Republic Steel Corporation

Andrew Stanya

Joseph E Franklin

David W Dickinson

An electrical resistance spot welding system and method is disclosed. The system has adjustable output power circuitry for applying electrical heating energy to a weld site by way of weld tips, in accordance with a welding operation. An energy monitor senses instantaneous accumulated energy applied during the welding operation, and terminates the operation when an adjustable predetermined total energy has been applied. Other circuitry monitors applied welding voltage, and derives therefrom a signal which is a function of the energy density per unit area applied at the weld site. Circuitry responds to the energy density sensing to control the energy monitor and the power circuitry to govern the total energy applied in the welding operation. As weld energy flux density decreases, such as happens when weld tips spread or 'mushroom', total applied energy is increased, compensating for weld tip changes, thereby holding the amount of applied energy per unit of weld site area relatively constant from one welding operation to another.

Control of welding energy flux density

An automatic plating current control system for an electroplating line. The plating line includes a plurality of power circuits, each including a rectifier and an electrode, for delivering plating current to affect electrodeposition on the workpiece surface. The automatic control system includes a reference generator, a first feedback circuit for controlling the total plating current applied by all the power circuits and a plurality of second feedback circuits each associated with a different power circuit. Each of the second feedback circuits co-operates with the first feedback circuit for regulating plating current output of the individual power circuits to apportion the current output among the operative power circuits. The reference generator produces a reference signal representing a desired plating current in response to information input to the reference generator, specifying workpiece speed, workpiece dimension and desired plating thickness. Each power circuit includes an output voltage control and a current metering circuit. The voltage control circuitry is provided for each power circuit to limit its plating current output to a predetermined maximum without disabling the power circuit. Compensation circuitry is provided for altering the reference signal for varying the fraction of plating current apportioned to each power circuit to compensate for inoperability of one or more power circuits.

Growing community of inventors

North Royalton, OH, United States of America

Andrew Stanya