This was one of my older projects. Many people think that pulsed TIG welding is a recent invention only accomplished through modern IC controlled pulser units. Truth is, basic pulsers have been around for quite some time. They allow for the variable adjustment of heat input into the weld by adjusting the frequency of the arc. Hence, very thin materials, and even exotic materials can be effectively welded through proper pulsed heat control.
This is an old AIRCO pulser (Model PTC-1A) that I found years ago on e-bay. It's quite rare, even at the time they were made (1970's) AIRCO didn't sell too many of them because of the extra expense it added to a commercial TIG welding outfit. It was made for the Heli-Welder line of industrial welding machines. Most of the late model Heli-Welders were actually rebadged Miller units, and this Pulser was made for the "Miller-based" TIG welders. Many will argue that pulsed units were not available for older Miller and AIRCO transformer welders -- here's one solution that was way ahead of it's time.
The pics show how I found it, but a little R&R with some new wires, a new power and secondary cord, a new switch, and two electrolytic capacitors later, the thing was painted "Miller Blue" and works fairly well.
Before:
After: (New capacitors, Power Cord, Contactor/Amperage Control Wires, and Switch)
