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:
Nov. 10, 1981
Filed:
Apr. 10, 1980
Ralph G Foose, Aurora, OH (US);
John D Crabtree, Cuyahoga Falls, OH (US);
The Nuarc Company, Inc., Chicago, IL (US);
Abstract
A bank of high power quartz iodine lamps is regulated so that changes in light output from the lamps for a 40 volt change in AC line voltage is reduced from 132% to 10%. To accomplish this, a regulating pulse width modulator is synchronized to the AC line so that pulse width modulated pulses are developed the trailing edge of which is coincident with the zero crossover points of the AC line voltage. The variable leading edge of these width modulated pulses is employed to control the firing point of semiconductor switching devices in series with the lamps, the average voltage across the lamps being sensed and employed by the regulating pulse width modulator to vary the width of the pulses in the correct direction to maintain the lamp voltage constant despite large changes in line voltage.