Alt-BEAM Archive
Message #10810
To: beam@sgiblab.sgi.com
From: Toby503@aol.com
Date: Thu, 24 Feb 2000 16:27:31 EST
Subject: [alt-beam] Re: BEAMLAND and Solarbotics bring you 'Bot of the Week'...
In a message dated 2/24/00 4:11:50 PM Eastern Standard Time, jfeser@ea.com
writes:
<< http://members.xoom.com/jfese
>>
Gret Idea! But I think that every week could be too much. Maybe every two
weeks give or take.
Rusty
10811 Thu, 24 Feb 2000 16:35:14 -0500 [alt-beam] Solar Cell tests beam@sgiblab.sgi.com "FCO Enr." greetings,
I did some tests with some various solar cell configurations
and here is some of the data I gathered as well as some questions
for those of you who can explain this phenomena.
First off, I tried various combinations to find the most efficient
low light (my ambient light level) setup. The winner is surprising=
considering
even my Solarbotics catalogue seems to point in the wrong direction.
A - SC2422 (3.5v @ 6ma)
B - SC2433 ( 2.7v @ 16ma)
( I also experimented with the SCPDs but I didn't write down and time
the results so I won't include them).
The goal was to see how fast the circuit could gain .01v in my ambient
light. I did my best to avoid any movement of cells.
A 11.5 seconds
A + B in series 6 seconds
A + B in parallel 2.5 seconds
B 3.5 seconds
Now this is pretty odd considering it seems like wiring these
cells in parallel improved their low light capability (not by much
considering the space it takes up).
WEIRD: When the voltage in the circuit reached 2.2 something volts
I noticed it was takin MUCH longer.. from 2.23v - 2.24 it took
1 minute 7 seconds!!! I looked at my meter again and it hasn't
budged from the 2.24v mark in over 2 mins!!
I also noticed the times I stated above were between 1.4 and
` 1.58v. It seems like the charging between 1.1v and 1.2 is almost two
times faster! Why does it vary depending on circuit voltage and why
did the voltage sort of plateau at 2.24v?
Now the light level hasn't changed AT all and I tried again when it got
to 2+ volts the cycling was a LOT slower to get the same 0.01v
WHY? So this also means if I get the lowest rated trigger it would
improve low light capability DRASTICALLY!
I would appreciate any feedback on this.
Andy
fco@total.net
hrdware's digital sanctuary - mindless oddities
http://www.angelfire.com/pq/hrdware
The Factory - TF Map Making Tutorial
http://www.planetfortress.com/factory
10812 Thu, 24 Feb 2000 16:47:18 EST [alt-beam] no more list beam@sgiblab.sgi.com HP1rac1ng@aol.com take me off the list
10813 Thu, 24 Feb 2000 17:04:34 EST [alt-beam] Re: shack caps beam@sgiblab.sgi.com BUDSCOTT@aol.com could you have blown the IC as well? perhaps it is just inferior quality
radio shack products. capacitors have a tolerance rating as well, so maybe
one is on one end of the scale and the other is way the hell on the other.
all i can say is that it's pretty easy to blow the living daylights out of
any electronic component especially 906's and 904's (when you get anxious
before the solar panels arive and blow em up with a 4.5v battery!). I'd be a
little suspicious of that cap rating myself. Good Luck, let us know how it
turns out!
-Spencer
10814 Thu, 24 Feb 2000 17:07:48 EST [alt-beam] Re: Aquabot Propulsion beam@sgiblab.sgi.com BUDSCOTT@aol.com if ya use a solenoid, make sure that you use something other than the
standard 1381 solar engine. solenoids take up a lot more current than one
might be led to believe, in some cases a few amps! that does sound really
cool though! if you can find a descent solenoid that is low on the amperage,
let me know, i'm still tinkering with the solenoid photopopper. GoodLuck!
-Spencer
10815 Fri, 25 Feb 2000 09:16:07 +1100 (EST) [alt-beam] Re: Combining Solar Cells beam@sgiblab.sgi.com Ben Hitchcock Hi,
> So I guess the BEST use for SCPD's is to boost voltage
> and not current, due to the fact that their current output is so low.
> But it's odd because I didn't notice the better low light charging
> when I had the SCPDs in series.
"Better" here means that it actually charged, as opposed to not reaching
the switch-on voltage for the SE.
> Now my next question is this, is there a way to split
> the SE circuit so two seperate solar cell arrays are loading the
> same Capacitor?
Yes there is! But you will sacrifice a tiny bit of voltage. What you
need to do is put all ten SCPD's in series. Call this the SCPD panel.
Connect the 0V rails of the SE, the solar panel, and the SCPD panel. Now
comes the tricky bit. You need to buy two Germanium diodes. Connect the
anode of each germanium diode to the positive terminal of each Solar
panel. Now bring the cathode of each germanium diode to the SE. (The SE
contains your capacitor as well).
For all this effort, I would think that this won't perform as well as the
previous circuit (the one I posted yesterday) with all ten SCPDs ganged up
in parallel, with the gang
in series with your other panel.
>
> I think if I could use my 2433 (2.7v 16ma) with 10 SCPD's
> in series ( 4v 1.4ma) then that would be excellent. But I am aware
> this probably isn't possible. How about two SEs triggering the same
> motors?
This is possible as well - put the collector and emitter of the output
transistors for both SEs in parallel. Seems a bit of a waste of time to
me, but then that's probably just me.
Ben
10816 Fri, 25 Feb 2000 09:20:16 +1100 (EST) [alt-beam] Re: Cheap calculator cells beam@sgiblab.sgi.com Ben Hitchcock They're not too bad.
Check out the Alf, Dragonfly and Seaplane robots on my site:
http://wollongong.apana.org.au/ben
Of course nothing beats a good quality sunceram, but calculator cells will
do in a pinch.
Ben
> 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
10817 Thu, 24 Feb 2000 16:31:35 -0600 [alt-beam] Re: Combining Solar Cells alt-beam@egroups.com Ben A Micklin DOn't the SCPDs have a current of 1.4 ma and voltage of .4?
Isn't that good? Or not?
~ben~
On Thu, 24 Feb 2000 15:14:53 -0500 "FCO Enr." writes:
> greetings Ben,
>
> So I guess the BEST use for SCPD's is to boost voltage
> and not current, due to the fact that their current output is so
> low.
> But it's odd because I didn't notice the better low light charging
> when I had the SCPDs in series. I was getting in ambient light
> over 5v which I thought was great! But the current was so low that
> it took VERY long to trigger. I am talking over 30 mins!!! I was
> using a 2433 solarcell which had 16ma current but low voltage.
> I figured I would use the SCPDs to boost voltage but I didn't
> know that the current would drop to whatever the SCPDs were
> outputting.
>
> Now my next question is this, is there a way to split
> the SE circuit so two seperate solar cell arrays are loading the
> same Capacitor?
>
> I think if I could use my 2433 (2.7v 16ma) with 10 SCPD's
> in series ( 4v 1.4ma) then that would be excellent. But I am aware
> this probably isn't possible. How about two SEs triggering the same
> motors?
>
> Thanks for your time and the schematic!
>
> Andy
> fco@total.net
>
> hrdware's digital sanctuary - mindless oddities
> http://www.angelfire.com/pq/hrdware
>
> The Factory - TF Map Making Tutorial
> http://www.planetfortress.com/factory
>
> *********** REPLY SEPARATOR ***********
>
> On 24/02/00, at 9:52 PM, Ben Hitchcock wrote:
>
> >This is exactly the conundrum I faced with my Seaplane robot:
> >
> >http://wollongong.apana.org.au/~ben/seaplane/
> >
> >I used a 2911 solar cell, and I used two SCPD's to boost the
> voltage. So
> >what's going on with your circuit?
> >
> >Well, the mini solar cells boost voltage, sure, but they HAVE A
> MAXIMUM
> >CURRENT THROUGHPUT. This means that as soon as you start pushing
> too much
> >current through them, they actually develop reverse voltage across
> them!
> >
> >So here's what to do:
> >
> >Put all ten SCPD's in parallel. Now attach the common negative
> terminal of
> >this SCPD bank to the positive terminal of your SC2433. Now you
> should have
> >an extra 0.45 volts to charge your solar engine with! That is, the
> voltage
> >of the SC2433 + 0.45 volts.
> >
> >I did this with two SCPD's on my Seaplane because I wasn't too
> concerned
> >with how long it would take to charge, but I did want good low
> light
> >performance. I would suspect that your ten SCPD's in parallel will
> boost
> >your performance a lot. I did notice that the maximum rate of
> firing slowed
> >from 3 times a second to once a second when I added the two SCPD's
> (This is
> >just like you described). But the low light performance is a lot
> better.
> >
> >Have a look at the schematic (attached) to see how I did it, and in
> your
> >case I would just keep adding solar cells in parallel with the two
> that I
> >have shown in my diagram.
> >
> >You could also make two lots of five SCPD's, and put each bank of
> five in
> >series with each other and the Solar panel to give you an extra 0.9
> volts.
> >This will boost your low light performance more, but you will pay
> for it in
> >terms of longer charging time in bright light.
> >
> >It's always a tradeoff, isn't it?
> >
> >Ben
> >
> >----------
> >>From: "FCO Enr."
> >>To: beam@sgiblab.sgi.com
> >>Subject: Combining Solar Cells
> >>Date: Thu, 24 Feb 2000 20:23
> >>
> >
> >> greetings,
> >>
> >> Well I've been experimenting with my 1381 SE and
> >> trying to figure out how to boost it's energy gathering
> capability.
> >> My idea was to use 10 SCPDs and a SC2433 together to make
> >> a solarengine that could work quite actively under my normal
> >> room lighting.
> >>
> >> I did a few tests, wiring the 10 SCPDs in series WITH
> >> the SC2433 under my regular lighting produced a pin to pin
> >> voltage of 5+v, but when I wired it to the SE circuit and
> monitored
> >> the circuit voltage, I was seeing a super slow increase in
> voltage.
> >> When I removed the 10 SCPDs I noticed it was charging FASTER!
> >>
> >> So then I tried using the SC2433 in parallel with the 10 SCPDs
> >> wired in parallel I noticed everytime I connected the 10 SCPDs
> into the
> >> loop whatever circuit voltage I had dropped to aprox 0.45 volts
> and
> >> it stayed there!
> >>
> >> I looked through my electronics theory book but I didn't
> >> see any mention of such wiring and so I don't know what could
> >> possibly be wrong.
> >>
> >> I would appreciate any help, especially theoretical info
> >> that could help me put it into perspective.
> >>
> >> thank you for your time!
> >>
> >> Andy
> >> fco@total.net
> >>
> >> hrdware's digital sanctuary - mindless oddities
> >> http://www.angelfire.com/pq/hrdware
> >>
> >> The Factory - TF Map Making Tutorial
> >> http://www.planetfortress.com/factory
>
>
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>
>
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10818 Thu, 24 Feb 2000 18:39:18 -0500 [alt-beam] Re: Aquabots beam@sgiblab.sgi.com "Sathe Dilip" I am sure many people will be interested. Also include the details re.
where you got the kitchen timers from. Are these new? What make? where
to buy from. In the absence of a steady source for the ideal BGmicro
gear motors, a combination like what you have used is always welcome.
By the way, what is the resultant RPM at the leg end? A rough estimate
will do.
Thanks
Dilip
-------------------------------
Robert Stein wrote:
SNIP
> OTU. So I used normal , everyday, kitchen timers (well the ones that have
> a metal insides). Strip most of the innards out and couple the motor to
> one of the gears, and you are in business. The timers are very cheap. I
> think they were $3 per timer. So $7 total for a motor gear combo. I am
> currently trying to come up with a tutorial for it for someone else, but I
> would be more than happy to post it somewhere if it is wanted.
>
> Thanks.
>
> Robert
--
----------------------------------------------------------------------
The early bird may get the worm, but the second mouse gets the cheese.
----------------------------------------------------------------------
10819 Thu, 24 Feb 2000 16:14:29 -0800 Re: BEAMLAND and Solarbotics bring you 'Bot of the Week'... beam@sgiblab.sgi.com Toby503@aol.com [mailto:Toby503@aol.com]
In a message dated 2/24/00 4:11:50 PM Eastern Standard Time, jfeser@ea.com
writes:
<< http://members.xoom.com/jfese
>>
Gret Idea! But I think that every week could be too much. Maybe every two
weeks give or take.
Rusty
10820 Thu, 24 Feb 2000 19:31:19 -0500 [alt-beam] Re: BEAMLAND and Solarbotics bring you 'Bot of the Week'... "Richard Caudle" No way it's too much! It's just right. Gotta update almost constantly to
stay fresh. New info means more hits! More hits means gravy!
Richard
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