Alt-BEAM Archive
Message #01448
To: "Ed Jones Jr." sargon@gte.net, Steven Bolt sbolt@xs4all.nl,
From: dennison dennlill@buffnet.net
Date: Thu, 11 Mar 1999 06:44:09 -0500
Subject: [alt-beam] Re: Seiko Thermic Watch
I don't think we can use thermal differences to get enough power to run our
robots. Thermocouples only work well when you have the difference between
like A peice of radioactive isotope and the coldness of space. Remeber,
watches are some of the most precision machines availible in the free world.
It may not seem like it's too big a deal, a good watch, but it is. The
companys go through untold money on research to build that better watch. As
a result watches take SUCH ENORMOUSLY small quantities of power to run, that
you can actually get away with it running ona thermocouple, or kenetic
energy, or water. Stuff like that.
Dennison
>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 #
>> ----------------------------------------------------------------------
>>
>>
------------------------------------------------------------------------
eGroup home: http://www.eGroups.com/list/alt-beam
Free Web-based e-mail groups by eGroups.com
Home