atheybey@lcs.mit.edu (Andrew Heybey) (07/17/89)
Yet another tale of woe (YATOW). I came home Friday night to find my 2000 (which is usually left running all the time) asking for Workbench. We had had a thunderstorm, so I assumed that the power had momentarily gone off. I didn't want to use it that night, so I turned it off. Saturday night, I turned on and was rewarded with a flash of the power light, and brief gronk from the disk drive, then nothing. I dismantled the thing, and found nothing obvious--the fuse is fine, and there aren't any melted components that I can see. Once dismantled, I can hear a very faint snap or zap from the PS when the power shuts down after it is turned on--possibly a spark. Also, twice the PS has supplied continuous power when switched on. Each time, however, I turned it off and started plugging things back together, and it then returned to its previous behaviour. I have been inside the PS case once before, when I replaced the fan whose bearings were starting to go. Questions: I am assuming that the PS was zapped by lightening. However, when I replaced the fan, the PS was run unloaded for a brief time (30 secs at most--just to make sure that the fan spun in the correct direction). Will running unloaded damage the PS? Has anyone tried sticking an IBM-type PS into a 2000? How much hacking is required? I already got a quote for a replacement Amiga PS, and it is quite expensive. Of course, I haven't priced a 200 watt IBM supply yet, but I would guess that one can be had for considerably less than $165. 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. -- ------------ Andrew Heybey, atheybey@ptt.lcs.mit.edu, uunet!ptt.lcs.mit.edu!atheybey MIT Laboratory for Computer Science Room 509, 545 Technology Square, Cambridge, MA 02139 (617) 253-6011
erk@americ.UUCP (Erick Parsons) (07/19/89)
<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..
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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.....
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Erick Parsons // Words for the wise: *If it works don't fix it.*
Sacramento Ca // mail to: ...pacbell!sactoh0!americ!erk
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