| 摘要 |
PROBLEM TO BE SOLVED: To provide electric discharge lamp lighting equipment which cuts down numbers of used elements, and reduces stress added to the used parts. SOLUTION: Between both ends of a smoothing capacitor C1, series circuits of switching elements Q1 and Q2, and series circuits of switching elements Q3 and Q4, are connected. Between a connecting point of the switching elements Q1 and Q2, and a connecting point of the switching elements Q3 and Q4, a load circuit R containing a high-pressure electric discharge lamp La, is connected, and between direct-current output terminals of a rectifying circuit DB is connected through inductor L1 to between the both ends of the switching element Q2. Here, the control circuit 2 makes a 1st period, which makes both the groups of the switching elements Q1, Q4 turn OFF, and makes the group of the switching elements Q2 and Q3 turn ON/OFF by high frequency, and a 2nd period, which makes the switching element Q3 turn OFF and makes the switching element Q2 and the group of the switching element Q1, Q4 turn ON/OFF by turns by high frequency, alternate by turn in a low cycle. |
