Do you mean say for use the own primary/secondary wires as leads?
It seems a good idea IMO as will be one less connection/solder in the signal path.
Anyway Iam curious for the reason.
More commonly they use braided non-expandable polyester sleeving for the strain reliefs on toroid trafo leads. I had no problem finding it in Mouser once I figured out how to find it in their database. The silicone-coated version can get expensive but you only need to buy one roll in your career.
Heat shrink is a polyolefin, no corrosive products, but it might split under continous heat as its shrinks further and embrittles/fails. Silicone rubber sleeving may be a more robust alternative, retaining mechanical properties on heating for extended periods. I know large magnetic components (motors/generators/transformers) use materials like Nomex for their insulation, which is mechanically tough and heat resistant. (Nomex is related to kevlar)
Yes, I think that was the reason. Thanks!
Yes. I have polyester tubes for a couple of diameters. It is what I use to insulate the enamel wire as it enters and exists the winding from/to the external leads. Don't you guys do the same?
The question about using heat shrink tubes instead, is because it is easier and cheaper to find for any diameter.
Exactly. Most of the transformers I have purchased over the years came that way, and when I add extra secondary windings (frequently) i always use it.
Trafos that I’ve acquired that don’t use the polyester sleeves use NON-shrink plastic tubing over bare magnet wires for the leads. I don’t really like that arrangement because it can’t go directly to a spade lug or Molex connector. It is tougher than heat shrink, and it’s ok that it doesn’t fit snugly because the end closest to the trafo gets held in place with the over-wrap tape, same as the polyester tubes. I suppose one could still use it if they soldered leads to the magnet wire. Anything is better than nothing, but it’s always best to stick with industry best practices in case there is ever a question of safety of some home brew concoction.
What about the thin magnet wires? Let's say, thinner than 0.3 mm (diameter). Just covering with any kind of insulation tubing seems not very dependable.
When you say that you can’t go directly to a spade lug or Molex connector, is it because of this?
Magnet wire has it own (fragile) insulation that can withstand a few hundred volts differential if not abraded. So, I slip a thin teflon tube over it, and have not had any problems (yet). I’m looking forward to expert answers on this question.
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