Boxy, blocky, black power bricks with coaxial power plugs, they're everywhere! Wouldn't it be nice to be able to connect wires to them in a non-permanent manner without any soldering or snipping required? Recently I wanted to use a computer fan as a desk fan, and I happened to have a 12 volt power brick from some (likely long-ago trashed) computer speakers. But I didn't want to cut or solder the wires because that means that I'd better be darn sure the computer speakers are toast, right? So here is a non-destructive solution using only two paperclips bent with some needle-nose pliers I had lying around. First, here's the finished product:
You'll need a pair of pliers or other bending device, a paperclip (a large sized paperclip was used for this example, but the smaller types may work just as well), and the plug you desire to attach leads to.
The first step is to make a smooth circular bend in end of the paperclip. This bend should conform as closely to the curve of the power plug as possible. The other pictures in this set show how the shape conforms neatly.
Bend the curve 90 degrees to the side as shown, then make a second bend that places the wire toward the other side of the imaginary circle formed by the first bend in the paperclip.
Make a third bend so that the wire comes up inside the imaginary circle of the first bend. This will form the pressure contact that pushes the outside of the coax plug into the cradle formed by the first bend.
Place the needle-nose pliers so that the paperclip will bend just below the circle of the first bend press the wire away and down to sweep the wire in the approximate direction desired. This fifth and last bend completes the plug by providing a pressure point to push the coax plug into the cradle of the first bend.
Adjust the spacing between the pressure point and cradle so that your coax plug fits into it with just enough force to securely hold it.
Try it out! Here are images from a variety of angles to show how it should work.
Now that we've made the outer clip, we just need to make an inner lead to connect to the inside of the coax plug. You will probably have to use a smaller, regular-sized paperclip for this part. Due to the need to make it springy enough to hold tension against the inner walls of the coax plug, we will need at least one 180 degree bend, so the paperclip wire diameter will have to be small enough to fit doubled inside of the inner coax plug area.
Here, we select a short section and make a 45 degree bend in it.
Place the pliers on the far side of the bend and complete the 180 degree bend. Ideally we want the end of the paperclip to be pressing directly against the main straight part of the paperclip, so make small adjustments until it does so.
Gently squish it down until it's fairly flat. It's easier to squish down than it is to undo the squish, so test frequently to see how it fits as you get closer to correct. Ideally you want a small remaining gap between the doubled wires. The doubled wire should slide in with some resistance.
There we go, two leads suitable for connecting small devices to. Personally, I use it to power a desk fan!