Abstract: A starter controller for a multiple parallel ballast for high pressure sodium lamps detects lamp "drop-out" or 'cycling" and enables restarting of the lamp if the drop-out was causded by line transients of a level sufficent to cause normally operating lamps to drop-out. If the detected lamp drop-out was caused by normal end-of-life conditions, the controller does not allow restarting of the lamp. In one embodiment, the starter controller constantly monitors the voltage across the lamp terminals. When lamp drop-out occurs, this voltage rises rapidly to the ballast open-circuit secondary voltage. This voltage is detected by a level detector and rate detector which then processes lamp voltage level and rate of change of voltage after the initial drop-out is sensed.