Once I had the (crazy) idea to use Litz wire.
The skin depth is defined as the depth below the surface of the conductor at which the current density has fallen to 1/e
δ ≈ √(2 ρ / ω μ)
ρ = resistivity of the conductor
ω = 2 π f = angular frequency
μ = magnetic permeability of the conductor
For copper at f=100 KHz
δ ≈ 0.21 mm
So, for audio transformers it does not make any sense.
Cost will increase, wire to wire capacitance will increase, and winding resistance will increase, a lose-lose-lose solution.
The skin depth is defined as the depth below the surface of the conductor at which the current density has fallen to 1/e
δ ≈ √(2 ρ / ω μ)
ρ = resistivity of the conductor
ω = 2 π f = angular frequency
μ = magnetic permeability of the conductor
For copper at f=100 KHz
δ ≈ 0.21 mm
So, for audio transformers it does not make any sense.
Cost will increase, wire to wire capacitance will increase, and winding resistance will increase, a lose-lose-lose solution.
Hi Popillin,
I have sent results of tests.
To have a confirmation about your theory, that is correct (in theory) , please send your test made on the field.
Walter
I have sent results of tests.
To have a confirmation about your theory, that is correct (in theory) , please send your test made on the field.
Walter
What test results?
You did present the results as they were two almost identical transformers, one with traditional magnet wire and the other with Litz wire.
After reading the whole thread I realized that the two transformers are completely different, so your test results are meaningless, you are comparing apples with oranges.
It is not "my" theory, it is basic physics. If it were "my" theory, Maxwell's equations should be called Popilín's equations. 😀
Nevertheless, the capacitance issue is debatable, Litz wire can have smaller wire to wire capacitance, depending on insulation thickness, its dielectric permittivity and the winding technique.
Skin depth does not need any test, it was already tested several times along more than a century.
Remind that transformer tests must be provided by you, the right ones BTW. 😉
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I think that you haven't realized the test I sent.
Please read from the first post.
The ratio for both trafo is similar and the bobbin is the same.
As you know at high frequencies the parasitic have a heavy weight we can say they are dominant. In fact after the resonace the L goes lower rapidly because the capacitance become higher. Also on RDH you can find the equivalent circuit for high frequencies.
Ii you look on the diagram on Fig. 5 of the first post you can see the different shape of the curves and, on top, the value of capacitance where on Litz is lower.
Then on diagram of Fig. 4 on post 4 you can see the different resonance for the two trafos.
And they are same fruit.
I am sure that the theory is correct but the test show what in practical fields what happen.
Remeber the Igor Ivanovic Sikorskij. 🙂
So you are able to demonstrate with your test on practical stuff what I sent is not the real world.
I think what I did can be considered a good start point; in next future I have other stuff where some aspect will be better than the old ones.
Ciao
Walter
Please read from the first post.
The ratio for both trafo is similar and the bobbin is the same.
As you know at high frequencies the parasitic have a heavy weight we can say they are dominant. In fact after the resonace the L goes lower rapidly because the capacitance become higher. Also on RDH you can find the equivalent circuit for high frequencies.
Ii you look on the diagram on Fig. 5 of the first post you can see the different shape of the curves and, on top, the value of capacitance where on Litz is lower.
Then on diagram of Fig. 4 on post 4 you can see the different resonance for the two trafos.
And they are same fruit.
I am sure that the theory is correct but the test show what in practical fields what happen.
Remeber the Igor Ivanovic Sikorskij. 🙂
So you are able to demonstrate with your test on practical stuff what I sent is not the real world.
I think what I did can be considered a good start point; in next future I have other stuff where some aspect will be better than the old ones.
Ciao
Walter
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OK, let's go...
On post#31 bobbins were different, now they are the same... 😕
For comparative test you must use the SAME transformer ratio, the SAME core, the SAME bobbin, and the SAME winding scheme.
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Hi
my error on explanation!
Must be: the bobbin are the same, the ratio is the same, the core is different , the wire is different.
The winding scheme is similar but with different occupation on bobbin, of course.
But, I repeat again, at high frequencies the parasitic are dominant .
I hope that you can understand the picture at fig. 5, post 1.
In every case instead to stay around this aspect I hope that one technician as you can replay about the test set we used at the lab as other people did.
Every suggestion is appreciated.
I think that if you have the tools and the capability you can easily confirm or not what I show about these stuff.
I repeat also that this is a start point that I consider good; I will work ( with Fabrizio) on the lab to reach a better results.
Ciao
Walter
my error on explanation!
Must be: the bobbin are the same, the ratio is the same, the core is different , the wire is different.
The winding scheme is similar but with different occupation on bobbin, of course.
But, I repeat again, at high frequencies the parasitic are dominant .
I hope that you can understand the picture at fig. 5, post 1.
In every case instead to stay around this aspect I hope that one technician as you can replay about the test set we used at the lab as other people did.
Every suggestion is appreciated.
I think that if you have the tools and the capability you can easily confirm or not what I show about these stuff.
I repeat also that this is a start point that I consider good; I will work ( with Fabrizio) on the lab to reach a better results.
Ciao
Walter
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Pieter
I am waiting new prototypes in next days. I am writing a new article about triode as 2A3 and 300B with the goal to introduce two project, one s.e. and one p-p.
I hope that what I have presented here can be a good start point for a discussion, that's all.
Walter
I am waiting new prototypes in next days. I am writing a new article about triode as 2A3 and 300B with the goal to introduce two project, one s.e. and one p-p.
I hope that what I have presented here can be a good start point for a discussion, that's all.
Walter
So... repeating with correctin
1) first transformer: EI core + Litz wire bobbin
2) second transormer: double C core + Litz wire bobbin.
test: transformer #1 vs transformer #2
That's correct?
Really puzzling 🙂
yes
but I have to find the data.
As the previous post I can't consider the differences between the coils important for the final use.
Walter
but I have to find the data.
As the previous post I can't consider the differences between the coils important for the final use.
Walter
Lisoformio
have you read the correction??
the bobbin are the same, the ratio is the same, the core is different , THE WIRE IS DIFFERENT means that the EI is normal and C is Litz.
This:
can you explain
Quote:
The winding scheme is similar but with different occupation on bobbin, of course.
Really puzzling 🙂
?????
Walter
have you read the correction??
the bobbin are the same, the ratio is the same, the core is different , THE WIRE IS DIFFERENT means that the EI is normal and C is Litz.
This:
can you explain
Quote:
The winding scheme is similar but with different occupation on bobbin, of course.
Really puzzling 🙂
?????
Walter
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Another try 🙂
1) first transformer: EI core + standard wire
2) second transormer: double C core + Litz wire
3) both windings are on identical bobbins
4) the winding schemes are different
test: transformer #1 vs transformer #2
That's correct?
1) first transformer: EI core + standard wire
2) second transormer: double C core + Litz wire
3) both windings are on identical bobbins
4) the winding schemes are different
test: transformer #1 vs transformer #2
That's correct?
Popillin,
ok.
I don't want to run again in this discussion.
It is normal that the space is different between the wire because the wire are different; a kid of three years old can understand this but the architecture is the same.
At the end, are you able to sent the real test or not?
If yes, please post so I can see what I have done wrong .
If not, please wait my future test so, maybe, you can learn something new.
Ciao
Walter
ok.
I don't want to run again in this discussion.
It is normal that the space is different between the wire because the wire are different; a kid of three years old can understand this but the architecture is the same.
At the end, are you able to sent the real test or not?
If yes, please post so I can see what I have done wrong .
If not, please wait my future test so, maybe, you can learn something new.
Ciao
Walter
Lisoformio ( very strange nick)
please wake up 🙂
4) the winding schemes are different
from post 58
It is normal that the space is different between the wire because the wire are different; a kid of three years old can understand this but the architecture is the same.
Walter
please wake up 🙂
4) the winding schemes are different
from post 58
It is normal that the space is different between the wire because the wire are different; a kid of three years old can understand this but the architecture is the same.
Walter
I am out of discussion, but for the sanity sake, I confirm that Popilin is right. Litz is used in HF coils to increase their Q, due to less losses on frequencies where skin effect causes losses. No way it decreases any capacitances, since they depend on the area, distance, and dielectric permeability, that are the same. I. e. the only what you can get, increased Q on resonant frequency, that means more troubles with compensation.
Now I am finally out of here...
Bye, and good luck!
Now I am finally out of here...
Bye, and good luck!
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