On Thu, 10 Feb 2005 22:24:27 GMT, "Backlash"
wrote:

I have a standard electrical outlet supplied by a 20 amp breaker, outputting
118 volts. For something being planned, that circuit is needed to output 125
volts at 20 amps capability. Is there a good method for this, and what is
the most economical, feasable, and most practical method? It needs to be
fairly close to the 125 volt figure, as much as practical. Obviously, a
step-up transformer might be the solution, but what about the ability to
find one to output the 125 volts? Is there a practical homebrew buck and
boost method? I've done a decent amount of industrial, automotive, house
wiring and troubleshooting, but I'm a relative newby at this type of theory,
so be gentle.

You need a device called a Variac, which is a variable
autotransformer.
http://www.variac.com/staco_Variable...former_Map.htm
Buying a new one would be pricey, but they've been around for a long
time and can be found at surplus outlets, auctions and even junkyards
that have electical/electronic stuff.

Trying to do it with a parasite transformer is tricky as the line
voltage is rather variable with time of day and local load.

Is the precise 125 volts really necessary? Is regulation critical?