ENGINE-DRIVEN DC WELDING DEVICE

摘要

PURPOSE:To enable remotely fine adjustment of welding current and changeover of current width widh a welding device using a single phase hybrid bridge rectifier for the excitation circuit of a generator by controlling the electric power of the generator by the operation of variable resistors and a rotary switch. CONSTITUTION:The current voltage to be impressed to an excitation coil 5 is controlled via a single phase hybrid bridge rectifier 13 bridge-connected with thyristors 14 and diodes and the welding output is obtd. from a generator 6. The terminals of a rotary switch 18 are connected respectively to one end of variable resistors 21-24 of a single shaft quadruplex variable resistor 17 having 300 deg. rotating angle and resistors 31-34 are connected respectively to the other ends. The resistance values of the resistors 21-24 are changed to change the pulse generating phase of a pulse generator 16 and the pulses from the generator 16 are applied to thyristors 14a, 14b by which the conducting angles thereof are finely adjusted. The switch 18 selects any one among the resistors 21-24 and selects the conducting phase width of the thyristors 14a, 14b.