I will order 0.35mm Z11 laminate (used in transformers by HiFi enthusiasts locally) and the cheapest junk laminate I can find from China - with the same core size. I can then evaluate the same winding on both laminates and be able to measure and listen objectively. I have a looper pedal somewhere, to loop the same riff on both laminates. This will be highly educational! Will remind myself to post sound samples here after testing.
The more porous your dielectric is, the higher the capacitance jump is. If using a dense paper, for example, with a measured epsilon of 3, my practical results from ceresin impregnation have led to 3.5. However, for a paper with a lower density and measured epsilon of 2.2, it would still skyrocket to 3.2. The small difference in the secondary setup is due to the ceresin having a lower epsilon than paper fibers, so the dielectrics kind of come to an average value, depending of their distribution ratio across the dielectric area.
The abundant capacitance within a typical OPT lies between high-impedance windings and presumably (grounded) secondary. These are the most critical layers, where one would desire the lowest epsilon dielectric possible.
If using solid dielectrics like mylar, polycarbonate or teflon, wax boiling / impregnation should give little to no difference, as there is nothing to fill, except turn-to-turn capacitance, which is of laughable value within an OPT.
Come to think about it, this sound like a very convenient method. And easy to disassemble if need be. But, won't it get awfully messy when the transformer is getting hot? I mean, the melting point can't be that high, right?
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You can look out for higher temperature waxes, there are 76-80C melting point grades. I'm also aware there are higher melting temp polyethylene based ones, but still haven't tasted. If going above this point, varnish would be a better option.
Thanks for this! I have no idea what to look for or where. Can you point to a product as a starting point for further search?
My distributor is local, but you get search on the web for high temperature waxes. Just remember to read the datasheets.
Hi
Has anyone tried vinyl wood glue or vinyl wall paper glue.
I used polyurethane sealer for parquet (cf P Turner) with good result.
Yan
Has anyone tried vinyl wood glue or vinyl wall paper glue.
I used polyurethane sealer for parquet (cf P Turner) with good result.
Yan
Do you mean veneer glue? As for polyurethane, I think there is variety among, but mostly, quoting:
Most polyurethanes have melting temperatures in the range of 150-250°F (65-121°C),
As does mine. It doesn't widthstand the temperature of hot wax, it melts.
What is the glue's purpose?
1. Impregnating the dielectric?
2. Fixing a transformer winding in place
3. Fixing wire outputs or winding edges in place?
Most polyurethanes have melting temperatures in the range of 150-250°F (65-121°C),
As does mine. It doesn't widthstand the temperature of hot wax, it melts.
What is the glue's purpose?
1. Impregnating the dielectric?
2. Fixing a transformer winding in place
3. Fixing wire outputs or winding edges in place?
Hi
I varnish with a brush layer by layer to block the coils mechanically
For wood glue, I 'm thinking about "white glue" for assembly, polyurethane sealer for parquet that I'm using is also water base.
I dry it in an oven at 100°C.
Parasitic capacities become less important during drying.
Here a pics off my last design : 6P36C circlotron at 20Khz
Yan
I varnish with a brush layer by layer to block the coils mechanically
For wood glue, I 'm thinking about "white glue" for assembly, polyurethane sealer for parquet that I'm using is also water base.
I dry it in an oven at 100°C.
Parasitic capacities become less important during drying.
Here a pics off my last design : 6P36C circlotron at 20Khz
Yan
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Hi
You can find a real winding varnish water based phenolic or aquarethane.
You just take time to dry it in a stoove
You can find a real winding varnish water based phenolic or aquarethane.
You just take time to dry it in a stoove
What was the filler? What was the insulation material? What material did you use for the bobbin? What material did you use for the EI's?
It was quite a while since I worked on that, so I do not remember vendor details anymore. I think the filler material was called Formvar, and laminations were 4% oriented grain silicon steel for the OPTs. Some other steel type was used for the power transformers. Don't remember bobbin material details except that the thin cardboard-like material was designed just for that purpose.