Heating wire temperature controller with controllable output power

Abstract

The utility model discloses a heating wire temperature controller with controllable output power, which belongs to the technical field of temperature controller circuit design, and comprises a temperature sensor, a micro-control unit and a power controller, the power controller is used for connecting a power supply with a heating wire, the temperature sensor is used for sending a temperature signal to the micro-control unit, and the micro-control unit is used for controlling the micro-control unit. The micro-control unit calculates the required output power according to the temperature signal, the power controller comprises a zero-crossing detection circuit and a COOL MOS circuit, the zero-crossing detection circuit outputs a zero-crossing point signal to the micro-control unit, and the micro-control unit controls the switching time point of a COOL MOS in the COOL MOS circuit to control the output power. The power controller is arranged to replace an existing relay, a variable power output method is used, energy waste caused by back-and-forth heating of the heating wire is reduced, energy is saved, and consumption is reduced; the zero-cross detection circuit can reduce the impact on the heating wire, and the COOL MOS can achieve small size and high power.

Description

Technical Field

[0001] The utility model belongs to the technical field of temperature controller circuit design, and in particular relates to a heating wire temperature controller with controllable output power. Background Art

[0002] When the indoor floor heating system with heating wire is working, the operation of the heating wire is usually controlled by a temperature controller, which includes two main structures, namely temperature sensing and on-off controller. Existing applications require setting two temperature thresholds. When the temperature reaches the high threshold, the relay is disconnected and the power supply to the heating wire is stopped. When the temperature is lower than the low threshold, the relay is connected and the power supply to the heating wire is re-energized. There is a problem with this control system. Repeated heating and heat dissipation of the space will cause energy waste in this repetitive process. Utility Model Content

[0003] The technical problem solved by the utility model is to provide a heating wire temperature controller with controllable output power to control the power output and avoid the heating wire from repeatedly heating the space.

[0004] Technical solution: In order to solve the above technical problems, the technical solution adopted by the utility model is as follows:

[0005] A heating wire temperature controller with controllable output power comprises a temperature sensor, a microcontroller connected to the temperature sensor, and a power controller connected to the microcontroller, wherein the power controller is used to connect a power source to the heating wire, the temperature sensor is used to send a temperature signal to the microcontroller, the microcontroller calculates the required output power according to the temperature signal, the power controller comprises a zero-crossing detection circuit and a COOL MOS circuit, the zero-crossing detection circuit outputs a zero-crossing point signal to the microcontroller, and the microcontroller controls the switching time point of the COOLMOS in the COOL MOS circuit to control the output power.

[0006] Preferably, the zero-crossing detection circuit includes two diodes set in reverse and used for rectification, a first resistor connected to the diode, a second resistor connected in series with the first resistor, and a voltage divider resistor connected to the second resistor, the second resistor is connected to the input end of the micro control unit, and the micro control unit turns on or off the COOL MOS after receiving a zero-crossing signal.

[0007] Preferably, the COOL MOS circuit includes two COOL MOS connected to the diode and arranged in reverse, one of the two COOL MOS is connected to the output end of the micro control unit through a third resistor, and the other COOL MOS is connected to the output end of the micro control unit through a fourth resistor, and the micro control unit controls the switch of the COOL MOS through the third resistor and the fourth resistor.

[0008] Preferably, the third resistor is connected to a corresponding COOL MOS gate, and the fourth resistor is connected to a corresponding COOL MOS gate.

[0009] Preferably, the micro control unit controls the switch of the COOL MOS by pulling up or down the voltage of the COOL MOS gate.

[0010] Preferably, the power supply includes an L terminal and an N terminal, the heating wire includes a first terminal and a second terminal, the N terminal is connected to the second terminal, the anode of one of the two diodes is connected to the L terminal, the anode of the other diode is connected to the first terminal, the first resistor is connected to the cathodes of the two diodes, the drain of one of the two COOL MOS is connected to the L terminal, the drain of the other COOL MOS is connected to the first terminal, and the sources of the two COOL MOS are grounded.

[0011] Preferably, a thermal relay is provided on the circuit connecting the diode and the power supply.

[0012] Beneficial effects: Compared with the prior art, the utility model has the following advantages:

[0013] 1. By setting up a power controller to replace the existing relay and using a variable power output method, a constant power output can be achieved to maintain the indoor temperature unchanged, reducing the energy waste caused by the heating wire heating back and forth, saving energy and reducing consumption;

[0014] 2. The zero-crossing detection circuit can reduce the impact on the heating wire and prevent high-voltage surges from directly impacting the heating wire. The use of COOL MOS can achieve small size and high power, which can adapt to the high power of the heating wire in the floor heating system. The overall size of the thermostat is small and can be placed in the electrical box on the wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the utility model;

[0016] Figure 2 is a schematic diagram of the connection structure between the micro control unit and the power controller of the embodiment;

[0017] Figure 3 is a circuit diagram of a power controller according to an embodiment. DETAILED DESCRIPTION

[0018] The present invention will be further explained below in conjunction with specific embodiments. The embodiments are implemented based on the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0019] like Figure 1 As shown, a heating wire temperature controller with controllable output power includes a temperature sensor 1, a microcontroller unit 2 and a power controller 3. The temperature sensor 1 adopts an existing temperature sensor. The temperature sensor adopts a material whose impedance value changes with temperature. In the circuit design, a resistor is connected in series with the temperature sensor to VCC. Then the MCU can know the current resistance value of the sensor through voltage division, and then the temperature value can be compared. The temperature sensor 1 is the only input variable of the temperature controller in this embodiment, which is used to monitor the indoor temperature and send the temperature signal to the microcontroller unit 2. The microcontroller unit 2 is connected to the temperature sensor 1. The microcontroller unit 2 is an MCU, which adopts an existing single-chip microcomputer, such as MS51FB9AE, to receive the temperature signal of the temperature sensor 1, calculate the required output power according to the temperature signal, and thus control the power controller 3. The power controller 3 is connected to the microcontroller unit 2, and the external AC power supply is connected to the power controller 3. The power controller 3 is connected to the heating wire 9. The output power of the power controller 3 changes to control the operation of the heating wire 9, thereby achieving the purpose of balancing heating and heat dissipation.

[0020] like Figure 2 and Figure 3 As shown, the power controller 3 includes a zero-crossing detection circuit 31 and a COOL MOS circuit 32. The zero-crossing detection circuit 31 outputs a zero-crossing signal to the micro control unit 2. The micro control unit 2 controls the switching time point of the COOL MOS 321 in the COOL MOS circuit 32 to control the output power.

[0021] like Figure 2 and Figure 3As shown, the zero-crossing detection circuit 31 includes two diodes 311, a first resistor 312, a second resistor 313 and a voltage-dividing resistor 314, the power supply includes an L terminal and an N terminal, the L terminal and the N terminal are connected to the mains, the voltage is 220V-250V, the frequency is 50Hz, the heating wire includes a first end and a second end, the N terminal is directly connected to the second end of the heating wire, the positive electrode of one of the two diodes 311 of the zero-crossing detection circuit 31 is connected to the L terminal, the diode 311 and the power supply connection line are provided with a thermal relay, which plays a protective role, and the other two The positive electrode of the diode 311 is connected to the first end of the heating wire, and the negative electrodes of the two diodes 311 are connected to form a reverse connection for simple rectification. The negative electrodes of the two diodes 311 are connected to the first resistor 312, and the second resistor 313 is connected in series with the first resistor 312 and the second resistor 313 is connected to the input end of the micro control unit 2. The first resistor 312 and the second resistor 313 perform a voltage drop on the input signal. A voltage dividing resistor 314 is also connected between the second resistor 313 and the input end of the micro control unit 2, and the voltage dividing resistor 314 plays a voltage dividing role.

[0022] like Figure 2 and Figure 3 As shown, the COOL MOS circuit 32 includes two COOL MOS 321, COOL MOS is a special power field effect transistor, which belongs to a super junction device, and has extremely low on-state resistance and ultra-fast switching speed; in the super junction structure, the charges in the N region and the P region are balanced with each other, so that the electric field distribution is different from that of the traditional MOSFET, and the longitudinal electric field of the device changes from a triangular distribution to a nearly rectangular distribution, thereby improving the relationship between RON and the breakdown voltage, breaking the silicon limit of the traditional structure, and can replace ordinary MOS tubes, reduce losses, and improve efficiency. The same power has a small package, a small node capacity, and a small switching loss; the drain of one COOL MOS 321 of the two COOL MOS 321 is connected to the power supply L end and to the positive electrode of a diode 311, and its gate is connected to the output end of the micro control unit 2 through the third resistor 322, the drain of the other COOL MOS 321 is connected to the first end of the heating wire, and its gate is connected to the output end of the micro control unit 2 through the fourth resistor 323, the sources of the two COOL MOS 321 are connected, and the middle connecting line of the two sources is grounded. The micro control unit 2 controls the gates of the two reverse COOL MOS 321 through the third resistor 322 and the fourth resistor 323, and controls the switch of COOL MOS 321 by pulling up or pulling down the voltage of the gate of COOL MOS 321. The micro control unit 2 turns on COOL MOS 321 after receiving the zero-crossing signal. The micro control unit 2 receives the temperature signal transmitted by the temperature sensor 1 to determine the power to be output. The micro control unit 2 calculates the closing time of COOL MOS 321 through the zero-crossing signal, and then turns off COOL MOS 321.

[0023] Working principle and process:

[0024] For example, if the room temperature is 16°C, and the preset temperature in the microcontroller unit 2 is 20°C, the temperature sensor 1 detects the temperature and sends a signal to the microcontroller unit 2, and the microcontroller unit 2 controls the output power of the power controller 3. Since COOLMOS321 switches on and off 120 times or 100 times in one second, it is related to the frequency of the AC power supply. The output power is controlled by the switching time ratio. If the on time is long and the off time is short, the output power is large, otherwise the output power is small. The microcontroller unit 2 increases the on time ratio of COOLMOS321, increases the output power, and the heating wire heats up to increase the temperature in the room.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A heating wire temperature controller with controllable output power, characterized in that: The invention comprises a temperature sensor (1), a micro control unit (2) connected to the temperature sensor (1), and a power controller (3) connected to the micro control unit (2); the power controller (3) is used to connect a power source to a heating wire; the temperature sensor (1) is used to send a temperature signal to the micro control unit (2); the micro control unit (2) calculates the required output power according to the temperature signal; the power controller (3) comprises a zero-crossing detection circuit (31) and a COOL MOS circuit (32); the zero-crossing detection circuit (31) outputs a zero-crossing point signal to the micro control unit (2); the micro control unit (2) controls the switching time point of a COOL MOS (321) in the COOL MOS circuit (32) to control the output power.

2. The heating wire temperature controller with controllable output power according to claim 1, characterized in that: The zero-crossing detection circuit (31) comprises two diodes (311) arranged in reverse and used for rectification, a first resistor (312) connected to the diode (311), a second resistor (313) connected in series with the first resistor (312), and a voltage-dividing resistor (314) connected to the second resistor (313), wherein the second resistor (313) is connected to an input end of the micro control unit (2), and the micro control unit (2) turns on or off the COOL MOS (321) after receiving a zero-crossing signal.

3. The heating wire temperature controller with controllable output power according to claim 2, characterized in that: The COOL MOS circuit (32) comprises two COOL MOS (321) connected to the diode (311) and arranged in reverse, one of the two COOL MOS (321) being connected to the output end of the micro control unit (2) via a third resistor (322), and the other COOL MOS (321) being connected to the output end of the micro control unit (2) via a fourth resistor (323), and the micro control unit (2) controlling the switch of the COOL MOS (321) via the third resistor (322) and the fourth resistor (323).

4. The heating wire temperature controller with controllable output power according to claim 3, characterized in that: The third resistor (322) is connected to the gate of the corresponding COOL MOS (321), and the fourth resistor (323) is connected to the gate of the corresponding COOL MOS (321).

5. The heating wire temperature controller with controllable output power according to claim 4, characterized in that: The micro control unit (2) controls the switch of the COOL MOS (321) by pulling up or pulling down the voltage of the gate of the COOL MOS (321).

6. The heating wire temperature controller with controllable output power according to claim 2, characterized in that: The power supply comprises an L end and an N end, the heating wire comprises a first end and a second end, the N end is connected to the second end, the anode of one of the two diodes (311) is connected to the L end, the anode of the other diode (311) is connected to the first end, the first resistor (312) is connected to the cathodes of the two diodes (311), the drain of one of the two COOL MOS (321) is connected to the L end, the drain of the other COOL MOS (321) is connected to the first end, and the sources of the two COOL MOS (321) are grounded.

7. The heating wire temperature controller with controllable output power according to claim 2, characterized in that: A thermal relay is provided on the line connecting the diode (311) and the power supply.

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