At 01:08 PM 14/12/98 -0800, you wrote:
>Martin McCormick wrote:
>
>>         Not quite.  A transformer with no load that is running
>> efficiently and not saturating or loosing flux to the big wide world
>> stores energy in itself that is almost equal and almost 180 degrees
>> out of phase as the energizing signal which means that when there is
>> no load on the secondary, there is almost no current being drawn at
>> the prinary.  If the transformer was 100% efficient, there would be no
>> current drawn at all and it would look like a totally open circuit.
>> The impedance at the secondary compared with that of the primary is
>> found by squaring the turns ratio.
>>
>>         Thank your lucky stars that it isn't just the resistance of
>> the wire.  Some of those primaries would truly make things smoke if
>> they were connected to 117 or 240 volts DC.
>
>I think that we're on the same page here.  I agree with everything that
you say.  My original
>statement is that _what power is being consumed_ is due to the resistance
in the wire.  I wasn't
>saying that the primary is a short.  Most transformers (especially cheap
ones) with no secondary
>load are warm (or downright hot) to the touch.  This heat is from some
amount of current running
>through the resistance in the primary windings, yes?
>
>Michael

  Nope, you have it wrong there. The current is limited by the inductance
of the transformer, if you run DC through them the resistance is very low
and would limit the current to about 10A primary, this is on a hammond 48VA
transformer. The wire is sized to carry about 1/2A. The heat actually is
caused by a LACK of iron in the core. The more iron you put in the more
current you can put through the transformer. Most transformers these days
appear to operate on the edge of the design limits.

        Barry