| alt.engineering.electrical, email@example.com says...
|> |> |> On 12/16/07 7:16 PM, in article
|> |> |>
|> |> |> > Its been qouted in one of the earlier discusions that autotransformer
|> |> |> > doesn't provide isolation. Why so?
|> |> |> > Also, what is the basic difference between autotranformer and a
|> |> |> > regular one?
|> |> |>
|> |> |> An autotransformer has only one, usually tapped, winding. There is no
|> |> |> separate primary and secondary. This saves on the copper and iron
|> |> |> to build. Some output current flows conductively from input to output.
|> |> |> construction greatly lowers the cost of the transformer.
|> |> |>
|> |> | Just a question... Is the winding ever *not* tapped? What would
|> |> | be the purpose?
|> |> I would think _you_ would know about autotransformers.
|> | Why me?
|> Not you alone. But you do seem to know lots of things around here, so this
|> might be one of those things.
|> I could be wrong.
| I'm not a power engineer (my father and two brothers did that). I
| do things microprocessor.
I'm not a power engineer, either. I do software (Linux distributions).
But I learned electronics and electricity all along the way, and continue
to learn when I get the chance. I think power stuff is fun (so you might
want to keep at a great physical distance when I roll out the pole pig).
I'm also a ham radio operator (and thus, know some RF stuff, too).
|> |> It would technically not be tapped if it were 2 windings that can be wired
|> |> in either a buck or boost configuration. But the electrical effect is the
|> |> equivalent of a tapped winding, anyway. You just get the flexibility of
|> |> wiring it either way, and the flexibility of having the lower voltage
|> |> winding rated for a proportionally higher current to maximize the rating
|> |> in a buck/boost purpose.
|> | Ok, I didn't consider separate windings as being an auto-
|> | transformer.
|> But it can behave as one if wired the right way.
| Sure, I see that. ...just hadn't considered it (two windings in
| series buck/boost) an auto-transformer, as it surely is.
It's more interesting when you do buck/boost cross-phased between different
phases in a three phase system. There are more wiring combinations and a
lot of crazy voltages are possible. I once wrote a program to calculate a
great many possibilities.
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
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