Alt-BEAM Archive

Message #07154



To: beam@sgiblab.sgi.com
From: "James Wilson" jameswilson11@home.com
Date: Fri, 29 Oct 1999 22:49:38 -0400
Subject: [alt-beam] Signing off for now



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Well as I finish packing for my move to Ga thats a brand new country for me=
I will be siginin off the list for a while. =


James :-))


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>
> >
> > If you are _honest_ you will not be affected in general. If you actually
> > intend to sell, just ask the individual (versus getting opinions of people
> > that don't know).
> >
> > Please again.. This list is for technical Robotics issues (not copyright
> > and patent law).
> >
> > Please get back on focus, if you have questions.. take it off-line.
> >
> > We have repeated this message on this specific subject numerous times.
> > All-in-all.. Be honest, respectful and ask the owners, not the list.
> > (No one is out to get you or out to make billions [all though that would
> > be nice], but rather anyone I know, is out to learn, develop new
> technology
> > and stop people from taking the technology away, so no one can use it).
> >
> > Mark
> >
> > >
> > > >>What makes you think the 'popper' design was ever protected by a
> patent?
> > > >
> > > >Popper design doesn't have to be. It's _copyright_. But that only
> applies
> > > >if they use the same circuit...
> > > So how different does it have to be? Just different values or a =
> > > slight modification to the circuit? Or more?
> > >
> > > Laterz
> > >
> > >
> > > --------
> > > There is only one true "SyNeT"
> > > BEAM Online - http://www.beam-online.com
> > >
> > --
> > Mark Dalton CH3-S-CH2 H H O H
> > Silicon Graphics, Inc. | | | \ |
> > Eagan, MN 55121 CH2-C-COO //\ ---C--CH2-C-COO C-CH2-C-COO
> > mwd@sgi.com | | || || | // |
> > NH3 \\/ \ / CH NH3 O NH3
> > NH
> > My home page: http://www.cbc.umn.edu/~mwd/mwd.html
> > Cell Biology: http://www.cbc.umn.edu/~mwd/cell.html
>


--
Mark Dalton CH3-S-CH2 H H O H
Silicon Graphics, Inc. | | | \ |
Eagan, MN 55121 CH2-C-COO //\ ---C--CH2-C-COO C-CH2-C-COO
mwd@sgi.com | | || || | // |
NH3 \\/ \ / CH NH3 O NH3
NH
My home page: http://www.cbc.umn.edu/~mwd/mwd.html
Cell Biology: http://www.cbc.umn.edu/~mwd/cell.html



7156 Fri, 29 Oct 1999 21:56:45 -0500 (CDT) [alt-beam] Re: Micro Motors, Skitters, and BeetleBots beam@sgiblab.sgi.com Mark Dalton
I do not censor ANYONEs postings.. Stop spreading false information.

THe focus of the list is Robotics, not patents and legal issues,
there are entire newsgroups that focus on these..

As we have spoken about this MANY times before, this is not really
a robotics or technical issue.

Again, if you have moral character, you will not violate the patent
or any copy rights. Any respectable person or company before selling
anything will do the proper research, contact the appropriate people,
and will do things legally.

Mark

>
> In a message dated 10/29/99 8:15:37 PM Eastern Daylight Time, mwd@sgi.com
> writes:
>
> > Look.. lets get off this silly stuff, and move to _TECHNICAL_ issues.
> Amazing how this subject gets squelched almost immediately, but discussions
> about bench accidents and old computers rule the band width for days. This is
> a very popular subject because the Patent made it that way by existing in the
> first place, and no one is allowed to discuss it openly in a public forum.
> Also, Mark D. I would appreciate it if you did not censor my postings by
> allowing this one, at least, to go through. That kind of selective censorship
> smacks heavily of fascism and is abhorrent in any venue.
>
> Jim
> http://www.geocities.com/SoHo/Exhibit/8281/beamart.html
>


--
Mark Dalton CH3-S-CH2 H H O H
Silicon Graphics, Inc. | | | \ |
Eagan, MN 55121 CH2-C-COO //\ ---C--CH2-C-COO C-CH2-C-COO
mwd@sgi.com | | || || | // |
NH3 \\/ \ / CH NH3 O NH3
NH
My home page: http://www.cbc.umn.edu/~mwd/mwd.html
Cell Biology: http://www.cbc.umn.edu/~mwd/cell.html



7157 Fri, 29 Oct 1999 20:53:50 -0700 [alt-beam] Re: Bicores...some technical questions beam@sgiblab.sgi.com Sean Rigter
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Hi Elmo,

Here is a simple animation of a bicore schematic that uses a range of
colors between red and blue to illustrate the principles of BEAM circuit
operation. In this example I used 5 colors representing: RED=V+,
ORANGE=3/4V+, YELLOW=1/2V+, GREEN=1/4V+, and BLUE=0V. The changing colors
indicate the charging and discharging of the capacitor voltages at the
bicore inputs and the rapid change in output (and input) state when the
input voltage crosses the 1/2V+ switching threshold. This should give you
some idea how the voltages at the inputs affect the outputs of a 74HC240.
If this is useful, I will add a set of 4 waveforms next to the schematic to
simulate an oscilloscope screen.

Of course this simple bicore simulation using Paint Shop Pro Animator is
just a start. Java applets with buttons to adjust variable resistors or
light sources shining on simulated photo diodes etc would give a much
better graphic simulation of beam circuit operation. Would anyone be be
willing to develop this into an (open architecture) beam circuit simulator?

Next here are some answers to the questions you raised.:

Elmo wrote:

> Hi there everyone,

> So i thought i would post a few questions to the list to see who knows
> what.

> So here's what i want to find out:
>
> I am assuming that larger cap values in the basic bicore circuit
> increase pulse width and smaller resistor values will increase the
> frequency. Am i right?
>

These are two related ideas:

1. The frequency of both outputs increases when the capacitor or resistor
values decrease.
2. The period is the time for one high/low cycle.
3. Pulse width depends on your definition: the "on" or "high" time of one
output is equal to the "off" or :low" time of the other output. They are
said to be complementary outputs.
4. Pulse width of the "on" time can be expressed in time units but in beam
circuits, it is better defined as a percentage of the period ie 50%
pulsewidth = symetrical on/off time. This is also known as duty cycle.

>
> Would it be better to have a circuit that has a fixed frequency and
> variable pulse width or fixed pulse width and varible frequency?

fixed frequency with variable duty cycle is perfect for beam applications


>
> Is it better to drive a bicore circuit at higher frequencies or lower
> frequencies?

A bicore used for a walker must have a frequency or more precisely a period
which gives the right angle of rotation for the legs.
A bicore used for a head must have a frequency which is high enough to give
smooth rotation. The dutycycle determines the direction of rotation ie
25%=left, 75%=right and. 50% duty cycle stops the head rotation.


>
> Is the resitance of the motor meant to affect the oscillation or pulse
> width of the circuit?

Resistance of the motor should have no direct effect on frequency but may
provide feedback to decrease the pulse width when the motor is "loaded" in
the direction of rotation.

>
> Why are bicores built using high pass oscilators rather than then more
> common low pass?
>
> i.e. High pass -||---|>o- Low Pass -R---|>o-
> | |
> R =
> | |
> gnd gnd
>

The bicore is a modern version of the ancient vacuum tube crosscoupled
astable multivibrator design which itself was named after a type of
mechanical vibrator used for example in Henry Ford's model T ignition coil.


>
> Most people seem to add extra inverters into the baasic circuit to
> increase the current output to the motors. Why do they add extra caps
> into these parts of the circuits rather than just adding extra inverters
> in paralell at the output of each of the main oscilating part of the
> circuit?

The caps you refer to could be part of a slave bicore or a monostable stage.



hope this helps




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7158 Sat, 30 Oct 1999 02:37:45 EDT [alt-beam] Re: Micro Motors, Skitters, and BeetleBots beam@sgiblab.sgi.com JVernonM@aol.com Weird, weird, weird. I just got this message from the server at 2: 30 in the
morning, but I sent it to the list at 12:30 in the afternoon! That's a 14
hour lag time. Several messages where sent after, but arrived on the list
almost immediately. Where the heck was this one all that time? And they say
the speed of light is a universal constant.

In a message dated 10/30/99 2:05:31 AM Eastern Daylight Time,
JVernonM@aol.com writes:

> > But the patent did run out so theres no problem with this kind of thing
> > right? Or did I miss something?
> >
> Yep, I think you did. This seems to be what a lot of people are thinking.
> The
> Patent did indeed expire. I have my doubts as to what it protected anyway.
> If
> you read the thing, you would have seen that it was all about an analog
> controller utilizing timed pulses to move robotic actuators. I never
> understood the legality of this since Walters was doing that 50 years ago.
I
>
> just don't think it would have held up under the double speak of the
modern
> court room. The real issue here, and always was, one of copyright. You
know,
>
> that little symbol or blurb at the bottom of all those schematics. That is
> the real protection, and thanks to Clinton, is automatic. It not only
covers
>
> Mark's circuits, it covers Wilf's, Steve Bolt's, and Craig Maynard's. If
you
>
> sell a product using one or more of these circuits, you are deep in legal
> territory. Patent or no patent. Which, in my opinion, is why the patent
was
> no longer maintained. It was useless fluff. It was undefendable in court.
> And
> it was completely unnecessary when compared to the protection of
copyright.
> So, I would humbly suggest anyone planning to sell these circuits, check
> with
> the author first.
>
> See ya,
> Jim
> http://www.geocities.com/SoHo/Exhibit/8281/beamart.html
>



7159 Sat, 30 Oct 1999 16:51:53 +0000 [alt-beam] Time Capsules beam "Ben Hitchcock" All,

I had an idea a couple of months ago regarding the possibilities of BEAM
technology.

Simply put, it's a BEAM time capsule.

Picture this:
In 50 years time, someone is digging around their backyard, putting in the
foundations for a new patio. The backhoe unearths a strange metal cube,
very strongly constructed. The operator gets out and takes a look at it.
It has no obvious method of opening, and the purpose is unclear. It has an
old fashioned amorphous silicon solar panel on one side, underneath some
thick glass. He wipes all the earth off the object, then looks at it some
more.

Baffled, the operator sits it down on the porch of the house, then gets back
to work.

A couple of hours later, the operator finishes his job, and goes inside to
tell the owner of the house about the strange object. They come out, and
the object has opened, revealing some mysterious compartment and circuitry
inside. The compartment is empty.

Some movement catches the owner's eye - it's a small robot that has wandered
almost to the edge of the porch and is about to venture onto the garden
path.



Sound like science fiction? Maybe. But think about how you could implement
something like this. Even putting one of your small robots into a film
canister and burying it to dig up later would be pretty interesting. I have
a solar panel here that puts out about 7 volts, and is about 20 cm x 20 cm,
and would be ideal for the case of the unit. It has an aluminium frame, and
is protected by glass. It would be perfect for something like this.

Of course, to make a robot that will later 'revive', you have to really
engineer a reliable solution. For example, tantalum capacitors are renowned
for not lasting a long time, as are the electrolytic caps normally used as
storage caps. We need some sort of cap (like ceramic) that will last a long
time without raising the leakage current value too much. The other
components aren't much of a problem - transistors will last for ages, as
will resistors. The two problem areas are the solar panel and the
capacitors. Maybe those capacitors that look like silver coins would be
good for the job - I seem to remember that they don't have an electrolyte,
but instead have some sort of ceramic with lots of holes in it.

Hopefully someone can shed more light on which types of these components are
best suited for the task.

Ben Hitchcock



7160 Sat, 30 Oct 1999 00:26:08 PDT [alt-beam] Re: Micro Motors, Skitters, and BeetleBots beam@sgiblab.sgi.com "Timothy Flytcher" >
>No we have just beat this to death a few times.. And really if you are
>ethical it is not a issue.
>
>Mark

Ok Mark, what dose ethics have to do with the free market??? Are we not all
benefiting from some ones "better, faster, cheaper"??? Last I looked I
didn't have a motel T ford... Are we or are we not seeking evolution???
Timothy...

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7161 Sat, 30 Oct 1999 00:38:14 PDT [alt-beam] Re: Time Capsules beam@sgiblab.sgi.com "Timothy Flytcher" Ben,
what about the magnets in the motors??? would the motors still run after ...
say 30 years???
>
>I had an idea a couple of months ago regarding the possibilities of BEAM
>technology.
>
>Simply put, it's a BEAM time capsule.
>

______________________________________________________



7162 Sat, 30 Oct 1999 03:41:35 -0700 [alt-beam] Dave beam@sgiblab.sgi.com Greg Powell BEAMembers:

I am curious. I have just built the SolarSpeeder kit from Solarbotics. It
flies! I breadborded the exact same solar engine (the 1381 voltage trigger
type) with a 4700uF, 6.3 volt capacitor and a Namiki motor and the same size
solar panel. It is not impressive at all. It pulses briefly at regular
intervals whereas the SolarSpeeder charges for a considerable time and then
flies off like a pocket rocket. It is because of the voltage rating of the
capacitor? Does the higher voltage rated cap not store as much charge? The
SolarSpeeder has a 2.5 volt 3300uF Gold cap; nice cap! Expensive though.

Any knowledge would be much appreciated :)
Greg

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