Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!amdahl!pacbell!sactoh0!americ!erk
From: erk@americ.UUCP (Erick Parsons)
Newsgroups: comp.sys.amiga
Subject: Re: Dead 2000 Power Supply (long)
Message-ID: <1198.AA1198@americ>
Date: 18 Jul 89 23:04:57 GMT
Followup-To: comp.sys.amiga
Distribution: na
Lines: 84


<From: atheybey@lcs.mit.edu (Andrew Heybey) Message-ID: <1S8JX7#3YQHSr=daemon@mintaka>
<On a different tack:  I have just moved into a house, and am now
<paying for my own electricity (horrors!).  How much does the
<A2000+A2052 (CBM 2MB board) + A1080 draw anyway?  It's a 200 watt
<PS--does it always draw 200 watts, or does it vary with load?  Or does
<it supply 200 watts, and draw more?  Is there a way to measure the
<load without unplugging everything in the house & reading the meter?
<I've got your basic VOM.
<
<Thanks for any & all answers.

Don't know about the A2000 but I've been told that the current draw on
an A2052 Expansion board is about 3 amps at 5 volts ~= 15 watts ! This
bugger of mine heats up the whole house :-) The monitor has its own PS
but I believe that it does require a minimal amount of TTL level sigs.
from your computer. 

	The 200 Watt rating is the amount of power that you can (Probably) 
draw from the PS at a constant rate without causing the thing to fry. 
It is usually the rating for the 5V supply, the most commonly used one.
There is also a 12 supply that will draw some for the drive motors,
floppy and hard drives. and a -12V supply that usually is negligable
draw.

	To figure out if you can add to the system without ruining the supply
you take away the power (watts) that is required to run the basic 
system ummm lets say for an example about 75 Watts (don't know what 
the actual rating is sorry) it leaves you 125 Watts. This in theory would 
allow you to run 125W / 15W or.. 8 A2052 Expansion boards were this 
physically possible. 200 Watts goes a LONG way with expansion boards. 
Bear in mind though that there are other perephirals which require 
differant PS voltages that aren't rated so high such as Xtra disk drives 
and hard drives. These require a substantial amount of 12V power to run 
the motors. A spec sheet would come in handy. Taking into account the 
machines that they are meant to run AT, A2000 these supplies will definatly 
supply enough 12V power to run Hard drives.

	There is a way to measure the current draw (Fairly cheaply 50.00 meter)
while it is plugged in. The instrument you need is called an Amprobe and
can be found at electrical supply outlets (not the ones in your wall :-)
The drawback is that you have to seperate the wires in the plug to use it.
The best way would be to buy a CHEAP extension cord that has zip cord (TM)
as the conductors. Seperate the two wire cord so as to have about a 3 inch
long gap inbetween the wires that you can easily access. Plug it in and 
slip the amprobe over ONE of the conductors it will measure a slight
magnetic field around the wire directly proportional to the current passing
through the wire. It converts this to Amps. Now take the reading and multiply 
it by 120 (Or your line voltage if you have a meter to measure that, 120 
should suffice) This will give you the wattage consumed by your beloved 
A2000. To translate that into $$ divide the Watts by 1000, for example:

1) 75 Watts / 1000 = .075  which is actually written .075 KWH.
                                                          ^^^
Now multiply that times your utility company rates which are measured in KWH
or Kilo (1000), Watt, Hours or how many 1000 watt units you use in an hour. The
price is suprisingly low, about 8 cents for 1000 watts for one hour.

2) 8 cents x .075 KWH 

3) hmmm.. 8 times .075 = .6 cents per hour to operate ! 
              YES 6 tenths of a CENT per hour.

This thing even at 200 Watts draws negligable current compared to your fridge !
(Or the kids bedroom light that never got turned off)

The monitor probably draws about 75 Watts (my 1084S does, so it says) which
would be a whopping .6 cents per hour surcharge or:
--------
1.2 cents per hour to operate. Yowwser.. 
--------

	Instead of worrying about electricity costs you (I) should concentrate 
the budget on all that great software out there. Last year I spent a WHOPPING
1,400.00 dollars on software !!!!!! only 340.00 dollars on Electricity for 
everything in my apt. including my Central AC and FRIDGE !!!!!!

What a World.....


--
 ------------------ // -----------Cut-Here----------------------------------
  Erick Parsons    //    Words for the wise:   *If it works don't fix it.*
  Sacramento Ca   //        mail to:   ...pacbell!sactoh0!americ!erk
 ------------- \\// --------------------------------------------------------