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:
Feb. 25, 1992
Filed:
Feb. 11, 1991
Charles R Bleich, Chicago, IL (US);
Mark Coldebella, Chicago, IL (US);
Lawrence E DeMar, Chicago, IL (US);
Williams Electronics Games, Inc., Chicago, IL (US);
Abstract
A lighting control system for pinball games employs a lighting circuit board that supports at least one string of lamps connected in parallel. The lighting board associates a triac with each lighting string for switching the output of an a.c. power supply to each lighting string. The triacs are controlled responsive to the output of a zero-cross detection circuit, which monitors the a.c. power supply. The intensity of the lighting strings is independently controllable responsive to conditions on the game playfield by varying the length of time the triac switches power relative to the zero-crossing point of the output of the a.c. power supply.