Gas discharge lamps ballast circuit - is for two lamps in series and has two RC voltage doublers and voltage regulating transistor

摘要

The ballast circuit, for supplying two series gas discharge lamps from the AC mains, consists of an ignition circuit and a ballast to stabilise the lamp voltage. The ignition circuit (X1-X4, C1-C4) consists of two opposing voltage doublers connected between the supply and the lamps. Each voltage doubler contains two ac-side capacitors and two diodes. The capacitors are large enough to produce the voltage needed to ionise the lamp gases. The ballast consists of a voltage regulator containing an electronic switch regulated by a control circuit.