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. 14, 1978
Filed:
Feb. 11, 1976
Mitsuyuki Kiuchi, Kadoma, JA;
Keizo Amagami, Kadoma, JA;
Takumi Mizukawa, Kadoma, JA;
Hideyuki Kominami, Kadoma, JA;
Abstract
An induction heating apparatus comprising a pair of inversely parallel-connected gate-controlled switching devices connected to an alternating current source, a resonant circuit including an induction heating coil and a variable frequency gating circuit for firing the switching devices to generate oscillations through the conducting device and the induction heating coil. The switching devices are gated into conduction in succession in a first order during the positive half cycle of the alternating current and in a reversed order during the negative half cycle. A zero crosspoint detector is provided to inhibit gating when the source voltage is near zero crosspoint level and to control the gating frequency in accordance with the instantaneous value of the source voltage to increase the turn-off time of the switching devices for lower input source voltage.