Running 3 phase 780s on single phase power

[Gordon JC Pearce MM3YEQ]

On Tue, 2009-01-20 at 13:06 -0800, Guy Sotomayor wrote:
> On Jan 20, 2009, at 12:35 PM, Rich Alderson wrote:
> >
> > The KL-10, like other DEC gear, uses 3-phase input power as the  
> > simplest
> > way to get lots of amps into the system:  60A @ 208 3-phase.  All of
> > this feeds into a single gigantic boat-anchor grade transformer which
> > forms the basis of a linear power supply.  2/3 of that power goes back
> > out as simple heat.
> 
> Umm.  No.  That transformer is a ferro-resonant transformer.  It  
> *needs* 3-phase to work!  It supplies the basic 12v DC that are then  
> used to by the linear regulators.  It's those that burn the power as  
> heat.  Replacing the linear regulators with switchers will reduce the  
> consumed power by a lot.

Since extremely high current switchers are relatively cheap (at least
compared to getting three-phase installed, and massive aircon systems),
is there any reason why you *wouldn't* go down this route?  Particularly
for a machine that's going to be on a lot?

Gordon