20 Jan
2009
20 Jan
'09
2:11 p.m.
>>>> "Chuck" == Chuck Guzis
<cclist at sydex.com> writes:
Chuck> On 20 Jan 2009 at 15:53, Paul Koning wrote:
> And finally, if you have a system that actually
has a 3-phase
> input to the DC supply (for example, 6 diodes from 3 center-tapped
> windings feeding the ripple filter), then rewiring that input as 3
> separate single phase circuits is not going to work quite right,
> because you will then have inadequate filtering (having replaced
> 360 Hz ripple by 120 Hz ripple). It doesn't sound like this shows
> up in VAXen; I don't know if it does in the KL-10; but I do know
> it is a consideration if you're working on a CDC 6000 series
> machine because it has such supplies.
Chuck> Yup, but there the ripple frequency is 2400 Hz (at least on
Chuck> the CPU supplies).
True. I thought there was 3phase 60 Hz in the console, but that's not
the case. The compressor motors (for the mainframe cooling system) do
use 3 phase 60 Hz.
paul