What is the difference between a heat switch and a potentiometer or continuous voltage control on some MIG machines?
(top) The wire feed speed in MIG welding controls amperage or welding heat. The higher the wire feed speed, the more amperage is required to melt the wire and this higher amperage penetrates or digs more into the base material. The voltage control can be a knife switch with specific setting or it can be continuous. With a knife switch voltage control you are limited to specific voltage settings. For a machine with 4 settings (1,2,3,4) the #4 setting will give the highest voltage or arc length. If you set the machine at #4, you have to turn the wire feed speed up to balance the arc or get the proper arc length. Continuous voltage dials allow more flexibility in adjusting the arc length as you an fine tune them.
