Patent ID: 7843141

Claim:
A dimming interface for use with an electronic ballast powering a gas discharge lamp, the electronic ballast including a ballast inverter circuit, the dimming interface comprising: first and second power input terminals for connecting an AC source; a first dimming switch coupled to the first power input terminal; a second dimming switch coupled to the second power input terminal; a rectifier circuit coupled to the first and second dimming switches, the rectifier circuit operative to generate a rectified output power signal for providing power to a ballast inverter circuit and to output a dimming interface signal for controlling the ballast inverter circuit; the rectifier circuit is responsive to manipulation of the first and second dimming switches to cause the dimming interface signal to be a half-wave rectified signal when each of the dimming switches is closed, and a full-wave rectified signal when one of the dimming switches is open and the other dimming switch is closed; a dimming control signal generator circuit operably coupled to the rectifier circuit to receive the dimming interface signal; and wherein the dimming control signal generator circuit is responsive to the dimming interface signal to generate a DC control signal, the DC control signal having a first value when the dimming interface signal is a half-wave rectified signal and having a second value when the dimming interface signal is a full-wave rectified signal.