Sometimes you wanna test a piece of USB hardware, but you don’t just want to plug it into a random old phone charger. [KS-Elektronikdesign] has whipped up a useful tool for just that case, allowing one to easily power USB hardware from a common bench supply.
It would have been simple enough to whip up an adapter board to connect banana jacks to the power pins of a regular USB port. Easing the hookup process was indeed a part of the motivation for this project, in making it easy to power hardware that hooks up via USB-A and USB-C. However, it also goes a little further. It includes TUSB319 chip to handle the all-important power negotiation, without which many USB devices will not feel confident drawing their required amount of current.
There is also polarity protection and over-voltage protection to stop you from blowing stuff up if you hook the board up wrong, which might save you a smartphone or three in the lab. The board will allow negotiated output power up to 10 W via USB-A and 15 W via USB-C, which isn’t heaps, but will be fine for lots of smaller devices. You can up that to 25 W and 35 W respectively if the board is switched to pass-through mode. We particularly like the physical design—the board will plug straight into the banana plugs on any supply with a jack spacing of 19 to 23 mm.
Overall, this is a useful tool to have in the lab if you want to run USB hardware with the flexibility of the voltage and current limits available on your bench supply. There are other ways to power modern USB devices, too, and you can do all kinds of wild stuff if you learn about USB PD and USB PPS. If you’re working up your own nifty lab tools for similar purposes, we’d love to know about it on the tipsline.
What would be really cool is to send the USB PD handshake results to the instrument through VISA/LXI, so the output of the supply matches the device’s request. That’s a whole lot more complicated to implement though.
Maybe for MK2 👍
‘Not feel cnfident’?
Why limit it to 15 W? Why not just use a better IC that can do PD itself?
Get crackin lazy butt!
I personally love this design
THX. 🥳
Well you are correct that it could be even more versatile. Now, to make the design output the full PD power it takes a negotiation chip that can handle it of course. I have really searched for a simple solution but not found anything that fits.
All IC’s i have looked at require some kind of mcu and also a SMPS that is controlled to output correct voltage.
That can be done. And i might do it as a MK2. But for now i decided to limit it to this scope.
Im not sure if you have ever tried manufacture a bigger batch of complete board but its a nightmare to get everything right. For every added step and functions it gets more and more complex and easier to make wrong.
Also I searched the net and my desig is far more better than whats already out there. The designs i found has only pcb, banana connectors and one USB-A out put. No Electronics whatsoever.
Hope you understand.
Cheers!
Found a bunch of devices that take a DC voltage and output USB PD, in case you want more inspiration: https://www.tinkervault.com/usb-power-sources/dc-pd30-adapters
Looked thru the links. Yes some of them are really interesting in many ways. And as i mentioned before it would be really cool to make another product with some kind of full PD support.
Although i would like to emphasize that i was talking about the exact form factor USBpwrME with the banana connectors, have no really comparable product. Products with this formfactor only has usb and banana connectors what i have found
I’m fully aware of other products with better PD coverage but they have a whole different approach and user case.
Thx