Re: [NTLK] External Power Packs for Newtons

From: Johannes Wolf (mp2100_at_mail-gw.estec.esa.int)
Date: Wed Apr 06 2005 - 05:10:01 PDT


Sonny,

sorry if I was not clear enough:

the most important criterium to decide whether an external power source
(booster pack) may be dangerous for the Newt or not is the VOLTAGE (to be
precise: the voltage difference between actual internal battery voltage and
external supply voltage).
The voltage drives the charging current and a too high charging current has
the potential to kill the Newt.

This is the whole theory behind.
Thats why as soon as you apply an external voltage above 6V - you can get a
nicely high charging current (that is a must for fast charging) BUT you have
to make sure that the charging current in no case exceeds 1.2 Amps. This is
normally done using current limitation.

conclusion:

As long as you are sure that your external power supply (whatever it may be)
does not provide more than 6V, you are fine and there is no risk for the
Newt to be damaged.
On the other hand you will get a quiet small charging current only, which
means long charging time.

Cheers
Johannes

> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net]On Behalf Of Sonny Hung
> Sent: Tuesday, April 05, 2005 3:43 PM
> To: newtontalk_at_newtontalk.net
> Subject: Re: [NTLK] External Power Packs for Newtons
>
>
> First off, does anyone use a external battery pack for their Newton on
> a regular basis?
> I am inquiring about anything other than the Newton Booster Pack or
> the specialized pack that was placed in the Newton 1x0 cases.
>
> I'm just fiddling around with a pack I bought and testing it out to
> see how long it lasts. My only concern is to understand the caution
> statement made by others regarding the recharging of the Internal
> Rechargeable Pack by this External Rechargeable Pack.
> Someone please clarify why this would be a problem - in laymen's terms...
>
> While testing my External Rechargeable Pack it has shown that it does
> indeed recharge the internal pack and IIRC the Newton drops to trickle
> charge after it's charged...
>
> --
> God bless,
>
> Sonny Hung
> the Hung Family
> --
> 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 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/


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