Electronic ballast for programmed rapid-start fluorescent lamps

A solid-state AC switch is added on the series-resonant electronic ballast to provide programmable starting for the rapid-start fluorescent lamp. The AC switch is turned on to have a zero voltage across the lamp to eliminate the glow current during the preheating interval. By adjusting the operating frequency, the electronic ballast produces first an adequate resonant current for preheating the cathode filaments, then a lamp voltage high enough for ignition, and finally a stable lamp arc of the required lamp power. A prototype of the electronic ballast with the proposed control scheme is built for a T8-36W rapid-start fluorescent lamp. Experimental tests exhibit the satisfied results.