Re: [NTLK] Two power-hungry cards in 2x00

From: Frank Gruendel (fg2_at_pda-soft.de)
Date: Thu Jan 15 2004 - 17:20:41 PST


> I have tried out CurWatch or whatever the name will be and have found
> that my WLAN card pulls alot of power. Everytime I use it to connect I

> get a warning from CurWatch that I went over 200mA (I'm using regular
> batteries).

Right. If you were using the rechargeable pack, the default warning
level
would be 500 mAh.

> It seems that when I use just the CF adapter, things are ok. I took
out
> the CF adapter all together and the WLAN card would still set off
> CurWatch with 250 - 280mA warnings.

I think WLAN and phone cards are the most power hungry cards out there.
Some modem cards are quite hugry, too.

> So..I am concerned. How big a deal is this? Am I about to fry my
Newt's
> brains?

Well, we don't know yet. Fact is that I just fixed a 2100 that had a
blown
capacitor, a blown fuse and a dead transistor. Said Newton worked fine
until it had both a WLAN card and a phone card in its slots;; That very
day it died. This might or might not have been a coincidence. Whatever,
it made me research a bit and I found a post from a former Newton
employee.
It said the following:

> The MP2K allows use of somewhere around 800mA when using the
> rechargeable batteries and about 500mA when using Alkaline batteries.
> It can also provide 800mA when the AC adapter is connected.
> These numbers apply to BOTH slots, and the serial port combined.
> One slot can consume all the power. If the use of other devices at
> the same time is attempted, the supply will go out of regulation.
> This can cause unpredictable behaviour.

So, if you are drawing 100 mA through the serial port, in your case
there'd be 400 mA left for the card slots. If nothing
is connected to the serial port at all, you'd have 500 mA. All this
is assuming that the post I found is correct. I think it might be,
these values make sense.

> I don't wanna give up my wireless ethernet, but I don't wanna
> kill my Newt either!!

As I said: All this, including the whole CurWatch package, is based
on the assumption that what is said in this post is true. After
I noticed the fuse F1 on the 2x00 main logic board, I checked all
my dead or half-dead boards. On about 30% of them F1 is
blown.

Cheers

Frank

-- Newton Software and Hardware at http://www.pda-soft.de

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