Just an FYI... I recently bought a small TDK-Lambda power supply for my 3.3V prototype system.

The 3.3V switching and regulated wall wart was okay, but it's output voltage would shift a bit now and then. As I've been pushing the prototype setup at 8MHz (with a 200ns AT28BV256 EEPROM), every once in a great while, it would go south... turn off the system and let the wal wart go without a load for a bit and it would become stable again.

The TDK LS Series provide a nice range of power and voltage with an adjustment pot. They also seem to be well made and easy to hook up. I bought their LS25-3.3 (3.3V 25-watt) supply, adjusted the voltage a bit over 3.4V and the 3.3v prototype system has been rock solid ever since.

Based on what I've found so far, I can certainly recommend them to anyone... and would also suggest that folks just getting started should consider this as a solid entry point for a cost-effective power supply.

Attached is the datasheet for the LS series.

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Regards, KM
https://github.com/floobydust

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

True... PC power supplies are certainly easily obtainable... costs vary widely as does the capacity and quality. They are quite flexible with multiple voltages, etc., but I wanted something a lot smaller and dead quiet (meaning no fan).

The LS25 series hovers around $20-$22, which isn't too bad considering. Add a grounded line cord and your preferred power plug and you're done, unless you want a switch and/or line fuse. I just clipped the IEC end off a typical power cord (I have dozens of them kicking around), tinned the leads and was done. Having the terminal block on the supply is a nice plus as well.

_________________
Regards, KM
https://github.com/floobydust

would Pico ATX Power Supplies be an option? they take a single 12V Input and generate all nesseary ATX voltages from that and are no larger than the ATX connector itself.
but they are quite expensive!

alternatively, make something custom. a pico ATX inspired board that takes 12V-ish in, uses a switching mode circuit to generate 5V, and then a linear regular to turn that into 3.3V (for a cleaner output). or you could also get one of those adjustable wall warts and only use a 3.3V Linear Regulator.
that's basically what i'm doing with my SBC, except with a 5V regulator.

Well, yes... you could use a Pico ATX supply, but again, you also need an external power source to drive it... and then a connector for the ITX plug for breakout. Building something custom in a similar format seems overkill unless you really want to build a custom supply or need multiple voltages for a specific hardware design. If you only need a single voltage and don't have parts lying about (like an existing PC supply) then something like the LS Series can likely fit the bill.

_________________
Regards, KM
https://github.com/floobydust