Alt-BEAM Archive
Message #02404
To: beam beam@corp.sgi.com
From: Sean Rigter rigter@cafe.net
Date: Fri, 16 Apr 1999 19:04:08 -0700
Subject: [alt-beam] Re: SE / alf circuit variation..
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Hi Darrell,
Your design should give better performance/lower parts count, since the
pulse generator current is higher than 5 uA. The 1381 circuit will also
cost more, which others addressed by designing this part out of the
circuit in the first place. But if you got it, use it 8^)
I'm not sure about the output structure of the 1381 you are using but if
it is a push/pull output then adding a 100K to 1M resistor as shown is
desirable to limit the current when the 1381 output goes low again and
the diodes have to source current or more likely, the circuit resets on
the basis of the 1381 hysteresis rather than the forward voltage of the
diodes. I believe there are several different types of output depending
on the part suffix. If the active high/open collector version is used,
then a 100K to 1M resistor from the output to GND should be used
instead. The value of the resistor will determine the dropout voltage
for the latch with higher resistor values resulting in lower voltage
level before the latch resets and the circuit starts the next charging
cycle .
enjoy
wilf
Darrell Johnson wrote:
>
> ok.. I've been messing around with the SE part of the alf circuit, and
> think I might have an improvement:
>
> Instead of the pulse generator and the series of diodes to trigger the
> latch, why not use a 1381 to start it. The 1381 only uses between 1 and
> 5 uA during operation, while getting rid of 2 resistors, a capacitor,
> and 4 diodes.. as well as freeing up 2 inverters on the 240.. (this is
> based on the bivore schematic by Justin Fisher)
>
> I've attached a 2k .gif file of the circuit... Let me know what you
> think, as my electronics background is a bit shaky.. I have breadboarded
> it, and it *does* work, so it's not just a theory..
>
> -darrell
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2405 Fri, 16 Apr 1999 20:36:24 -0600 [alt-beam] Re: Beam genome - waste of time.... beam Dave Hrynkiw At 05:52 PM 4/16/99 , Sean Rigter wrote:
>> > But consider how Beamers and Beam technology would benefit from such a
>> > (genealogy) document.
>
>> Exactly, and that's the real reason for doing it. Get it straight, write it
>> down, and let everyone interested benefit from the history and how they can
>> add to it.
Sorry guys, but I just don't understand your need to classify the whole
"BEAM" thing. I think a fundamental flaw with it is that it won't be used.
It doesn't matter if a genome would be possible, practical, or appreciated.
My impression is that people want to sit down, build their own little
robot, and appreciate it for what it is. I can't say how many times I've
seen or heard "Boy, that Spyder robot is cool - I want to build one of my
own!". Ditto for many of the other of (mainly) MarkT's creations. And a
genome won't cut it for helping them build one - they want plans and
schematics. I'm guilty of that too - I've constructed knock-off's of other
people's work (Randy Sargent's Herbie; Mark's 2 motor BigFoot; and others),
and a genome was in no way of help or interest to me in this regard.
Perhaps it would be of use in a University or research setting, but we're
talking mainly about BEAM hobbiests that couldn't care less if it's been
done before - they want to try it themselves and build on that work. And
we've seen these results in the variations of Photovore development in the
last "Fang" contest. A much better use of time and energy.
Carry on if you want to develop a genome, but don't count on my
participation. I'd rather be at the workbench rather than developing
classifications...
Sincerely,
Dave
ps: This isn't a slam/flamebait. Just voicing my opinion...
---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com
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