EEV Power Supply and floating ground

[joegtp]

I'm building up Dave's power supply but I want to have it plugged in instead of battery powered. What is the best way to get the outputs floating? Are those cheap wall wart power supplies floating usually?

[firewalker]

If it uses a simple transformer yes. I would choose a transformer one to avoid any noise of a switching one.

Alexander.

[amspire]

You still need the switching pre-regulator from Dave's RevC circuit if you want a full 20V 1A output.

If you are going back to a heatsink + fully linear regulator, you will probably have to make the supply 0-10V @ 1A or 0-20V  @ 0.5A.

Richard.

[gxti]

Any safe mains supply is intrinsically isolated. It's just that sometimes one output, usually the negative one, is then tied to earth to keep the output from floating. If your wall wart does not have an earth connection then it will (hopefully!) be floating.