Voltage conversion from 220V to 110V.

Jea48,

I use two hot legs and one neutral conductor. Since the line is a dedicated one I haven't had any hum problems. About the polarity, I guest that when I change the voltage selector switch the unit does make all of the necesary adjustments.

Some of the components use a Switch Mode Power Supply (Kairn-Pro & Ikemi), the others use a regular thoroidal
transformer (Klouts, Kudos & Av-5150). The transformers have dual inputs leads, my feling is that they are each propely wired(polarity) for each woltage. In my case it was easy, just had an electrician install the 220V line,
change the voltage setting on the units and replace the fuses, from 6.3A to 3.15A. Hector

Eldartford; yes I know the neutral is bonded to ground at the service panel only, and not at the equiptment.That could prove to be quite dangerous if it was connectd to the chasis.Just think what would happen if the plug on the equipt.was pluggeg into an old non polarized recept.with a ground cheater,and the polarity was reversed. You would have, ONE HOT AMP.You missed the point I was trying to make.

Hector, thanks for your answer.Got to ask!What is the neutral for? Or did you mean equiptment ground.It gets confusing some times. The neutral,white wire, is the grounded conductor.The green ,or bare,the equiptment grounding conductor. Jim

Jea48...Polarity of the AC power should be of no concern because the rectifier makes it into DC anyway. Power transformers that I have worked with don't even identify the primary and secondary winding wires as to polarity, so, short of running a test on every transformer as the equipment was being built, it is not always the same from unit to unit.

I remember when there were cheap table radios (and some other stuff) that had no transformer, and the metal chassis would be hot if the plug was in one way. Furthermore, the 2-prong plugs were not polarized either. These devices relied on their plastic cases to protect the user, but sometimes an exposed screw would be hot. The occasional tingle kept us alert!