JPS57152370A - Dc welding electric power source - Google Patents

Abstract

PURPOSE:To eliminate output fluctuations, and to provide transient response characteristics which are superior despite the abrupt fluctuations of load by making the 1st output circuit of an open loop system and the 2nd output circuit of a closed loop system which performs feedback controlling attachable. CONSTITUTION:A titled electric power source consisting of an AC transformer 11, a rectifier circuit 12 which rectifies the output thereof, the 1st output circuit 1 of an open loop system which supplies electric power to welding load with a switching element 13, the 2nd output circuit 2 of a closed loop system of small capacity with the same constitution as that of the circuit 1, a reference voltage setting circuit 7 for setting the output voltage of the circuit 2, a voltage detecting circuit 8 which detects the terminal voltage of model load 6, a comparator 9 which compares the output voltages of the circuit 8 and the circuit 7 and obtains a differential voltage, and a driving circuit 10 which controls the quantity of conduction of the elements 13, 23 of the output circuits 1, 2 in accordance with the output corresponding to the output of the comparator 9. By the above-mentioned electric power source, the output fluctuations against external disturbance are eliminated and the superior transient characteristics are provided despite the abrupt load fluctuation during welding.