Dec 9, 2009
Beginner Ham Radio Project: 12 Volt Power Supply
If you’ve priced switching power supplies lately, you may have noticed that they can be a bit pricey. To combat these cost you can convert an old PC’s power supply into a 12 volt source to power your radio gear. The picture on the left is of a power supply whose real exhaust fan died. The power supply still works great, but without a rear exhaust fan it tends to get a little hot inside of a computer case. Once I converted to a 12 volt source and took it out of the computer case it ran cool. This was a simple project to do and only cost a few bucks. If you don’t have an old computer power supply lying around you can still pick one up for pretty cheap.
Supplies Needed
- Old PC Power Supply
- Wire Cutters
- Paper Clip
- Alligator Clips
Putting It All Together
The key to getting the power supply to work properly is to short the Power On Supply wire with a ground wire. The Power On Supply wire is what turns the power supply on and off. The Power On Supply wire is located in pin 16 is and is green in color. In order to short this pair out I created a jumper out of a paper clip and stuck it into the socket of pin 16 and a nearby black ground wire. Next you’ll want to gather all of the yellow and black wires. These are the ones you’ll need for the 12 volt power supply. Once you add connecters to the end of these wires you’ll be good to go. I used alligator clips, but you can use whatever you like. This is just a quick power supply conversion; you’re welcome to make this a complicated as you like.
Hello, I was wondering how many amps is this pwr supply? Can always use another pwr supl. 73, Al. N3TTC
Hey Al,
I don’t really know. I didn’t measure it yet, but I think this would depend on a lot of factors. One being the wattage of the power supply (The one here is rated at 350 watts) and how many of the yellow 12 volt wire you used. I used six of the twelve available.