The Weldestroyer 3000 is a circuit that connects to a tig welder and allows for “cold welding” technique.
Cold welding is a welding technique utilizing short (~1mS to ~100mS) high amperage pulses to rapidly fuse metal. It is a way to quickly tack pieces together without significantly heating either. This makes for easy spot welding for workpiece holding.
The Weldestroyer 3000 is a circuit that is installed inline with a tig torch finger control. When the finger button is pressed, the circuit will create a short pulse that momentarily pulls the control pins on the footswitch connector to ground creating the spot weld. The magnitude of the pulse is controlled by the amperage setting on the welder and the duration of the pulse is controlled via a potentiometer on the weldestroyer 3000.
The first iteration of this project was going to use a 555 timer circuit in a “one shot” mode. The circuit was initially intended to be powered by the control signal of my tig welder, but I have found that this pin is not capable of sourcing much current. The weldestroyer 3000 will instead need to be powered by a battery.
Here is the initial schematic concept:
And the layout:
Given that the circuit cannot be powered by my welder, I am planning to switch over to an arduino for the control instead of an analog solution. This will allow easier control over the pulse width and offer extra options like multiple pulses per button press if I find that to be useful.