Current control device and crime prevention of spot welder

摘要

The present invention relates to a point welder for controlling an amount of effective current applied to an electrode by controlling an ignition angle of a thyristor, and more particularly, to a point welder comprising an energization detecting unit connected to an electrode and detecting a current-A first table in which an effective value current for an ignition angle is stored at a predetermined power factor angle; A second table storing information on an ignition angle and a power factor angle with respect to a cylinder angle; Detecting a current flowing through the die list in accordance with the energization state of the energization detecting section, detecting a power factor value corresponding to the ignition angle and the energizing angle of the thyristor using the second table, And a control means for igniting the thyristor by detecting the ignition angle corresponding to the detected power factor value using the first table.