The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 1992
Filed:
May. 22, 1990
Naoyoshi Maehara, Nara, JP;
Takahiro Matsumoto, Nara, JP;
Kazuho Sakamoto, Kyoto, JP;
Daisuke Bessyo, Yamatokoriyama, JP;
Takashi Niwa, Nara, JP;
Shigeru Kusunoki, Yamatokoriyama, JP;
Takao Shitaya, Yamatokoriyama, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
A high-frequency heating apparatus comprises an inverter including a semiconductor switch and a resonance capacitor, a boosting transformer for a supplying high-voltage power and heater to a magnetron an inductance device inserted in the heater circuit of the magnetron, and an inverter control unit for controlling the semiconductor switch. The inverter control unit is controlled by a start control at the start time of the inverter so that the conduction time of the semiconductor switch becomes shorter than that under a normal operating condition and the non-conduction time thereof becomes longer than that under a normal operating condition and so that the switching period of the semiconductor switch becomes substantially an integral multiple of a resonance period of the resonance circuit formed by the resonance capacitor, whereby the operating frequency of the inverter at the time of starting thereof becomes substantially equal to its normal operating frequency.