The Welding Institute

Malcolm D Hannah

Keith I Johnson

Vernon Boyd

Timothy J Jessop

A method of controlling the duration of a resistance weld in which a preprogrammed AC current is fed to welding electrodes, the program including an abrupt increase in welding current after a predetermined number of cycles so that the weld duration can be extended into the high amplitude portion if the heat input has been insufficient. The voltage across the welding electrodes is monitored, the peak voltage detected, a reference voltage derived by dropping the peak voltage 2 - 20% and the weld terminated when the subsequent peaks fall to the reference voltage.

Growing community of inventors

Cambridge, United Kingdom

Malcolm D Hannah