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:
May. 05, 1992
Filed:
Jun. 09, 1989
Teruya Tanaka, Yokohama, JP;
Yoshiyuki Noguchi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In an electromagnetic cooking apparatus, low heating power control is carried out by turning ON/OFF a DC power supply circuit, or rectifier circuit, at a commercial frequency lower than an inverting frequency of DC/AC inverter. The electromagnetic cooking apparatus includes: a DC (direct current) power supply for producing DC power from low-frequency AC (alternating current) power; a DC-to-AC inverting circuit coupled to the DC power supply and including a switching element and also a heating coil, for inverting the DC power inputted from the DC power supply into high-frequency AC power so as to heat a metal pan by energizing the heating coil with the high-frequency AC power, thereby electromagnetically inducing eddy currents within the metal pan; a monitoring circuit for monitoring switching conditions of the switching element so as to output a switching condition signal; and an ON/OFF-controlling circuit for turning ON/OFF power supply operation of the DC power supply, or inverting operation of the DC/AC inverter circuit in response to the switching condition signal at a timing period defined by a time constant smaller than a thermal time constant determined by a heat capacity of a metal material of the pan.