Date   : Sun, 25 Apr 2010 11:18:59 +0100
From   : info@... (Sprow)
Subject: Model B Sync issue / Master 128 PSU issue

In article <B2D7DF78C7C2461A8B3D7C1AF82476B2@...>,
   Mark Haysman <jumbos.bazzar@...> wrote:
> > This is a Master PSU question though - so the main transistor is a 
> > Hitachi 2SC2928 (different spec)
>
> Yes it is a different spec, it's lower. The BU208A has higher current and 
> power ratings, and can be used as a direct replacement.

In the fun world of power supplies it's not all about power - 80W (2SC2928)
and 150W (BU208A) are both over spec in that respect - look at other
parameters such as Vceo and hfe.

In my view, if the direct replacement is readily available use that rather
than changing it for some other random part when the original design
parameters are not known,
Sprow.