METHOD AND DEVICE FOR DRIVING AN HID LAMP

摘要

A method for driving and dimming an HID lamp (2), the method comprising the steps of: providing a controllable HBCF current source stage (20); using the HBCF current source stage (20) to generate commutating DC lamp current (I) having alternating current direction; supplying the HBCF current source stage (20) with an intermediate voltage (Vo). In normal mode, the commutating DC lamp current (I) is generated with a predetermined nominal current magnitude (IN) while the intermediate voltage (Vo) has a predetermined nominal level (VN). In a dim mode, the commutating DC lamp current (I) is generated with a current magnitude lower than said nominal current magnitude (IN) while the intermediate voltage (Vo) has a level (VH) higher than said nominal level (VN).