I think it is a bad idea. You will not get the windings tight enough? And it is possible that the cotton do not like the heat?
it is more like a silk-cotton insulated enamel wire that can withstand lukewarm temp,actually i am more refer to audio signal transformer like step up or coupling transformer that doesn't produce much heat.
I think the cotton insulation is only applied on the lead-in cables, not
within the core. Cotton was once considered a good insulation, but now
we have better products. ( cotton absorbs moisture)
I don't think the cotton will do anything for you other than reduce the number of turns you can fit in the winding window.
Really only useful in RF applications. For audio the more copper inside the transformer the better. Nothing says you can’t use it though.
Some say it sounds better. From experience with audio transformers I don't deny the possibility, by I find the type of copper itself more important to the sound. And you can always add cotton cloth between layers if you need.
You won't improve parasitics much. Leakage will increase due to distance, Rdc as well, capacitance between layers will decrease. You can't simply say "Q factor improvement". A transformer has usually three main resonances. To avoid repeating it all over, you can check my blog link. Parasitic parameters of audio transformers. – Muse coils
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Short answer: NO
And saying "cotton insulated" and "enamel insulated" in the same phrase is a contradiction, it´s either one or the other.
IF somebody knits cotton thread over an already insulated wire I strongly smell future snake oil based on that .
Copper or Aluminum is still preferred for thick/hugh section round wire or rectangular plate in VERY high current situations, think welding machines, distribution transformers and such, a poor choice in Audion transformers at the current levels we handle.
*Maybe* in a 2V 60A winding , nowhere else.
FWIWv I just checked our local Factory
JCK Trefilados, Alambre de Cobre y Aluminio en todos los tipos y medidas
they currently manufacture double layer cotton insulated wire in 1 sq mm to 9 sq mm sections and plate/strip in 1 to 80 sq mm.
Well cotton is moisture absorbing, leading to high / variable dielectric constant, so the intra-winding capacitance won't be well defined perhaps. Its also not great in storage or moist climates.
If its "enamel" wire to start with, its already insulated though, so I'm a bit confused.
If its "enamel" wire to start with, its already insulated though, so I'm a bit confused.
Cotton was the bane of telephone relays because it held dampness and rotted fine wire.
JM's local factory does do cotton, but I suspect this is for oil-filled power transformers. In these, the oil is the insulation and the cotton is just the spacer. The oil protects the fabric from dampness. (Constant monitoring keeps the oil dry, because otherwise it is a terrible insulator.)
Thread-wrap insulation really goes back to the dawn of electric wire. There was no real flexible plastic or enamel, or the tooling to apply it consistently. However the fabric factory had a wide variety of thread-wrappers to make braid and gimp for decorating clothing.
Braiding machine - Digital Commonwealth
Artist's cartoon version of braiding machinery [graphic] - Digital Commonwealth
Braiding machine, New England Butt Company, Providence, R.I. [graphic] - Digital Commonwealth
A very minimal (even broken) braid machine can do a simple wrap which was all the coil-winders needed to start making electromagnets.
JM's local factory does do cotton, but I suspect this is for oil-filled power transformers. In these, the oil is the insulation and the cotton is just the spacer. The oil protects the fabric from dampness. (Constant monitoring keeps the oil dry, because otherwise it is a terrible insulator.)
Thread-wrap insulation really goes back to the dawn of electric wire. There was no real flexible plastic or enamel, or the tooling to apply it consistently. However the fabric factory had a wide variety of thread-wrappers to make braid and gimp for decorating clothing.
Braiding machine - Digital Commonwealth
Artist's cartoon version of braiding machinery [graphic] - Digital Commonwealth
Braiding machine, New England Butt Company, Providence, R.I. [graphic] - Digital Commonwealth
A very minimal (even broken) braid machine can do a simple wrap which was all the coil-winders needed to start making electromagnets.