Supplying Power to External Mods


What with all this modding to PC peripherals going on, adding LEDs to stuff, EL lighting to keyboards etc. Here's an example of one. It can be useful to have some means of powering all this extra stuff, after all not every item you want to mod will have a suitable power source for the desired extras. The power supply inside your PC would be ideal but connecting external gear to it is awkward to say the least. That's were this cheap and simple mod comes in. It allows you to tap into your PCs +12V and +5V supply lines by bringing them out to sockets mounted on a PCI slot blanking plate. It also bring the advantage that anything you plug into the sockets is automatically powered when the PC is switched on. The whole project should take about an hour to complete.

I chose to fit one +5V and two +12V supply sockets. Of course you can have as many or few of each as you can fit on the blanking plate. These are the parts I used along with Rapid Electronics order numbers were applicable:

3 x 2.5 mm DC Power Socket (20-1072)
1 x 5.25" Disk Drive "Y" splitter power cable (19-6150)
1 x spare PCI blanking plate
Heat shrink insulation
Tools - see text

Suitable mating plugs for the sockets are 2.5 mm DC Power Plug (20-0920)

I used the "Y" splitter because I considered that for most people it was easier and cheaper than making your own. I included the packs of "DIY" plugs in the picture just for comparison. Later, the "Y" splitter will have the two end plugs removed.

A closer look at the sockets. The centre contact will be the "Live" connection, (+V), and the outer body connection will be ground, (0V). I chose this particular socket for its looks and robustness. There are other, cheaper types available, but these seemed the most suitable I could find.

Firstly the blanking plate was marked out and drilled to suit the sockets. I drilled at 20 mm centres. Any burrs can be removed with a counter sink bit, larger drill or a small round file. The required hole size is 11 mm. If you don't have an 11 mm drill use a 10 mm and open the hole with a small round file.

After drilling, the sockets were mounted to the blanking plate. Note which side they are fitted from!

Turning our attention to the "Y" splitter, first the redundant plugs were cut off and discarded, since I only wanted one +5V connection the surplus red and black wire was also cut from the remaining plug.

The wire ends were stripped back and tinned, and a length of heat shrink sleeving slipped onto each wire. The wires ends were then soldered to the socket connections.

Once the soldered joints had cooled, the heat shrink insulation was pushed over the bare connections and "shrunk" with a hair drier to retain it.

Just to add a final finishing touch, cable braiding was fitted along with some fluorescent yellow cable ties to hold the ends in place. More details on fitting the cable braid can be found here. The final picture shows the finished project fitted in the PC case, all that remains is to plug it into a spare PSU connector and away you go! There you have it, a quick, cheap and simple mod allowing external circuits to be powered from your PC.