[Amps] Transformer Calcs

[Bill, W6WRT]

ORIGINAL MESSAGE:

On Thu, 10 Jun 2010 19:24:58 +0100, "Dr. David Kirkby"
<david.kirkby at onetel.net> wrote:

>Personally I would have thought just because a transformer is not too hot to 
>touch, it would not be safe to assume it is ok. I've run many transformers up to 
>their maximum ratings and they are nowhere near being too hot to touch.
>
>The perception of too hot will also change with person. I recall once finding a 
>radiator too hot to touch, but someone else could hold their hand on it 
>continuously.

REPLY:

I stand by what I said. Heat is the enemy of transformers because it
deteriorates the insulation. I agree the concept of "too hot to touch"
varies from person to person, but not that much. Transformer ratings
furnished by a manufacturer are not an exact science either. Some will
be conservative and some not.  

Run your transformer cool and it will last a long time. Run it hot and
get ready to buy another one.

73, Bill W6WRT