[AMPS] Transformer Current ratings

[2]

>
>For "ordinary" old power transformers:
>
>Is there a rule of thumb to help estimate transformer KVA capacity from the 
>iron (or total) weight? If not, why?
>
>Prior to hypersil, weren't most transformers made from similar iron in 
>similar configuration? If so, wouldn't capacity be directly related to core 
>weight?
>
//  This is pretty much true for ordinary E-I core transformers.  
However, some were made from higher-Mu core material than ordinary 
transformers.  More Mu allowed using fewer turns of wire per volt.  Fewer 
turns needed meant that heavier gauge wire would fit, so current 
capability increased.  I use one of these transformers.  The 24v, 30A 
secondary is a layer of copper tape c. 3" in width, sandwiched with a 
layer of 3.5" w. plastic tape, wound like a clock-spring.   It has 
surprisingly (to me) low winding resistance for a transformer of its 
weight. 

cheers, Jerry

-  R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.  
end


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