Previously, dougw shared a bench power supply video where he used an adapter he made. It had 4mm banana plugs and a USB port on it. The idea was that he could connect USB devices to a bench power supply.
I loved the idea and he did a great job with it.
But I didn't like how large it seemed. Also, I wanted something that could be inserted in either orientation without blocking the controls of my supplies. After looking around for "PCB mount banana plugs," I found... well, none. There are jacks, sure. But no plugs. You're left with components designed to be attached to a cable. Then I found Ponoma makes panel mount plugs!
So that got me thinking. If I used that type of hardware, then how would you get the USB port to be in a usable direction? (Instead of pointing up or down.) THEN, I thought: hey, I can practice making PCBs with mouse bites.
In my design, you break off part of the PCB (left side) and then solder (to right side) at 90 degrees using the edge tabs. A Ponoma 4mm Plug with M3 mounting hardware connects to the plated holes. And a short GCT USB-A connector solders to the board.
The result is a very compact adapter.
However. Do not build this one.
There are several issues with my first design.
- After breaking off the plug tab, I soldered it backward. So it results in the USB port's +5 and GND being backward. (Some might consider that a bad thing.)
- The plug-tabs are not long enough. They only solder to the top side of the USB board, meaning the solder joints act as a lever point. I should have made the plug-tabs longer so that both the top and bottom could be soldered.
- Some minor issues with the mouse bits I still need to resolve.
All that said, I am happy with the break-off design. It worked as I expected. Although, I still have some improvements to make there.
For the second revision, here's my plan:
- Add some indicators on the silk screen to clarify which side is the "top" for the USB connector.
- Create "slots" for the plug-tab board to "plug" into. That way, I can have four solder points on each tab (instead of 1).
- Thinking about a design to support supplies that have an earth ground terminal between + and -
- Also, considering a barrel jack version
- Need some 3d-printed parts (red and black) to better indicate polarity.
Anyway, you can download the design files from here. But, as I said, do not build it yet! Hopefully, version two is a bit better. In the meantime, do you have any thoughts on what could be improved?
