| US 7,432,484 B2 | ||
| Current control for high-frequency heating apparatus | ||
| Hideaki Moriya, Nara (Japan); Haruo Suenaga, Osaka (Japan); Shinichi Sakai, Nara (Japan); Nobuo Shirokawa, Nara (Japan); and Manabu Kinoshita, Nara (Japan) | ||
| Assigned to Matsushita Electric Industrial Co., Ltd., Osaka (Japan) | ||
| Appl. No. 11/577,344 PCT Filed Oct. 17, 2005, PCT No. PCT/JP2005/019047 § 371(c)(1), (2), (4) Date Apr. 16, 2007, PCT Pub. No. WO2006/043513, PCT Pub. Date Apr. 27, 2006. |
||
| Claims priority of application No. 2004-304095 (JP), filed on Oct. 19, 2004. | ||
| Prior Publication US 2008/0061055 A1, Mar. 13, 2008 | ||
| Int. Cl. H05B 6/68 (2006.01) | ||
| U.S. Cl. 219—716 [219/721; 219/761; 315/39.51; 331/185] | 4 Claims |
| 1. A high frequency heating apparatus which drives a magnetron (12) by allowing a semiconductor switching element (3,4) to perform a high frequency switching operation using a commercial power supply (1), said high frequency heating apparatus comprising:
input fixing control means (19) for providing accumulation information based on a variation amount of a current of said commercial power supply (1) and a reference signal (Ref);
ebm-tracking bias means (20) for providing an bias value on the basis of the voltage of said commercial power supply (1) and said accumulation information;
frequency modulation means (15) for providing a frequency modulation waveform on the basis of the voltage of said commercial power supply (1), said frequency modulation waveform being given a bias in accordance with said bias value;
driving unit (16,17,18) for providing driving signals which drives said semiconductor switching element on the basis of the signal output from said
frequency modulation means (15),
wherein said ebm tracking bias means (20) performs a feedback control by controlling said bias value in accordance with a variation of an oscillation threshold ebm
caused by a change in a temperature of said magnetron (12).
|