> Well Tom, that's not what the 15-20 or so books I've read
> on the subject says, nor what the
> manufacturers of the iron lams say either. I can quote
> these if you want. Are all these authors
> wrong on the subject?
Perhaps I just didn't understand what you are trying to say
Will, but you finally added core cross-section to the
equation.
>The amount of iron in the core in square inches (or square
>CM) is
>exactly what determines the flux density and the amount or
>power in watts it's capable of.
I think I understand what you are trying to say.
I just wanted to be sure we weren't perpetuating the myth
that a conventional transformer, for a given flux density,
"limits" at a certain power from flux saturation. The only
thing a marginal design does is have more equivalent series
resistance. It does not deliver 1000 watts just fine, and
then start to fall apart at 1100 watts. With constant
primary voltage, flux density does not increase with
increased load power and limit at a certain value, stopping
the transformer from delivering "more power".
The normal practice is to set core flux density at a no-load
highest voltage value that won't saturate the core. The VA
rating (core power rating) or maximum flux density for a
given cross section is part of determining heating and ESR,
but it doesn't actually "limit" power except through losses.
I wouldn't want anyone to walk away thinking maximum
available power is somehow limited in a conventional
transformer except by equivalent series resistance (ESR) and
heating.
73 Tom
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