Winding Inductors with Teflon Wire

The dude tried to netkkkop me. from altopia. Pity for him and his group.

Looks like you been drinking again.

Fetch...I heard your group here was going to get rained on, and I heard it was you who asked for it.

So simple. Did the big boys beat you up in school?

"SuperM" wrote in message news: snipped-for-privacy@4ax.com...

Also, for serious high current applications, they tend to be wound with copper tape, and not wire at all.

Tam

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In my experience, except for toroids that require several layers of windings, the core was most often the bigger culprit for temperature rise. It's easy to underestimate core losses, because loss formulae are usually based on sine waves. What is your core material, Dave from BC? Have you tried any of the more exotic materials like Kool Mu? Paul Mathews

You do use a shuttle when winding toroids, don't you?

It has been years since I last had to get into the details of ordering wire but:

Raychem's polyolefin wire is also worth a look.

It was a pun, dude. Don't get all wound up over it.

John

With any luck he'll have a "Massive" brain aneurysm soon, and we won't have to keep updating kill filters.

The most common symptom of a brain aneurysm is a severe headache. There are many symptoms of a brain aneurysm and each person with an aneurysm may not ...

He sure fits that description.

LOL.

I still can't believe that the dumb cunt still hasn't figured out the 'litz' joke.

I thought I could wind 2 toroids before I could build a shuttle... (not a space shuttle.. :) I may make my own toroids for prototypes but if I'm using many toroids, then it gets sub'd out.. D from BC

Have you ever seen a toroid wound with copper tape? D from BC

Core loss is from deltaB..(flux change) My app has a tiny inductor ripple current compared to the average current. Therefore delta B is small. (This is not a transformer where deltaB can be huge.. Worst example is near saturation in 2 quadrants.) Low ripple current means low deltaB which means low core loss. In my app, the DC component is dominant and is to blame for all the heat.

By the way, I'm using cheapo Sendust (IIRC that's also called Kool Mu). Which reminds me to consider using gapped ferrite for more permeability for less windings for less copper loss..

Anyways.. I just want to pick on plain ol winding resistance. That's why I'm interested in thin jacketed stranded #14 wire for easy toroid winding by hand. D from BC

Oh noooo...not the exotic stuff... Who do I meet in a dark alley with an envelope of cash? Or What kid do I pay off at the loading dock. :)

I was hoping for microthin Teflon jacketed stranded #14 wire that's is off the shelf or orderable online. D from BC

I will look it up, but basically we are talking about high current DC/DC supplies.

Tam

These people invented that structure:

and I think Coilcraft entered the market when the basic patents expired. The Piconics parts seem to be cheaper and easier to get.

These are phenomenal, nearly perfect inductors up to the 40 GHz range. They can be tail-ended with bigger inductors or active pseudo-inductors to extend the low-frequency end. Some Big Name companies use these in their expensive bias tees.

John

Ahhh...so you haven't tried copper tape on a toroid. :P

I'm skeptical of "gift wrapping" a toroid with copper tape. I've yet to see a picture nor see inductor companies boosting a revolutionary breakthrough in reducing resistive losses with copper tape on toroids. Yes... The inductor is used in a high current DC/DC convertor... (continuous mode type) I'm learning about high current inductor design methods..

Isn't there some software out there that simulates the performance of inductors with any crazy core and wire shapes? Magnetics CAD? D from BC

No, I haven't gotten into that kind of power. The first application of copper tape that I found today was in the SGS power supply book. 5VDC 100 Amp supply, the transformer core is Ferrox EC52-3C8 EE. I guess that means E laminate. The secondary had two winding, each 2 turns of .01 x 0.8 copper strap. Interestingly, the inductor had 5 pieces of #12 wire in parallel on a Ferrox 1F30-3C8 core.

I have seen copper strap mentioned in other manufacturers ap notes, but can't remember if any were wound on a toroid. Strap .8 in wide is probably too wide to put on a toroid; .25 might be doable. The whole idea is to have a conductor that is just thick enough, consistent with the skin depth. The SGS example ran at 100 KHz. Actually, I didn't think of the fact that with a toroid, it is the *inside* circumference that limits the number of turns per layer - keeping in mind that you have to leave an air gap between turns.

Tam

Tam