[Boatanchors] 125 VAC Line? Make Your BA's Happy, Cheap.

[David Stinson]

Got 125 VAC + on you shack's AC power buss?
Ronnie, W5SUM and I worked this problem.

There must be a zillion old, broken Uninterruptable
Power Supply (UPS) units laying around.  These typically
have an AC cord going in and AC sockets going out 
plus circuit breaker, etc.   In 99% of the cases, the
transformers in these units are still good and are perfect
for building a "line bucker."

We found a couple of dead 12 Amp APC units.
The transformers had a 120 V primary,
a lo-current 15 V and a Hi-current 15 V windings.
The lo-current winding is not used, unless you want
to light a pilot light or something.

Pulled the "hot" leads from the dead circuit board
and directly powered the transformer through
the circuit breaker.  Wired the Hi-current 15 V
winding in the "bucking" configuration with one 
side to the junction of the incoming "hot" and the 
other side going to the "outgoing Hot" sockets on
the back.  Left all neutrals connected together
as normal.
If the voltage is boosted instead of bucked,
swap the 15V secondary wires.
Mine drops my line voltage from 125 V to 110 V
and my boatanchors are happy.
12 A service will run a lot of stuff 
and broken UPSs are cheap, so you can add more.

Important Tip:  A transformer "line bucker" acts as
an "autotransformer."  To measure the output voltage
accurately, you must connect a load- even a small one.
The load current sets-up the magnetic field the 
autotransformer needs to work.

73 Dave AB5S