Heating temperature measuring circuit and electric blanket

Abstract

The application discloses a heating temperature measurement circuit, which comprises a first branch, a second branch, a switch tube and a sampling circuit; the first branch comprises a first diode and an electric heating wire, the positive electrode of the first diode is connected with a single-phase alternating current power supply, and the negative electrode of the first diode is connected with the electric heating wire; the second branch comprises a second diode and a thermistor, the positive electrode of the second diode is connected with a direct current working power supply, and the negative electrode of the second diode is connected with the thermistor; the first branch and the second branch are connected in parallel, and are connected in parallel through the electric heating wire and the thermistor sharing a PCB welding point; the sampling circuit comprises a voltage dividing resistor; the parallel circuit of the first branch and the second branch, the switch tube and the voltage dividing resistor are connected on the same bus. The application further provides an electric heating blanket comprising the heating temperature measurement circuit. The circuit of the application has simple structure, few components, and reduces hardware cost and labor cost.

Description

Technical Field

[0001] This invention belongs to the field of electric blanket technology, specifically relating to a heating and temperature measuring circuit and an electric blanket. Background Technology

[0002] Currently, the thermistor for temperature measurement and the heating wire for output in electric blankets are both manually connected to the control board via two separate solder joints. The thermistor branch and the heating wire branch are independently connected to the system bus, with a total of four manual solder joints (two for thermistors and two for the heating wires). As labor costs increase, the production cost of electric blankets also rises.

[0003] Meanwhile, the existing electric blanket temperature measurement and heating circuits have many components and complex structures, and further simplification of the design is needed to reduce hardware costs. Summary of the Invention

[0004] The purpose of this invention is to reduce the structural and labor costs of electric blankets. It proposes a brand-new heating and temperature measurement circuit that combines the solder joints of the thermistor and the heating wire, and uses a microcontroller to control the temperature detection and adjustment of the electric blanket.

[0005] This invention provides a heating and temperature measurement circuit, including a first branch, a second branch, a switching transistor, and a sampling circuit. The first branch is a heating branch, including a first diode and a heating wire. The anode of the first diode is connected to a single-phase AC power supply, and the cathode of the first diode is connected to the heating wire. The second branch is a temperature measurement branch, including a second diode and a thermistor. The anode of the second diode is connected to a DC power supply, and the cathode of the second diode is connected to the thermistor. The first branch and the second branch are connected in parallel, and the heating wire and the thermistor are connected in parallel by sharing a PCB solder joint. The sampling circuit includes a voltage divider resistor. The parallel circuit of the first branch and the second branch, the switching transistor, and the voltage divider resistor are connected to the same busbar.

[0006] Furthermore, the sampling circuit also includes a filtering circuit, which includes a filtering resistor and a filtering capacitor; wherein the filtering resistor is connected in series on the bus, and the filtering capacitor is connected in parallel at the output terminal of the sampling circuit.

[0007] As a preferred embodiment, the thermistor has a negative temperature coefficient or a positive temperature coefficient.

[0008] As a preferred method, the switching transistor is a high-power transistor or a silicon controlled rectifier.

[0009] The present invention also provides an electric blanket, including an MCU, a power supply circuit, a temperature setting circuit, and any of the aforementioned heating and temperature measuring circuits.

[0010] As a preferred embodiment, the electric blanket also includes a temperature display circuit.

[0011] The heating and temperature measuring circuit of this invention has a simple structure and few components, which simplifies the production process, improves production efficiency, and reduces hardware and labor costs. Attached Figure Description

[0012] Figure 1 This is the heating and temperature measuring circuit of the present invention;

[0013] Figure 2 This is a circuit diagram of the electric blanket of the present invention. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings:

[0015] See appendix Figure 1 The present invention provides a heating temperature measurement circuit, which mainly includes a first branch, a second branch, a switching transistor Q, and a sampling circuit.

[0016] The first branch is a heating branch, which includes a first diode D1 and a heating wire Rd. The positive terminal of the first diode D1 is connected to a single-phase AC power supply, and the negative terminal of the first diode D1 is connected to the heating wire Rd.

[0017] The second branch is the temperature measurement branch, which includes a second diode D2 and a thermistor Rt. The positive terminal of the second diode D2 is connected to the DC power supply, and the negative terminal of the second diode D2 is connected to the thermistor Rt.

[0018] The first branch and the second branch are connected in parallel, and are connected in parallel by the heating wire Rd and the thermistor Rt sharing a PCB solder joint A.

[0019] The sampling circuit includes a voltage divider resistor R1.

[0020] The parallel circuit of the first branch and the second branch, the switch Q, and the voltage divider resistor R1 are connected to the same bus.

[0021] The sampling circuit further includes a filtering circuit, which comprises a filtering resistor R2 and a filtering capacitor C. The filtering resistor R2 is connected in series on the busbar, and the filtering capacitor C is connected in parallel at the output terminal of the sampling circuit. P ADC ).

[0022] Preferably, the thermistor Rt is a negative temperature coefficient NTC or a positive temperature coefficient PTC.

[0023] Preferably, the switching transistor Q is a high-power transistor or a silicon controlled rectifier.

[0024] The present invention also provides an electric blanket having the above-described heating and temperature measuring circuit. (See attached diagram) Figure 2 As shown, the electric blanket includes an MCU, a power supply circuit, a temperature setting circuit, and a heating and temperature measurement circuit. Preferably, the electric blanket also includes a temperature display circuit.

[0025] See appendix Figure 1 and 2 The working principle of the heating and temperature measuring circuit and the electric blanket of the present invention will be described in detail below.

[0026] When the mains power (single-phase AC power) is in the positive half-wave, the MCU controls the switch Q to turn on, thereby starting the heating wire Rd to work; when the mains power is in the negative half-wave, the first diode D1 blocks the first branch, and the heating wire Rd stops heating.

[0027] The operating power supply VCC supplies power to the thermistor Rt and voltage divider resistor R1 through the second diode D2. The sampling signal is fed back to the MCU through an RC filter circuit (filter resistor R2 and filter capacitor C). The MCU determines the temperature value of the heating wire Rd based on this voltage feedback signal (e.g., by using a lookup table), and can display it through a temperature display circuit.

[0028] Meanwhile, the MCU adjusts the PWM duty cycle of the switching transistor Q according to the sampled voltage signal to increase or decrease the heating power so that the temperature of the electric blanket is stabilized at the set value.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0030] 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.

[0031] This invention is not limited to the above description of the embodiments. Any improvements and modifications made by those skilled in the art based on the content disclosed herein without creative effort should be within the protection scope of this invention.

Claims

1. A heating temperature measuring circuit, characterized in that: This includes the first branch, the second branch, the switching transistor, the sampling circuit, the MCU, and the power supply circuit; The power supply circuit includes a unidirectional AC power supply and a DC working power supply. The first branch is a heating branch, which includes a first diode and a heating wire. The positive terminal of the first diode is connected to a single-phase AC power supply, and the negative terminal of the first diode is connected to the heating wire. The second branch is a temperature measurement branch, which includes a second diode and a thermistor. The positive terminal of the second diode is connected to a DC power supply, and the negative terminal of the second diode is connected to the thermistor. The first branch and the second branch are connected in parallel, and are connected in parallel by the heating wire and the thermistor sharing a PCB solder joint; The sampling circuit includes voltage divider resistors; The parallel circuit of the first branch and the second branch, the switching transistor and the voltage divider resistor are connected to the same busbar; the positive terminal of the switching transistor is connected to the busbar and the negative terminal is grounded. The sampling circuit further includes a filtering circuit, which includes a filtering resistor and a filtering capacitor; wherein the filtering resistor is connected in series on the bus, and the filtering capacitor is connected in parallel at the output terminal of the sampling circuit. When the single-phase AC power supply is in the positive half-wave, the switching transistor turns on, causing the heating wire to work; when the single-phase AC power supply is in the negative half-wave, the first diode blocks the first branch, and the heating wire stops heating. The DC power supply supplies power to the thermistor and the voltage divider resistor through the second diode; The MCU adjusts the PWM duty cycle of the switching transistor based on the voltage feedback signal from the sampling circuit to increase or decrease the heat power of the heating wire.

2. The heating temperature measuring circuit according to claim 1, characterized in that: The thermistor has a negative temperature coefficient or a positive temperature coefficient.

3. The heating temperature measuring circuit according to claim 2, characterized in that: The switching transistor is a high-power transistor or a thyristor.

4. An electric blanket, characterized in that: It includes a temperature setting circuit and a heating temperature measuring circuit as described in any one of claims 1 to 3.

5. An electric blanket according to claim 4, characterized in that: The electric blanket also includes a temperature display circuit.

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