whit3rd wrote:

I think he was confused. Look at a transformer-style soldering gun,
the hairpin secondary doesn't have ANY helical orientation at all,

** Huh ?

See hi-res pic of soldering gun tranny.

http://en.wikipedia.org/wiki/Soldering_gun

Note use of copper strip and close coupling of the secondary.


Output windings on such high-ratio transformers don't couple capacitively
to the primary

** Do they ever ?

and it's hard to imagine any importance of flux
coupling defects at low (50 to 60 Hz) frequency with soft-iron cores.

** Mick Faraday used soft iron in his toroidal job, but it was judged no much good. Silicon steel laminations have been the norm for over a century.

Also, many power transformers have separate windings on adjacent limbs of a U or C core. Invariably, there are primary and secondary coils wound on each limb that are later coupled in series or parallel.

Never seen the primary on one and the secondary the other - cos that results in a tranny with very poor regulation due to high leakage reactance.



..... Phil