Dear JB VE3EAR - VE3WZL,
Leakage inductance increases with separation between primary and secondary,
even if you had adjacent bobbins. I've done some frequency response tests
on what I thought could be wideband transformers that had separated primary
and secondary and the measured results were more narrowband than I thought
they could be. I believe the reason is incomplete flux linkages as the
ferrite core material is not the only magnetic path, even if it is the main
one, and the "bypass flux" can be considered to contribute to leakage
inductance. Wideband performance continues to need "transmission line"
winding technique.
For use in transmitter finals, leakage reactance stored energy can result in
spikes.
73, Bob ZL2CA
----- Original Message -----
From: "J. B. Weazle McCreath" <[email protected]>
To: <[email protected]>
Sent: Tuesday, October 25, 2005 11:01 AM
Subject: LF: Toroid winding question
Hello LFers,
How critical is the spacing between the windings and the core material
when
winding a toroidal transformer? I have a core taken from a television
flyback
transformer that I'd like to experiment with using different winding
techniques.
To simplify things, I was thinking of putting the windings onto bobbins
that
could quickly be slipped on and off of the core. Would I be OK with using
a bobbin with 1/8 inch (3 mm) wall thickness or should I look for
something
with a thinner wall? Any and all comments welcome.
73, J.B., VE3EAR - VE3WZL
Solar and wind powered
EN93dr
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