| 摘要 |
PROBLEM TO BE SOLVED: To avoid the overheat of an ignition transformer or a switching element when discharge does not occur in an emission stand or when the emission stand is in a short-circuit state.SOLUTION: A switching element driving part 15 is configured to turn on a switching element 4 for allowing discharge to occur, and to turn off the switching element 4 in a period when the polarity of currents flowing through a primary coil 3a of an ignition transformer 3 is inverted. Thus, LC resonance ends in one period of a resonance period. Also, currents flowing through the primary coil 3a in an opposite direction during resonance are suppressed by a damping circuit 8 connected in parallel with the primary coil 3a of the ignition transformer 3. Thus, even when discharge does not occur in an emission stand or the emission stand is in a short-circuit state, a power loss in the ignition transformer 3 or the switching element 4 is reduced such that heat generation is suppressed. |
