Re: isolation transformers
Joe:
Just to add to what Dereck has already stated (and this is a huge, varied subject your question touches upon) but simply stated...
Transformers are a major class of coils with two or more windings electrically isolated from each other. The ratio of primary to secondary turns of these windings determines the output voltage. Transformers that have the ability to transform voltage to higher levels (step-up) will have more turns on the secondary coil. Conversely, step-down transformers will have more turns on the primary coil. If the number of turns on the primary and secondary coils are equal, i.e., 1:1, the voltage and current is transferred unaltered from the primary to secondary -- these are often called Isolation Transformers.
Isolation transformers in turn have many applications; industrial, audio, telecom, utility, medical, military, etc., etc. I happen to have one on my boat, isolating the shore power connection to the boat's on-board electrical system to help prevent galvanic corrosion. You mentioned sensitive equipment which is another major use as isolation transformers can be very effective at cleaning up dirty street power, eliminating/reducing ground loop, ground line noise, and interference.
I'll stop at this point and let your questions dictate to what extent you want more info. or technical details. I know a little, but Dereck is extremely knowledgable, the real expert here, so you are in good hands.
Edit: Just after posting my reply I see charlie steped in which is fine. So some of my verbage unintentionally duplicates what he has said. Now Joe, you have two real experts to answer any additional questions you may have.
[ March 25, 2003, 12:30 PM: Message edited by: mikeackley ]