling the bidirectional thyristor T1 and T2 to disconnect, cut off the power supply, and generate an alarm error code to send to the display module for display; by detecting the change in the coupling voltage between the heating wire and the protective winding, the power supply can be discovered and cut off in time to prevent the heating wire from burning and causing safety hazards.

[0042] Furthermore, if Figure 7 As shown, the electric blanket also includes: a zero-crossing detection and voltage reference module, which is connected to the control module and is used to detect the zero-crossing point of the alternating current and provide a voltage reference for the control module; wherein, The zero-crossing detection and voltage reference module includes a capacitor C11, a diode D8, a resistor R20, a resistor R21, and a resistor R22; The input end of the diode D8 is connected to the live wire AC1, the output end of the diode D8 is respectively connected to one end of the resistor R20 and one end of the resistor R21, the other end of the resistor R20 is connected to the PA5 pin of the chip FT61F145-RB, the other end of the resistor R21 is respectively connected to one end of the resistor R22, one end of the capacitor C11, and the VREEP pin of the chip FT61F145-RB, the other end of the capacitor C11 is respectively connected to the other end of the resistor R22 and the ground end.

[0043] Specifically, the AC power is directly introduced into the chip FT61F145-RB through the PA5 pin through the diode D8 and the resistor R20. The voltage is controlled within a reasonable range through the clamping circuit inside the chip FT61F145-RB, and the zero point of the sine wave can be accurately determined to achieve zero-crossing detection. In addition, the AC power can be converted into a weak voltage signal through the resistor R21, the resistor R22 and the capacitor C11, and given to the chip FT61F145-RB through the VREEP pin as the external reference power supply of the chip FT61F145-RB, so as to read the voltage at any point of the current AC power sine wave.

[0044] Furthermore, if Figure 8 As shown, the electric blanket also includes: a button module connected to the control module, used to set the working state of the electric blanket; wherein, The button module includes button W1, button W2, and button W3; One end of the button W1 is connected to one end of the button W2, one end of the button W3 and the ground end respectively. The other end of the button W1 is connected to the AN0 / CLKO pin of the chip FT61F145-RB. The other end of the button W2 is connected to the ISPCLK / USART-RX pin of the chip FT61F145-RB. The other end of the button W3 is connected to the ISPDAT / AN6 pin of the chip FT61F145-RB.

[0045] Exemplarily, one end of the power button W1, the heating button W2 and the timing button W3 are all grounded, and the other ends of the power button W1, the heating button W2 and the timing button W3 are respectively connected to the AN0 / CLKO pin, the ISPCLK / USART-RX pin and the ISPDAT / AN6 pin of the chip FT61F145-RB; when the power button W1 is activated, the chip FT61F145-RB is powered on and initialized, and when the heating button W2 is activated, the chip FT61F145-RB starts to control the conduction of the bidirectional thyristors T1 and T2, so that the AC power supply supplies power to the thermistor heating wire, and the thermistor heating wire performs heating work, and the timing button W3 is used to set the heating time, which is also the timing time; by equipping the button module, including the power button, the heating button and the timing button, the user can set the heating time as needed, realize the timing off function, and improve the convenience of use.

[0046] Furthermore, if Fig. 9 As shown, the electric blanket also includes: a program burning interface module, connected to the control module, for burning or updating the program in the control module; the program burning interface module is also used for external keys when the keys are damaged; wherein, The program burning interface module includes interface Link1, the first pin of interface Link1 is connected to the VDD pin of chip FT61F145-RB, the second pin of interface Link1 is connected to the ground terminal, the third pin of interface Link1 is connected to the ISPDAT / AN6 pin of chip FT61F145-RB, the fourth pin of interface Link1 is connected to the AN0 / CLKO pin of chip FT61F145-RB, and the fourth pin of interface Link1 is connected to the ISPCLK / USART-RX pin of chip FT61F145-RB.

[0047] Exemplarily, the program burning interface Link1 can be used as a button backup interface. When the power button W1, heating button W2 and timing button W3 are damaged, an external button can be connected through the program burning interface Link1 to implement the functions of the power button W1, heating button W2 and timing button W3. Thus, it can be used as a button backup interface to implement functions through external buttons when the buttons are damaged, thereby enhancing the flexibility and maintainability of the circuit.

[0048] Furthermore, if Fig.10 As shown, the electric blanket also includes: a display module, connected to the control module, for displaying the current temperature or working state of the electric blanket; wherein, The display module includes a resistor R23, a resistor R24, a light emitting diode L1, a light emitting diode L2, a light emitting diode L3, a light emitting diode L4, a light emitting diode L5, a light emitting diode L6, a light emitting diode L7, a light emitting diode L8, a light emitting diode L9, a light emitting diode L10, a light emitting diode L11, a light emitting diode L12, a light emitting diode L13, and a light emitting diode L14; One end of the resistor R23 is connected to the control module, and the other end of the resistor R23 is respectively connected to the output end of the light-emitting diode L1, the output end of the light-emitting diode L2, the output end of the light-emitting diode L3, the output end of the light-emitting diode L4, the output end of the light-emitting diode L5, the output end of the light-emitting diode L6, and the output end of the light-emitting diode L7, and the input end of the light-emitting diode L1, the input end of the light-emitting diode L2, the input end of the light-emitting diode L3, the input end of the light-emitting diode L4, the input end of the light-emitting diode L5, the input end of the light-emitting diode L6, and the input end of the light-emitting diode L7 are respectively connected to the control module; One end of resistor R24 ​​is connected to the control module, and the other end of resistor R24 ​​is respectively connected to the output end of light-emitting diode L8, the output end of light-emitting diode L9, the output end of light-emitting diode L10, the output end of light-emitting diode L11, the output end of light-emitting diode L12, the output end of light-emitting diode L13, and the output end of light-emitting diode L14, and the input end of light-emitting diode L8, the input end of light-emitting diode L9, the input end of light-emitting diode L10, the input end of light-emitting diode L11, the input end of light-emitting diode L12, the input end of light-emitting diode L13, and the input end of light-emitting diode L14 are respectively connected to the control module.

[0049] Specifically, the display module is used to display the current temperature of the thermistor heating wire. The display module is implemented by a digital tube array composed of discrete lamp beads, and a plastic part is put on the lamp beads for light collection, which can effectively reduce costs; the input end of the light-emitting diode L1 and the input end of the light-emitting diode L8 are connected to the PB3 pin of the chip FT61F145-RB, the input end of the light-emitting diode L2 and the input end of the light-emitting diode L9 are connected to the PB4 pin of the chip FT61F145-RB, the input end of the light-emitting diode L3 and the input end of the light-emitting diode L10 are connected to the PB2 pin of the chip FT61F145-RB, and the input end of the light-emitting diode L4 is connected to the PB6 pin of the chip FT61F145-RB. The input end of the light-emitting diode L5 and the input end of the light-emitting diode L12 are connected to the PA0 pin of the chip FT61F145-RB, the input end of the light-emitting diode L6 and the input end of the light-emitting diode L13 are connected to the AN1 pin of the chip FT61F145-RB, the input end of the light-emitting diode L7 and the input end of the light-emitting diode L14 are connected to the AN2 pin of the chip FT61F145-RB; the chip FT61F145-RB also displays the current temperature of the thermistor heating wire through the display module.

[0050] For example, when the electric blanket needs to heat up, first press the power button W1 to connect the control circuit to the AC power supply, and the chip FT61F145-RB is powered on and initialized, such as the clock, RAM, watchdog and various functions. After successful initialization, the chip FT61F145-RB enters the standby state. When the heating button W2 is pressed, it is activated, and the chip FT61F145-RB outputs a PWM control signal through the PB5 pin. The PWM control signal is divided into two paths. One path controls the intermittent conduction of the bidirectional thyristor T1 through the resistor R12, the capacitor C7, the resistor R11 and the resistor R10, and the other path controls the intermittent conduction of the bidirectional thyristor T2 through the capacitor C8 and the resistor R13. When the bidirectional thyristor T1 and the bidirectional thyristor T2 are both turned on, the branch where the thermistor heating wire is located forms a passage, and the thermistor heating wire obtains the working voltage through the live wire AC1 of the AC power supply and generates heat during operation. The temperature can be controlled by controlling the duty cycle of the PWM control signal. The larger the duty cycle, the longer the conduction time of the bidirectional thyristors T1 and T2, the higher the heat generated by the thermistor heating wire, and the higher the temperature. When the duty cycle is small, the conduction time of the bidirectional thyristors T1 and T2 is reduced, the heat generated is reduced, and the temperature is reduced, thereby achieving Conduction control and temperature control; Among them, the chip FT61F145-RB can detect the temperature of the thermistor heating wire through the signal of the AN5 pin, and obtain the current temperature of the thermistor heating wire. If the current temperature is higher than the preset range, a PWM control signal with a small duty cycle is output to reduce the heat of the thermistor heating wire. If the current temperature is lower than the preset range, a PWM signal with a large duty cycle is output to increase the heat of the thermistor heating wire, so that the current temperature is maintained within the preset range and the temperature is kept constant; Among them, the chip FT61F145-RB can detect the working status (on or off) of the bidirectional thyristor T1 and T2 through the signal of the AN3 pin, and realize the monitoring of the bidirectional thyristor T1 and T2; Through precise temperature control and PWM signal adjustment, precise control of the heating power of the electric blanket is achieved, unnecessary energy waste is avoided, and the energy efficiency ratio is improved.

[0051] Based on the same inventive concept, the present invention also includes an electric blanket control circuit, which includes all the modules in any of the above electric blankets.

[0052] It should be noted that the electrical connection between the above-mentioned units does not necessarily mean the connection between the lines. The indirect connection method can be applied to the embodiments of the present invention as long as the purpose of the present invention is achieved. The above are only exemplary embodiments of the present invention and cannot limit the scope of the present invention.

[0053] That is, any equivalent changes and modifications made according to the teachings of the present invention are still within the scope of the present invention. After considering the disclosure of the specification and the truth of practice, those skilled in the art will easily think of other embodiments of the present invention. This application is intended to cover any variation, use or adaptive change of the present invention, which follows the general principles of the present invention and includes common knowledge or customary technical means in the art that are not described in the present invention.

Claims

1. An electric blanket, characterized in that: The electric blanket includes: a conversion module, a control module and a switch module; wherein, A conversion module, used for converting AC power into DC power; A control module, connected to the conversion module, for receiving a DC power supply and controlling the heating temperature of the electric blanket; A switch module, connected to the control module, used to switch on or off according to the instruction of the control module to control the heating state of the electric blanket; Among them, the control module detects the current temperature of the thermistor heating wire by collecting the resistance change of the thermistor heating wire, and compares it with the preset temperature range, thereby adjusting the conduction time of the switch module to maintain the electric blanket working within the preset temperature range.

2. An electric blanket according to claim 1, characterized in that The conversion module includes: chip KP3310, fuse F1, diode D1, diode D2, capacitor C1, capacitor C2, capacitor C3, resistor R1, varistor VR, resistor R2, resistor R3, resistor R4; wherein, One end of the fuse F1 is connected to the live wire AC1, the other end of the fuse F1 is respectively connected to one end of the varistor VR, one end of the capacitor C1, one end of the resistor R1, and one end of the resistor R2, the other end of the resistor R1 is connected to one end of the resistor R3, the neutral wire AC2, the other end of the varistor VR, the other end of the capacitor C1, and the other end of the resistor R3 are all connected to the ground terminal; The other end of the resistor R2 is connected to the input end of the diode D1, the output end of the diode D1 is connected to the input end of the diode D2, the output end of the diode D2 is respectively connected to the four Drain pins of the chip KP3310, the VOUT pin of the chip KP3310 is respectively connected to the control module and one end of the capacitor C3, the SEL pin of the chip KP3310 is connected to one end of the resistor R4, the VDD pin of the chip KP3310 is connected to one end of the capacitor C2, and the GND pin of the chip KP3310, the other end of the capacitor C2, the other end of the capacitor C3, and the other end of the resistor R4 are respectively connected to the ground end.

3. An electric blanket according to claim 1, characterized in that: The control module includes: chip FT61F145-RB, capacitor C4; among them, The VDD pin of the chip FT61F145-RB is connected to one end of capacitor C4 and one end of capacitor C3 respectively, the other end of capacitor C4 is connected to the ground, the AN3 pin of the chip FT61F145-RB, the AN5 pin of the chip FT61F145-RB, and the PB5 pin of the chip FT61F145-RB are connected to the switch module respectively, and the GND pin of the chip FT61F145-RB is connected to the ground.

4. An electric blanket according to claim 3, characterized in that The switch module includes: bidirectional thyristor T1, bidirectional thyristor T2, diode D3, voltage regulator D4, diode D5, capacitor C5, capacitor C6, capacitor C7, capacitor C87, capacitor C9, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16; wherein, One end of the thermistor heating wire is connected to the live wire AC1, the other end of the thermistor heating wire is respectively connected to the input end of the diode D3 and the second anode of the bidirectional thyristor T1, the output end of the diode D3 is connected to one end of the resistor R5, the other end of the resistor R5 is respectively connected to one end of the resistor R6, one end of the resistor R7, and one end of the capacitor C5, the other end of the resistor R6 and the other end of the capacitor C5 are both connected to the ground end, the other end of the resistor R7 is respectively connected to one end of the resistor R8, one end of the resistor R9, the first anode of the bidirectional thyristor T1, and the second anode of the bidirectional thyristor T2, the other end of the resistor R8 is respectively connected to one end of the capacitor C6 and the AN3 pin of the chip FT61F145-RB, and the other end of the capacitor C6 is grounded; The other end of the resistor R9 is connected to the control electrode of the bidirectional thyristor T1 and one end of the resistor R10 respectively, the other end of the resistor R10 is connected to one end of the resistor R11, the other end of the resistor R11 is connected to one end of the capacitor C7, the other end of the capacitor C7 is connected to one end of the resistor R12 and the output end of the voltage regulator D4 respectively, the input end of the voltage regulator D4 is grounded, the other end of the resistor R12 is connected to the capacitor C8 and the PB5 pin of the chip FT61F145-RB respectively, the other end of the capacitor C8 is connected to one end of the resistor R13, the other end of the resistor R13 is connected to the control electrode of the bidirectional thyristor T2 and one end of the resistor R14 respectively; The other end of the resistor R14 is respectively connected to one end of the resistor R15, one end of the resistor R16, and the first anode of the bidirectional thyristor T2. The other end of the resistor R16 is respectively connected to one end of the capacitor C9, the output end of the diode D5, and the AN5 pin of the chip FT61F145-RB. The other end of the resistor R15 is respectively connected to the other end of the capacitor C9, the other end of the diode D5, and the ground end.

5. An electric blanket according to claim 4, characterized in that The electric blanket also includes: a burn-through detection module, which is connected to the switch module and the control module, and is used to detect whether the heating wire in the electric blanket is burnt through, and cut off the power supply when burn-through is detected; wherein, The burn-through detection module includes an auxiliary heating wire, a diode D6, a diode D7, a capacitor C10, a resistor R17, a resistor R18, and a resistor R19; One end of the auxiliary heating wire is connected to the second anode of the bidirectional thyristor T1, and the other end of the auxiliary heating wire is respectively connected to the input end of the diode D6 and the output end of the diode D7, the output end of the diode D6 is connected to one end of the resistor R17, the other end of the resistor R17 is respectively connected to one end of the capacitor C10, one end of the resistor R19, and the AN4 pin of the chip FT61F145-RB, the other end of the resistor R19 is respectively connected to the other end of the capacitor C10, one end of the resistor R18, and the ground end, and the other end of the resistor R18 is connected to the input end of the diode D7.

6. An electric blanket according to claim 4, characterized in that The electric blanket also includes: a zero-crossing detection and voltage reference module, which is connected to the control module and is used to detect the zero-crossing point of the alternating current and provide a voltage reference for the control module; wherein, The zero-crossing detection and voltage reference module includes a capacitor C11, a diode D8, a resistor R20, a resistor R21, and a resistor R22; The input end of the diode D8 is connected to the live wire AC1, the output end of the diode D8 is respectively connected to one end of the resistor R20 and one end of the resistor R21, the other end of the resistor R20 is connected to the PA5 pin of the chip FT61F145-RB, the other end of the resistor R21 is respectively connected to one end of the resistor R22, one end of the capacitor C11, and the VREEP pin of the chip FT61F145-RB, the other end of the capacitor C11 is respectively connected to the other end of the resistor R22 and the ground end.

7. An electric blanket according to claim 4, characterized in that The electric blanket also includes: a button module, connected to the control module, for setting the working state of the electric blanket; wherein, The button module includes button W1, button W2, and button W3; One end of the button W1 is connected to one end of the button W2, one end of the button W3 and the ground end respectively. The other end of the button W1 is connected to the AN0 / CLKO pin of the chip FT61F145-RB. The other end of the button W2 is connected to the ISPCLK / USART-RX pin of the chip FT61F145-RB. The other end of the button W3 is connected to the ISPDAT / AN6 pin of the chip FT61F145-RB.

8. An electric blanket according to claim 4, characterized in that The electric blanket also includes: a program burning interface module, which is connected to the control module and is used to burn or update the program in the control module; the program burning interface module is also used to connect an external key when the key is damaged; wherein, The program burning interface module includes interface Link1, the first pin of interface Link1 is connected to the VDD pin of chip FT61F145-RB, the second pin of interface Link1 is connected to the ground terminal, the third pin of interface Link1 is connected to the ISPDAT / AN6 pin of chip FT61F145-RB, the fourth pin of interface Link1 is connected to the AN0 / CLKO pin of chip FT61F145-RB, and the fourth pin of interface Link1 is connected to the ISPCLK / USART-RX pin of chip FT61F145-RB.

9. An electric blanket according to claim 1, characterized in that: The electric blanket also includes: a display module, connected to the control module, for displaying the current temperature or working state of the electric blanket; wherein, The display module includes a resistor R23, a resistor R24, a light emitting diode L1, a light emitting diode L2, a light emitting diode L3, a light emitting diode L4, a light emitting diode L5, a light emitting diode L6, a light emitting diode L7, a light emitting diode L8, a light emitting diode L9, a light emitting diode L10, a light emitting diode L11, a light emitting diode L12, a light emitting diode L13, and a light emitting diode L14; One end of the resistor R23 is connected to the control module, and the other end of the resistor R23 is respectively connected to the output end of the light-emitting diode L1, the output end of the light-emitting diode L2, the output end of the light-emitting diode L3, the output end of the light-emitting diode L4, the output end of the light-emitting diode L5, the output end of the light-emitting diode L6, and the output end of the light-emitting diode L7, and the input end of the light-emitting diode L1, the input end of the light-emitting diode L2, the input end of the light-emitting diode L3, the input end of the light-emitting diode L4, the input end of the light-emitting diode L5, the input end of the light-emitting diode L6, and the input end of the light-emitting diode L7 are respectively connected to the control module; One end of resistor R24 ​​is connected to the control module, and the other end of resistor R24 ​​is respectively connected to the output end of light-emitting diode L8, the output end of light-emitting diode L9, the output end of light-emitting diode L10, the output end of light-emitting diode L11, the output end of light-emitting diode L12, the output end of light-emitting diode L13, and the output end of light-emitting diode L14, and the input end of light-emitting diode L8, the input end of light-emitting diode L9, the input end of light-emitting diode L10, the input end of light-emitting diode L11, the input end of light-emitting diode L12, the input end of light-emitting diode L13, and the input end of light-emitting diode L14 are respectively connected to the control module.

10. An electric blanket control circuit, characterized in that: The control circuit comprises all modules in the electric blanket according to any one of claims 1 to 9.

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