POWER SUPPLY DEVICE, DISCHARGE LAMP-LIGHTING SYSTEM, AND LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce generation of unbalance and connection failures by inputting the DC voltage of a DC power supply device for alternately turning on and off for switching, and by setting voltage applied between the gate and the source of a P-type FET to be larger than that for an N-type FET for alternately turning on and off a switching device. SOLUTION: A drive means 9 applies a voltage between the gate and the source of FETs 7 and 8 and alternately turns on and off the FETs 7 and 8. A load circuit 10 is provided in parallel with the P-type FET 8. The switching devices 7 and 8 input a DC voltage from a DC power supply device 1 for switching by the output signal of the drive means 9. The output of the drive means 9 sets voltage applied between the gate and the source of the P-type FET 8 is set larger than that applied between the gate and the source of the N-type FET 7, thus allowing the calorific values of the FETs to be close, and hence providing heat radiation countermeasures and balancing the service life.