[Beowulf] power usage, Intel 5160 vs. AMD 2216

[Jim Lux]

At 02:19 PM 7/13/2007, you wrote:
>>(you could cobble one together cheaper.. a high quality charger is 
>>probably $50-100, good quality battery is around $20, a high 
>>quality inverter is $200 or so, and then you'd need some sort of 
>>transfer switch.
>
>wouldn't it be nice to find a PSU which could simply take a 12V input?
>battery->inverter->switchingPS->DCelectronics is kind of gross...


They're available..but expensive and pretty inefficient.
More efficient, but not much cheaper, are PSUs running off 48V (a 
standard voltage for telecom installations).

Last time I checked, I think they were in the several hundred dollars range.

(just found a website for www.powerstream.com

for a 12V 300W supply, they say 65% efficiency

for 48V, they give 70% efficiency

James Lux, P.E.
Spacecraft Radio Frequency Subsystems Group
Flight Communications Systems Section
Jet Propulsion Laboratory, Mail Stop 161-213
4800 Oak Grove Drive
Pasadena CA 91109
tel: (818)354-2075
fax: (818)393-6875