James Knott said the following on 09/14/2010 11:24 AM:
Anton Aylward wrote:
What is more ironic is that in the net room there is this huge UPS that takes AC power (220V actually) and converts it to 12V. It uses that 12V to charge batteries. The batteries then power an alternator that converts it back up to 110V which goes to the racks. Where the units I just mentioned convert it back down to 12V and 5V.
There are now some UPS systems that deliver high voltage DC to the computer, which then converts it down to the voltage required by the system. This eliminates a couple of conversion steps. The telecom industry has been running on 48V DC for a very long time.
It used to that each rack had a PSU (for some stupid reason they always seemed to be at the bottom) that delivered DC (+/-12V, +/-5V) on busbars to items in the racks. "Yes it used to be but we changed all that..." I think a distorted form of consumerism (and multiplier effect) had something to do with it. If the per item PSU costs $X they can charge $Xx4 for it, and its "mandatory". What do you want to bet that removing that PSU from each rack-able item is going to be an 'additional charge item' - yes even though there's less to it. Hey, does you telco charge extra for 'tone dialling' instead of rotary, even though DTMF is the default/norm and rotary/pulse needs special configuration? -- But it doesn't have to be this way. We can do things better. We need to stop doing business as usual and start focusing on end-to-end quality. Security needs to be built in from the start -- not slapped on after the fact. -- Gene Spafford, at the 23rd National Information Systems Security Conference in October 2000 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org