Magnetic Laptop power connector

Step 3 Creating the molds

I decided to encase the whole enchilada in epoxy resin to minimize the possibility of errant electrical connections. I picked up some casting resin from the local Hobby Lobby, as well as some candle wax to use for molds. (if you look at the wax block, you can see my initial asymmetric connector molds that I never ended up using. They taught me a little about how to use the epoxy, though.)

The second picture is not quite accurate, as the brass anode terminals were added prior to pouring in the epoxy. The molds were made by using drill bits to hog out the main design of the connectors, the using an XActo knife to refine the design. As it turns out, I forgot to "refine" the outlet side connector mold, so it ended up just being a 1/2" hole flanked by 3/8" holes, but it turned out alright.

The magnets were soldered to a piece of 18 ga wire before being fitted into the molds. I left about a 1/32" around the magnets as possible to insulate them.

At this time I also decided I wanted cool green LEDs to indicate that power was connected (another prod from my wife!), so I fashioned up some LEDs from some SMD components I had lying around (eventually when I learn to program AVRs, I'll be using them for firefly projects). As you can see, they are easy to fit in, being so small. Initially I only soldered them the cathode ends to the magnets and left the anode lead sticking out slightly above the level of the epoxy. This was done so that I wouldn't have to disturb the brass terminals which were only tentatively held in place by being stuck into the wax. After the epoxy cured, I soldered a small jumper from the LED lead to the brass terminals. Had I thought it out, I would have made the leads longer and just bent them over to the brass terminal at this point.