Alt-BEAM Archive

Message #10651



To: beam@sgiblab.sgi.com
From: Bernard Nazari Bernard.Nazari@jpl.nasa.gov
Date: Tue, 22 Feb 2000 11:05:56 -0800
Subject: [alt-beam] Walker problems


Hey all,
Well, I finally bought the RC servos for the walker the other day and for
some reason, they are just don't work....once in a while, they might turn a
couple of times, then the gait becomes fully saturated and the motors stop.
The next thing that happens is that they just barely 'click' when they are
suppose to be on, with not actual movement. I even stacked up to 4 of the
74HCT245's, but that didn't work either. (I couldn't get my hands on the
74HC245's...which might be the cause of the problem.) Without the motor's,
the circuit works great. With the cheap motors that I got surplus (just for
the sake of trying the circuit out), they work well with two of the
74HCT245's stacked. Now when I stick on the servo's, they just either don't
work, or they go into fully saturation and then they don't work. The
servo's drink about 150 mA's, which should mean I could stack 3 or 4 of the
245's and be in the clear by far. I am going to try to get some of the
74HC245's, (which I think have a wider range of input voltages.) The 7805
didn't change anything, so I didn't try that for long. Any ideas on what I
can do? Is it common for servos to use that much power? How many of the
245's can I stack? Is there something I can use that's not the 245, that
can handle higher load? Is the H-bridge something I should be looking at?
Take care and thanks in advance!
Bernie



10652 Tue, 22 Feb 2000 12:14:16 -0700 [alt-beam] Re: BEAM: Tendency toward miniaturization beam@sgiblab.sgi.com Robert Stein At 10:16 AM 2/22/00 -0800, you wrote:
>No, I don't think so. You can't honestly believe that genetic material
>makes one act a certain way. You are taught whether intentionally or
>unintentionally whatever it is that make you you, throughout your lifetime.
>Modern American psychology upholds this belief.

I would take anything from "modern psychology" with a huge grain
of salt. Look at the history of this science (insert cringes and grimaces
at this misrepresentation......just my opinion..no flames on this one),
there have been "modern" beliefs that are total crap. Besides we hardly
know nothing of the brain. That is simple truth. Heck we hardly know
anything about moth brains, and they are simple comparatively. It has been
shown that the core of human behavior IS passed down through the genes, but
that "core" can be influenced by outside forces ie social pressures.


> Now I can understand that maybe someone who reacts to stress with say an
> ulcer, may have children who
>react in the same way....but when it really comes down to it, a violent
>person TEACHES his/her children to react violently...it isn't just passed on
>through genetics. Twin studies have proven this to be more than often true.

And what about those that act out violently without this
"teaching". This just brings up the point that we know very little about
the brain and how it develops, and are far from getting close.


>Sorry...don't mean to get my feathers ruffled up....I just can't fathom that
>my personality was passed on from my parents by any means other than good
>old fashioned authoritative teaching.
>
>Dane Gardner

I agree that the projected personality was, in part (don't forget
other social influences), shaped by authoritative teaching. There had to
be a core personality to you when you were first born. Ask people with a
newborns. They each have their own personality. I doubt that they started
authoritative teaching straight from the womb.



Robert


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