Dimmable self-ballasted fluorescent lamp and discharge lamp operating apparatus having an output current limiting means in the preheating circuit

摘要

A dimmable self-ballasted fluorescent lamp includes a fluorescent lamp, a ballast and a lamp base that are formed as one unit. The ballast includes a preheating current supply circuit for supplying a preheating current to the fluorescent lamp; an inverter circuit portion for supplying a high frequency AC voltage to the fluorescent lamp; and a control circuit portion for controlling a driving frequency of the inverter circuit portion. The ballast is provided with an output current limiting element for limiting an output current from the preheating current supply circuit.