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:
Aug. 31, 1976
Filed:
Jul. 15, 1975
Keizo Amagami, Kadoma, JA;
Takao Kobayashi, Kadoma, JA;
Yoshio Ogino, Kadoma, JA;
Mitsuyuki Kiuchi, Kadoma, JA;
Matsushita Electric Industrial Co., Ltd., Kadoma, JA;
Abstract
An induction heating apparatus is provided with protective circuit arrangements which ensure against surge currents caused by inappropriately timed gating-on of a gate controlled rectifier or by erroneous use of a load material such as non-magnetic or ferro-magnetic material. The timed gating of the gate-controlled rectifier is accomplished by means of a delay circuit which serves to count timing after a rectified excitation potential drops to the zero voltage point. A coincidence circuit is provided to detect coincidence of two signals, one is a pulse having a predetermined width and the other is a signal derived when the periodic cycle of the energization currents departs from the predetermined cycle period.