Jim, you are quite right. But I don't think John and I disagree
about that.

Since the mains is not 100Hz, your's is not a practical
approach to transformer design.

If Casino simply wants a transformer for twice the mains voltage
whilst not changing his other requirements or his mains frequency,
then he wants one with more turns of thinner wire. That is all.

I don't think you have read my posts very well. Or John's. Or we
are not making ourselves clear. Not coming from an electronics
background, I sometimes don't fit in with received wisdom. Perhaps
I need a translator?

Current saturates. Not voltage. The relationship between the
current and the voltage depends on frequency. Hence the voltage at
which a transformer saturates depends on frequency. The *current*
at which the transformer saturates does *not* depend on frequency.

John got very cloudy, and increasingly muddled about saturation, the
more he got into fencing for the sake of it. He knows about it if
he considers the issue in cooler light.

But listen...Adrian and I seem to be the only ones who have learned
anything here. Since we have done learning now, and you apparently
know already, we might as well stop, eh?

Unless you want to bet on whether this 120V tranny will go "POOF" or
"BzzzzzzZzzzZzzZzZzZZZZ......pft, or whatever, at 240V.

cheers, Ian


"Jim Adney" wrote in message
...
On Thu, 10 Jul 2003 19:10:23 +0100 "Ian Iveson"
wrote:

No, John. The original question demonstrates that
input voltage is not a fixed quantity. That is what the
pertinent
parts of the thread are about.

The core size has nothing to do with voltage for a given quality
transformer. I'm sure you know this really. You're just trying
to
wind me up.

You really should listen to John here. At least in this case he's
right.

Once a transformer is built, if you take its design voltage and
divide
by its lowest design frequency (ie 50 in the case of a 50-60Hz
transformer) you'll get a number which you should be careful not
to
exceed if you should want to use this transformer in a different
application. Do this caluclation using any winding you like on
this
transformer, but use the same winding each time you do it.

So if you have a 50-60Hz transformer with a 120V primary that you
want
to use on 220V this will only be possible if you have 100Hz power
available.

Really. Honest. No one's trying to wind you up.

-
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Jim Adney
Madison, WI 53711 USA
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