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:
Jan. 17, 1989
Filed:
Jul. 02, 1987
Yuji Ishizaka, Kanagawa, JP;
Kabushiki Kaisha Meidensha, Tokyo, JP;
Abstract
A method of measuring an effective heating power applied to a workpiece at a position to be heated by a high frequency heating apparatus having a source of high frequency AC power connected to a resonant circuits having a supply of high frequency AC power from the source for applying a high frequency AC power to the workpiece. An effective power P.sub.HF for the power supplied to the resonance circuit is measured. An effective value I.sub.t for the current sensed in the resonance circuit is measured. A power loss W produced in components following the source is calculated as a function of the measured effective value I.sub.t. The effective heating power Pw is calculated as Pw=P.sub.HF -W. In another aspect of the invention, the calculated effective heating power Pw is compared with a target value. The power to the resonance circuit is controlled in a direction zeroing the difference between the calculated effective heating power and the target value.