I’ve had the honor of mentoring a local High School’s FIRST Robotics team. Their robot runs on a 12vdc battery. During most of the testing, the robot doesn’t need to move too far, and watching the battery charge just seems like an unnecessary item to monitor.  So, the alternative is to make a cheap, dedicated power supply.

This thing started off as an old discarded laptop(or similar device) power supply. It had a plug on it, emphasis on ‘had’. It got chopped in order to add a couple of binding posts. These bad boys will accept a bare wire or banana plug. I designed up a couple ‘caps’ and 3D printed them. They are pretty simple and made to fit a little snugly over the power supply. Eventually they will just be glued on to the power supply housing.

In addition to the binding posts, there’s an on/off switch and power indicator LED. Making these caps seemed like a great idea at the time but it was tight getting the components installed, wired and then crammed in there such a way that the cap would go on the power supply brick. I actually had to take it apart after gluing it because something was shorting inside (ground wire on the positive binding post stud).

But the end result is a pretty slick looking dedicated power supply. Being non-adjustable is perfect for the Robotics Team as they can’t turn it up too high!

3D model of the caps.

Everything crammed inside.

Original power supply.