Re: [NTLK] Do I need the Apple AC?

From: Johannes Wolf (
Date: Wed Jul 31 2002 - 11:09:53 EDT

The other issue is that the Newton is very well matched to the
voltage/current characteristics of the original power adaptor.
So you can achieve optimum results for charging the battery inside the Newt
in case of you use the original power supply only.

The ideal alternative power adapter should have voltage regulation AND
active current limitation as well.

Most of the ac adaptors you can find are very simple - only one way
rectifier, no regulation, no active current limitation.
I do not recommend using such an adaptor.

If you use a regulated adaptor with an output of 6 V I do not expect any
risk for the Newt, but the batteries will charge very slowly.

If you intend to use an regulated adaptor with 7.5 V output voltage you
should be very careful regarding the max. charging current.

What I successfully did was using a laboratory power supply, set to max. 7 V
output voltage and max. 1A output current. But charging in this
configuration is still remarkably slower compared to charging with the
original power supply.

You should be very very careful doing experiments with different power
sources - I am burned already - I destroyed my MP2100 once completely.


> -----Original Message-----
> From:
> []On Behalf Of Laurent Daudelin
> Sent: Wednesday, July 31, 2002 4:41 PM
> To: NewtonTalk
> Subject: Re: [NTLK] Do I need the Apple AC?
> on 31/07/02 11:29, jrackley at wrote:
> > Just curious, if I were to purchase a messagepad missing the AC adapter,
> > could I just run down to radio shack and get an adapter that
> would work with
> > it? Or would I specifically need the apple version?
> You can basically use any adapter, as long as the power
> characteristics are
> acceptable for the Newton. So, you have to watch for the voltage and
> current, and also make sure that the tip's polarity is right. Quite a few
> things to match. If something is not appropriate, you could fry
> your little
> green friend. And out of specs adapters can also kill him. Out of specs
> means that, even if the adapter is rated for specific voltage and current,
> cheaper ones will deliver way more than what they're supposed to, which
> could be harmful to your Newton. That's why I guess the vast majority of
> users only use Newton specific adapter.
> -Laurent.
> --
> ==================================================================
> ==========
> Laurent Daudelin
> <>
> Logiciels Nemesys Software
> fiber-seeking backhoe: [common among backbone ISP personnel] Any
> of a genus
> of large, disruptive machines which routinely cut critical backbone links,
> creating Internet outages and packet over air problems.
> --
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