Patent ID: 6124682
Filing Date: 2000-09-26
Classification: H05B,Y02B

Abstract:
A lamp driver for a discharge lamp, said driver comprising: A.C. power supply means for supplying power to the lamp and control means for controlling the power supply means to operate at a first output frequency for starting the lamp, and at a second output frequency, lower than the first output frequency, for powering the lamp after discharge is initiated, the lamp driver further including a tuned circuit, which is substantially resonant at said first frequency, coupled to the output of the power supply means so as to generate a greater voltage across the lamp at said first frequency than at said second frequency, the lamp driver further including transformer means including a primary winding coupled in series with the tuned circuit and a secondary winding coupled to boost the voltage supplied to the lamp, the primary winding being connected in series with the secondary winding, wherein at said first frequency, a higher voltage is developed across the secondary winding than at said second frequency.