A series-resonant electronic ballast for rapid-start fluorescent lamps with programmable starting

A series-resonant energy-tank is added onto the series-resonant electronic ballast to improve the starting performance of the rapid-start fluorescent lamp. The series-resonant energy-tank is used as the starting-aid circuit to eliminate the glow current in the lamp during the preheating interval. By adjusting the operating frequency, the electronic ballast is able to provide an adequate filament current for preheating with nearly zero lamp voltage, a lamp voltage high enough for ignition, and then the required lamp power and filament current at steady-state. A prototype of the electronic ballast with the proposed control scheme is built for a T8-36 W fluorescent lamp. Experimental tests exhibit satisfied results.