Winding Inductors with Teflon Wire

Apr 25, 2007 80 Replies

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Air gap between turns?? The only way I can justify an air gap between turns in the toroid window area is when inductor resonance is too low or in other words..the equiv parallel capacitance causes problems. My app is very tolerant of inductor AC parasitics.. D from BC

Yes, I know about core loss and ripple, but still would have the same advice. It's easy to understimate core loss. Still, if you're already using a very low loss material... Just a final reminder that electrical insulation also insulates heat. Paul Mathews

The Raychem red 14 AWG about 2/3rds of the way down this page looks pretty thin.

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And, the 1/4 inch copper braid in plastic sheath might be good for high current windings, too.

I meant a gap (space), because it is uninsulated copper conductor.

Tam

Cool...I've never seen that company.. The red insulated teflon wire looks good.. And the insulation thickness is shown too at 0.09"!! I'll just to search around a bit more to see if I get less insulation.

Thanks D from BC

Here is another surplus outfit that sells by the foot:

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On Thu, 26 Apr 2007 07:05:30 -0700, John Larkin Gave us:

You're lost, Johnny. Stop playing on their side of the fence, dipshit.

I'd expect to see wire rope not tape when it is a toroid.

Sure, because *nobody* who's into electronics could *possibly* object to the way that Prongy floods the electronics groups with his bullying & his childish temper tantrums. Right?

W "Some people are alive only because it is illegal to kill them." . | ,. w , \|/ \|/ Perna condita delenda est ---^----^---------------------------------------------------------------

Nice work, dimwit. You managed to miss John's joke as well.

W "Some people are alive only because it is illegal to kill them." . | ,. w , \|/ \|/ Perna condita delenda est ---^----^---------------------------------------------------------------

Based on the pictures, what they are calling insulation thickness, I think really means outside diameter. I think the red wire has 10 to

12 mil insulation thickness based on the size of 14 AWG stranded wire.
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14 AWG Strand 19/27 TC Nom Insul Thk 0.09 " 0.09" could mean the nominal thickness of the insulation..2.3mm is wacky..especially with teflon.. Or means the total diameter including the insulation.. 0.09"=2.3mm #14AWG=1.63mm 2.3-1.63=0.67mm 0.67mm/2= 0.34mm thickness or ~13mil

I'm still gonna look around a bit for thinner insulation.. :)

D from BC

I wonder why that is. Maybe one can see them as a distributed series of different inductances, each having a different resonance frequency with its parasitic capacitance -- the reciprocal concept of paralleled capacitors of different values.

robert

This may be a bit picky but eddy current is a magnetic loss, not a copper loss.

JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.   --Schiller

This may also be picky, but eddy current losses occur any time magnetic field through a conductor changes magnitude. Skin effect losses are eddy current losses. Proximity effect losses are eddy current losses.

I'm guessing that the tiny dimensions raise the srf's way up, and the copper+ferrite losses kill the Qs. And as you mention, the resonances are distributed by the tapered structure.

We made some wideband inductors out of strings of progressively larger inductors, and it got nasty. Each inductor had its own resonances so we had to stagger values all over the place and add a lot of damping resistors. Having this nice distributed cone thing to handle the fast end is very handy.

John

On Fri, 27 Apr 2007 11:43:55 +1000, Lionel Gave us:

You fucktards are the idiots making nearly 300 LAME posts a day.

On Fri, 27 Apr 2007 11:44:42 +1000, Lionel Gave us:

You didn't make a joke. You showed your utter stupidity... again.

Shuttle is just a stick with notches on the ends something like a popsicle stick with wire wound on it. Then just pass the shuttle through the hole of the toroid.

On 27 Apr 2007 18:09:23 -0700, kell Gave us:

from

#12

It makes managing longer lengths of wire much easier.

Typically kind of dog bone shaped, inasmuch as it is better to neck it down in the middle a little bit, and the ends are smaller than the final ID that the finished wind is expected to be.

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