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. 03, 1994
Filed:
Feb. 19, 1993
Simo P Hakkarainen, Bethlehem, PA (US);
David G Luchaco, Macungie, PA (US);
Scott McConnell, Coopersburg, PA (US);
Lutron Electronics Co. Inc., Coopersburg, PA (US);
Abstract
In a fluorescent lighting controller, a switching circuit operates to selectively couple a bank of electronic ballasts to an AC power source (100-277 Volts, 50-60 Hertz). The switching circuit comprises a pair of relays, preferably connected in parallel, with one of such relays having a controllably conductive device, such as an electronic switch, and preferably a triac, connected in series therewith. With the relays open, an air gap isolates the power source and ballasts. In closing the relays in sequence, one relay provides a conductive path from the power source to the triac. After a suitable delay to allow the relay contacts to stabilize in the closed position, the triac is triggered to provide a conductive path from the power source to the ballasts, and a large current surge (as much as 300 amps) flow to the ballasts. After the current surge has subsided, the other relay is closed to provide a direct conductive path between the power source and ballasts. As a result of this arrangement, the switching circuit is low cost, compact and reliable over an extended period of time.