[Amps] Switching Power Supplies

[Steve Thompson]

Colin Lamb wrote:
> "I can't imagine why an amateur would want to use a 
> switching supply for a filament. What reason is there to do 
> that?"
> 
> There could be a few reasons:  
> 1. The amp has to be transported and weight is an issue.

Not this one - but it would apply to another one in the planning.

> 2. There are no suitable transformers available and a surplus switching supply is handy.

No transformer in stock, but enough bits to build a switcher - so I get 
to learn something too.

> 3. Real power transformers cost money and the amp builder is almost penniless and a switching supply is given to him.

Not quite penniless, but certainly parsimonious :-)

> 4. The builder, in true amateur spirit, likes to complicate something simple.  

Guilty as charged.

> 5. Just wants to see if it can be done.  

Yep - and it's more interesting than the other 200 jobs I really should 
be doing....

73, Steve