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. 04, 1977
Filed:
Feb. 14, 1975
Mark Edward Eberhardt, Jr, Troy, OH (US);
Hobart Corporation, Troy, OH (US);
Abstract
A control for a microwave oven is disclosed in which cooking time is set by touching one of a number of touch plates on the oven control panel. An oscillator provides an asymmetric signal to a plurality of level detectors by way of the touch plates and associated circuitry. When a touch plate is touched by an operator, the resulting capacitance to ground acts to integrate the oscillator signal and prevent this signal from dipping below a predetermined minimum threshold level. This condition is sensed by the associated level detector and the timer is set accordingly. The oscillator is then disabled to prevent an accidental touching of one of the touch plates from affecting oven operation. Also disclosed is a power control circuit which switches on power to several magnetrons in a staggered manner to limit surge current.