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:
Apr. 20, 1999
Filed:
Apr. 30, 1997
Jeff D Walters, Marshfield, MA (US);
Lucinda Seigel, San Francisco, CA (US);
Other;
Abstract
A photoelectric load control system for applying power to a light or load as a function of ambient light level and as a function of the length of daylight or darkness. The system includes a switching circuit for selectively applying power to the light or load for turning the light or load on and off; an ambient light level sensor for providing a signal which varies between a first state and a second state in response to the ambient light level; and a uniquely programmed processor responsive to this signal for activating the switching circuit. The processor includes a routine for activating the switching means to turn the light or load on in response to one of the states, a timing routine for timing the total darkness period, a counter for counting the period of darkness or daylight, a routine for determining when the count exceeds a predetermined percentage of the total darkness or daylight period, and a routine for activating the switching circuit to turn the light or load off or on after the count equals or exceeds the predetermined percentage of the darkness or daylight period.