Alt-BEAM Archive

Message #04311



To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Wilf Rigter Wilf.Rigter@powertech.bc.ca
Date: Sun, 6 Jun 1999 11:10:20 -0700
Subject: [alt-beam] Re: Wow, ever tried this...


Of course! (smacks himself in the had)

Nice going Bob.

regards

Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
tel: (604)590-7493
fax: (604)590-3411

> -----Original Message-----
> From: Bob Shannon [SMTP:bshannon@tiac.net]
> Sent: Sunday, June 06, 1999 9:42 AM
> To: beam@sgiblab.sgi.com
> Subject: Wow, ever tried this...
>
> If you want to try something strange...HOT OFF THE BENCH!
>
> Get a three terminal, NPN phototransistor. I'm using some surplus GE
> parts
> (non-standard markings).
>
> Simply replace the 2N3904 with the phototransistor in the standard 1381
> SE.
>
> Think about a photopopper, and now start getting rid of all the extra
> parts you
> no longer need!
>
> I've heard of a photovore in Chiu's last contest that replaced the
> photodiodes
> with phototransitors and got some interesting behaviors as a result. I
> have
> some SYMETs
> that have phototransistor sensors on them, and its amazing to see that a
> phototransistor
> with a built-in lens (they often look just like LEDs) can actually 'see'
> contrasts at well
> over 4 meters in range!
>
> The point here is that the optics of the phototransistor are a major
> factor in
> the behaviors
> it will produce. Its not easy to know what the phototransistor is
> responding to
> if its optics are that good.
>
> If you alter the optics of the phototransistor (sandpaper, or a dremel
> tool can
> be used!)
> there are profound changes in the sensors response. Also the small metal
> can,
> three lead phototransistors have very different optical properties, and
> produce
> different behaviors.
>
> An interesting photovore can be made with 2 'Photosensitive SE's', and by
> mounting the
> phototransistors under small shadow 'brows' you can get some very complex
> behaviors!
>
> Without a 'unicore' no less! What should we call this thing?
>
> I can't wait to play with the UJT/SCR SE circuit, and some LASCR's I
> found.
>
> Now back to making it move in an interesting, new way!
>
>
>
>

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