To provide a capacitor charging device for an electromagnetic welding machine which can charge a capacitor in a short time and, after the completion of charging, can keep the voltage of the capacitor constant.
This capacitor charging device for an electromagnetic welding machine comprises a first rectification circuit 1 for rectifying a commercial power source, a single-phase inverter 3 for converting the output of the first rectification circuit 1 to alternating current power, a boosting transformer 4 for boosting the output of the single-phase inverter 3, and a second rectification circuit 5 for rectifying the second output of the boosting transformer 4 to charge a capacitor 9 of an electromagnetic welding machine. Measuring means for measuring the charge current and the terminal voltage of the capacitor 9 is provided to control the single-phase inverter 3 in such a manner that, until the terminal voltage of the capacitor 9 reaches a set value, the charge current of the capacitor 9 is constant.
OZAKI TAKASHI
MASUDA KOICHI
YONENAGA YUJI
MATSUDA MASABUMI
CHUO SEISAKUSHO
Akio Najima
Fumio Yamamoto