Abstract: A filament coil is connected in series with an arc tube to form a self ballasted lamp. An internal starting coil is connected across the arc tube through a bimetal switch, which is normally closed, for energizing the starting coil. When an arc is struck and the tube temperature rises, the bimetal switch opens to cut out the starting coil. A fuse wire is connected across the bimetal switch to facilitate flashing of the filament coil by application of less than rated voltage during evacuation of the lamp envelope when the bimetal switch is normally open because of the elevated temperatures required for glass working and sealing. Upon subsequent application of rated voltage, the fuse wire melts and the lamp operates in its normal manner.