- Vote on answer
- posted
20 years ago
DarkMatter wrote: [snip]
Please, move on to the 20th century (if you can't manage the 21st) and use metres (mm in this case). This is the perfect example of why metric is overwhelmingly superior to the array of units that constitute that various imperial systems still in use in some parts of the world.
They were nice when we had to do calculations in our heads. Those days ended decades ago. Move on.
Tim
I read in sci.electronics.design that DarkMatter wrote (in ) about 'Help winding my own inductor?', on Sun, 21 Dec 2003:
It isn't worth discussing with you, because you are blatantly dishonest. I wrote that Litz weaving works only for certain numbers of strands, ROUGHLY as twisting...
LITZ is woven, not twisted.
I read in sci.electronics.design that John Fields wrote (in ) about 'Help winding my own inductor?', on Sun, 21 Dec 2003:
Oh, no, John, no, John, no, John, no! Not if the turns are close- coupled, as they are in a pot core.
I've often wondered when winding these little toroids you get that are only about an inch across what effect, if any, scraping off the wire's enamel has on the finished job. I mean it would be tragic to end up accidentally shorting turns out... But there again I don't think the mateial they're made from is particularly conductive, is it?
No it's not. You're an idiot. :->
That's right, John. Litz was a German composer, as in "Brahms and Litz" :-)
Screw the metric system. Long live Imperial measures!
I've never in my life used AWG and I don't intend to ever work with it, but the interesting thing is that one doesn't have to know shit about gauges to see that your two above statements just contradict each other.
According to you, they do: "WIre size doubles every three gauges."
--Daniel
How about if you adjust the gap to hold a constant flux for a given current as you change the number of turns?
What is this "gap" to which everyone is referring? The spacing between turns or something else?
I'd appreciate it if you didn't so severely truncate my posts, and then respond to an incomplete "answer" that I didn't give.
In fact, unless the number of strands is very small (i.e. one layer after twisting, which is rare for litz) simple twisting does NOT suffice to make litz wire. I've spec'd, purchased and measured different types of litz from wire manufacturers. Their solution to an inability to make a genuine weave is to twist a modestly-small number of strands, then use multiple sets of these as fatter wires in a secondary twist, then twist sets of these thicker ropes to make up a completed wire. The goal of multiple-layer schemes should be to move each individual strand of wire through as many of the available locations within the completed "cable" as possible, in such a manner that would approximate the result from a true weave. One cannot do this with simple twisting.
It's not useful to characterize the result as "twisted wire," and certainly not "simple twisted," as you asserted. Litz performs decidedly better than conventional twisted wire, simple or not.
Sadly, many (if not most) modified-twist schemes in fact fail to fully distribute each wire's pathway throughout the complete area, which can lead to substantial litz performance failures, with the high-frequency Rac/Rdc exceeding unity in multilayer inductors and transformers. Dark Matter, many of the examples on the cover-page of your web-page reference would perform poorly against a properly- designed litz wire (I see a few good prospects there as well).
Finally, I know of no wire manufacturer who makes simple bundles of multi-strand insulated wire and calls this "litz wire." None of the manufacturers I've used offer such a "weave" option, and I would not purchase such wire if they did, because it would not succeed in solving common severe proximity-effect problems.
Thanks, - Win
whill_at_picovolt-dot-com
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.