[Amps] Transformers in series

[Bill Turner]

ORIGINAL MESSAGE:

At 06:16 AM 3/12/2006, Theo Bellamy wrote:
>Or you can "mix n' match" ... here is an amp I built years ago with multiple
>power transformers.
>Each secondary was 320 volts, so I wired them in series to get a 1280 volt
>center tapped secondary.
>I wired the primaries in series/parallel so I could feed it 220. Worked
>great.

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Using four transformers like this is not good design practice unless 
you know for sure the insulation between windings and core will 
handle the increased voltage on the two "outer" transformers. With TV 
transformers like this example, one can only guess.

When I was doing TV repair back in the '50s through the '70s I worked 
on tens of thousands of TVs and never saw a bad power transformer, so 
I would say they are pretty well built, but only for the original 
design. TV manufacturers never put a penny more than necessary into 
their products, so be careful.

Bill, W6WRT