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Thread: Laser beam break detector w/photocell

  1. #1

    Default Laser beam break detector w/photocell

    I have received several emails from people who want the schematic for the
    laser beam break detector but dont want to download and use Pspice to view
    it. I made up a BMP version of the schematic so that everybody can
    view/print the schematic. Here are the links:

    Pspice Schematic:
    http://home.earthlink.net/~dankgus/S.../photocell.sch

    BMP Schematic:
    http://home.earthlink.net/~dankgus/S.../photocell.bmp


    PSPICE V9.1 STUDENT VERSION
    http://www.orcad.com/Download/Pspice...t/91pspstu.exe

    Have fun!
    --Dan
    Last edited by ForumTools; 10-02-2010 at 12:59 AM. Reason: Forum Migration

  2. #2

    Default

    Dan and any others,

    Regarding the laser photocell circuit posted on 10-08-00:

    Is the ambient light filtered out in your circuit so that only the 650nm
    laser triggers it?

    If not how can this be accomplished?

    Thans, John Bell

    -----Original Message-----
    From: Dan Gustafson <dankgus@e...>
    To: basicstamps@egroups.com <basicstamps@egroups.com>
    Date: Sunday, October 08, 2000 1:08 PM
    Subject: [basicstamps] Laser beam break detector w/photocell


    >I have received several emails from people who want the schematic for the
    >laser beam break detector but dont want to download and use Pspice to view
    >it. I made up a BMP version of the schematic so that everybody can
    >view/print the schematic. Here are the links:
    >
    >Pspice Schematic:
    >http://home.earthlink.net/~dankgus/S.../photocell.sch
    >
    >BMP Schematic:
    >http://home.earthlink.net/~dankgus/S.../photocell.bmp
    >
    >
    >PSPICE V9.1 STUDENT VERSION
    >http://www.orcad.com/Download/Pspice...t/91pspstu.exe
    >
    >Have fun!
    >--Dan
    >
    >
    >
    >
    >
    >
    >
    Last edited by ForumTools; 10-02-2010 at 12:59 AM. Reason: Forum Migration

  3. #3

    Default

    At 11/8/2000 09:29 AM, you wrote:
    >Dan and any others,
    >
    >Regarding the laser photocell circuit posted on 10-08-00:
    >
    >Is the ambient light filtered out in your circuit so that only the 650nm
    >laser triggers it?
    >
    >If not how can this be accomplished?
    John-

    Check message 5182 where it states:

    "I had the photocell mounted in a tube about 1.5" deep so that ambient
    light would not interfere with the photocell. "

    For future refeence, it's far easier to access the eGroups messages by
    NUMBER, than by date.



    >Thans, John Bell

    Surely

    Regards,

    Bruce Bates

    >-----Original Message-----
    >From: Dan Gustafson <dankgus@e...>
    >To: basicstamps@egroups.com <basicstamps@egroups.com>
    >Date: Sunday, October 08, 2000 1:08 PM
    >Subject: [basicstamps] Laser beam break detector w/photocell
    >
    >
    > >I have received several emails from people who want the schematic for the
    > >laser beam break detector but dont want to download and use Pspice to view
    > >it. I made up a BMP version of the schematic so that everybody can
    > >view/print the schematic. Here are the links:
    > >
    > >Pspice Schematic:
    > >http://home.earthlink.net/~dankgus/S.../photocell.sch
    > >
    > >BMP Schematic:
    > >http://home.earthlink.net/~dankgus/S.../photocell.bmp
    > >
    > >
    > >PSPICE V9.1 STUDENT VERSION
    > >http://www.orcad.com/Download/Pspice...t/91pspstu.exe
    > >
    > >Have fun!
    > >--Dan
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    Last edited by ForumTools; 10-02-2010 at 12:59 AM. Reason: Forum Migration

  4. #4

    Default

    There is no filter, but if you mount the photocell in a small tube you wont
    have any problems. I did LOTS of experimenting with amnbient light and I
    could not trigger the circuit accidentally with ambient light. I think the
    photocell I used was particularly sensitive in the 650nm range so that was
    helpful (just the standard radio shack photocells). Even with the photocell
    sitting right out in open light, the resistance doesnt go as low as it does
    when the laser is pointed directly at the photocell.

    --Dan

    ----- Original Message -----
    From: "John A. Bell" <jababell@i...>
    To: <basicstamps@egroups.com>
    Sent: November 08, 2000 6:29 AM
    Subject: Re: [basicstamps] Laser beam break detector w/photocell


    > Dan and any others,
    >
    > Regarding the laser photocell circuit posted on 10-08-00:
    >
    > Is the ambient light filtered out in your circuit so that only the 650nm
    > laser triggers it?
    >
    > If not how can this be accomplished?
    >
    > Thans, John Bell
    >
    > -----Original Message-----
    > From: Dan Gustafson <dankgus@e...>
    > To: basicstamps@egroups.com <basicstamps@egroups.com>
    > Date: Sunday, October 08, 2000 1:08 PM
    > Subject: [basicstamps] Laser beam break detector w/photocell
    >
    >
    > >I have received several emails from people who want the schematic for the
    > >laser beam break detector but dont want to download and use Pspice to
    view
    > >it. I made up a BMP version of the schematic so that everybody can
    > >view/print the schematic. Here are the links:
    > >
    > >Pspice Schematic:
    > >http://home.earthlink.net/~dankgus/S.../photocell.sch
    > >
    > >BMP Schematic:
    > >http://home.earthlink.net/~dankgus/S.../photocell.bmp
    > >
    > >
    > >PSPICE V9.1 STUDENT VERSION
    > >http://www.orcad.com/Download/Pspice...t/91pspstu.exe
    > >
    > >Have fun!
    > >--Dan
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    >
    >
    >
    >
    >
    >
    Last edited by ForumTools; 10-02-2010 at 12:59 AM. Reason: Forum Migration

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