Patent ID: 6114816
Filing Date: 2000-09-05
Classification: H05B

Abstract:
A step-dimming system for a discharge lamp comprising the combination of:an alternating current power source comprising a line voltage wire for carrying a line voltage and a neutral wire for supplying at least one line voltage;a fixture housing comprising no more than four terminals for controllably operating said discharge lamp and connecting said alternating current power source to said fixture housing, the four terminals including a first terminal connected to said line voltage wire, a second terminal connected to said neutral wire, a third terminal and a fourth terminal connected to ground;a ballast disposed within said fixture housing and comprising an input side connected to said first and second terminals, respectively, for receiving said line voltage, an output side connected to said lamp, and a tap;a first capacitor and a second capacitor disposed within said fixture housing and connected to said ballast to store energy therefrom;a first control relay and a corresponding contact set disposed within said fixture housing and connected to said first capacitor to selectively increase and decrease energy provided to said lamp from said ballast, one end of said relay being connected to said tap and the other end of said relay being connected to said third terminal; anda second control relay and a corresponding contact set located remotely with respect to said fixture housing, one contact of said second control relay being connected to said neutral wire and another contact being connected to said third terminal to provide only a single output control wire to control said discharge lamp, said second control relay being operable to selectively connect and disconnect said single output control wire to said neutral wire to activate said first control relay, said first control relay in turn being operable to connect and disconnect said first capacitor from said ballast in response to said connection and disconnection of said single output control wire to said neutral wire to increase and decrease energy provided to said lamp from said ballast.