Alt-BEAM Archive

Message #09751



To: "beam mailing list" beam@sgiblab.sgi.com
From: "David Perry" davidperry@geocities.com
Date: Fri, 4 Feb 2000 13:45:01 +1100
Subject: [alt-beam] 25ma motors in OZ



content-transfer-encoding: quoted-printable

As much as i hate dick smith electronics occasionally they do have good bar=
gains and products.
They now have a motor at $2.95 that uses 1.5v at 25ma - designed for solar =
applications. It's a little big but it should work.

David


content-transfer-encoding: quoted-printable






> with possibly an h-bridge motor driver, ...

Sparky built a very nice one, using the circuit at Beam-online. Take a
look at:

http://www3.telus.net/rfws/beam/sparky/index.html

Bruce



9754 Thu, 3 Feb 2000 21:50:25 -0800 [alt-beam] Re: The 240 microcore - was Bicore question "'beam@sgiblab.sgi.com'" Wilf Rigter 74HC240 is a octal buffer so you get more gates and more drive in one chip
compared to a 74HC14.

It is however quite possible to make a suspended bicore with a 74HC14 but
you must use two unequal capacitors ie 0.22uf and 0.47uf to force the input
with the smaller cap to have a sufficiently large voltage swing to cross the
upper and lower Schmitt trigger thresholds.

The question of microcore versus bicore is almost a philosophical one:

A master slave bicore with a reverser circuit can be constructed with one
chip. The bicore operates in the saturated mode anyway so there's no need
for a PNC. It is barely possible to drive very small motors directly from
the output of bicores in which case there is no need for a motor driver
stage.

On the other hand, the microcore behaves more like a simple model of a
neural network with "processes" propagating from one neuron to the next,
each influenced by local sensor conditions .

Neurons, neurons everywhere and look at all those pulses!

Here is a little thought experiment: in an open ended 6Nv (74HC14) chain
with LED indicators, what is the maximum number of processes (output low
pulses/LED on) that can be active at a time? I have not tried this but I
predict that if you try to "stuff" more that 3 processes in a 6Nv chain some
interesting things may happen. Since each process is independently
controlled by a sensor, for example a photodiode, it is possible for the
first few Nvs to generate short pulses and later Nvs generate long pulses.
Now what happens when short processes collide with the longer processes? Is
each process still independent or do they interact? Like a microcore ring,
I'm sure the Nv chain can be "saturated" when the maximum duration of any Nv
pulse in the chain is dictated by the shortest process. To inject processes
into the chain, the first Nv can be "stimulated" with a beam flip-flop
triggered with a pushbutton. That way you can manually control the input
pulse widths to see the effect it has on process generation and propagation.
Longer chains of n Nv should be capable of maximum n/2 processes but no more
before saturating. A bottom up tree-like Nv structure would see a process
propagate down the trunk before radiating along the branches. Kind of
interesting stuff if you plan to control a complex sequence of motor motions
for example in a multi-jointed beam worm. What about a top down tree with
processes propagating down the branches toward the central neural chain
(trunk). Add some logic such that two processes must be counted or be
present at a junction where branches meet before processes can propagate any
further. With only one Nv triggered ie by a sound or light "event", the
process may die at the nearest junction but with many Nvs triggered,
processes join up at junctions and can reach major branches or the central
neural chain to activate some action ie fire a motor neuron.. How about some
memory (Nu) at the junctions so that the junction remembers the last process
and "sensitizes" the junction to lower the propagation threshold. How about
bottom-up and top-down Nv trees connected at each end in a branched but
closed loop structure like the circulatory system.

Well that's the nature of a thought experiment, ideas happen, propagate off
in different directions until one or more hit fertile ground and then you
gotta built and test it.

regards

wilf


> -----Original Message-----
> From: Senior [SMTP:kyled@cruzers.com]
> Sent: Wednesday, February 02, 2000 3:36 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: The 240 microcore - was RE: Bicore question
>
> Hey Wilf... ;)
> I've got the opposite problem:
> No '240's,
> Excess of '14's.
> How bout a 14 bicore? PSH? :)
>
> Laters,
> kyle
>
> SG wrote:
> >
> > WOOWW !



9755 Fri, 4 Feb 2000 02:14:08 -0500 [alt-beam] Re: The 240 microcore - was Bicore question "Dennison Bertram"

Here is a little thought experiment: in an open ended 6Nv (74HC14) chain
with LED indicators, what is the maximum number of processes (output low
pulses/LED on) that can be active at a time? I have not tried this but I
predict that if you try to "stuff" more that 3 processes in a 6Nv chain some
interesting things may happen. Since each process is independently
controlled by a sensor, for example a photodiode, it is possible for the
first few Nvs to generate short pulses and later Nvs generate long pulses.
Now what happens when short processes collide with the longer processes?

It's far to late for me to read all of this, :-) And I'm delerius from the
rollercoaster that person-life-problems bring. But anyway, by coincidence,
in the patent, or living machines, you can't really 'stuff' pulses. They
would act much like the 'rollercoaster' point in a closed loop. The output
of a neuron has less importance than the input, and regardless of the output
state, the input state will change the output. So it will simply, eject the
pulse. And if there is a whole string of uneven pulses around, they will
each just eject each other till they all fall out. Not really stuffing, just
sort of 'hyper-accelerating'. Anyway, that ends my experiment in thought.

:-)
dennison



Is
each process still independent or do they interact? Like a microcore ring,
I'm sure the Nv chain can be "saturated" when the maximum duration of any Nv
pulse in the chain is dictated by the shortest process. To inject processes
into the chain, the first Nv can be "stimulated" with a beam flip-flop
triggered with a pushbutton. That way you can manually control the input
pulse widths to see the effect it has on process generation and propagation.
Longer chains of n Nv should be capable of maximum n/2 processes but no more
before saturating. A bottom up tree-like Nv structure would see a process
propagate down the trunk before radiating along the branches. Kind of
interesting stuff if you plan to control a complex sequence of motor motions
for example in a multi-jointed beam worm. What about a top down tree with
processes propagating down the branches toward the central neural chain
(trunk). Add some logic such that two processes must be counted or be
present at a junction where branches meet before processes can propagate any
further. With only one Nv triggered ie by a sound or light "event", the
process may die at the nearest junction but with many Nvs triggered,
processes join up at junctions and can reach major branches or the central
neural chain to activate some action ie fire a motor neuron.. How about some
memory (Nu) at the junctions so that the junction remembers the last process
and "sensitizes" the junction to lower the propagation threshold. How about
bottom-up and top-down Nv trees connected at each end in a branched but
closed loop structure like the circulatory system.

Well that's the nature of a thought experiment, ideas happen, propagate off
in different directions until one or more hit fertile ground and then you
gotta built and test it.

regards

wilf


> -----Original Message-----
> From: Senior [SMTP:kyled@cruzers.com]
> Sent: Wednesday, February 02, 2000 3:36 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: The 240 microcore - was RE: Bicore question
>
> Hey Wilf... ;)
> I've got the opposite problem:
> No '240's,
> Excess of '14's.
> How bout a 14 bicore? PSH? :)
>
> Laters,
> kyle
>
> SG wrote:
> >
> > WOOWW !

Home