Hope this helps, looking at the system is is really simple.
DURO DYNE PINSPOTTERS
LF-1000 / LF-2000 Hand Held Pinspotter
See Parts Listing for LF
The LF-1000 and LF-2000 Pinspotter are portable units that weld 14 Gauge PN style pins up to 22 Gauge. Insert PN Pin into the TP-2 magnetic tip and depress trigger. A timed burst of electricity fuses the pin to the steel. Can also weld LN style pins up to 2-1/2" with the use of TPL-2 Tip purchased separately. Available in 110V & 220V, 50 to 60hz; fuse for 15 amps.
http://www.durodynecanada.ca/canada/...inspotters.htm