Alt-BEAM Archive

Message #08488



To: beam@sgiblab.sgi.com
From: Dave Hrynkiw dave@solarbotics.com
Date: Thu, 16 Dec 1999 11:32:47 -0700
Subject: [alt-beam] Re: Miller Engine - licensing...--I'm behind dave on this one.


At 11:04 AM 12/19/99 , Bob Shannon wrote:
>Dave's post opened the door to the subject of the license, and of restrictions
>on its use. Unfortunately there are some valid legal issues with the
>statements
>Dave posted.


Regardless the legal debate, we have to prefix such posts with some
legalese, just to protect ourselves in the light of what we do for a
living. Sorry if it provokes unwanted discussions, but we can't post such
info without the legalese.

Regards,
Dave

---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com



8489 Thu, 16 Dec 1999 11:26:23 -0700 [alt-beam] Re: silicon VS SunCeram beam@sgiblab.sgi.com Dave Hrynkiw At 10:48 AM 12/19/99 , Bob Shannon wrote:
>I disagree with Adams views below.
>
>Silicon cells are not used in BEAM because the early SE circuits would
>lock up
>solid with that high a current demand.
>
>The concept that the SunCeram cells are more efficient in lower light
>levels is an
>interesting assertion, but I think its false.


I can't comment about the low-light performance, but there is definitely a
cost factor in there, otherwise solar-powered calculators would be using
silicon in their calculators, which for the most part operate in low light.

As for using silicon in most robot designs, yes - you're correct. They ARE
more powerful, but at the expense of being extremely fragile (thing "potato
chip"), low voltage by themselves, and dangerously sharp if mis-handled.

Them's my 2 cents!

Regards,
Dave

---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com



8490 Mon, 20 Dec 1999 10:50:39 -0800 Re: silicon VS SunCeram beam@sgiblab.sgi.com owner-beam@sgiblab.sgi.com [mailto:owner-beam@sgiblab.sgi.com]On
I disagree with Adams views below.

Silicon cells are not used in BEAM because the early SE circuits would
lock up
solid with that high a current demand.

The concept that the SunCeram cells are more efficient in lower light
levels is an
interesting assertion, but I think its false.

Silicon cells will deliver far less than their rated power in low light,
but the total
wattage per cell area still seems to be higher than SunCeram cells.
>From my experiance
this difference remains in favor of the silicon cells even after a
voltage booster circuit
is used to bring the current/voltage delivery up to the levels expected
from a SunCeram.

Make some measurments, and see for your self. There is a reason NASA
sends silicon
cells out into the dim regions of space, rather than send an amorphous
cell technology.

adam-m wrote:

> Yes Silicon or monocrystalline pv panels (blue) have significant
> amperage over the SunCerams... but there good reasons you don't see
> them in many beam applications...1. They suck like a tornado in
> anything other than bright sunlight. Those wonderful SunCerams
> produce an amazing amount of light in 'less than really bright'
> conditions. To get the numbers you read for the Blue panels, you need
> to be in noon Texas sun.2. Their voltage output is poor, necessitating
> hooking a bunch in series. Now your robots get big and ugly.If you
> want to make big bots that only run outside in direct sunlight, then
> go for the blue PV's.. They will kick ass, and really go fast. BUT
> take them inside and prepare to be underwhelmed.I bought a bunch of
> Monocrystalline cells a while back and after a few tests i was
> completely filled with anticipointment.I like bots that wander around
> on my desk at work under halogen lamps and in bright room lighting.
> For that, SunCerams are the best thing.

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