Discharge lamp ballast with DC-DC converter

摘要

An improved ballast for a discharge lamp includes a DC-DC converter which receives an input DC voltage from a voltage source to provide a pre-starting voltage to make the lamp ready for being ignited or started. The DC-DC converter has a switching element which is driven to turn on and off for generating the pre-starting voltage. A start-accelerating means is included in the ballast in order to vary at least one of the switching frequency and the on-period of the switching element based upon the monitored input DC voltage in a direction of accelerating the increase of the output DC voltage to the pre-starting voltage until the output DC voltage reaches the pre-starting voltage.