Method of operating vehicle instrument fluorescent lamps over wide range of settings

摘要

In the method of operating the fluorescent lamp an alternating voltage of a higher frequency than the operating voltage and a rectangular voltage of lower frequency, with an adjustable pulse width for blocking and enabling the alternating voltage to the fluorescent lamp, are generated. The blocking of the alternating voltage occurs in dependence on one of the parameters which characterises the amounts of radiation of the fluorescent lamp. In one embodiment the blocking occurs when the parameter reaches a defined threshold value.