Patent ID: 7973490

Claim:
A voltage control transformer circuit for controlling an operating voltage level applied to a high intensity discharge (HID) lamp, said voltage control transformer circuit including a transformer, a single pole, double throw (SPDT) switch in a first position connecting a full AC line voltage to said HID lamp for starting of said HID lamp, and in a second position said SPDT switch connecting a reduced voltage less than the full AC line voltage from said transformer to said HID lamp for sustained operation of said lamp with reduced power consumption, and a timing circuit switching said SPDT switch from said second position to said first position in response to detection of a voltage transient on the AC line which is greater than a determined duration thus restoring application of the full AC line voltage to said HID lamp, whereby the voltage transient of greater than said determined duration is to extinguish said HID lamp and application of full line voltage restores operation of said HID lamp.