I’ve been slowly assembling a collection of camera gear, and as part of that I’ve been assembling a whole mess of batteries to run that equipment on the fly. Most of the accessories I use in conjunction with my camera use a Sony NP-F550 style battery. These are pretty good for powering a light pad or monitor for about 20 minutes, but if I’m in place in a studio shoot or for a multiple takes for video, it’s just not enough juice.

In parallel, I’ve also been converting all of my EDC chargers and cables to the wonderful USB-C. High data speeds, reversible connectors, and with the PD specification it can supply up to 100 watts of power. As part of this I’m now the proud owner of a 100 watt-hour battery pack that lives in my backpack.

So, rather than having to constantly swap batteries on my camera equipment, I put together an all-in-one solution to power all of my camera equipment at once. Using the power of USB-C!

In short, what I’m going to be doing is making an in-line adapter to trigger 12v DC output from my USB battery bank. That 12v output can be used to power a whole host of accessories for my camera, including my supplemental light panels (6.5-17v input) and my video monitor (12v). This will allow me to completely skip using the Sony batteries and instead use the power bank, which I always have with me. Based off of the wattage use I measured while testing those accessories, I should be able to get 3 hours run time using the external battery pack.

This project was mostly inspired by a video I’d stumbled upon by electronics guru Great Scott, that goes into detail all about the capabilities of the spec of the Power Delivery feature of this new connector. In particular, these handy little dummy boards that handle all of the finicky communications back to the controller IC in the host.

Pretty neat, right?

So I ordered myself a few parts and got to work…

Truth be told, I’d ordered these boards for another project before I came up with this idea, but that project hasn’t come to fruition in total, but when the idea for this popped into my head I opted to requisition them for this project, especially as it would have taken a few weeks for the controller boards to come in from China.

Throw in a few 5.5 x 2.1mm barrel jack extension cables, and I was good to go…

If you missed the bit in the video, the short explanation of what these boards do is that USB-C has a protocol called USB Power Delivery (rev. 3, if you care). USB PD allows the device sending current and the device receiving current to negotiate the DC voltage that is being sent along the cable. This can be 5v, 9v, 12v, 15v, or 20v, with some chargers made for laptops able to supply up to 5 amps at any of those voltages.
These sink boards allow you to press and button to set the output voltage to any of those available, and save that configuration. In my case, 12v DC. From there, you just connect the output side to whatever you’re tying to power and bob’s your uncle.

My next step was to remove the screw terminals and solder on the cables for the barrel jack extension…

And after that just bodge on some electrical tape and heat shrink to insulate it…

I added on the zip ties on either side of the configuration button to keep from accidentally bumping it up to 20v. It aint pretty, but it’ll work.

After setting the boards to output 12v and double checking they saved that configuration after power loss, I gave it a test…

Works pretty good!

All told I’m pretty happy with the two I made. There’s plenty of cabling left over if I need to make extended runs, and as the cable is passing 12v, I don’t have to be wary about voltage drop over the line.

Neat!

That’s all for now, it’ll likely be quite a while before I get to post again, as I’m moving my studio to a new facility (and almost tripling my work space. Lots to pack and subsequently set up. Until then…

Cheers,

Mac