Re: [NTLK] Moving away from MP2K internal charging

From: Joel M. Sciamma (joel_at_inventors-emporium.co.uk)
Date: Fri Oct 22 2004 - 03:24:14 PDT


Hi David,

> By far the greatest failures of a 'modern' device like the Newton would be
> due to 'tinkering' or operation outside the intended envelope.

One of the machines (belonging to a friend) I have known since it was new
and was never abused. This could have been simple component failure.

The other two were not known to me before they were presented with this
problem so might have been abused but both owners only had the Apple
adaptors (9W) with their machines.

> Now we can start the urban legend that emate will explode sooner or later -
> even if the correct PSU is used.

> Things are not always as they first seem.

I have no desire to start any kind of urban legend and fully agree that this
assumption I have made, for my own personal reasons, is not proven.

The only way to get more data is to allow machines to fail with this problem
(if in fact they do) so that we have a chance to analyse a statistically
valid sample with known histories.

However, I would make three points:

1/. If the machine has been abused and is ready to fail in this way, then
not charging the machine internally may avoid the problem and one less
machine is affected. All our Newts are getting old have have mostly passed
through a number of hands, so if not charging internally lessens the chance
of damage, then it seems like a reasonable precaution.

We have no schematics so making a rational determination of the issue is
very tricky.

If owners, understanding that this idea is unproven and only my suggestion,
decide to continue with internal charging, then that's fine.

2/. The change in approach I have adopted does not require one to modify any
part of the Newton or its accessories and has no 'voodoo' connotations with
dodgy engineering or a sales pitch. Because of the way the MP2K is designed,
this is a supremely easy option to adopt.

I have no knowledge of failures of the kind I have described with any other
Newton model, including the eMate, which I continue to charge internally and
which probably has very similar circuits to the MP2K.

3/. I actually much prefer this new system than internal charging. A swap of
batteries for a charged set means the Newt is back in business in a few
seconds at home or in the field. Swapping out old cells for higher capacity
ones is an absolute doddle (especially compared to maintaining the
rechargeable packs) and the Newt is spared getting cooked. My LCDs needed
contrast readjustment in summer after a charge cycle because that whole
region was heated.

A battery tray-based approach allows you to use readily available batteries
worldwide, so no need to carry a charger on your hols. A set of good
Alkaline batteries gave me two months of daily use.

Best regards,

Joel.

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