POWER SUPPLY EQUIPMENT, LIGHTING DEVICE FOR DISCHARGE LAMP AND ILLUMINATING APPARATUS USING THEM

摘要

PURPOSE:To improve the efficiency of a preregulator by avoiding a disadvantageous preregulator design which presumes chopper operation during light loading such as preheating and starting. CONSTITUTION:This power supply equipment comprises a step-up chopper type preregulator 3 consisting of a switching element 6, inductor 5 and smoothening capacitor C1 connected to a power supply 1 and an operation start control means 14 for performing stop control for the operation start of a switching element 6 within the preregulator until a detection signal is output from a detection means 13 detecting the start of operation of a load 7. And the switching operation of a switching element 6 within the preregulator 3 is prohibited by operation start control means 14 until the start of operation of the load 7 is detected, thereby eliminating the circuit design for providing stable chopper operation during time period described above.