Controlling the electrode force is a critical part of successful resistance welding. Repeatable weld force provides for consistent welds. For this reason, all Miyachi Unitek weld heads include a standard force-firing feature that initiates the power supply when a preset electrode force is reached. In addition to force firing, a sufficient amount of squeeze time, typically 150 milliseconds (9 cycles @ 60 Hz.), is required to allow the weld head to settle prior to the application of weld current.
For more information, read our paper on 'The Importance of Squeeze Time in Resistance Welding'
And for more information about the resistance welding process read our Fundamentals of Resistance Welding.