Alt-BEAM Archive
Message #06740
To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Wilf Rigter Wilf.Rigter@powertech.bc.ca
Date: Thu, 14 Oct 1999 06:33:58 -0700
Subject: [alt-beam] Re: Power Smart Head Schematics
Try
http://home.pacbell.net/wundoba/psh.html
regards
Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
> -----Original Message-----
> From: Elmo [SMTP:andrewe@ilid.com.au]
> Sent: Wednesday, October 13, 1999 11:43 PM
> To: Beam Mailing List
> Subject: Power Smart Head Schematics
>
> Hi everyone, i really want to have a go at building a power smart head
> unit!
>
> Can anyone direct me to a site where i can get some information on how
> head units work and how to build them.
>
>
> Thanks
>
> Elmo....the enthusiatic one!
6741 Thu, 14 Oct 1999 06:47:18 -0700 Wow, ever tried this... beam@sgiblab.sgi.com Bob Shannon [SMTP:bshannon@tiac.net] 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!
> -----Original Message-----
> From: Phillip A. Ryals [SMTP:phillip@ryals.com]
> Sent: Wednesday, October 13, 1999 5:27 AM
> To: beam@sgiblab.sgi.com
> Subject: Re: Phototransistor switch
>
> Thanks Wilf, That was a really awesome explanation.
>
> I'm not sure if I was around when Bob Shannon explained it.. are there
> any
> links with some info?
>
> I think I'm going to go ahead and try using these switches, they would
> really work great as whiskers (aka, touch sensors). If I happen to be
> successful I'll share.
>
>
> -----Original Message-----
> From: Wilf Rigter
> To: 'beam@sgiblab.sgi.com'
> Date: Wednesday, October 13, 1999 2:53 PM
> Subject: RE: Phototransistor switch
>
>
> >Hi Phil,
> >
> >The slotted type can be used for detecting "end of leg travel". The
> >reflective type used in some faxes to detect paper, could be used for
> line
> >following and edge detector applications. You can often find the slotted
> >photo interrupter in printers and older 514 disk drives as well the fax
> and
> >mouse you mentioned. Most use photo transistors for detectors and are
> >usable in SEs as was shown by Bob Shannon or as relatively insensitive
> PDs
> >as well by connecting the base-collector pins only.
> >
> >While a non-contacting switch is great since it never wears out, it does
> >consume power even when the "switch" is not closed.
> >Typically the LED draws 10ma continuous but with a power supply > 4V,
> two
> >LEDs can be put in series to conserve power.
> >
> >regards
> >
> > Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
> > tel: (604)590-7493
> > fax: (604)590-3411
>
6742 Thu, 14 Oct 1999 11:42:10 -0500 [alt-beam] PSH BEAM Richard Piotter 37x33 5.5 volt solar panel
Ok, I got these.
5.5 volt .047F capacitor
I'm sure I can find this
74HC240
Wirl HCT work?
1381L voltage trigger
What is the triger voltage for that? How different is it from J?
Escap 16 DC motor
What's the current/volts for those motors?
And also, what are the light/dark resistances for the LDRs?
--
Richard Piotter
richfile@rconnect.com
The Richfiles Robotics & TI web page:
http://richfiles.calc.org
For the BEAM Robotics list:
BEAM Robotics Tek FAQ
http://people.ne.mediaone.net/bushbo/beam/FAQ.html
6743 Thu, 14 Oct 1999 13:07:46 -0400 Re: PCB etching James Wilson
> There are two very inexpensive ways to hand etch a pcb.
> 1> Use a permanent marker on the copper board.
> 2> Use rub on transfers on the copper board.
>
> In both cases make sure you have clear (or any color) nail polish to coat
> the board with after it is etched before you solder to it to preven
> oxidation.
>
> Both really cheap.
>
> James:-))
> ----- Original Message -----
> From: Chris <123abc@chek.com>
> To:
> Sent: Wednesday, October 13, 1999 7:11 PM
> Subject: PCB etching
>
>
> > Is there any way to hand etch PCB? What do I need to do it? About how
> much will it cost? Are there any tutorials on the web?
> >
> > Win a LAPTOP Computer and get your FREE E-mail Account at
> http://mail.chek.com
>
>
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