Alt-BEAM Archive
Message #01444
To: "Steven Bolt" sbolt@xs4all.nl, beam@corp.sgi.com
From: "Ed Jones Jr." sargon@gte.net
Date: Thu, 11 Mar 1999 01:54:42 -0500
Subject: [alt-beam] Re: Seiko Thermic Watch
Dear Steven,
Popular Science ,April 99 , Pg.# 17, shows a watch that runs off a persons
body heat . Extra power is diverted to a storage cell that keeps the watch
ticking for up to 10 months even while it's off your wrist . ( price= a
whopping $ 2,600 !! ) Is there anyway we could not only use a solar cell to
collect energy but to somehow use the sun's heat to power our beam bots as
well ? Any thoughts ??
Ed Jones
sargon@gte.net
----------
> From: Steven Bolt
> To: beam@corp.sgi.com
> Subject: Re: Surface mount H-bridge chip
> Date: Wednesday, March 10, 1999 9:18 AM
>
> On Wed, 10 Mar 1999, Ben Hitchcock wrote:
>
> > What I do for a solar powered reversing circuit is to have an enable
> > transistor that switches the power on to the H-bridge when the motor
needs
> > to be run.
> ---8<---
>
> The disadvantage of that idea is that you get three instead of two
> VCEsats in series with your motor. Yes, it's only another 0.1V or
> 0.2V, normally, but when the `bot really needs power it will add
> up to between 0.5V and 1V or even more.
> If solar power is used, imho it is best to drive all four bridge
> transistors individually, using 74HC logic to get the states you
> want. For instance, if `non-smoke' is required you might do something
> like this:
>
> http://www.xs4all.nl/~sbolt/Other/Hlp-bridge.gif
>
> Best,
>
> Steve
>
> ----------------------------------------------------------------------
> # sbolt@xs4all.nl # Steven Bolt # popular science monthly KIJK #
> ----------------------------------------------------------------------
>
>
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