When I constructed my AppleCrate II, I measured the average power
consumption of an Apple //e main board (no cards) at about 4.2 Watts.
Additional cards can change this significantly, with large RAM cards
and accelerator cards being among the biggest power consumers.
A Disk ][ and Controller consumes very little power except when it
is actually running.
Monitor power consumption ranges from a few watts to over a hundred
watts (for a large color monitor). Monitors will list a conservative
(high) power consumption on their labels. CRT Monitor power consumption
actually varies slightly depending on the average brightness of the
screen, but this is typically a negligible effect.
It's safe to say that the monitor will be the biggest power drain
in any typical setup.
There are several variations of the ubiquitous "Kill-a-Watt" power
meter on the market for very reasonable prices. I'd recommend it
as a way of determining power consumption for your particular system.
NadaNet 3.1 for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."
If this could helpl you, I measured the power consumption of my european
Apple //c with it's 9" monitor last year, at the power outlet:
Apple //c: around 25 Watts
Monitor: around 60 Watts
The IIe power consumption should not be so far.
Kensington System Saver
87 watts on power-up
72 watts after a few seconds while one drive boots
66 watts with no drive running
Cédric, Charlie, thanks!
Charlie, any chance you have a reading your system without the
Sure. Without the monitor:
34 watts on power-up
29 watts after a second or two while the drive boots
24 watts with no drive running
The System Saver by itself uses 7 watts.
but Michael J. Mahon wrote earlier:
>When I constructed my AppleCrate II, I measured the average power
>consumption of an Apple //e main board (no cards) at about 4.2 Watts.
you're measuring 20 more watts that Michaels setup with no cards.
24 - 7 (for system saver)
17 watts... You mention that you have duodisk and serial card. Do
these two cards take this much power?
Maybe Michael J. Mahon was measuring the power consumed by the board at
the output of the power supply. I'm measuring is at the line side. The
power supply efficiency could be low. If we say 50% (just a guess) then
17 watts / 2 = 8.5 watts. Still higher than Michael gets but did he
have a keyboard attached? I also failed to mention I have a standard
64K card in the AUX slot which I consider normal. I don't know if
Michael had a card in the AUX slot. He said (no cards).
You are correct--I measured the DC power consumption of the +5v supply. The
+12v drain is about 2 watts (it's actually used to take some load off the
+5v supply, for some reason--maybe just to load it enough to keep it in
The Aux slot RAM card (which I did not include) is potentially a 2-3W
drain, so maybe that's a significant factor.
Still, I'd be surprised that the switching power supply is less than 50%
That would certainly make a case for battery powering an Apple II directly
rather than using an inverter and "plugging it in"!
-michael - NadaNet 3.1: http://home.comcast.net/~mjmahon