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. 16, 1980
Filed:
Feb. 24, 1978
Allan T Chow, Wilmington, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
The power control circuit described functions to vary the duty cycle of the alternating current signal supplied to the load. The duty cycle is varied by periodically generating a first signal, each half cycle of the alternating current signal, that is proportional to the actual power supplied to the load as a function of the duty cycle and wave form of the alternating current signal. A comparator compares this first with an error signal to vary the duty cycle in accordance with the power demanded by the error signal. The first signal is derived by evaluating the integral of the square of the voltage over each half cycle of the alternating current signal.