PURPOSE: To provide a titled power source which reduces the size of a semiconductor inverter circuit of a power source for welding and operates effectively and uniformly said circuit by using a capacitor transformer output method for said inverter circuit and prohibiting semiconductor elements from restarting until the capacitor discharges thoroughly.
CONSTITUTION: An AC power source 1 is rectified by a rectifier circuit 2 to DC which enters an inverter circuit 3. The current of which the frequency is increased by semiconductor switching elements 31W34 is converted to prescribed AC by a transformer 36 for taking out output. The AC is again rectified to DC by a rectifier circuit 4 and the DC is fed via a DC reactor 5 to an output terminal 6. When an inverter start-stop circuit 7 is turned on, an inverter control circuit is actuated by a time limiting circuit 9 to prohibit operation of the elements 31W34 for specified time. The discharge circuit 12 of a capacitor 35 is switched S on so that the capacitor discharges thoroughly during this time. The failure of the elements 31W34 is prevented by the through discharge of the capacitor 35. The iron core for the transformer 36 is thus minimized and the circuit 3 is effectively and uniformly actuated.
NAKAMATA TOSHIAKI
YAMAJI SUSUMU
Next Patent: JPS6064766