didn't someone tell me that telco equipment had 40vdc racks once?

[David Nicol]

On Dec 21, 2007 2:09 PM, Billy Crook <billycrook at gmail.com> wrote:
> Another consideration is that this would effectively put 42 machines
> on the same 12v rail, and the same 5v and so on.  So if a component in
> one machine failed in such a way that it shorted across that rail, it
> would take all devices on the rail down unless they each had
> individual load breakers for each rail.  There's also a fairly good
> chance the short would happen during node insertion, so the breaker
> would need to be outside of the node, possibly ruling out the cheap
> bus-bar idea unless the breakers were inbetween the busbar and chasis.


if DC-powered racks were standardized, with bare copper on some spot on them,
and a circuit breaker on each component meant to be slid in, that would work
and would be no more complex than, say, Dell blades.  In fact I wonder if Dell
blades don't do that already, with the power supply being the unit that the
individual "blade" is inserted into.