PURPOSE: To generate stable spark, by using two condensers, by connecting them in series and by applying twofold condenser voltage to a primary winding of an ignition transformer, in a petroleum igniter.

CONSTITUTION: A condenser 10 and a charging resistance 9 are connected in series, and a chargings condenser 12 and a charging resistance 13 are connected in series. The condensers 10 and 12 are each charged through resistances 2, 9 and resistances 2, 13 during the positive semi-cycle period of an AC power source 1. When discharge, current is discharged by a loop of the condenser 10→ a thyristor 14→ the condenser 12→ a primary winding of an ignition transformer 6→ the condenser 10, and the chaging charges of the condensers 10, 12 are instantaneously discharged to the primary winding of the ignition transformer 6, thus generating high voltage at a secondary winding of the ignition transformer 6, then forming spark at a discharge gap 7.