Discrete 120vac to 3VDC switching power supply source tips?

For that size have you considered a Game Boy Wall Wart type? Do not think it is a switcher but at 0.3 amp who cares. It is 3 volt though. I have one I use it works perfectly with one of my Mini-Disc (Sony) recorders that also needs 3 volts and is a very very very picky eater.

allelectronics has all kinds of stuff
but i'm not understanding the Idea behind this one
since i know you have all kinds of meters and testers

this 3v indicator for 120vac BEGS WHY ?

Not exactly what you want, but cheap enough. The 9vdc is a wall wart, going in to a 3.3vdc regulator. Under $15 combined, and if you removed the wall wart from the case, very compact.

Have you given any thought to using one of the USB chargers?
I have several that ingest 115Vac and output 5Vdc at 500ma
I'm sure you can get one for next to nothing
If need be add a 5vdc to 3Vdc three terminal regulator on the output

MEXICOWANDERER wrote:
Ideal unit would be a circuit board with solder tab connections. 300 ma would be plenty

Hopefully not that expensive. For power pedestal power available indication. If I have to settle for 5VDC final I'll take that.

Do you need isolation from primary power?

There are quite a few evaluation boards out there, plus lots of application notes if you are interested in designing your own.