ELECTRIC POWER SUPPLY APPARATUS AND DISCHARGE LAMP LIGHTING APPARATUS AND LIGHTING SYSTEM USING POWER SUPPLY APPARATUS

摘要

PURPOSE: To make tertiary winding of a saturable current transformer unnecessary and lower the cost and the loss by connecting a specified saturation time controlling circuit to a secondary coil in one side of the saturable current transformer. ;CONSTITUTION: Regarding a saturation time controlling circuit 21, an impedance component is composed of an impedance variable circuit 25 which is a series circuit of resistors 22, 23 and an FET 24. The output in the secondary side of a saturable current transformer 4, that is, the output of the secondary winding 14, is voltage-doubled and rectified by a voltage doubling and rectifying circuit 30, smoothed by a smoothing capacitor 31, and then sent to a variable circuit 25 and thus the flowing current level alters. Consequently, the saturation time of the transformer 4 also alters and the operation of the inverter circuit 1 is controlled automatically. Without a tertiary winding being set in the transformer 4, operation control can be done by self-excitation type inverter circuit. As a result, the cost and the loss of the transformer 4 are lowered.;COPYRIGHT: (C)1995,JPO