We use batteries to power a lot of our electronics. But there are some battery powered devices that don’t necessarily need to be portable all the time. One example is my son’s battery powered swing. It can be moved around but it usually stays in the same general area. In cases like these it might be nice to power these devices with an AC adapter and save the batteries. So in this project, I am going to show you how you can use an old power adapter to power your electronics in place of batteries. I will share how to modify the adapter and two different ways to connect it to your electronic devices.

Jason Poel Smith

Jason Poel Smith

My name is Jason Poel Smith. I have an undergraduate degree in Engineering that is 50% Mechanical Engineering and 50% Electrical Engineering. I have worked in a variety of industries from hydraulic aerial lifts to aircraft tooling. I currently spend most of my time chasing around my new baby. In my spare time I make the how-to series "DIY Hacks and How Tos."


  • foobard

    I wish it was better explained. Why do the dummy batteries have a short between their terminals? If there is a short between them, what is the point of labelling them positive and negative?

    • jobo

      The bottom dummy battery, which has the regulator circuit attached to it, should be labeled + and – as shown so you know which way to put it in. The other batteries don’t need to be labelled + and – as they are just functioning as wires. He just wants to connect the regulator to both leads of the swing and has determined that the most convenient way to do this is with dummy batteries that can be easily put in and out (if you still want to run the device with normal batteries sometimes). As is, the current flows in a circuit from the wall, through the regulator, through the dummy batteries, through the device, and back through the regulator to the wall.

  • Craig

    This is something I was wondering about for awhile now. Can this be done to Cordless tools such as a 19.2v Craftsman Cordless Drill or Saw? Somehow make a circuit that fits inside the shell of a gutted battery so when I have to, I can put that into the saw / drill and plug her in to the wall?