Alt-BEAM Archive

Message #11895



To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@telus.net
Date: Wed, 15 Mar 2000 13:09:31 -0800
Subject: [alt-beam] Re: BEAM circuit contribution.


Hi, Ben.

Thanks for the FRED circuit. I've added it to the circuits page and I'll
be uploading the revisions in the next couple of days.

Bruce



11896 Wed, 15 Mar 2000 16:17:20 EST [alt-beam] Re: Miniature video transmitter? beam@sgiblab.sgi.com BUDSCOTT@aol.com In a message dated 3/15/00 12:21:18 AM Central Standard Time,
JAF60@student.canterbury.ac.nz writes:

<< No, I've seen transmitters small enough that you could load them and the
CCD onto a photopopper. You'd have to put the solar panel on top of
them, but the level of miniaturisation does exist and I think kits were
sold, just too expensive for me (circumstances would also suggest that
the expense was largely for R&D and profit, rather than component
costs). Anyway, the point of this message is to say that it _is_
possible, we just need to find out how :-)
>>

Thats the problem i've seen too. The really good kits that are really really
small are really reallly expensive, Plus it depends on the photopopper, both
of mine (a chiu and a no chiu popper) are way too small, plus the CCD camera
is about the diameter of a "c" cell battery and about as long as a 4700 uF
cap, small, but still too big for something with that little torque! What
would be neat would be to put that in an RJP and get internet video from it!
Best bet would be a BEAMant style photovore with geared motors with kinda big
wheels, the package would end up a little heavy for nongeared pager motors.
Good luck if you wanna try it!

-Spencer



11897 Wed, 15 Mar 2000 16:19:47 EST [alt-beam] Re: Vibration sensor from Silly Slammer beam@sgiblab.sgi.com BUDSCOTT@aol.com At one point in time somebody on the list asked for a "cricket" cirucut that
used a piezzo buzzer to make a chirp sound, am i right? Does anybody know
where this is, i'm curious and would kinda like to see what its like. ThAnKs!

-Spencer



11898 Wed, 15 Mar 2000 16:21:57 EST [alt-beam] Re: Photodiodes beam@sgiblab.sgi.com BUDSCOTT@aol.com In a message dated 3/15/00 1:40:17 PM Central Standard Time,
william@characterlink.net writes:

<< Even that's more expensive that buying some from the Shack mail order. The
s/h is only $2, and the diodes are 1.09. I *think* they are part 900-1871 (I
know it's 900, and I know it's 71). Do a search on the webpage.
-William >>

A buck and 9 cents! for a single photodiode! you might be better off just
ordering digikey bulk, theres a minimum order cost but you might as well just
buy enough that you never need to order them again! depends on how badly you
want em i guess.

-Spencer



11899 Wed, 15 Mar 2000 16:24:28 EST [alt-beam] Re: Once more, a reminder for the Lego MotorsMini beam@sgiblab.sgi.com BUDSCOTT@aol.com Can you purchase these motors at local toy stores or are they too specific a
part to get locally and are just mailorder? + would they make good motors for
turbots with the BEAMant cirucut? also how expensive are these buggers?

-Spencer



11900 Wed, 15 Mar 2000 15:31:05 -0500 [alt-beam] Re: Photodiodes - make your own beam@sgiblab.sgi.com "Sathe Dilip" Someone mentioned getting 2907s (or was it 2222?) in a metal can package
(TO-18). If you have some of these, cut open the top of the can (you
can grind off along the edge till the top falls off in a disk shape).
Then use the Base-emitter junction like a photo diode while exposing the
innards to your light source. In fact the tin can will give you some
directional properties. One disadvantage could be because you are
exposing the silicon to the atmosphere. So it may reduce the life of
the device somewhat. Closing the top again with some clear acrylic &
epoxy might help although it is not the same as the original hermetic
seal.

I have tried this with success but haven't tested it for duration as
such (meaning to see how long it survives - considering many Silicon
solar cells are in a similar environment & last reasonably long, I
suspect it should last long enough) Give it a try in a pinch.

Dilip
-----------------------------------------------------------------------------

William Cox wrote:
>
> Even that's more expensive that buying some from the Shack mail order. The
> s/h is only $2, and the diodes are 1.09. I *think* they are part 900-1871 (I
> know it's 900, and I know it's 71). Do a search on the webpage.
> -William

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The early bird may get the worm, but the second mouse gets the cheese.
----------------------------------------------------------------------



11901 Wed, 15 Mar 2000 16:02:47 -0800 [alt-beam] power filter caps question "Jeffrey B. Williams"
content-transfer-encoding: quoted-printable

Hey everyone!!

Okay, time for me to belly up with a simple and possibly stupid question. =
Power Filter Caps..... I can attest that they work great. In fact one ta=
med the rambunctious behavior of my Chiu two motor, and its PNC... But my =
knowledge of electronics is mostly guilt by association.. so here is the li=
st of questions.

1) Does the cap, in parralell to the power pins of the IC filter all the va=
riations (AC current) through it to the ground rail so that they do not inf=
luence the chip? (In other words, I'm clueless and would like an idea on w=
hy it works..)

2. Can a put a single capacitor in parralell to a series of chips, cores, .=
...whatever to stabilize them, instead of a cap per chip.

3. What's a good size for these beasts. To be honest a single .22uf worked=
to stabilize my walker, but I still don't have that warm fuzzy feeling tha=
t tells me its not just waiting to go up in flames. I have the impression=
that they should be larger, but what is too large?



Any advice would be greatly appreciated.

Jeff
Recenctly bitten by the BEAM bug.

P.S.

Now that it's tamed, I don't know why its called a walker.... The thing r=
uns and scampers pretty darn quick... =



content-transfer-encoding: quoted-printable



>

a series of chips, cores, ....whatever  to stabilize them, instea=
d of =

a cap per chip.
 

3. What's a good size for these beasts.&nb=
sp; To be =

honest a single .22uf worked to stabilize my walker, but I still don't have=
that =

warm fuzzy feeling that tells me its not just waiting to go up in flames.&n=
bsp; =

I  have the impression that they should be larger, but what is too =

large?

 

 

 

Any advice would be greatly =

appreciated.

 

Jeff

Recenctly bitten by the BEAM bug. DIV>
 

P.S.

 

Now that it's tamed, I don't know why its =
called a =

walker....   The thing runs and scampers pretty darn quick...&nbs=
p; =





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