New DIY USB PSU for Raspberry Pi

Thermionics

Post Whore In Training
I just finished this nifty Pete Millett-designed Linear USB power supply for the Raspberry Pi / HiFiBerry Digi PRO + in my primary system. It's not that expensive (other than getting the front and rear panels milled), and it provides very clean power to my Pi that would otherwise be coming from a wall-wart.

The board (sorry it's a bit blurry):



Front panel:



Rear panel:



It took me less than an hour to stuff and solder the board, and another 15 minutes to box it up (getting that damn LED on the front to line up with the hole was a cast-iron bitch). I'm getting much 'blacker' backgrounds when listening to FLAC files through the Pi with the new PSU - it wasn't terrible before, but the absence of noise with the new PSU is very striking.

Note: the 1A rating machined on the front panel is (per Pete) overly conservative - mostly because of potential heat concerns with the small enclosure. Given that the transformer output is 5V @ 12VA, that realistically corresponds to around 2.4A of current capacity - more than enough for a Raspberry Pi 3B + I2S hat.

Highly recommended!

-D
 
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Thermionics

Post Whore In Training
That's... I...

Dangit, I didn't need another project! :-P
To be fair, Pete even provides the .FPD files for the front and rear panels, so this really is a path of least resistance DIY project. I always check up on his site to see what's cooking as I've built several of his DIY projects over the years (Engineer's Amplifier, low voltage hybrid headphone amp, Starving Student headphone amp, bipolar power supply) and they all are fantastically engineered and (mostly) dead simple to build. The lone exception - and it's my fault for being a beta tester - is a hybrid power amp using Korg NuTubes in the driver stage, but that's because it's mostly SMDs and my eyes aren't what they used to be. It'll get finished someday (maybe this winter).

-D
 

billfort

Administrator
Staff member
Now that's cool - nicely done!

I messed around with using linear PSs on USB powered DACs a bit in the past and still use one with my Korg DS-DAC-10R - nice improvement over wall-warts or the typical power these things would see via a USB port off a computer. Yours is a much nicer (and better looking) alternative to the old surplus bench-top linear I use!
 

Thermionics

Post Whore In Training
Now that's cool - nicely done!

I messed around with using linear PSs on USB powered DACs a bit in the past and still use one with my Korg DS-DAC-10R - nice improvement over wall-warts or the typical power these things would see via a USB port off a computer. Yours is a much nicer (and better looking) alternative to the old surplus bench-top linear I use!

Well, if you are up for some soldering, Pete makes it very easy to build. He sells the boards on eBay, includes the BOM with all parts on his website, and even includes Front Panel Designer files for the chassis.

:)
 

MikeyFresh

Moderator
Staff member
Well, if you are up for some soldering, Pete makes it very easy to build. He sells the boards on eBay, includes the BOM with all parts on his website, and even includes Front Panel Designer files for the chassis.

Very cool for a low cash outlay.

I'm up for some soldering, but whats involved with the front/rear panels in terms of sourcing and cost?
 

Thermionics

Post Whore In Training
Very cool for a low cash outlay.

I'm up for some soldering, but whats involved with the front/rear panels in terms of sourcing and cost?

Front and rear panels can be ordered from Front Panel Express, using their Front Panel Designer software (Pete already did all the drafting for the panels, so all you have to do is download the .FPD files, open them in Front Panel Designer, and order them). I believe the front and rear panels came out to approximately $85 milled (the countersunk screw holes and the engraving add to the cost). You might be able to do something in your shop at home if you are so inclined, but I don't mind spending a little extra to avoid the time and stress (I suck at machining).

The best part of ordering from Front Panel Express - when they box up and ship you your panels, you get a little bag of Haribo Gummy Bears in the box. :)
 

je2a3

Senior Member
Great job on a nice project @Thermionics!

I've been contemplating building a linear PS to replace the SMPS on my RPi3B+/Allo DigiOne but since I borrowed my wife's Anker laptop power bank, I've gotten a bit lazy. Once I get the urge again, I'll re-visit your post.:)
 
@Thermionics can you share what the total cost with everything was for this build? Thanks for providing the thread here, cause now it has me intersted in building one! Especailly since the Nirvana SMPS seems to be out of stock in the places where it is reasonably priced.
 

Thermionics

Post Whore In Training
@Limberpine - let's see, best as I can remember it the breakdown of costs was (approximately) the following:
  • Circuit Board: $20 (eBay)
  • Electrical components: $50 (Mouser)
  • Front & back panels: $100 (Front Panel Express)
A bit ironic that the panel machining was more than the cost of the actual power supply. If you are handy with a drill-press and a file, you might be able to machine the front & back panels yourself. I'm too lazy / unskilled for that.
 
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@Limberpine - let's see, best as I can remember it the breakdown of costs was (approximately) the following:
  • Circuit Board: $20 (eBay)
  • Electrical components: $50 (Mouser)
  • Front & back panels: $100 (Front Panel Express)
A bit ironic that the panel machining was more than the cost of the actual power supply. If you are handy with a drill-press and a file, you might be able to machine the front & back panels yourself. I'm too lazy / unskilled for that.
Thanks! I like the way yours looked, so I'd probably go with a machined one or something else that may work off the shelf.
 
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