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Old August 27th 10, 04:57 PM posted to rec.radio.amateur.homebrew,sci.electronics.design
amdx amdx is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 349
Default Heating in 4-1/2 turn inductor


"raypsi" wrote in message
...
Hey OM:

First how many newsgroups do you have this thread cross posted on?


How many do you see it on?

Second: A 1/2 turn is equal to 1 turn in a pot core so 4 and 1/2 turns
is the same as 5 turns.


I don't think so. If I put 4-1/2 turns on a potcore and measure inductance,
then unwind the 1/2 turn, do you think the inductance will measure the same?

Lastly OM: I think you are looking at a classic case of proximity
effect.


It may be, but I can't explain to myself how that would happen. I do think
it has
something to do with the flux through the coil though.
Thanks, MikeK


73 OM
de n8zu






On Aug 25, 4:09 pm, "amdx" wrote:
Several years ago while making inductors for tuning a class E amplifier we
end up with a 4-1/2 turn inductor. The inductor used a 3F3 potcore, gapped
I
think,
but it has been awhile. The inductor was driven hard but below saturation.
The problem; the 1/2 turn got HOT. Four turns or five turns were ok.
My physicist friend had an EE verify the problem 2000 miles away.

So, can anyone tell me why 1/2 turn would make such a difference in the
heating?

Thanks, MikeK