USB-C PD:

With the world seeming to converge on USB-C as a power supply standard for nearly all portable electronic devices, the problem of how you get just the right voltage and power for your product has been addressed. The solution, USB-C Power Delivery (PD) means that any compatible USB-C supply is capable of supplying a wide range of voltages at powers easily up to or exceeding 100 Watts. 

So, how does your device tell the supply what to provide? The answer is that through the USB-C Power Delivery standards, these supplies have a standard protocol for being told what voltage to deliver. It also means there are standard chips that manage this communication, and that these chips have been built into “spoof boards” so you can force a power brick into whatever mode you need.  

Our Solution:

We’ve been playing around with building these spoof boards into all kinds of prototypes, so we can power them from a standard source, but we also realized we need a quick and dirty power source that’s compact, portable, and cheap for when we don’t want to lug a bulky lab supply around. With two simple printed parts, we created a compact cable accessory that can output 5, 9, 12, 15, or 20V. Best of all, it has interchangeable leads so we can provide power to a pair of alligator clips, test leads, or even screw terminals. 

How to make it:

There are lots of options for spoof-boards, test leads, and USB-C bricks, but for our design we used these parts:

• 200 W USB-C Power Brick: This set of two comes with cables 

  

• Spoof-Boards: There are lots of varieties, we chose this one because it has dip switches to set output  and because they came in a pack of 10. 

  

• Test Lead Kit: This kit comes with interchangeable ends so you can choose how you want to hook it up. It also comes in a nice box that can store your finished device and accessories. 

  

• Super Glue: Enough said 

  

• Small Black Zip Ties: We used these to strain-relieve where wires exit the enclosure but you can use any number of things here. 

  

• USB-C Meter: This is completely optional, but it allows us to verify the voltage setting, and monitor the power draw of whatever we are testing.

  

Steps:

1. Print the attached files (or your version of them). The main enclosure has the dip switch settings modeled into the surface for easy reference. 

2. Cut the DVM side of the test leads off leaving as much excess cable with the modular end as you want in your final assembly. 

   

3. Strip the cut ends, leaving ⅛” to ¼” of bare wire and feed both through the holes in the enclosure cap.

   

   

4. Solder the positive and negative leads to the spoof-board in the appropriate locations, and use a side-cutter to trim the excess soldered wire as close to the board as possible.

   

5. Attach a small zip-tie to each lead so that it will sit inside the cap and take any pull forces before the leads pull on the spoof-board.

   

6. Slide the spoof-board into the enclosure so the dip-switches are aligned with the opening, the USB-C connector is seated in the end of the connector, and push the cap onto the open end of the enclosure.

7. Affix the cap with Superglue, only after testing to ensure the board functions as expected.

   

8. That’s it!  We use the box that came with the test leads to hold all our spare ends, power brick, USB Cables, and the power meter so we have a nice portable power supply kit, that cost us less than $50.

   

Pro-Tip: The dip-switches are hard to access, but the test leads are the perfect tool to reach in and set up your power supply to whatever voltage you desire.

Disclaimer

Please note that this project involves working with electrical components and power supplies, which can be dangerous if not handled properly. Ensure you follow all safety precautions and double-check your work. We are not responsible for any damage, injury, or loss that may occur as a result of following this guide. Proceed at your own risk and always prioritize safety.