Frequency-modulated electric element control
View Patent ↗A system, method, and computer-readable medium for controlling power applied to a heating element. A rectifier receives AC voltage supplied from an AC voltage supply and rectifies the AC voltage to DC voltage. A pulse-width modulation controller generates and transmits a pulse-width modulation signal, and a DC voltage modulator receives the DC voltage from the rectifier and the pulse-width modulation signal from the pulse-width modulation controller. Based on the pulse-width modulation signal, the DC voltage modulator supplies an analog DC voltage signal to the heating element. A feedback circuit reports the actual DC voltage applied to the heating element to a microcontroller and, if the actual DC voltage deviates from the DC voltage encoded in the pulse-width modulation signal, the pulse-width modulation controller modulates the pulse-width modulation signal to minimize or eliminate the deviation.
1. A home appliance having a heating element and a system for controlling power applied to the heating element, the home appliance comprising:
a user interface to set a target temperature for a medium heated up by the heating element;
a temperature sensor to detect an actual temperature of the medium heated up by the heating element;
a microcontroller to receive the target temperature from the user interface and the actual temperature from the temperature sensor; to compare the target temperature to the actual temperature; and to determine a temperature comparison result that is based on the comparison of the target temperature to the actual temperature;
a pulse-width modulation controller to generate and transmit a pulse-width modulation signal based on the temperature comparison result; and
a DC voltage modulator to receive a predetermined DC voltage level and to supply an analog DC voltage signal to the heating element based on the pulse-width modulation signal.
2. The home appliance of claim 1 , wherein the pulse-width modulation controller modulates the pulse-width modulation signal based on the temperature comparison result.
3. The home appliance of claim 1 , further comprising:
a feedback circuit between the DC voltage modulator and the microcontroller;
wherein the pulse-width modulation controller encodes a desired DC voltage value in the pulse-width modulation signal;
wherein the DC voltage modulator supplies an actual DC voltage value to the heating element;
wherein the feedback circuit reports the actual DC voltage value to the microcontroller; and
wherein the microcontroller compares the actual DC voltage value to the desired DC voltage value and determines a DC voltage value comparison result that is based on the comparison of the actual DC voltage value to the desired DC voltage value.
4. The home appliance of claim 3 , wherein the pulse-width modulation controller modulates the pulse-width modulation signal based on the DC voltage value comparison result.
5. The home appliance of claim 3 , wherein the pulse-width modulation controller varies the desired DC voltage value encoded in the pulse-width modulation signal based on the temperature comparison result.
6. The home appliance of claim 3 , wherein the pulse-width modulation controller varies the desired DC voltage value encoded in the pulse-width modulation signal based on the DC voltage value comparison result.
7. The home appliance of claim 1 , wherein the DC voltage modulator includes an Insulated-Gate Bipolar Transistor.
8. A method for controlling power applied to a heating element within a home appliance, the method comprising:
determining a target temperature for a medium heated up by the heating element;
determining an actual temperature of the medium heated up by the heating element;
comparing the target temperature to the actual temperature;
determining a temperature comparison result that is based on the comparison of the target temperature to the actual temperature; and
generating a pulse-width modulation signal based on the temperature comparison result to generate an analog DC voltage signal; and
supplying the analog DC voltage signal to the heating element.
9. The method of claim 8 , further comprising:
setting a target temperature for a medium heated up by the heating element.
10. The method of claim 9 , further comprising modulating the pulse-width modulation signal based on the temperature comparison result.
11. The method of claim 9 , further comprising:
encoding a desired DC voltage value in the pulse-width modulation signal;
supplying an actual DC voltage value to the heating element;
comparing the actual DC voltage value to the desired DC voltage value; and
determining a DC voltage value comparison result based on the comparison of the actual DC voltage value to the desired DC voltage value.
12. The method of claim 11 , further comprising modulating the pulse-width modulation signal based on the DC voltage value comparison result.
13. The method of claim 11 , further comprising varying the desired DC voltage value encoded in the pulse-width modulation signal based on the temperature comparison result.
14. The method of claim 11 , further comprising varying the desired DC voltage value encoded in the pulse-width modulation signal based on the DC voltage value comparison result.
15. A home appliance having a computer-readable medium with computer-readable instructions recorded thereon for controlling power applied to a heating element of the home appliance, the computer-readable instructions comprising:
determining a target temperature for a medium heated up by the heating element;
determining an actual temperature of the medium heated up by the heating element;
comparing the target temperature to the actual temperature;
determining a temperature comparison result that is based on the comparison of the target temperature to the actual temperature; and
modulating a pulse-width modulation signal based on the temperature comparison result to generate an analog DC voltage signal that is supplied to the heating element.
16. The home appliance of claim 15 , wherein the computer-readable instructions further comprise:
encoding a desired DC voltage value in the pulse-width modulation signal;
comparing an actual DC voltage value supplied to the heating element to the desired DC voltage value; and
determining a DC voltage value comparison result based on the comparison of the actual DC voltage value to the desired DC voltage value.
17. The home appliance of claim 16 , wherein the computer-readable instructions further comprise modulating the pulse-width modulation signal based on the DC voltage value comparison result.
18. The home appliance of claim 16 , wherein the computer-readable instructions further comprise varying the desired DC voltage value encoded in the pulse-width modulation signal based on the temperature comparison result.
19. The home appliance of claim 17 , wherein the computer-readable instructions further comprise varying the desired DC voltage value encoded in the pulse-width modulation signal based on the DC voltage value comparison result.