Subject:
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Re: CdS cells
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Fri, 8 Aug 1997 12:01:23 GMT
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Original-From:
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Donald W Boys <dboys@spruce.flint.umich!StopSpammers!.edu>
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Viewed:
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1632 times
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David,
I believe you will want to purchase ones that have a dark resistance
more than say 20K. The sensor is part of a divider circuit that includes
a 47K resistor. The sensed signal equals (sensor resistance)/(sensor +47K)
multipled by 255. If your sensor has too low a dark resistance the
difference between bright light and no light is like 0 and 3.
That's what I got with the sensors I received from Gleason. They
have a dark resistance of about 1K. If you really want to differentiate
between light and dark you need a much larger dark resistance.
Don
Donald W. Boys, Assoc. Prof. Physics dboys@spruce.flint.umich.edu
Dept. of Physics, 303 E. Kearsley (810) 762-3397
University of Michigan-Flint Fax: (810) 762-3687
Flint, MI 48502
On Tue, 5 Aug 1997 David.J.Dostal@lawrence.edu wrote:
> hi everyone,
>
> I am looking to purchase a batch of CdS photo cells but I think that I
> need more information before I order. The catalogs (Digi-Key, Mouser, etc.)
> list several different photocells (different resistances, power dissipation,
> etc.) and I am wondering which one is optimally suited to be used as a light
> sensor on the HB. Does anyone know enough specs to help me narrow this search
> down a bit? I have two cells from Gleason Research's sensor/motor kit and
> duplicates of those would work fine if I knew where to order them. Yes, I have
> contacted Gleason, but have gotten no reply yet.
>
> Thanks,
>
> David
>
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Message is in Reply To:
 | | CdS cells
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| hi everyone, I am looking to purchase a batch of CdS photo cells but I think that I need more information before I order. The catalogs (Digi-Key, Mouser, etc.) list several different photocells (different resistances, power dissipation, etc.) and I (...) (27 years ago, 5-Aug-97, to lugnet.robotics.handyboard)
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