From: Johannes Wolf (mp2100_at_mail-gw.estec.esa.int)
Date: Wed Jun 16 2004 - 01:44:42 PDT
PLEASE CHECK BEFORE PLUGGING IT TO YOUR NEWT!!
From my own experience I can tell you that it is really bad when you realise
a bed smell coming out of your Newt and the display switches off forever...
It is a very easy thing to to - take a multimeter and measure the output
voltage of your adapter.
The most important thing is to check that the voltage in no load condition
does not exceed 7.5 V!
If this is the case the risk to damage your Newt is much lower but still not
zero.
The remaining risk is that the power adapter may provide too much current
and/or a different impedance curve.
If you have a look at the power adapter designers guide (available at Unna)
you get a clear description on how the power adapters output voltage shall
behave with respect to output current. The main thing is that there is a
current limitation (may be even with fold back characteristics) that limit
the current to a total maximum of 1.3 Amps.
In case this maximum current is exceeded (this can hapen only during the
fast charging of the Newton battery) you also risk to damage your Newt.
The best way to find this out is to measure the voltage/current
characteristics of the adapter.
But a current measurement while applying a short to the output will do as
well - the max. current shall be 1.3 Amps or below.
Cheers
Johannes
> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net]On Behalf Of
> dlandown_at_chroma.med.miami.edu
> Sent: Wednesday, June 16, 2004 2:14 AM
> To: newtontalk_at_newtontalk.net
> Subject: Re: [NTLK] After-market power adapter
> Unfortunately I did not search the archives before going to ebay.
> I just received a power adapter I "won" (5702385252). The add looks very
> similar to the (5700198547) described below. The ad says
> 9W AC Power Adapter For Apple Newton Message Pad Brand New in white box.
> Input Voltage: 100-120V
> Output voltage: 7.5V
> THESE UNITS WERE CUSTOM PRODUCED USING THE SAME SPECIFICATIONS AS THE
> ORIGINAL APPLE NEWTON CHARGER. THEY HAVE BEEN TESTED ON NUMEROUS 2000 AND
> 2100 MODELS AND HAVE WORKED FLAWLESSLY.
> But the unit says
> Model: SYS1089-1209L-W2
___
> Output +9V --- 1.33A
> Output Power 12W max
> (It smells new and has a white box)
> On query the seller says
> "I forgot to attach a label explaining that the unit has incorrect
> printing on it. The unit has correct specs."
> Is it safe to plug it in to my precious Newton? Is there some other way
> to test it? Has anyone had experience with this power adapter?
> tia
> David
-- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries Official Newton FAQ: http://www.chuma.org/newton/faq/ WikiWikiNewt for all kinds of articles: http://tools.unna.org/wikiwikinewt/
This archive was generated by hypermail 2.1.5 : Wed Jun 16 2004 - 06:00:01 PDT