How to build a $20 47A power supply

[BrianG]

Well, that's weird. I did a quick search and the stickers I saw didn't say that. It should work fine then.

If you have a positive and negative supply rated for the same current, you can hook up your load across the two; load+ to supply+ and load ground to supply-. You see that all the time with regular power transformers: you'll have your main outputs, but then also a center tap. If you use the center tap you get a + and - supply. But if you just use the main outputs (not center tap), you get the full voltage. RadioShacks transformers are like this. Like their 12v models; they're rated 12.6v, but if you use the center tap you get +6.3v and -6.3v.