VARIABLE POWER SOURCE

PROBLEM TO BE SOLVED: To control a current value by controlling a set value E1 in such a way that only when AC power voltage V gets over the set voltage E1, a capacitor C1 is charged or discharged, and when the AC voltage V falls under the set voltage E1, the voltage of the capacitor C1 is kept at E1, and a load current is generated when the capacitor C1 is charged or discharged, and the value of this current becomes the function of the above set voltage E1. SOLUTION: A switching element S1 and the capacitor C1 are connected in series between an AC power source V and load. The switching element S1 can be turned on at all times to a current in the direction of charging the capacitor C1 in the positive half cycle of the AC power source V and can be controlled to be on or off to a current in other directions, and when the voltage across the capacitor C1 gets over the set voltage E1, it is controlled to be on, and when the voltage is under the set value E1, it is controlled to be off. COPYRIGHT: (C)2003,JPO