WTB: Tower case for IBM model 80, 60 or 65 (PS/2)

Tony Duell ard at p850ug1.demon.co.uk
Wed Sep 21 18:46:43 CDT 2005


> I was advised that to change this 220VAC unit to 115VAC would 
> not work even I knew what exactly to do just install voltage doubler 
> circuit.

It's not unheard-of for SMPSUs to contain a mains-frequency transformer, 
running off the AC mains, to provide the startup supply (or maybe all the 
supplies for the control electronics). If that's the case, you do need to 
do more than change the rectifier for a voltage doubler circuit to get 
the right DC voltage across the mains smoothing capacitor

I would be _very_ suprised if this thing cared about mains frequency 
(within sensible limits). I can see no reason why giving it 220V from a 
step-up (auto)transformer wouldn't work.

-tony


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