Compact USB-to-Banana Adapter -- my take on dougw's design

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

jasper1000 — Mon, 13 Jan 2025 19:03:20 GMT

I've just made my own version using similar banana plugs but with a vertical mounting USB so that I can use a single pcb. The pcb measures only 32mm x 22mm.

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

Gough Lui — Wed, 01 Mar 2023 10:55:44 GMT

I've only just finished work and thought ...

Why doesn't the @baldengineer just use a vertical USB-A socket and get rid of all the mouse-bite, soldering complexity. It's not going to break the bank to use something like this: https://au.element14.com/gct-global-connector-technology/usb1040-gf-l-b/usb-conn-2-0-type-a-rcpt-4p-th/dp/3873308

Have that vertically in-between your threaded banana contacts (https://au.element14.com/multicomp-pro/mp770525/conn-banana-plug-50a/dp/3514774) connected by an M3 screw (no idea of length - the drawing's pretty bad) or live with some "protruding" studs like you already have and you'd be as compact and cheap as can be?

Maybe I oughta build one myself ...

- Gough

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

wolfgangfriedrich — Wed, 01 Mar 2023 02:37:33 GMT

Ah, the USB-A PD connector of doom. Love it.

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

shabaz — Wed, 01 Mar 2023 00:50:27 GMT

Hi James,

Cute board! I too often want to power from a supply, and in the past have cut a USB cable to access the wires, which isn't great.

It could also be interesting to add a resistor for current sensing, and either another couple of banana plugs for that, although then the board will get bigger. Maybe the connections for the current sensing could be just pin headers (if there will be an enclosure, then the pin headers could be pin sockets instead).

Another option could be to have the banana plugs on wire ends, so that they can fit any PSU. If red/black cables are purchased and cut in half, then two of the adapters could be made (keep one, share one : ).

I use this stripboard-assembled adapter, but instead of banana plugs, it has pin headers for connecting the supply (the red/black pin headers at the center of the image), which is non-ideal.

Alternatively, it is possible to power from a USB supply or a PC, using the USB connector at the bottom-left of the photo (and remember not to plug in a power supply simultaneously! : ) A slide or toggle switch could be used to select between the options.

I used two SMA connectors, one for the current, and one for monitoring the voltage. The data lines are passed through (not recommended on stripboard, but it was a short length). It was all quite fragile so lots of epoxy glue was used.

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

Gough Lui — Tue, 28 Feb 2023 22:47:21 GMT

Hmm. I don't know about you, but I've used a mixture of Multicomp Pro banana contact M3 or M4 studs/threaded types with gold/nickel plating variations.

https://au.element14.com/multicomp-pro/mp770523/conn-banana-plug-50a-gold-plating/dp/3514772

https://au.element14.com/multicomp-pro/mp770525/conn-banana-plug-50a/dp/3514774

https://au.element14.com/multicomp-pro/mp770528/conn-banana-plug-50a-nickel-plating/dp/3514777

https://au.element14.com/multicomp-pro/mp770526/conn-banana-plug-50a-nickel-plating/dp/3514775

https://au.element14.com/multicomp-pro/mp770524/conn-banana-plug-50a-nickel-plating/dp/3514773

https://au.element14.com/multicomp-pro/mp770527/conn-banana-plug-50a-gold-plating/dp/3514776

They're pretty well priced, as compared to the brand-name Stabuli stuff

https://au.element14.com/staubli/22-1053/banana-plug-50a-4mm-screw-m4/dp/1085560

https://au.element14.com/staubli/22-1054/plug-50a-gold-plated-screw/dp/1085561

I've never used the Pomona stuff before, but I get the feeling they're probably similarly expensive.

I've used mine to build an "all channels parallel" adapter for the HMP4040's front-panel and some binding-post replacements, aside from just using them as a quick way to connect crimp ring lugs to banana sockets. I might consider building your USB one too eventually ...

- Gough

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

colporteur — Tue, 28 Feb 2023 22:38:45 GMT

I'm curious to know how the breakoff design will impact PCB production cost.

Don't manufactures frown on the practice and increase cost if that is what they think you are doing?

RE: Compact USB-to-Banana Adapter -- my take on dougw's design

dougw — Tue, 28 Feb 2023 22:33:45 GMT

Good idea to do a right angle.