Teflon insulated magnet wire?

[serengetiplains]

Has anyone any experience with transformers wound with teflon insulated magnet wire? Polypropylene insulated magnet wire? Seems to me either of these dielectrics should render an audible improvement to a transformer (lower capacitance, lower dielectric absorptive effects). Is teflon perhaps too difficult to handle for winding purposes?

[fdegrove]

Hi,

Has anyone any experience with transformers wound with teflon insulated magnet wire?

No....but then I have a hard time believing such magnet wire even exists...

Cheers,

[serengetiplains]

Originally posted by fdegrove
No....but then I have a hard time believe such magnet wire even exists...

Frank, I've researched the issue somewhat. A few wire manufacturers in the USA offer teflon enameling (not sure about polypropylene). I obtained a roll of PTFE enameled silver wire from one such manufacturer, California Fine Wire, and the enameling seems possibly sufficient for tranformer winding. The enamel is somewhat loose on the wire---slips around if you force it---is not too thick from measured specs (don't have them with me at the moment) and was hi-pot tested to 5000VDC (!). I sent an email to Tribute transformers asking their opinion on winding a transformer with this type of material. If you help me communicate with them, I'd be happy to send you some of the silver wire I had manufactured to inspect and test?

[serengetiplains]

Frank, here's an article perhaps of interest:

http://www.calfinewire.com/magazine/ptfe2.pdf

[serengetiplains]

http://www.calfinewire.com/magazine/ptfe.pdf

[fdegrove]

Hi,

If you help me communicate with them, I'd be happy to send you some of the silver wire I had manufactured to inspect and test?

Sure, no problem.

In the meantime I'll go through the documents...I'm really curious about this as it opens alot of perspectives.

Cheers,

[Pjotr]

Originally posted by fdegrove
Hi,

No....but then I have a hard time believing such magnet wire even exists...

Cheers, [/B]

Hi,

I’ve used Tefzel isolated wire in switch mode PSU’s for commercial purposes on recommendation of the transformer manufacturer. Due to the limited space in a small ferrite transformer it is difficult to comply with regulations for double isolation (4 kV test). The teflon isolation solved that. The wire used was 26 awg, original intended for wire-wrap purposes. Don’t think it is of use for regular 50/60 Hz mains transformers. There are other ways to obtain low coupling capacitance between primary and secondary.

If it is for audio trannies, note that the teflon isolation is rather thick. It will waste valuable space in such a trannie (low fill factor). The result is higher copper resistance.

Cheers

[fdegrove]

Hi,

If it is for audio trannies, note that the teflon isolation is rather thick. It will waste valuable space in such a trannie (low fill factor). The result is higher copper resistance.

That's indeed the major concern if the insulation is regular PTFE as in Tefzel wire.
However if it has the insulation thickness of a coating such as normal enamel then we're talking.

I know AudioNote prefers polyurethane over polyimide (ML?) for both the OPTS and their range of hook-up wire for sonic reasons but maybe they're as unaware of the existence of PTFE enamels as I am.

Cheers,

[Steve Eddy]

Cooner Wire sells Teflon enameled wire (quad build) in a variety of gauges and metals. I priced their 30 gauge copper with Teflon (because of the enameling process, the copper doesn't have to be tin or silver plated) and they want $2.75 a foot for 100 feet.

http://www.coonerwire.com/Products/MEW.tml

se

[Steve Eddy]

Originally posted by fdegrove
I know AudioNote prefers polyurethane over polyimide (ML?) for both the OPTS and their range of hook-up wire for sonic reasons but maybe they're as unaware of the existence of PTFE enamels as I am.

And maybe they just don't like the sound of Teflon. It's been known to happen among those who don't worship techincal specs.

se