I built a buck transformer system, using a commercial new
autotransformer, to deal with a high voltage situation, 15 amps rating.
Info on my web site below. If you know your voltage in and out and
amps, call the supplier and they will recommend a specific autotransformer.

http://peregrino.home.att.net/camper/transformer.html

There is nothing wrong with using a 5 or 7 volt transformer to buck or
boost, as long as it is rated for the required current.

Check the wiring twice and check the voltage in and out before you try
to use your buck/boost transformer system.

I wonder also what is so critical that it cannot run on 118 volts. Most
equipment will run at +5% - 10% voltage.

Richard


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.

Thanks,
RJ