Bud Rogers wrote in message ...

In an autotransformer the same principles apply, but a portion of the
inductance is common to both circuits. A voltage applied across the tapped
portion of the coil will produce a higher voltage across the whole coil. A
voltage applied across the entire coil will produce a proportionately lower
voltage across the tapped portion. The current in the tapped portion will
be the sum of the currents flowing in the two circuits. Not good if you
need isolation, but not an issue if all you want is to transform voltage,
current, or impedance. Does that make sense?

It makes sense now. That's the main question that I wanted answered. I
had a faint notion that was how it worked. You clarified it quite well
for me!

Thanks!

Jeff