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:
Jul. 10, 1990
Filed:
Aug. 31, 1989
Applicant:
Inventor:
Edgar M Smith, Millersville, PA (US);
Assignee:
Burle Technologies, Inc., Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340567 ; 250210 ; 250340 ; 307117 ; 340587 ;
Abstract
A digital control circuit uses a single infrared detector to control the clock pulse on a digital counter so that the sensitivity control is based on the length of time a change in infrared radiation persists. A pyroelective detector is located in a voltage divider and the intermediate voltage of the divider is digitally compared to the intermediate voltage in a fixed divider as a digitaly controlled pulse is applied to both dividers. Either an increase or a decrease of infrared radiation causes the digital circuit to permit the counter to be activated.