First, you'll need a 12v AC wall wart, one that's screwed together rather than glued. Pop it open and make sure you have room for the screw head and wires, and remove the transformer.
Then, search out the dimensions for a "NEMA Plug" (this will give you the dimensions for the ground lug relative to the hot and common blades).
Then lay out the hole location and drill a hole to clear the threads on the 8-32 screw, drill the hole in the housing.
Then, take your brass tubing and cut a piece .875" long. Round the end over a bit to ease insertion.
Tap the other end of the tubing with the 8-32 tap.
Then, cut the "output" wire of the transformer on the side that feeds the outside of the barrel connector. Solder in a short pigtail and crimp the eyelet on the end.
Then place the eyelet on screw and tighten the screw through the body and into the tube.
Make sure everything is insulated and put the wall wart back togther, you're done!
I realized I didn't take any pics of the actual wiring but that's simple enough...connect the ground lug to the wire that goes to the outside of the barrel connector.
Materials:
12v AC wall wart with appropriate barrel connector to fit the command base
3/16" x .014" wall thickness brass tube (K&S rack at nearly any hobby shop)
8-32 machine screw
Crimp-on wire ring thingy (could be omitted - a loop of wire under the screw would work fine too)
8-32 tap and tap handle
It works PERFECTLY!
. So I ordered a spare and then replaced the fuse on the two chargers. Had me going for a few minutes.
