POWER SUPPLY FOR MAGNETIZATION

PROBLEM TO BE SOLVED: To provide a power supply for magnetization in which a charging capacitor C3 on the secondary can be charged at high rate and can be settled with high precision on the premise that a resonance inverter is provided on the primary of a step-up transformer 8. SOLUTION: A resonance inverter comprises a switching circuit consisting of switching elements IGBT1-IGBT4 connected in reverse parallel with circulation diodes D1-D4, and a resonance capacitor C2 resonating with leakage inductance of a step-up transformer 8. The resonance inverter is attached with a means 13 performing switching control of the resonance inverter at a high rate charging frequency equal to one half of the resonance frequency and switching to low rate charging frequency before the charging voltage of a charging capacitor C3 reaches a predetermined level, and a constant voltage control means 12 for interrupting switching control when a voltage divider 9 detects a fact that the predetermined voltage level is reached and performing switching control at the low rate charging frequency when a predetermined voltage drop from the predetermined voltage level is detected. COPYRIGHT: (C)2006,JPO&NCIPI