That last requirement removes most laptop power supplies from the list of hopefuls. But, it does shine some light on my favorite gaming platform, the Xbox 360. The 360 variants feature external power supplies with some funky 8 pin output cable. Furthermore there are variants that output some 135W (Xbox 360 Slim) to 203W (Xbox 360 original console) of power. My favorite part about these power supplies is they can be obtained for cheap because they are available everywhere. I grabbed a 150W variant off ebay for $18 free shipping.
Alright! Hacking time! I received my box and noted many familiar items. Wall plug, power brick, lalala... oh wait.
|8 pins wtf|
It turns out, six of the pins are used for power transmission and two are used for a "standby" state. This is probably the minimum power required for the sleeping state on the Xbox (I mean how else do you turn it on using the wireless controllers?). Here is the pinout:
|Courtesy of that website. Kudos go to them.|
Anyway, I unplugged the charger cord, and immediately sliced into the cable behind the connector. Conveniently enough, the cables are colored accordingly.
|8 pins, 8 wires. Life is good.|
Strip away more wire and begin soldering things together. Three BLACK in paralle, three YELLOW in parallel, and connect the BLUE and RED/PURPLE.
Your choice on the shrink wrap and external connector. A good choice might be a power strip in case you want to power multiple items with it. Since this power supply is single duty, I soldered in an XT60 connector used for hobby RC.