Alt-BEAM Archive

Message #10849



To: beam@sgiblab.sgi.com
From: "Sathe Dilip" sathe_dilip@bah.com
Date: Fri, 25 Feb 2000 11:09:56 -0500
Subject: [alt-beam] Re: shack caps


I can think of a few things (electronic) that can go bad with
time/storage.

Electrolytic capacitors: With time, the electrolytic dries up affecting
the capacitance. But his should take many years of storage with modern
manufacturing techniques. There is also some thing like depolarization
taking place with time. This increases the internal resistance of these
capacitors. But this can be cured with what is called forming -
charging the capacitor over a long duration. For a detailed text on
shelf life of electrolytics, try this page:

http://www.faradnet.com/deeley/chapt_06.htm#shelf

Some information on reforming can be found here:

http://www.angela.com/catalog/how-to/about_caps.html

Assemblies: If the solder used is corrosive & not properly cleaned, it
can eat away at the copper traces & component leads/joints.

I have also seen some gold plated component leads corroding badly. I
think this must be because of the intermetallic compound formation &
subsequent local battery cell like chemical reactions.

Semiconductors: Usually this class of devices should last long on the
shelf without problems except for surface tarnishing of pins etc.
However if you lose package integrity for some reason, lots of things
can go bad. For an example look at:

http://www.calce.umd.edu/general/demos/defects/defects/wbcorr.html

Semiconductors can also fail if exposed to electrostatic discharge or
high intensity electromagnetic pulses during storage/handling.

Printed circuit boards: Surface tarnishing of exposed metal surfaces.
Phenolic & Paper Phenolic types can warp.

Dilip
------------------------------------------
Daniel Grace wrote:
>
> Do electronics have a shelf life, without being in a
> circuit?? I've never heard of this . . . . then again,
> I've never delt with electronics from the 80's.
> Wouldn't the components still be good as long as they
> weren't in a circuit?
SNIP
----------------------------------------------------------------------
The early bird may get the worm, but the second mouse gets the cheese.
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10850 Fri, 25 Feb 2000 10:47:41 -0600 [alt-beam] Re: BEAM: Tendency toward miniaturization beam@sgiblab.sgi.com Richard Piotter Haha! Yeah, I've been meaning to bring that thing to the school and
finish the controller. I get to do the work and count it for class now,
which is one reason I waited on working on it. Other reasons include
broke, poor, moneyless, and very, very lazy! :)

Fortunately, In about a month, Quadrapod may get it's first infusion of life!!!

Stat tuned!!! Money and a day to sleep, followed by much less sleep is
on it's way soon! :)

Oh, and the "hopeful" date of the calc.org server's return is March 1st.
I hope it remains that. It got pushed back 2 days from the previous
date. Either way, there are new videos of Walkman and Bronco. I've been
playing around with Strata VideoShop, so it's got titles and fades. It
looks decent. Most pathetic part of the whole deal is the camera itself,
which is a micro color camera, but it works well enough and has
adjustable focus. I used a Roboticx set (those snap together plastic
pieces with the octagonal joints) to build a "Cambot". It features a
wheel for steering as wel as drive wheels and a motorized vertical
panning arm for the camera. I'm going to redesign it to use one drive
motor and one pan motor. Stupid thing comes with three motors but only 2
control switches. Either way, the videos are great, despite the poor
camera. They show the walking gaits well enough and what type of speed
the robots get. For reference, each tile on the floor is one square
foot, so every alternating tile line that's visible is 6 inches. Both
robots are about 4-3/4 inches long (12 cm).

I may put them up on my iDrive shared folder if there is enough interest
to see them before my web page goes back up.


> Richard, get thy Spyder in gear!
> It's time for a brain (or backbone) transplant! :)
>
> Peace out!
>
> Rob Rix
>
> This has been a recording.

--


Richard Piotter The Richfiles Robotics & TI web page:
richfile@rconnect.com http://richfiles.calc.org

-- Make Money by Simply Surfing the Net or responding to E-Mail!!!
-- Click below!!!

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10851 Fri, 25 Feb 2000 12:17:41 EST [alt-beam] Re: BEAM: Tendency toward miniaturization beam@sgiblab.sgi.com JVernonM@aol.com In a message dated 2/25/00 10:39:53 AM Eastern Standard Time,
rastein@dakotacom.net writes:

> Once you get
> the money, weather or not you soon determine viability, you spend the
> money. If not, it is harder than hell to get grants in the future.
Oh yes, I understand the concept of use it or lose it.
I also understand that impossibilities exist only in the mind. If it can be
imagined, it can happen. I have had this proven to me many times over. I
would even go so far as to say that if it is imagined then it must happen.
Thought and concentration are forces all their own. They are apart as well as
integral to what we call reality. Reality is molded by them more than we yet
understand. I know this sounds like mysticism, but all things do until you
truly understand. I'm not saying that I understand it. Just that I see it
everyday. The religious call it the power of prayer. Occultists call it the
power of Satan. Wickens call it the power of nature. Psychics call it the
power of the mind. Science usually calls it bullshit. So far :).

See ya,
Jim
http://www.geocities.com/SoHo/Exhibit/8281/beamart.html
ICQ# 55657870



10852 Fri, 25 Feb 2000 11:08:31 -0600 [alt-beam] Re: Cheap calculator cells alt-beam@egroups.com Ben A Micklin They should work, but not very well. Depends on how much voltage and mA.

~ben~

On Fri, 25 Feb 2000 10:16:44 -0400 (GMT-0400) Venturino Carmelo Miranda
Paulino writes:
> Down here, in Venezuela, is so hard to find solar cells, that I
> decided to
> buy some cheap calculator (from casio), destroy them and use they
> solar
> cells, they cost about $ 2,75 over here. I don't sure if they work
> well
> for BEAM applications but this is that I have in my hands for my
> BEAM
> projects right now.
>
>
> On Thu, 24 Feb 2000 BUDSCOTT@aol.com wrote:
>
> > now i recall on somebody's web site that some cheap calculators,
> 4-5 bucks,
> > have decent enough solar cells for BEAM applications, can anybody
> verify this
> > suspicion, before i waste money to destroy a calculator. thx
> >
> > -Spencer
> >
>
> ******************************************
> ** VENTURINO MIRANDA **
> ** Facultad de Ingenieria **
> ** Escuela de Ingenieria Quimica **
> ** Grupo: F.I.R.P. **
> ** U.L.A. Merida - Venezuela **
> ******************************************
>
>
>
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10853 Fri, 25 Feb 2000 11:18:55 -0600 [alt-beam] Re: BEAM: Tendency toward miniaturization alt-beam@egroups.com Ben A Micklin Ya right. YOu think we came from some germ cells too? HAHA.
Try again. WELL, I'm suprised "nature" made us smart enough to build
computers, cars, boats,planes...etc...


~ben~


On Fri, 25 Feb 2000 09:31:52 EST JVernonM@aol.com writes:
> In a message dated 2/25/00 8:47:00 AM Eastern Standard Time,
> wtnewton@nc5.infi.net writes:
>
> > It took nature over 3 billion years to create
> > us and pack together the number of elements necessary to make
> something
> > alive and conscious of its environment... to think us dumb humans
> can
> > do it in 50-100 years is... no comment.
> Yes, but nature did it randomly. We have systems in place to ensure
> more
> timely outcomes. If you say it can't be done, then for sure, without
> a doubt,
> you won't do it. It takes the starry eyed dreamer who is to stupid
> to realize
> what he's doing is considered impossible in order to achieve it. Of
> course,
> once it's accomplished, suddenly it was not so impossible. I can
> think of
> dozens of impossibilities that became common place with the advent
> of a
> simple device or idea. Besides, you are arguing from an unknown
> premise. Just
> what is a soul anyway? Just what is consciousness? Do dogs have
> conciseness?
> Their brains are much less complex than ours. At just what level
> does
> consciousness appear? No, I think you are making assumptions based
> on present
> knowledge and levels of technology, that's always a mistake. I also
> think
> your argument is heavily biased by western religious dogma.
> Possibly, if you
> were Hindu, you would consider all life to contain a soul. No matter
> how
> basic or simple. Making achieving the gold ring of consciousness a
> much
> closer goal. If indeed, what you say is true, then Mr. Brooks is
> wasting his
> time and a lot of lab fees. He should just pack up and go home to
> sell
> cheeseburgers. I don't buy that, and thank God Rodney doesn't
> either. And if
> you can't realize the importance of fiction, dreaming, and tenacity,
> than I
> have no comment. Except to say, the next time you are driving in
> your car,
> make sure not to exceed 30 miles an hour. It is impossible for the
> human body
> to withstand speeds greater than that. It will explode. This was
> common
> knowledge 100 years ago. Now ain't you glad someone didn't believe
> in the
> impossible?
>
> See ya,
> Jim
> http://www.geocities.com/SoHo/Exhibit/8281/beamart.html
> ICQ# 55657870
>
>
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10854 Fri, 25 Feb 2000 12:02:44 -0500 Re: shack caps Bruce Robinson
> Dennison Bertram wrote:
> >
> > Actually Archer components are pretty much the same as anyones
> > elses. It's takeing it a bit far to say that rat shack products
> > are inferior. They are actually quite good products. Especially
> > the electronics components. In addition, if your talking about
> > consumer electronics, Rat shack will repair everything they sell.
>
> Ya know, Dennison, I have purchase a LOT of faulty electronic components
> from "the shack". As in about 25% were non-working. That was 20 years
> ago, and it's been the same in the last year (much smaller sample the
> last time). And trying to return faulty electronics ... uh, un. "You
> must have damaged it when you hooked it up." Switches, wire, connectors,
> PCB material, no problem. IC's and LED's are a BIG problem.
>
> However, I've discovered something else. The shack is a franchised
> operation, and I have learned over the years that there is a tremendous
> variation in the quality of service. So much so, that I don't think the
> parent organization spends enough time monitoring what goes on in their
> more remote operations.
>
> The (current) local dealer not only finds reasons not to repair faulty
> consumer electronics (or replace it), they also don't bother to stock
> stuff they don't think is profitable enough. And PLEASE don't
> inconvenience them by asking them to order stuff in.
>
> I think the lesson here is, "Approach each store as a separate business
> and see for yourself". This seems to be one franchise you can't expect
> to be consistent.
>
> Bruce

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