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:
May. 12, 1992
Filed:
Dec. 28, 1990
George E Burke, Jr, Raleigh, NC (US);
Square D Company, Palatine, IL (US);
Abstract
A photoelectrical sensor (10) provided with a multistaged, filtered amplifier circuit (16) for amplifying voltage pulses from a phototransducer (12) and a filtering I/V converter (14) includes three voltage amplifier stages (28, 30, 32) and three respectively associated band pass filters (34, 36 and 38) for cascade connecting the amplifier stages (28, 30, 32) between the phototransducer (12) and the detector circuit (18) and accumulating attenuation of response to signals at a frequency equal to the frequency of full wave rectified AC line voltage to maximize desensitization of the photoelectrical sensor (10) to AC powered ambient light fluctuations while broadening the pass band at the low frequency end for maximum response to the desired signal. A gain control circuit (40) is associated with the first stage amplifier (28), while a temperature compensation circuit (42) adjusts the gain of a second stage amplifier stage (30) to correct for temperature variations.