Safety electric blanket

Abstract

The present invention relates to a safety electric blanket, comprising a main control circuit, a constant temperature circuit, a detection circuit, a heating wire, an overheat protection circuit for overheat detection and fusing, a power circuit for connecting to a mains power supply, and a fuse F1 for being arranged between the mains power supply and the power circuit; the power circuit is respectively connected to one end of the heating wire, the main control circuit, the detection circuit, and the overheat protection circuit to provide power; the main control circuit is respectively connected to the detection circuit, the overheat protection circuit, and the constant temperature circuit; the overheat protection circuit is connected to the fuse F1 to control the fuse F1 to fuse, and the constant temperature circuit is connected to the other end of the heating wire to control the working state of the heating wire; the electric blanket plays an automatic over-temperature protection role, improves the overall safety of the electric blanket, prolongs the service life of the electric blanket, ensures the personal safety of the user, and can also detect the local overheating of the electric blanket.

Description

Technical Field

[0001] The invention relates to the technical field of electric blankets, in particular to a safe electric blanket. Background Art

[0002] With the continuous development of science and technology, people's living standards are getting higher and higher, especially the requirements for living and working environment, such as the requirements for electric blankets, which are warming products. Electric blankets are products that people often use indoors. They can be placed on the ground, on a chair, or on a bed.

[0003] The existing electric blanket has poor safety. Once the temperature is too high and the power cannot be turned off in time, it will endanger the personal safety of the user and also shorten the service life of the electric blanket.

[0004] Therefore, in the patent application of the present invention, the applicant has carefully studied a safe electric blanket to solve the above problems. Summary of the invention

[0005] The present invention aims to overcome the deficiencies in the above-mentioned prior art and its main purpose is to provide a safe electric blanket, which has an automatic over-temperature protection function, improves the overall safety of the electric blanket, extends the service life of the electric blanket, ensures the personal safety of the user, and can also detect local overheating of the electric blanket.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme:

[0007] A safety electric blanket, comprising a main control circuit, a constant temperature circuit, a detection circuit, an electric heating wire, an overheat protection circuit for overheat detection and fusing, a power supply circuit for connecting to a mains power supply, and a fuse F1 for being arranged between a live wire in the mains power supply and the power supply circuit;

[0008] The power supply circuit is respectively connected to one end of the heating wire, the main control circuit, the detection circuit and the overheat protection circuit to provide power;

[0009] The main control circuit is connected to the detection circuit, the overheat protection circuit and the constant temperature circuit respectively. The overheat protection circuit is connected to the fuse F1 to control the fuse F1 to melt. The constant temperature circuit is connected to the other end of the heating wire to control the working state of the heating wire.

[0010] As a preferred solution, the main control circuit includes a main control chip U1, and the main control chip U1 has main control pins 1 to 20;

[0011] The main control pin 1 is connected to the analog ground, the main control pin 20 is connected to the analog ground through capacitor C7, the power supply circuit connects the main control pin 19 and the main control pin 20, the main control pin 16 and the main control pin 17 are connected to the detection circuit, the main control pin 15 and the main control pin 18 are connected to the overheat protection circuit, and the main control pin 13 is connected to the constant temperature circuit.

[0012] As a preferred solution, the detection circuit includes resistors R2, R10, R11 and R12, wherein the resistor R11 has a first detection end and a second detection end for connecting to the AC power supply, the first detection end is connected to the analog ground through the resistor R12, and the main control circuit is connected to the first detection end; the two ends of the resistor R2 are respectively connected to the analog ground and the digital ground, and the main control circuit is connected to the digital ground through the resistor R10.

[0013] As a preferred solution, the overheat protection circuit includes a diode D4, a diode D3, a transistor Q2, a resistor R21, a resistor R17, a resistor R39, a resistor R9 and a temperature detection unit;

[0014] The diode D4 has a first anode and a first cathode for connecting to the neutral line of the mains, the diode D3 has a second anode and a second cathode, the first anode and the second anode are connected to the temperature detection unit through a resistor R21, the temperature detection unit is connected to the main control circuit through a resistor R39, and the main control circuit is also connected to the analog ground through a resistor R9;

[0015] The second cathode is connected to the analog ground, the base of the transistor Q2 is connected to the analog ground, the emitter of the transistor Q2 is connected to the main control circuit through the resistor R17, and the collector of the transistor Q2 is connected to the temperature detection unit.

[0016] As a preferred solution, the temperature detection unit is a thermistor.

[0017] As a preferred solution, the resistor R21 is a heating resistor, and the heating resistor is arranged on one side of the fuse F1 so that the heat generated by the heating resistor melts the fuse F1.

[0018] As a preferred solution, the resistor R21 is a heating resistor, and the heating resistor is closely connected to the fuse F1.

[0019] As a preferred solution, the constant temperature circuit includes a unidirectional thyristor Q1, a resistor R19, a resistor R20 and a capacitor C6;

[0020] The control electrode of the unidirectional thyristor Q1 is connected to the main control circuit through the resistor R20 and the capacitor C6, the T1 electrode of the unidirectional thyristor Q1 is connected to the digital ground, the T1 electrode of the thyristor Q1 is also connected to the control electrode of the unidirectional thyristor Q1 through the resistor R19 and the resistor R20, and the T2 electrode of the unidirectional thyristor Q1 is connected to the other end of the heating wire.

[0021] As a preferred solution, a display circuit is also included, the display circuit includes a display chip LCD1, a resistor R13, a resistor R15, a resistor R16 and resistors R3 to R7, and the display chip LCD1 has display pins 1 to 9;

[0022] The main control pin 11 is connected to the display pin 1, the display pin 1 is connected to the analog ground through the resistor R5, and the display pin 1 is connected to the power circuit through the resistor R6;

[0023] The main control pin 12 is connected to the display pin 2, the display pin 2 is connected to the analog ground through the resistor R3, and the display pin 1 is connected to the power circuit through the resistor R4;

[0024] The main control pin 2 is connected to the display pin 3, the display pin 3 is connected to the analog ground through the resistor R15, and the display pin 1 is connected to the power circuit through the resistor R16;

[0025] The main control pin 3 is connected to the display pin 4, the display pin 4 is connected to the analog ground through the resistor R13, and the display pin 1 is connected to the power supply circuit through the resistor R7.

[0026] As a preferred solution, a function button circuit is also included, and the function button circuit includes a power button SW1, an upshift button SW2, a downshift button SW3, a first timing adjustment button SW4, a second timing adjustment button SW5, a resistor R26, a resistor R29, and resistors R31 to R33;

[0027] One end of the power button SW1 is connected to the display pin 7 through the resistor R31, and the main control pin 8 is connected to the display pin 7; one end of the upshift button SW2 is connected to the display pin 5 through the resistor R26, and the main control pin 10 is connected to the display pin 5; one end of the downshift button SW3 is connected to the display pin 6 through the resistor R29, and the main control pin 9 is connected to the display pin 6; one end of the first timing adjustment button SW4 is connected to the display pin 9 through the resistor R33, and the main control pin 6 is connected to the display pin 9; one end of the second timing adjustment button SW5 is connected to the display pin 8 through the resistor R32, and the main control pin 7 is connected to the display pin 8;

[0028] The other end of the power button SW1, the other end of the upshift button SW2, the other end of the downshift button SW3, the other end of the first timing adjustment button SW4 and the other end of the second timing adjustment button SW5.

[0029] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, the present invention can detect the temperature of the electric blanket in real time through the detection circuit. Once the maximum temperature is exceeded, the main control circuit will control the overheat protection circuit to make the fuse blow, thereby playing an automatic over-temperature protection role, improving the overall safety of the electric blanket, extending the service life of the electric blanket, and ensuring the personal safety of the user. In particular, through the design of the overheat protection circuit, the local overheating of the electric blanket can be detected;

[0030] Secondly, through the display circuit and the function button circuit, the working status of the electric blanket can be intuitively understood and adjusted, and the controllability is good;

[0031] Furthermore, the heating resistor is set on one side of the fuse F1 or is closely connected to the fuse F1. When the temperature of the electric blanket exceeds the set maximum temperature, the main control circuit increases the current passing through the heating resistor, causing the heating resistor to generate high heat and then melt the fuse F1. The fusing method is simple, and the automatic fusing function is achieved, which has good practicality. In addition, the overall circuit structure design is ingenious and reasonable, ensuring the stability and reliability of the electric blanket during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a control principle block diagram of an embodiment of the present invention;

[0033] Figure 2 It is a schematic circuit diagram of an embodiment of the present invention.

[0034] Description of Figure Numbers:

[0035] 10. Main control circuit 20. Constant temperature circuit

[0036] 30. Detection circuit 40. Heating wire

[0037] 50. Overheat protection circuit 60. Power supply circuit

[0038] 71. Display circuit 72. Function key circuit. DETAILED DESCRIPTION

[0039] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0040] like Figure 1 and Figure 2 As shown, the present invention is a safe electric blanket, comprising a main control circuit 10, a constant temperature circuit 20, a detection circuit 30, a heating wire 40, an overheat protection circuit 50 for overheat detection and fusing, a power supply circuit 60 for connecting to the mains, and a fuse F1 for being arranged between the live wire in the mains and the power supply circuit 60, one end of the fuse F1 is connected to the live wire, and the other end of the fuse F1 is connected to the analog ground.

[0041] The power supply circuit 60 is respectively connected to one end of the heating wire 40, the main control circuit 10, the detection circuit 30 and the overheat protection circuit 50 to provide power; in this embodiment, the power supply circuit 60 includes a varistor VR1, a resistor R1, a resistor R8, a resistor R18, a resistor R22, a capacitor C1, a capacitor C3, a polar capacitor C4, a capacitor C5, a diode D2, a diode D1, a Zener diode Z1 and a Zener diode Z2, wherein the anode of the polar capacitor C4 outputs a 5V voltage.

[0042] The main control circuit 10 is connected to the detection circuit 30, the overheat protection circuit 50 and the constant temperature circuit 20 respectively. The overheat protection circuit 50 is connected to the fuse F1 to control the fuse F1 to melt. The constant temperature circuit 20 is connected to the other end of the heating wire 40 to control the working state of the heating wire 40.

[0043] In this embodiment, the main control circuit 10 includes a main control chip U1. Preferably, the model of the main control chip U1 is HT66F018. The main control chip U1 has main control pins 1 to 20.

[0044] The main control pin 1 is connected to the analog ground, the main control pin 20 is connected to the analog ground through the capacitor C7, the power supply circuit 60 is connected to the main control pin 19 and the main control pin 20, the main control pin 16 and the main control pin 17 are both connected to the detection circuit 30, the main control pin 15 and the main control pin 18 are both connected to the overheat protection circuit 50, and the main control pin 13 is connected to the constant temperature circuit 20.

[0045] In this embodiment, the detection circuit 30 includes a resistor R2, a resistor R10, a resistor R11 and a resistor R12, wherein the resistor R11 has a first detection end and a second detection end for connecting to the mains, the first detection end is connected to the analog ground through the resistor R12, and the main control pin 17 of the main control circuit 10 is connected to the first detection end; the two ends of the resistor R2 are connected to the analog ground and the digital ground respectively, and the main control pin 16 of the main control circuit 10 is connected to the digital ground through the resistor R10. The main control pin 17 and the main control pin 16 of the main control circuit 10 are used to receive the signal (such as the current signal and the voltage signal) detected in the detection circuit 30, and the main control circuit 10 will calculate the real-time temperature of the heating wire 40 according to the above signal combined with the characteristics of the heating wire 40. The main control circuit 10 monitors the temperature of the heating wire 40 in real time. When the temperature of the heating wire 40 is lower than the set temperature value, the constant temperature circuit 20 is controlled to increase the temperature of the heating wire 40; when the temperature of the heating wire 40 is higher than the set temperature value, the constant temperature circuit 20 is controlled to stop increasing the temperature of the heating wire 40, and this process is repeated continuously to achieve a constant temperature effect.

[0046] The overheat protection circuit 50 includes a diode D4, a diode D3, a transistor Q2, a resistor R21, a resistor R17, a resistor R39, a resistor R9 and a temperature detection unit;

[0047] The resistor R21 is a heating resistor, and the heating resistor is arranged on one side of the fuse F1 so that the heat generated by the heating resistor melts the fuse F1, or the heating resistor is closely connected to the fuse F1. If the temperature of the electric blanket exceeds the set maximum temperature or there is uncontrollable continuous heating, the main control pin 18 controls Q2 to turn on, and at the same time, the main control pin 15 outputs a high current, and the high current flows back to the neutral line through the resistor R21 and the diode D4 in turn. Since the resistor R21 is a heating resistor, the current increases, causing the resistor R21 to generate high heat, and then fuse F1 is melted, realizing the active fusing function and improving user safety.

[0048] It should be noted that the detection circuit 30 of the present embodiment can also monitor in real time whether an uncontrollable electrical signal occurs when the main control chip U1 is powered on but not used by the user (i.e., in the off state). If an uncontrollable electrical signal occurs, the main control circuit 10 will output a high current to the resistor R21. Since the resistor R21 is a heating resistor, the current increases, causing the resistor R21 to generate high heat, which then blows the fuse F1, thereby realizing an active fusing function and further improving user safety.

[0049] The diode D4 has a first anode and a first cathode for connecting to the neutral line of the mains, the diode D3 has a second anode and a second cathode, the first anode and the second anode are connected to the temperature detection unit through a resistor R21, the temperature detection unit is connected to the main control circuit 10 through a resistor R39, and the main control pin 15 of the main control circuit 10 is also connected to the analog ground through a resistor R9;

[0050] The second cathode is connected to the analog ground, the base of the transistor Q2 is connected to the analog ground, the emitter of the transistor Q2 is connected to the main control pin 18 of the main control circuit 10 through the resistor R17, and the collector of the transistor Q2 is connected to the temperature detection unit. Preferably, the temperature detection unit is a thermistor. The temperature detection unit is used to detect whether the electric blanket is partially folded for use. If local overheating is detected, the electric blanket is judged to be partially folded for use. At this time, the main control circuit 10 controls the constant temperature circuit 20 to suspend heating the heating wire 40 through the main control pin 15. When the local overheating reaches the safety limit of the fuse F1, the passive fusing will be activated, that is, the temperature of the local overheating is allowed to reach the temperature at which the fuse is blown.

[0051] The thermostatic circuit 20 includes a unidirectional thyristor Q1, a resistor R19, a resistor R20 and a capacitor C6; preferably, the model of the unidirectional thyristor Q1 is BT134. The control electrode of the unidirectional thyristor Q1 is connected to the main control pin 13 of the main control circuit 10 through the resistor R20 and the capacitor C6, the T1 electrode of the unidirectional thyristor Q1 is connected to the digital ground, the T1 electrode of the thyristor Q1 is also connected to the control electrode of the unidirectional thyristor Q1 through the resistor R19 and the resistor R20, and the T2 electrode of the unidirectional thyristor Q1 is connected to the other end of the heating wire 40. The main control circuit 10 controls the thermostatic circuit 20 to heat the heating wire 40 through the main control pin 15.

[0052] It also includes a display circuit 71, through which the gear position and the timing time can be displayed. The display circuit 71 includes a display chip LCD1, a resistor R13, a resistor R15, a resistor R16, and resistors R3 to R7. The display chip LCD1 has display pins 1 to 9;

[0053] The main control pin 11 is connected to the display pin 1, the display pin 1 is connected to the analog ground through the resistor R5, and the display pin 1 is connected to the power circuit 60 through the resistor R6; the main control pin 12 is connected to the display pin 2, the display pin 2 is connected to the analog ground through the resistor R3, and the display pin 1 is connected to the power circuit 60 through the resistor R4; the main control pin 2 is connected to the display pin 3, the display pin 3 is connected to the analog ground through the resistor R15, and the display pin 1 is connected to the power circuit 60 through the resistor R16; the main control pin 3 is connected to the display pin 4, the display pin 4 is connected to the analog ground through the resistor R13, and the display pin 1 is connected to the power circuit 60 through the resistor R7.

[0054] It also includes a function button circuit 72, through which the power can be turned on and off, and the temperature level and timing can be adjusted. The function button circuit 72 includes a power button SW1, a gear up button SW2, a gear down button SW3, a first timing adjustment button SW4, a second timing adjustment button SW5, a resistor R26, a resistor R29, and resistors R31 to R33;

[0055] One end of the power button SW1 is connected to display pin 7 through resistor R31, and the main control pin 8 is connected to display pin 7; one end of the upshift button SW2 is connected to display pin 5 through resistor R26, and the main control pin 10 is connected to display pin 5; one end of the downshift button SW3 is connected to display pin 6 through resistor R29, and the main control pin 9 is connected to display pin 6; one end of the first timing adjustment button SW4 is connected to display pin 9 through resistor R33, and the main control pin 6 is connected to display pin 9; one end of the second timing adjustment button SW5 is connected to display pin 8 through resistor R32, and the main pin 7 is connected to display pin 8; the other end of the power button SW1, the other end of the upshift button SW2, the other end of the downshift button SW3, the other end of the first timing adjustment button SW4 and the other end of the second timing adjustment button SW5.

[0056] The key points of the design of the present invention are: it can detect the temperature of the electric blanket in real time mainly through the detection circuit. Once the maximum temperature is exceeded, the main control circuit will control the overheat protection circuit to make the fuse blow, which plays an automatic over-temperature protection role, improves the overall safety of the electric blanket, extends the service life of the electric blanket, and ensures the personal safety of the user. In particular, through the design of the overheat protection circuit, it can detect the local overheating of the electric blanket;

[0057] Secondly, through the display circuit and the function button circuit, the working status of the electric blanket can be intuitively understood and adjusted, and the controllability is good;

[0058] Furthermore, the heating resistor is arranged on one side of the fuse F1 or is connected close to the fuse F1. When the temperature of the electric blanket exceeds the set maximum temperature, the main control circuit increases the current passing through the heating resistor, so that the heating resistor generates high heat and then melts the fuse F1. The fusing method is simple, and the automatic fusing function is achieved, which is more practical.

[0059] In addition, the overall circuit structure design is ingenious and reasonable, ensuring the stability and reliability of the electric blanket during use.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A safe electric blanket, characterized in that: It includes a main control circuit, a constant temperature circuit, a detection circuit, a heating wire, an overheat protection circuit for overheat detection and fusing, a power supply circuit for connecting to the mains, and a fuse F1 for being arranged between the mains and the power supply circuit; The power supply circuit is respectively connected to one end of the heating wire, the main control circuit, the detection circuit and the overheat protection circuit to provide power; The main control circuit is connected to the detection circuit, the overheat protection circuit and the constant temperature circuit respectively. The overheat protection circuit is connected to the fuse F1 to control the fuse F1 to melt. The constant temperature circuit is connected to the other end of the heating wire to control the working state of the heating wire. The detection circuit includes a resistor R2, a resistor R10, a resistor R11 and a resistor R12, wherein the resistor R11 has a first detection end and a second detection end for connecting to the mains, the first detection end is connected to the analog ground through the resistor R12, and the main control circuit is connected to the first detection end; the two ends of the resistor R2 are respectively connected to the analog ground and the digital ground, and the main control circuit is connected to the digital ground through the resistor R10; The overheat protection circuit includes a diode D4, a diode D3, a transistor Q2, a resistor R21, a resistor R17, a resistor R39, a resistor R9 and a temperature detection unit; The diode D4 has a first anode and a first cathode for connecting to the neutral line of the mains, the diode D3 has a second anode and a second cathode, the first anode and the second anode are connected to the temperature detection unit through a resistor R21, the temperature detection unit is connected to the main control circuit through a resistor R39, and the main control circuit is also connected to the analog ground through a resistor R9; The second cathode is connected to the analog ground, the base of the transistor Q2 is connected to the analog ground, the emitter of the transistor Q2 is connected to the main control circuit through the resistor R17, and the collector of the transistor Q2 is connected to the temperature detection unit; The resistor R21 is a heating resistor, which is closely connected to the fuse F1 or arranged on one side of the fuse F1 so that the heat generated by the heating resistor melts the fuse F1.

2. The safety electric blanket according to claim 1, characterized in that: The main control circuit includes a main control chip U1, and the main control chip U1 has main control pins 1 to 20; The main control pin 1 is connected to the analog ground, the main control pin 20 is connected to the analog ground through capacitor C7, the power supply circuit connects the main control pin 19 and the main control pin 20, the main control pin 16 and the main control pin 17 are connected to the detection circuit, the main control pin 15 and the main control pin 18 are connected to the overheat protection circuit, and the main control pin 13 is connected to the constant temperature circuit.

3. The safety electric blanket according to claim 1, characterized in that: The temperature detection unit is a thermistor.

4. The safety electric blanket according to claim 1, characterized in that: The constant temperature circuit includes a unidirectional thyristor Q1, a resistor R19, a resistor R20 and a capacitor C6; The control electrode of the unidirectional thyristor Q1 is connected to the main control circuit through the resistor R20 and the capacitor C6, the T1 electrode of the unidirectional thyristor Q1 is connected to the digital ground, the T1 electrode of the thyristor Q1 is also connected to the control electrode of the unidirectional thyristor Q1 through the resistor R19 and the resistor R20, and the T2 electrode of the unidirectional thyristor Q1 is connected to the other end of the heating wire.

5. The safety electric blanket according to claim 2, characterized in that: Also included is a display circuit, the display circuit includes a display chip LCD1, a resistor R13, a resistor R15, a resistor R16, and resistors R3 to R7, the display chip LCD1 has display pins 1 to 9; The main control pin 11 is connected to the display pin 1, the display pin 1 is connected to the analog ground through the resistor R5, and the display pin 1 is connected to the power circuit through the resistor R6; The main control pin 12 is connected to the display pin 2, the display pin 2 is connected to the analog ground through the resistor R3, and the display pin 1 is connected to the power circuit through the resistor R4; The main control pin 2 is connected to the display pin 3, the display pin 3 is connected to the analog ground through the resistor R15, and the display pin 1 is connected to the power circuit through the resistor R16; The main control pin 3 is connected to the display pin 4, the display pin 4 is connected to the analog ground through the resistor R13, and the display pin 1 is connected to the power supply circuit through the resistor R7.

6. The safety electric blanket according to claim 1, characterized in that: It also includes a function button circuit, which includes a power button SW1, an upshift button SW2, a downshift button SW3, a first timing adjustment button SW4, a second timing adjustment button SW5, a resistor R26, a resistor R29, and resistors R31 to R33; One end of the power button SW1 is connected to the display pin 7 through the resistor R31, and the main control pin 8 is connected to the display pin 7; one end of the upshift button SW2 is connected to the display pin 5 through the resistor R26, and the main control pin 10 is connected to the display pin 5; one end of the downshift button SW3 is connected to the display pin 6 through the resistor R29, and the main control pin 9 is connected to the display pin 6; one end of the first timing adjustment button SW4 is connected to the display pin 9 through the resistor R33, and the main control pin 6 is connected to the display pin 9; one end of the second timing adjustment button SW5 is connected to the display pin 8 through the resistor R32, and the main control pin 7 is connected to the display pin 8; The other end of the power button SW1, the other end of the upshift button SW2, the other end of the downshift button SW3, the other end of the first timing adjustment button SW4 and the other end of the second timing adjustment button SW5.

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