Abstract: A corrective device for an inverter output voltage error in which a current sensor is connected in series with the output of an inverter, the polarity of current detected by the current sensor is discriminated by a polarity decision current, a value corresponding to an input D.C. voltage is found by a D.C. voltage sensor, a signal with the polarity of the value inverted according to the discriminated result delivered from the polarity decision current is generted by a polarity inverter circuit, and the signal is applied as a correction signal to the PWM (pulse-width modulation) circuit of the inverter so as to correct the output voltage error.

Abstract: A rectifier device which includes a first radiating fin, a flat type semiconductor element which is disposed in contact with one surface of said first radiating fin, a substantially cylindrical insulating envelope which envelopes the flat type semiconductor element and one side of which is coupled with said first radiating fin, a second radiating fin which is coupled with the other side of the insulating envelope, and a through conductor which is threadably inserted through a central part of said second radiating fin and which lies in contact with said flat type semiconductor element.