API Transformers
- Thread starter CJ
- Start date
Help Support GroupDIY Audio Forum:
Hi CJ,
I have been looking at winding some transformers for the first time and have read Wolpert's books and designed an input and output transformer for Altec 436C, but havn't wound them yet. Currently I am interested in this API 2503 transfomer you have kindly posted a design for.
My question;
I have some EI42 lamination in the 29M6 variety that I purchased and have not used. I thought it might do as a substitute for the EI48 (625 EI) you have specified if i left out the third (often unused) secondary winding.
My rough calculations suggest Flux Density of 10.5 KG and a primary Inductance of more than 1.2 H. (meaningless figure without empirical testing).
The question of fill; EI48 to EI42 is approx 33% window volume reduction, the trade off of removing the third secondary winding is a 25% decrease in wire volume. Was there a (33-25%) 8% or greater unfilled region in the EI48 design? Or do I go down to the next smaller wire size? 30 AWG.
Wolpert's THD table furnishes a figure of 0.33%THD for 10.5KG compared to 0.2%THD for the 8.65KG you have on your winding sheet.
Q. Will this work? I guess i'll have to wind and test my EI42 version of the 2503 (let's call it 2503EI42) in a CCT with a reference against the EI48 version. Could be a while until that happens. It will come down to fill firstly, then tone secondly.
I have been looking at winding some transformers for the first time and have read Wolpert's books and designed an input and output transformer for Altec 436C, but havn't wound them yet. Currently I am interested in this API 2503 transfomer you have kindly posted a design for.
My question;
I have some EI42 lamination in the 29M6 variety that I purchased and have not used. I thought it might do as a substitute for the EI48 (625 EI) you have specified if i left out the third (often unused) secondary winding.
My rough calculations suggest Flux Density of 10.5 KG and a primary Inductance of more than 1.2 H. (meaningless figure without empirical testing).
The question of fill; EI48 to EI42 is approx 33% window volume reduction, the trade off of removing the third secondary winding is a 25% decrease in wire volume. Was there a (33-25%) 8% or greater unfilled region in the EI48 design? Or do I go down to the next smaller wire size? 30 AWG.
Wolpert's THD table furnishes a figure of 0.33%THD for 10.5KG compared to 0.2%THD for the 8.65KG you have on your winding sheet.
Q. Will this work? I guess i'll have to wind and test my EI42 version of the 2503 (let's call it 2503EI42) in a CCT with a reference against the EI48 version. Could be a while until that happens. It will come down to fill firstly, then tone secondly.
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