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Northern California — Parallax Forums

Northern California

ArchiverArchiver Posts: 46,084
edited 2000-10-09 23:53 in General Discussion
I'm working with a laser diode module and a
photo detector and was looking for some
help in northern California. Anyone with
knowledge or experience, student or pro?
Thank you...

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-10-07 22:59
    www.gorobotics.net/clubs.shtml - Look here for some folks.
    -William


    Original Message
    From: Hank <fhb2000@p...>
    To: <basicstamps@egroups.com>
    Sent: Saturday, October 07, 2000 3:15 PM
    Subject: [noparse][[/noparse]basicstamps] Northern California


    > I'm working with a laser diode module and a
    > photo detector and was looking for some
    > help in northern California. Anyone with
    > knowledge or experience, student or pro?
    > Thank you...
    >
    >
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-08 03:24
    What are you trying to do? I once designed a circuit (really simple but
    effective) using a photocell to detect a break in a laser beam. The laser
    source was ~650nm and I just used a standard photocell. It was even
    interfaced to a basic stamp. Email me and I can probably dig up the
    schematic. Oh, and I am in Northern California too, but I am sure I can
    help you via email.

    --Dan

    dankgus@e...

    Original Message
    From: Hank <fhb2000@p...>
    To: <basicstamps@egroups.com>
    Sent: Saturday, October 07, 2000 12:15 PM
    Subject: [noparse][[/noparse]basicstamps] Northern California


    > I'm working with a laser diode module and a
    > photo detector and was looking for some
    > help in northern California. Anyone with
    > knowledge or experience, student or pro?
    > Thank you...
    >
    >
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-08 04:20
    I found the schematic, it has been a while since I was working on that
    particular project so I don't remember all the details of the photocell, but
    if I remember correctly, the photocell had a resistance of about 1.5K when
    the laser diode was aimed directly at the photocell and when the beam was
    broken, the resistance went up to around 20K very rapidly. The schematic is
    in PSPICE version 8.0. I used an inverter to interface the
    transistor/photocell circuit to the stamp, kind of a buffer. I had the
    photocell mounted in a tube about 1.5" deep so that ambient light would not
    interfere with the photocell. When the laser was aiming at the photocell,
    the output of the inverter was low. When the beam broke, the output was
    high. The PSPICE Ver 8.0 that I have always used was an evaluation from
    Microsim. I think somebody else bought them out so the demo is available
    from somebody else now. Please don't make fun of my design, it is simple
    and it worked GREAT. I have never felt like an expert with transistors but
    with PSPICE on my side, I can usually design damn near anything. Here is
    the link to the schematic:

    http://home.earthlink.net/~dankgus/SCHEMATICS/photocell.sch

    Let me know if there is any questions.

    --Dan

    Original Message
    From: Dan Gustafson <dankgus@e...>
    To: <basicstamps@egroups.com>
    Sent: Saturday, October 07, 2000 7:24 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Northern California


    > What are you trying to do? I once designed a circuit (really simple but
    > effective) using a photocell to detect a break in a laser beam. The laser
    > source was ~650nm and I just used a standard photocell. It was even
    > interfaced to a basic stamp. Email me and I can probably dig up the
    > schematic. Oh, and I am in Northern California too, but I am sure I can
    > help you via email.
    >
    > --Dan
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-08 19:27
    Thank You !!

    William Cox wrote:

    > www.gorobotics.net/clubs.shtml - Look here for some folks.
    > -William
    >
    >
    Original Message
    > From: Hank <fhb2000@p...>
    > To: <basicstamps@egroups.com>
    > Sent: Saturday, October 07, 2000 3:15 PM
    > Subject: [noparse][[/noparse]basicstamps] Northern California
    >
    > > I'm working with a laser diode module and a
    > > photo detector and was looking for some
    > > help in northern California. Anyone with
    > > knowledge or experience, student or pro?
    > > Thank you...
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-09 23:53
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