Alt-BEAM Archive
Message #05100
To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Steven Bolt sbolt@xs4all.nl
Date: Thu, 8 Jul 1999 10:36:55 +0200 (CEST)
Subject: [alt-beam] Re: Supercaps
On Wed, 7 Jul 1999, Wilf Rigter wrote:
> In the latest Newark Electronics Cat.117, page 83
> ELNA super caps
> DZ series - radial lead
> 100F @ 2.5V $81.10
Boggles the mind. Tad expensive, too - may not compare well with an
NiMH battery.
> and perhaps more interesting
> DC series - coin
> 2.2F@2.4V $3.12 (5/8" diameter by 1/16" thick)
Caps are basically two strips of foil rolled up together. Current
is taken from the ends, so narrow strips deliver less current than
wide strips.
In tall caps with a small diameter, the strips are wide and
relatively short --> less internal resistance, more current for
your motors.
In coin type caps with a large diameter, the strips are very long
and narrow --> high internal resistance, not good for the usual
BEAM applications.
Just thought I'd mention it.
Steve
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# sbolt@xs4all.nl # Steven Bolt # popular science monthly KIJK #
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