Subject: Re: Just how many of the group are actively running NetBSD on their Vaxen?
To: None <port-vax@netbsd.org>
From: Jochen Kunz <jkunz@maja.unixag-kl.fh-kl.de>
List: port-vax
Date: 10/25/2002 14:09:08
On Fri, Oct 25, 2002 at 03:00:50AM +0200, der Mouse wrote:

> Or, of course, I could be burbling nonsense.  
You are not. If you have non-sin wave forms for the current, computing 
the integral of instantaneous values is the only correct way. Even if
you try to measure the current and the cos( phi) cou can be wrong, 
as many ammeters display wrong values for non-sin wave forms. 
The only way to be save is to use the same type of meter that uses your
power company. In Germany that is mostly a "eddy current work meter"(?).
(Somthing with a rotating aluminium slice, that rotates faster the 
more power is drawn and drives a mechanics, that counts the revolutions
of the slice.) 

I used an electronic Watt-meter to measure the power requirements
of my machines. I don't trust it to measure exact, but I have nothing 
better... Bigest heater is a DEC 3000/600. 230 W (only the machine).
The MV 4k2 with some RAM, adapters, disk, floppy was around 160 W.
The MV4k400 (only CPU and 1 x 64 MB RAM) 160 W. MV3100m95 100 W, 
various VAXstations around 80..90 W each. Ethernet switch 80 W
(I know why I prefer DAS FDDI. ;-) ) DECsystem 5k240 loaded with
8 MB RAM modules only 75 W (without disk and terminal). 
The smalest was a Sun SPARCstation ELC mainboard (sans broken monitor, 
supplied by an PSU from an external SCSI case): only around 15W. 
-- 



tschüß,
         Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/