SIMPLE AUTOMATIC WELDING MACHINE

摘要

PURPOSE:To execute precise welding so that the uniform and sure welding to good quality is made possible by subjecting the arc light detected by a photodetector for photometry to current control. CONSTITUTION:The current value at which optimum conditions are obtainable is preliminarily determined and the value corresponding thereto is preliminarily set to a reference value setting knob. The photocurrent detected by the photodetector for photometry is amplified and is compared with the reference voltage value set by the reference value setting knob in a comparator circuit. A current control circuit is so operated that both values are made equal. The current control circuit operates to increase the current when the amplified output from the photodetector for photometry is lower than the reference voltage value and conversely the current control circuit operates to decrease the current when said output is higher than said reference value. The circuit is so operated as to maintain the current value is said stage when both values are equal. The precise arc welding is thus executed while the current is automatically controlled so as to obtain the optimum discharge at all times.