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Thread: Manual scanner

  1. #1
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    Default Manual scanner

    Anyone know a way to control the position of scanners using Variable resisitors and two PP3s.

    I need to make a small simple unit for setting scanner possitions without a laptop or DAC.

    I am thinking we can do this with some pots but not sure where to start and maybe somebody already did it.

    +5v -5V X
    +5v -5V Y

  2. #2
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    PP9 battery to a lm7805 for regulated 5 V, then a DPDT switch to flip polarity, followed by a 10K pot. Float the battery ground from the ilda connector.

    Steve

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    Hi Steve

    I was thinking in a cleaner switchless way and have differencial.

    Did you eversee any LPT1 Dac schematics? I did a long time ago and if I remember it was based on two 0-5V DAC chips and some op-amp circuit to get the differencial.

    I suppose what I need is the final stage of LPT DAC circuit and instead of the DAC chips I use pots for X and Y.

  4. #4
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    i'll draw up something this evening

    the 8 norms dacs are single ended.

    I have one here someplace

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    That will be just great of you Steve.

    From what I have been looking up in the past 30 minutes I see I need something very simple like:

    Battery powered ( Maybe 2 x PP3 ) to get + 0 and -
    Opp amp for the + and - swing
    variable resistors for X & Y to give the full scan angles.
    and a sexy little box with a db25 female.

    I suppose we could have a little competition, who does the best one i will send a ..... I must think.

    Ahhh, the winner gets a surpize...
    Last edited by andyf97; 03-26-2009 at 09:12.

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    Here's one that requires no op amps, so it would be rather static insensitive.



    you could use these pots:
    ebay item 360140501329
    with built-in switch to open the battery circuit for shut-off, but you might just want to use a separate power switch so you can turn it off when the galvos are at the middle
    Last edited by drlava; 03-26-2009 at 09:25.

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    That is ok but I need to use only 1 pot per axis as eventually i might want to use an analog joystick instead of the pots.

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    Hi All,

    I've used ICL7660 Voltaage Converters quite a bit. They work great and they're cheap ($1.37 from Digikey).

    Here's links to the data sheet and Digikey:

    http://www.intersil.com/data/an/an051.pdf
    http://search.digikey.com/scripts/Dk...ICL7660CPAZ-ND

    Also, a block diagram of the device andyf97 asked for...

    If you need details, let me know.

    Tim
    Attached Thumbnails Attached Thumbnails Scanner Posn Supply.jpg  


  9. #9
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    Tim,

    Thats looking excellent, can you expand the detail.

    Also I have a feeling I have some ICL7660 some place, the part sounds very familiar.

    I go to search my box of bits.

  10. #10
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    Quote Originally Posted by andyf97 View Post
    That is ok but I need to use only 1 pot per axis as eventually i might want to use an analog joystick instead of the pots.
    That uses 2 pots per axis to create differential outputs with a total differential swing of +/- 10V (the way scanners typically are intended to be driven)

    If you don't need differential, such as trwalters diagram, then only one pot per axis is needed.

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