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:
Sep. 28, 1982
Filed:
Jul. 29, 1980
Kunihiro Fujishima, Moriyama, JP;
Takaki Kuramoto, Kyoto, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
An induction heating cooking apparatus comprises a self-controlled inverter which comprises a series connection of an induction coil and a switching element, a resonance capacitor connected in parallel with the switching element, and a flywheel diode. An inverter driver circuit triggers the inverter with a starting pulse obtained from a starting signal generator. A voltage signal associated with a current flowing through the switching element is obtained by means of a current transformer. A voltage source of the inverter is implemented as a ripple current voltage source. A comparator of a gate signal generator compares a reference level changing in accordance with the ripple current voltage and the voltage detected by the current transformer, thereby rendering the switching element non-conductive when the voltage level reaches the reference level. A load detecting circuit detects a ratio of the conduction period of the flywheel diode with respect to the oscillation cycle of the inverter, thereby detecting a proper or improper state of a load placed on the top plate in accordance with the above described ratio. The oscillation of the inverter is stopped upon detection of the improper state of the load by means of the load detecting circuit.