Variable-frequency electric heater

Abstract

The utility model discloses a variable frequency electric heater, which relates to the technical field of household appliance heaters, and comprises a controller, a gallium nitride power tube I, a gallium nitride power tube II, an alternating current signal source and a heater, and the signal passes through the gallium nitride power tube I and the gallium nitride power tube II and then returns to the alternating current signal source to form a power-on loop. According to the utility model, through connection and use, the old power control element can be replaced by utilizing the characteristics of high working voltage, high power, high speed and low conduction impedance of a new generation of semiconductors; the temperature of the heater can be quickly changed due to the quick PWM pulse width, so that the temperature change amplitude of the heater is reduced, the power change of various heaters can be reduced, and the purpose of saving energy is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of household appliances, in particular to a variable frequency electric heater. Background Art

[0002] Gallium nitride (GaN) is a very hard and mechanically stable wide bandgap semiconductor material. As a third-generation semiconductor material, GaN has the advantages of high temperature resistance, high compatibility, high thermal conductivity, and wide bandgap.

[0003] At present, the control methods of the heaters of household appliances are all relay control, thyristor control, and bimetallic temperature control. These control methods have the disadvantages of high cost, large temperature control range, and large size, which are specifically manifested in:

[0004] 1. The relay requires a higher current DC voltage to drive the relay on and off, and the life of the relay switch contact is short;

[0005] 2. The operating temperature of the thyristor is high and needs to be maintained by a large heat dissipation metal;

[0006] 3. The temperature control range of the bimetallic thermostat is up to ±20 degrees. Utility Model Content

[0007] The variable frequency electric heater proposed by the utility model changes the problem that the control methods of the heaters of current household appliances are all relay control, thyristor control, and bimetallic temperature control, and provides a variable frequency electric heater using a gallium nitride power tube.

[0008] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0009] The variable frequency electric heater comprises a controller, a gallium nitride power tube 1, a gallium nitride power tube 2, an AC signal source and a heater. The controller outputs a high level potential from a pin 1, and the positive AC voltage is transmitted from the AC signal source to the heater, and then returns to the AC signal source after passing through the gallium nitride power tube 1 and the gallium nitride power tube 2, thereby forming a power-on loop.

[0010] Preferably, the negative voltage of the alternating current is transmitted from the alternating current signal source through the gallium nitride power tube 1 and the gallium nitride power tube 2 to the heater and then returns to the alternating current signal source, thereby forming a power-on loop.

[0011] Preferably, the positive alternating current voltage and the negative alternating current voltage are energized and heated by the heater through an alternating current signal source.

[0012] Preferably, when the controller outputs a pulse signal from pin 1, the power of the heater is reduced, thereby changing the output temperature of the heater.

[0013] Preferably, an NTC is provided inside the heater, and a temperature sensor is provided inside the controller.

[0014] Preferably, the controller senses the temperature of the heater through NTC, and after inputting it into the controller through pin 2, changes the pulse width, thereby changing the power of the heater.

[0015] The beneficial effects of the utility model are:

[0016] By adopting the connection structure of the utility model, the controller senses the temperature of the heater through the NTC, and after inputting it into the controller through pin 2, the pulse width is changed, thereby changing the power of the heater. The change of the heater power will change the temperature; because the fast PWM pulse width will cause the temperature of the heater to change rapidly, combined with the application of gallium nitride power tubes, the temperature change amplitude of the heater is reduced, thereby reducing the power change of various heaters, achieving the purpose of energy saving, and realizing the use of semiconductor power elements as switches of AC heaters; using the high working voltage characteristics and high power characteristics of semiconductor power elements to switch AC heating products; using the high frequency characteristics of semiconductor power elements to adjust the power of AC heating products; using the low on-resistance characteristics of semiconductor power elements to reduce the working heat of the elements and reduce the number of heat dissipation devices.

[0017] The high operating voltage, high power, high speed and low on-resistance characteristics of semiconductors are utilized to replace the above old power control components. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a circuit schematic diagram of the utility model.

[0019] Figure 2 It is a structural diagram of the gallium nitride power tube 1 and the gallium nitride power tube 2 of the present invention.

[0020] Numbers in the figure: 21, GaN power tube 1; 22, GaN power tube 2; 31, AC signal source; 61, heater; 62, controller; 63, pin 1; 64, pin 2; 65, NTC; 201, pin; 202, low-voltage silicon chip; 203, high-voltage GaN chip; 204, gold wire. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0022] Reference Figure 1, a variable frequency electric heater, comprising a controller 62, a gallium nitride power tube 1 21, a gallium nitride power tube 2 22, an AC signal source 31 and a heater 61, wherein an NTC 65 is arranged inside the heater 61, and a temperature sensor is arranged inside the controller 62. The controller 62 outputs a high level potential from a pin 1 63, and the positive voltage of the AC power flows from the AC signal source 31 to the heater 61, and then passes through the gallium nitride power tube 1 21 and the gallium nitride power tube 2 22 and returns to the AC signal source 31, forming a power-on loop;

[0023] The structures of the GaN power tube 1 21 and the GaN power tube 2 22 both include a pin 201 , a low-voltage silicon chip 202 , and a high-voltage GaN chip 203 , which are connected by a gold wire 204 .

[0024] The negative voltage of the AC power flows from the AC signal source 31 through the GaN power tube 1 21 and the GaN power tube 2 22 to the heater 61 and then returns to the AC signal source 31, forming a power-on loop.

[0025] The above AC positive voltage and AC negative voltage are energized and heated by the heater 61 through the AC signal source 31 .

[0026] Furthermore, when the controller 62 outputs a pulse signal from the pin 1 63 , the power of the heater 61 is reduced, thereby changing the output temperature of the heater 61 ;

[0027] The controller 62 senses the temperature of the heater 61 through the NTC 65. After the temperature is input to the controller 62 through the pin 2 64, the pulse width is changed, thereby changing the power of the heater 61. The power change of the heater 61 will change the temperature. Because the fast PWM pulse width will cause the temperature of the heater 61 to change quickly, the temperature change amplitude of the heater 61 will become smaller, thereby reducing the power change of various heaters and achieving the purpose of saving energy.

[0028] Realize the use of semiconductor power elements as switches for AC electric heaters; utilize the high operating voltage and high power characteristics of semiconductor power elements to switch AC electric heating products; utilize the high frequency characteristics of semiconductor power elements to adjust the power of AC electric heating products; utilize the low on-resistance characteristics of semiconductor power elements to reduce the operating heat generated by the elements and reduce heat dissipation devices.

[0029] The above are only preferred specific implementation methods of the utility model, but the protection scope of the utility model is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the utility model, who makes equivalent replacements or changes based on the technical scheme and utility model concept of the utility model, should be covered by the protection scope of the utility model.

Claims

1. A variable frequency electric heater, characterized in that: The invention comprises a controller (62), a gallium nitride power tube 1 (21), a gallium nitride power tube 2 (22), an AC signal source (31) and a heater (61). The controller (62) outputs a high-level potential from a pin 1 (63). The positive AC voltage is transmitted from the AC signal source (31) to the heater (61), and then returns to the AC signal source (31) through the gallium nitride power tube 1 (21) and the gallium nitride power tube 2 (22), thereby forming an electric circuit.

2. The variable frequency electric heater according to claim 1, characterized in that: The negative alternating current voltage is transmitted from the alternating current signal source (31) through the gallium nitride power tube 1 (21), the gallium nitride power tube 2 (22) to the heater (61) and then returns to the alternating current signal source (31), thereby forming an electric loop.

3. The variable frequency electric heater according to claim 1, characterized in that: The positive alternating current voltage and the negative alternating current voltage are energized and heated by the heater (61) through the alternating current signal source (31).

4. The variable frequency electric heater according to claim 1, characterized in that: When the controller (62) outputs a pulse signal from the pin 1 (63), the power of the heater (61) is reduced, thereby changing the output temperature of the heater (61).

5. The variable frequency electric heater according to claim 1, characterized in that: The heater (61) is provided with an NTC (65) inside, and the controller (62) is provided with a temperature sensor inside.

6. The variable frequency electric heater according to claim 5, characterized in that: The controller (62) senses the temperature of the heater (61) through the NTC (65), and after the temperature is input to the controller (62) via the pin 2 (64), the pulse width is changed, thereby changing the power of the heater (61).

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