CONTROL DEVICE FOR CONVERSION OF ELECTRIC POWER

PURPOSE:To reduce the level of noise, by a method wherein the phase control of a phase controlling unit is effected by a small phase angle for providing an electric power conversion device with an electric power control information. CONSTITUTION:The phase of an AC voltage from an AC power source P is controlled in a phase control unit 1 by a small phase angle. The voltage, whose phase is controlled, is inputted into a power converting unit 2 and a phase angle detecting unit 1c and said small phase angle is detected to input the detecting signal thereof into the power converting unit 2 whereby an output power, corresponding to said phase angle, is supplied to a load 3. As a result, a supplying voltage to the load may be secured easily in a case in which a voltage, higher than a given value, is necessitated for the stable operation of the load 3, and a stress for a constituting part as well as the noise level in a power cable may be reduced, further, a circuit constitution may be simple and the reliability of signal transmission may be improved compared with an electric power transmission system.