Remote Control Method of a-c Arc Welding Machine (2nd. Method)

Abstract

The authors' previous method shown in the journal of Japan Welding Society in 1956 adopted a special reversible d-c control motor and a control box containing half wave dry rectifiers. This method, however, uses a small a-c motor which rotates only unidirectionally and a control box with a resistor. The welding current is controlled by connecting the control box between the electrode and the work.
Since the motor circuit is connected to the secondary terminals of the welding transformer and the starting motor voltage is set to be 60V, the motor never rotates during the arc time, thus resulting in high stability of circuit operation. On the other hand, application of the control box makes the motor voltage 70V, thereby the motor being able to rotate to adjust welding current.
The method has the following advantages :
(1)Non-use of control cables;(2)Non-use of relays;(3)Simpler circuit;(4)Smaller and lightercontrol box;(5)Operation with higher stability;(6)Easier maintenance;(7)Longer life.