Alt-BEAM Archive

Message #05645



To: beam@sgiblab.sgi.com
From: "Simpson, Bob" BSimpson@msx.advsys.com
Date: Wed, 11 Aug 1999 17:23:40 -0400
Subject: [alt-beam] To Schmitt or no to Schmitt ...



Many explanations of microcores claim the necessity of Schmitt inverters,
but other similar circuits are built without them? In fact, some sites say
that the Schmitt piece is vital, but then go on to show all the circuits
built around the 74x240 chip, which doesn't have the Schmitt triggers. What
gives?

-Bob



5646 Wed, 11 Aug 1999 14:30:32 -0700 [alt-beam] Re: LEM videos now on-line. beam@sgiblab.sgi.com Chiu-Yuan Fang As am I...

Darrell Johnson wrote:

> Sorry for venting.. just kind of disappointed by the turnout..

--
Chiu-Yuan Fang
chiumanfu@home.com
ICQ=5614919
http://www.geocities.com/SouthBeach/6897/beam2.html



5647 Wed, 11 Aug 1999 17:39:08 -0400 [alt-beam] Re: "Linear Wheels" (was: LEM videos now on-line) beam@sgiblab.sgi.com "Mark W. Noakes"
>At 11:31 AM 08/11/1999 , Sean Rigter wrote:
>
>>I found that net linear motion does results in my 3 motor design but is very
>>inefficient with a lot of wheel dragging and slipping resulting in high
>>frictional losses compared to, for example, Bolt's 2 motor design!
>>These losses are caused by the "toe in" of the 3 wheels which oppose
>> all net linear motion. Even if one wheel is held perfectly stationary
>>causing
>> the platform to rotate about that relatively low friction pivot point , the
>> sideways dragging and slipping between wheel and
>>surface (ie friction losses) of the other 2 wheels is very high.
>>
>>So my question are:
>>
>>Am I missing something?
>
>This might have no bearing (pardon the pun) on what you are talking about,
>Sean, but I strongly suggest that you take a look at a two
>degree-of-freedom "linear wheels". They are more complex than everyday
>wheels, but they ARE free to move (with quite low friction) in directions
>other than the driving direction. See:
>
> http://carol.wins.uva.nl/~leo/lego/killough.html
>
>for the basic description and the following mpg movies to see the Killough
>platform in motion:
>
>http://www.net-info.com/~dcarlson/klw1.mpg high resolution/shorter
>length movie
>http://www.net-info.com/~dcarlson/klw2.mpg low resolution/longer
>length movie with several different motions
>
>
>
>Zoz
>


Zoz,

This is cool to see Steve Killough's stuff mentioned; I work with Steve and
am very familiar with this approach.

Mark Noakes
====================================
Mark W Noakes
Robotics & Process Systems Div
Oak Ridge National Laboratory
PO Box 2008, Bldg 7606, MS-6426
Oak Ridge, TN 37831-6426
Phone:423-574-5695 Fax:423-576-2081
Email: mqn@ornl.gov
====================================



5648 Wed, 11 Aug 1999 23:49:07 +0200 [alt-beam] Re: list problems beam@sgiblab.sgi.com, bot@yahoo.com Roters I have the same problems. I mailed this problem to
'beam-approval@postofc.corp.sgi.com' and 'beam@sgiblab.sgi.com' but i
got no
solution or even an answer.

hope you get a solution, bacuse it's no fun to get about 30 mails every
day.
keep cool,
christoph roters

Travis D. schrieb:

> Hey everyone...
>
> sorry to send this to the list, but I'm having trouble
> signing of the list. I tried signing off from the
> majordomo list, but it said that there was no 'beam'
> club. I've been looking around w/o success to find a
> way to sign off. A suggestion would be greatly
> appreciated.
>
> Thanks,
> Beam_bot
> _________________________________________________________
> Do You Yahoo!?
>


5649 Thu, 12 Aug 1999 08:59:20 +1000 [alt-beam] [Fwd: Thermo-PV cells-candle powered radio] beam@corp.sgi.com television_is@mindless.com Is this candle discussion connected to this??
Wilf If the candle can power a radio can't it power a solarengine?

This is a site with some explanation of the different types of solar
cells. About halfway down this page there is a candle powered radio
using cells designed to take advantage of infra-red from heat (as far as
I gather). http://153.96.32.2/Projects/Solcells98/kap54.html

http://www.ise.fhg.de/ is the main page of Institute of Solar
Engineering

Rob



5650 Tue, 10 Aug 1999 00:16:40 -0500 [alt-beam] Re: BEAM contest question. beam@sgiblab.sgi.com SG I'd like to send you a pic (not the list) of a 4 motor cat (poodle?) size
aluminumn Tildon bot that I'd like a try at copying. big bots can be fun
too!

ALSO: I'm happy er.. no lets say EXSTATIC to report that all the bugs are
werked out of LOTUS my 2 motor walker. Little guy werks perfectly and
walks very straight. Speed is about 5FT at 12 seconds on charged batteries.
I even had the audacity to improve on Ian's homade tactile sensor, but
more on that later.
now i just have the boring part... trimming and tucking all the extra wire!
-Sparky

At 06:52 AM 8/10/99 -0700, you wrote:
>I have talked about it in BEAM chat once or twice. I
>haven't really worked on it lately. I've been having
>problems with controllers and the big motors I'm
>using.
>Currently I'm waiting on that, still haven't adapted
>the motors for the frame yet.
>
>
>
>--- SG wrote:
>> At 05:57 AM 8/10/99 -0700, you wrote:
>> >Thats fine I have one of those too
>> >
>>
>> Really? i would love to see a pic of your werk
>> on this.
>> -Sparky
>>
>>
>
>===
>Everything I say can mean one of two things...If something I say makes you
mad....I meant it the other way.
>
>James Taylor
>URL: http://fly.to/springmeadows
>_____________________________________________________________
>Do You Yahoo!?
>Bid and sell for free at http://auctions.yahoo.com
>
>

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