Authenticity opinions

Tony Duell ard at p850ug1.demon.co.uk
Mon Jun 7 13:21:59 CDT 2010


> Ya... thanks guys.  The transformer is rated at 7.25V @ 10A.  But it's
> not even able to do 7.25V at 5A so I think it is the culprit.

Does it have just a simple 2-terminal secondary winding, or is it 
centre-tapped? What sort of rectifier are you using (bridge, 2 diode 
biphase, etc)?

Does the thransformer 'look big enough'? If it is 7.25V at 10A, that's 
72.5VA. Is the core comparable in size to other 72VA transformers? No, 
this isnot an exact thing, but in general the size of a small transformer 
core (small being less than a couple of kVA...) gives a good idea as to 
its VA rating.

I am wondering just what sort of fault could cause this other than a 
mislabelled transformer.

> I think I have converged on my solution.  I have two new Triad
> transformers that when bolted to a piece of aluminum angle stock,
> suitably cut to size, will fit stacked in the same footprint as the
> original transformer.  Therefore, I won't need to drill any new holes
> in the chassis, will have a "period" accurate modification and the thing
> should work as was originally intended.
>

Sounds like a good modification. Totally reversable, and it keeps the 
circuit design much the same. 

I just hope the problem is just the transformer...

-tony



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