SOFT START CIRCUIT FOR SWITCHING REGULATOR AND DRIVING SYSTEM FOR INVERTER CIRCUIT

摘要

PURPOSE:To prevent the increase in rush current, by using a positive DC voltage generated at the primary side of an auxiliary circuit and applying the voltage to a gate of a thyristor. CONSTITUTION:A primary circuit 10 and a secondary side 20 are isolated with isolation transformers T1, T2, T3 and T4. When charging is made up to about 80% of a potential of a capacitor 3 of a soft start circuit 12 with an AC input, a transistor TRQ3 of an auxiliary power supply circuit 14 starts oscillation and a voltage charged in a capacitor C9 is given to a gate of a thyristor SCR. An oscillating energy from the circuit 14 applied from the transformer T4 drives a TRQ4 via a secondary winding L5 and an inverter circuit 13 and a driving circuit 15 via the transformers T3 and T2. The oscillation energy from the circuit 13 is delivered to an output circuit 21 via the transformer T1 and a DC voltage rectified into a constant voltage is outputted.