It’s Super Easy To Build Yourself A USB-C Variable Power Supply These Days

Once upon a time, building yourself a power supply required sourcing all manner of components, from transformers to transistors, knobs, and indicators. These days, everything’s a bit more integrated which helps if you’re trying to whip something up in a hurry. This build from [Ricardo] shows just how straightforward building a power supply can be.

The build is a simple mashup, starting with a ZY12PDN USB Power Delivery board. This board talks to a USB-C supply that is compatible with the Power Delivery standard, and tells it to deliver a certain voltage and current output. This is then used to supply power to a pre-built power supply module that handles current limiting, variable voltage output, and all that fancy stuff. It even comes with a screen built-in! Simply slap the two together in a 3D printed case with a couple of banana plugs, and you’re almost done.

All you need then is a USB-C power supply – [Ricardo] uses a portable power bank which allows him to use the power supply on the go. It’s a great alternative to a traditional heavy bench supply, and more than enough for a lot of hobby uses.

We’ve seen a lot of interest in USB Power Delivery recently, and its likely hackers will continue to enjoy the standard for some time to come. If you’ve got your own USB PD hack, be sure to let us know!

27 thoughts on “It’s Super Easy To Build Yourself A USB-C Variable Power Supply These Days

    1. Sorry about the dead link, blame Amazon for not being able to keep old links alive as a reference :D
      Just search for “LCD Digital Programmable Constant Voltage Current Step-down Power Supply Module” and you will find many options. Somebody also commented here they basically sell in China something like this, but ready to go (and cheaper then what I spent only on parts!). However, there’s one advantage in my build: size, it’s as tiny as it gets and it would be even smaller with the right pair of banana sockets.

  1. The Author [Ricardo’s] link to the actual DC buck-converter (step-down) module he used doesn’t work for me:

    https://smile.amazon.co.uk/gp/product/B01I9LQIU2/

    I tried searching for the ASIN B01I9LQIU2, that didn’t work either. Anyway, the buck converter module looks like a generic “Hangzhou Ruideng Technology Co., Ltd.” or “Riden” clone. Here’s an example:

    * UCTRONICS Numerical Control DC 6-55V to 0-50V 5A Step Down Stabilized Power Supply Constant Voltage Current Buck Power Converter Power Supply Adjustable Module 4.7 out of 5 stars 167 ratings Amazon’s Choice for “dc voltage regulator” $35.98

    https://www.amazon.com/UCTRONICS-Numerical-Stabilized-Converter-Adjustable/dp/B01LWXAC5E

    Here’s the U.S. link for the USB-C PD to DC module [Ricardo] used to feed the buck-converter module:

    * Type-C USB-C PD2.0 3.0 to DC USB decoy fast charge trigger Poll detector 100W MA
    Brand: aikeec 4.5 out of 5 stars 96 ratings $10.99

    https://www.amazon.com/Type-C-USB-C-charge-trigger-detector/dp/B07T6LPP9W

    Yeah, there’s no way to mount that module and I don’t believe for a second the “100W” allusion.

    USB-PD input is a nice option to have if you really need a portable power supply that can run off of a USB-C PD battery bank. But I think [Ricardo] should add a second barrel-jack DC input to use on the workbench with something like an inexpensive laptop AC/DC power supply. For example, one of these at 19.5VDC, 70W, will give 3.6A maximum input to the buck-converter:

    * POWSEED 70W Universal Laptop Charger for Dell HP Asus Acer Samsung Toshiba Lenovo IBM Sony Gateway Notebook Ultrabook Chromebook, DC Output 15V 16V 18.5V 19V 19.5V 20V Power Adapter Supply Cord 65W 4.4 out of 5 stars 1,215 ratings $20.90

    I have a 90W version of these POWSEED supplies that has a clean output right up to the rated 90W. Unfortunately like lots of electronic devices lately, these are currently unavailable:

    * POWSEED 90W Universal Laptop Charger for HP Acer Asus Toshiba Dell IBM Samsung Sony Gateway Fujitsu Chromebook Ultrabooks, DC 15V 16V 18.5V 19V 19.5V 20V Power Adapter W/5V2a USB, AC + DC Plug $29.90

    https://www.amazon.com/Universal-Charger-Toshiba-Chromebook-Ultrabooks/dp/B07289HQDG

    Finally, you don’t need to resort to 3D printing an enclosure for these DC buck-converters, they are available as pre-made kits. Here’s an example:

    * Communication Type CNC Power Supply Housing Casing Box Kits without Module $28.99

    https://www.ebay.com/itm/302749787180

    1. I don’t see any “hacking” involved, just buy/assemble ready made parts from Amazon/eBay.
      I would rather buy a brand name laptop power supply, for example second-hand Lenovo 90W (20V 4.5A) can be easily found on eBay for ~10 USD or EUR.

      1. I personally enjoy both types of articles, since with this one I can learn about new modules or how someone cobbled something together (hack!) to solve a particular problem. Your comment is also helpful since it points to better (different!) ways of solving the same problem ;) I have a ton of those laptop power bricks but wasn’t aware of this particular module, so when need comes where i need both voltage/current control and measurement (and not just a simple adjustable buck converter), I will know what works. Cheers and smell the roses.

  2. I’m still looking for an inline directional usb-c pd filter. Probably need a chip that neglects to tell one side that the other can source power…

    Really annoying that my smaller battery banks always want to charge the larger ones, and I can’t convince them otherwise, unless I use a usb-a cable and lose PD.

      1. They are not. Someone with some Dewalt batteries at hand needs to design the adapter part. This was surprisingly easy for the Makitas. So may be someone may just do that.

        1. The hard part with Dewalt is the batteries are dumb, no built in BMS. I’ve used conversion adapters to get a full pin set, and wired up a 5s bms. I’d like to try charging one that way, see if the bms does as promised and balances safely.

          1. Well, the idea here is to just yank the battery out and place it in a proper charger. The DSP5005 and friends show the input voltage. So you don’t really need fancy battery management. Having at least basic under voltage protection would make this much less exiting, though.

      1. Darn Jekyll! Thanks for fixing, I’ll try to print one as I have all the parts already :)

        Been thinking on making a similar myself and didn’t want the DC6006L as I want software compatibility with remote control of the DPS series PSU (DPS3005, DPS5005 and so on) :)

  3. I reworked one of my Tindie products (a GPS Discipline board for the FE-5680 rubidium oscillator) not too long ago to take USB-C power input instead of a barrel connector. The original power requirement was 18-24V @ 35W, and the idea was that you’d source an old laptop power supply, but I found it much easier to find a USB supply that could do 35W @ 15V, which also allows me to eliminate the first buck converter stage.

  4. I am looking for something like this to power hundreds of LED lights strips in a row I try using a boost converter but once you up the voltage back to the 12 volts it starts to make the lights blink probably because of back feed, so I’m running an experiment to use a battery and then step up the voltage and step down the voltage but keeping it from going back into the LED strip. I also need the power from the LED strip which has gone down from 12 volts to 9 v and use that 9 volts to charge the battery the battery charger must be pass through charging, it would be nice to have someone show us what passed through charging is and how to build it ourselves but it’s important to do this project to get one step forward can anyone help me.

  5. Coincidentally I use the same configuration.
    I’m a little happy to see someone thinking the same thing!

    However, I usually supply power from DC Jack using an AC adapter.
    Because the USB-PD power supply is expensive.
    I use a connector with a DC plug on the USB decoy board only when I want to mobile.
    This usage is also convenient.
    [pics]
    https://twitter.com/kusu_gi/status/1417717570312962051

    It is also convenient to operate with Modbus. try it.
    [modbus link(Japanese)]
    https://blog.braveridge.com/blog/archives/143

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