| 摘要 |
PURPOSE:To cut time required for lighting by making the time for finishing charging of a condenser of a time constant circuit composed of resistances and the condenser, identical with that where descending voltage of one resistance becomes zero. CONSTITUTION:In a lighting operation of a discharge lamp 5, the time required from the output of a comparator CP1 is opened until the charging of a condenser C2 is finished is made identical with that required from the open status of the output of the comparator CP1 until the output of a comparator CP2 is opened. For example, by determining resistance values r2, r4 of resistances R2, R4, as well as capacity values C2, C4 of condensers C2, C4 properly (r2.c2=r4.c4), when the generating frequency of an inverter 2 reaches f2 and the lighting of the discharge lamp 5 is started thereby, a resistance R5 is opened, whereby generating frequency is instantly switched over to f3. The time required for lighting can thus be cut. |
