From: Johannes Wolf (mp2100_at_mail-gw.estec.esa.int)
Date: Mon Apr 04 2005 - 02:15:38 PDT
The only thing I can tell you for sure is that for the electrical interface
the power adapter specifications do apply.
Thinking about an external power pack - one problem is to avoid charging of
the internal rechargeable pack while having the external booster connected.
This can be solved easily if you
a) use a standard (not modified) battery tray with alkalines or
rechargeables
b) there is possibly a way to prevent the Newt from charging via SW
As far as the solution for the external power pack is concerned I could see
a high efficiency dc/dc converter, providing the correct output specs for
the Newt (in case you prevent the Newt from charging, the requirements
regardig current limitation are much more relaxed).
In principle you are free to do what you like then:
either you choose a higher battery voltage (12V) to feed the converter (that
can be a simple buck converter in that case) or you decide to boost a lower
battery voltage up to 7.5V.
The most important things are:
1) to stabilise te output voltage to 7.5V max.
2) to prevent the Newt from charging, in this case the current limitation
required for the ac power adaptor is not important and not really needed.
Cheers
Johannes
> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net]On Behalf Of Sonny Hung
> Sent: Saturday, April 02, 2005 5:30 AM
> To: NTLK
> Subject: Re: [NTLK] External Power Packs for Newtons
> Not sure if this was discussed before or if anyone has a solution yet
> regarding an External Power Packs for Newtons other than the Booster
> Pack that was designed for the OMP/MP100 wich used AAA batteries.
> I also recall there were packs that were used with the MP100 and the
> MP1x0 series externally that fit in the Leather Communications Case
> that had a connector to plug directly into your Newton.
>
> I have a decent suggestion for one but wanted to know if anyone on the
> list has tried in the past or present to use something to power their
> Newton other than the stock rechargeable, booster or specialized pack
> that fit in the case I mentioned above.
>
> Of you know of anything give the specs, possible manufacturer and any
> other details that would help everyone out... it seems that people are
> selling on eBay, others are re celling on list but officially there
> are no current manufacturers of pre-made pack for the Newton.
> Sonny Hung
> the Hung Family
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