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:
Dec. 15, 1992
Filed:
Oct. 31, 1990
Kunihiro Fujishima, Moriguchi, JP;
Hitoshi Yoshioka, Kawasaki, JP;
Sanyo Electric Co., Ltd., both of, JP;
Yutaka Electric Mfg. Co., Ltd., both of, JP;
Abstract
The present invention relates to a switching power supply a microwave oven in which DC power is changed to a pulse form by means of a switching element coupled to a primary winding of an inverter transformer to supply the power to a high frequency oscillator (hereinafter referred to as a magnetron) coupled to a secondary winding. A reference voltage is set lower than an ordinary state from the time of turning on until the oscillation of the magnetron starts. Accordingly, power supplied from the secondary winding of the inverter transformer to the magnetron is set to a low level. The reference voltage increases when oscillation of the magnetron starts, and returns to the ordinary state when the oscillation returns to the ordinary state.