A hybrid power connector

2.1mmBarrelPlug

You love screw terminals. You love barrel jacks.

These things seem so standard to you, so convenient, and you dream of their lovechild, a sweet hybrid of convenience, solder-free terminals coupled with that 2.1mm silver power plug that powers myriad devices (e.g. Arduinos and most of the boards we sell).

Believe or not – this slightly monstrous adapter lives!  Soldering standard barrel plugs onto wall-adapter and battery-pack wires is not rocket science, but there are two principle challenges:

  1. You have to put the barrel plug insulator onto the wires, in the correct direction, BEFORE you solder the wires.
    This simple act is cunningly easy to forget and evades me a fair percentage of the time I solder plugs on wall warts and guitar cords. So I end up with a perfect solder joint on the connector, and the insulating sleeve is lying on the bench, and I have to do it all twice.
  2. The other challenge is soldering well enough, and making tidy enough solder joints, so that the sleeve will slide down over the wires and screw on. This never bothers me anymore, but it often taxes my student’s soldering abilities.

This screw-terminal power plug eliminates both problems, perhaps at the expense of aesthetics. Also you don’t really have much strain relief with this jack, but it could easily be added with hot glue or epoxy putty. Perhaps at the further expense of aesthetics.

This also a great way to reuse all those power adapters in your junk box.

We have a short tutorial on using the plug below.

2.1mmBarrelPlug

 

Unscrew the terminals,

Tin the wall-adapter or battery-holder wires, Tinning the wires is not strictly necessary but is a good idea.

Insert the wires into the adapter. The marked “+” terminal is positive. This is way more standard than center-negative. Center-negative adapters do exist, but not in Arduino land. Double check your specs and the polarity.

redwire

And screw the terminal back down again.

hands-screwing

If you’re seeking permanence, the wires can be soldered in place, though it takes a while. (this iron is off, use a hot one for best results).

soldered

 

It’s ready to go in the shop here! It’s never too early for nerd gifts for the holidays.

By Nadya on September 30, 2014.