USB power has become ubiquitous — everything from phones to laptops all use it — so why not your lab bench? This is what [EEEngineer4Ever] set out to do with the BenchVolt PD USB adjustable bench power supply. This is more than just a simple breakout for standard USB PD voltages, mind you; with adjustable voltages, SCPI support, and much more.
The case is made of laser-cut acrylic, mounted to an aluminum base, not only providing a weighted base but also helping with dissipating heat when pulling the 100 W this is capable of supplying. Inside the clear exterior, not only do you get to peek at all the circuitry but there is also a bright 1.9-inch TFT screen showing the voltage, current, and wattage of the various outputs. There is a knob that can adjust the variable voltage output and navigate through the menu. Control isn’t limited to the knob, mind you; there also is a Python desktop application to make it easy changing the settings and to open up the possibility to integrate its control alongside other automated test equipment.
There are five voltage outputs in this supply: three fixed ones—1.8 V, 2.5 V, and 3.3 V—and two adjustable ones: 0.5-5 V and 2.5-32 V. All five of these outputs are capable of up to 3 A. There are also a variety of waveforms that can be output, blurring the lines between power supply and function generator. While the BenchVolt PD will be open-sourced, [EEEngineer4Ever] will soon be releasing it over on CrowdSupply for those interested in one without building one themselves. We are big fans of USB PD gear, so be sure to check out some other USB PD projects we’ve featured.
Nice, thank you for sharing! Been looking for the amateur-level stable bench power supply for some while, maybe this will do just nicely.
IMHO, finally, someone figures out that signal generator AND regulated power should have been a standard some long, long time ago (in a galaxy far, far away, where designers work with customers directly, unimpeded by the marketing department fantasies).
Lots of time spent on making it look good while inside it uses the worst, cheapest switching power supply modules from AliExpress which tend to break and burn just from looking at them. A perfect YouTube project.
Yeah, for those interested, these are modules based on the XLSEMI XL6009 Buck/Boost DC/DC converter chip:
https://www.xlsemi.com/datasheet/XL6109-EN.pdf
Sorry, this datasheet : https://beriled.biz/data/files/XL6009.pdf
Can someone please counter this with good reasoned arguments?!
Because when I saw the image and looked closer I came to a similar conclusion and that’s a bit depressing (the existence of the video at all + that it was featured on HaD).
What could possibly go wrong?!
Man like 10 years ago i got an oscope and a bench supply that each had (roughly) one knob per function. i’m never going back. People talk about all of these specs and features and it turns out, that’s the one i care about on my bench
Yeah, let me just plug that into my laptop and drive the voltages!
He’s showing it with nothing under load. Unless it’s programmed to shut down past a certain current level it’s a fire hazard waiting to happen.
can’t say I like the interface. Too small and with the knob…as mentioned above “what could possibly go wrong”
Hard Pass
This… has a lot of concerning issues given that you could be supplying a lot of current.
The adjustable output 1 uses an LDO, but it follows a super-basic totally unshielded switcher, and that is not easy to make low noise. It’ll cut down on the ripple, sure, but noise is more than ripple and without a doubt the switching transients will cut right through the LDO. Which isn’t easy to measure either.
The overall physical architecture just doesn’t work for low noise either. Just trace the input and return current path for the adjustable output: the input’s gotta flow along the top, which is going to be right under where the LDO is, so you’re not going to get the full PSRR from the LDO just due to the ground currents.
There’s another subtle issue too: you’ve got a bunch of separate outputs + a single ground at the end. And you’re talking about supplying like 10+ amps there. Think about that last power supply closest to the ground output. It’s normally sitting there seeing like 5-6 amps coming in the ground connector plus its own. And then at some point you unplug the first supplies… and all that current disappears and you get a shift due to the overall finite resistance. Single ground input just doens’t make sense when you’ve got multiple outputs and that much current.