Alt-BEAM Archive

Message #02324



To: "BEAM Mail" beam@corp.sgi.com
From: "Nigel Joyce" nigel.joyce@qr.com.au
Date: Thu, 15 Apr 1999 09:52:41 +1000
Subject: [alt-beam] Re: component identifcation and SE Comparison


Thanks Kyle for the info, I was hoping for a bit more about this bit here
from the rest of the board.

> > I just got my first electronics catalogue from
> > dick smith electronics, (our local electronics store, also stocks the
> > cybug and higher function add-ons) and I cannot find the 1381's or the
> > 3906's in it, the 3904's are there as well as a heap of other stuff
> > but as I am new to this stuff, are there other names these components
> > are known as?

Is there equivalent transistors for the
a. 3906 PNP's = = ?
b. 3904 NPN's = 2n2222 ? = ?
c. 1381 Voltage Detectors = ?


Has there been a discussion previously on the advantages/disadvantages of
each of the SE's?
I got a couple of the LM3909's from the shop, Yet to build SE's from them
though,

I don't understand why they aren't used more, they seem very simple to me,
and perhaps smaller? easier to tune?

With regards to the standard solarbotics photopopper circuit, Isn't there a
bit of redundancy there? I mean, all it is 2 SE's that are biased so the 1
receiving less light fires first right?

Wouldn't it be simpler to have just 1 SE and then have some sort of simple
circuit to decide which side gets the current. Is there any sort of chip
that flips a switch depending on which input has a larger/smaller
resistance?

I am new to this so I still don't understand what is possible and what is
not possible. I guess it's the programmer in me trying to remove the
redundancy.
Blue Skies
---Buzz---

I didn't just kiss death, I slipped it the tongue!

nigel.joyce@usa.net

> > Hey everyone,
> > I just got my first electronics catalogue from
> > dick smith electronics, (our local electronics store, also stocks the
> > cybug and higher function add-ons) and I cannot find the 1381's or the
> > 3906's in it, the 3904's are there as well as a heap of other stuff
> > but as I am new to this stuff, are there other names these components
> > are known as?
>
>
> Hmm, don't know about this. They probably don't carry the 1381 though,
> you'll most likely have to get it from DigiKey.
>
>
> > Also, I have sofar pulled apart 1 old computer, 1 old video player,
> > about 20 old pagers (16 great motors) and a bunch of other old
> > electronics that had been collecting dust under the house (I knew
> > there was a reason I didn't chuck it all out). anyway, I have a bunch
> > of IC's that are marked with 74****** something, something. I was
> > wondering which ones of these are handy for BEAM?
>
> These are useful:
> 74**14 - Microcore
> 74**245 - Microcore
> 74**00 - Suneater 2,3
> 74**02 - Suneater 3
>
> ** = hc, als, hct, etc.... Soem are better than others, check the
> schematics.
> Info on the Suneaters series (They're great) can be found on Steven
> Bolt's (He's cool) site:
> http://www.xs4all.nl/~sbolt/e-index.html
>
> It's on there somewhere....
>
> > Also, I pulled apart a mouse that was stuffed, what do the led's in
> > them detect, and emit? is it IR?
>
> >From what I know, yes.
>
> > On another note, I am building my first photopopper in the case of 1
> > of the pagers as a tribute to the source of these great motors. A
> > calculator solar panel will fit perfectly where the LCD screen was. so
> > the only visible parts will be the motor shafts and the holes where
> > the eyes get the light. What sort of Voltage and Current can I expect
> > from a calculator solar cell? I've read that a 1381 SE needs about
> > 3v, is there a SE design that uses less?
>
> I only use calcuslator cells cause that's all I can get. They're great,
> usually put out about 2.8 volts. I use FLED SE's because they trigger at
> around 2.1v, but aren't as effecient as the 1381's. You can get 1381's
> that will trigger at 2.1v, so yes, you can use your cells with a 1381
> SE.
> Adios,
> Kyle
>
> -
> "If you can..."


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