You can really believe me,
and I am talking here as an electrical engineer:
If you are going to use such a cheapo adaptor with your Newt
1) you still might be lucky enough not to kill your Newt
2) in most cases you will have a big mismatch between the source impedance
of the power adaptor and the Newt resulting in very slow charging or no
charging at all (if the adaptor is not powerful enough - in your case)
The Newt is designed to work perfectly with the original power adaptor and
the battery charging is exactly matched to the output behaviour of this
adaptor:
you have constant voltage up to approx. 1 A and then the current limitation
comes into play.
In other words: if you use an adaptor with output parameters different from
the original adaptor there are exactly two possibilities:
1) you toast and kill your Newt
2) you can charge the batteries only very very slowly or not at all
Thats why I had the idea to design an adaptor which matches perfectly to the
Newt and allows you to use any dc source from 8 to 40 Volts 1 A minimum.
This can be done using only one regulator chip and a few external parts.
I am currently in the phase of testing it.
Regards
Johannes
> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net]On Behalf Of Glen Warner
> Sent: Friday, November 08, 2002 9:51 AM
> To: newtontalk_at_newtontalk.net
> Subject: Re: [NTLK] Generic AC adapter
>
>
>
> John Acuff <jacuff1_at_earthlink.net> wrote:
>
> > On Thursday, November 7, 2002, at 06:57 PM, im-wired_at_attbi.com wrote:
> >
> >> Greetings from Oregon!
> >>
> (*snip*)
> >
> > I use an old Radio Shack adapter that i had laying in my pile of
> > "wall-warts". 7.5 VDC @ 700ma, tip +, sleeve-. I did have to change
> the
> > plug to one that matches the Newt (2100).
> > Been using it for a couple weeks now with no problems.
>
> (*snip*)
>
> I've also been using a RadioShack adapter (meant as a replacement for
> the adapter for a digital camera) with no problems -- at least, on my
> eMate and 2100.
>
> BUT .... just in case, I installed Newt's Battery on both of my Newts
> ... keeps track of battery temperature, chargeing current, etc. ...
> but its indicator says my newt is 10% charged, and when I unplug the
> charger, it shows full.
>
> Perhaps I need another battery monitor ....
>
> (*snip*)
>
> --gdw
>
> > John
>
>
>
> --
> This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries
> List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html
> Official Newton FAQ: http://www.chuma.org/newton/faq/
>
-- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html Official Newton FAQ: http://www.chuma.org/newton/faq/
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