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Laser Burglar Alarm -- Need Help

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Anonymous321, May 4, 2008.

  1. Anonymous321

    Anonymous321 New Member

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    I was worried you were gone there for a sec, even though you were online.
     
  2. john1

    john1 Active Member

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    can you tell me what the blue drawings are under the springs .....

    Or is there really nothing there ... ?
     
  3. Anonymous321

    Anonymous321 New Member

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    There are blue lines connecting springs. But those are just labels that were part of the box. You can ignore them. The labels mean nothing.
     
  4. dave

    Dave New Member

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  5. john1

    john1 Active Member

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    sorry to keep you,
     
  6. Anonymous321

    Anonymous321 New Member

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    It's absolutely ok. I just hope that we will be able to accomplish something here. My heart's going to be pumping at 10beats/second until this whole ordeal is over.
     
  7. john1

    john1 Active Member

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    Okay, so there arent components and stuff underneath, its just labels on the box.

    The transistor in that last pic,
    cant quite see which leg goes where ....
     
  8. john1

    john1 Active Member

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    I take it that its placed as per the blue drawing , yes ?
     
  9. Anonymous321

    Anonymous321 New Member

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    The spring where the red wire goes down to the -ve of 9V is the emitter. The spring where the red wire goes to the -ve of the siren is the collector. The other silver thing going up to the spring with no red wire coming/going from it is the base.
     
  10. Anonymous321

    Anonymous321 New Member

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    Only the transistor and the 9V battery clip are placed according to the labels on the box. The siren (and the wires coming to it) are in the resistors section.
     
  11. john1

    john1 Active Member

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    Okay.
    stick your voltmeter across the siren connections,
    and connect the battery briefly, then disconnect the battery.

    Any siren sound ?
    Any voltage show on the meter ?
     
  12. john1

    john1 Active Member

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    Just to check,
    the transistor is the NPN type, yes ?
     
  13. Anonymous321

    Anonymous321 New Member

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    No siren. No voltage.
     
  14. Anonymous321

    Anonymous321 New Member

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    Yes, it is. I'm a little afraid that it may be busted from so much previous use. So I might just pluck in another one.
     
  15. Anonymous321

    Anonymous321 New Member

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    Is everything going according to plan?
     
  16. john1

    john1 Active Member

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    dont change anything,
    its fine
     
  17. Anonymous321

    Anonymous321 New Member

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    Ok, I won't. Oh ok.
     
  18. john1

    john1 Active Member

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    could you now pick a resistor, around thirty K please.
     
  19. john1

    john1 Active Member

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    Ha,
    my last post crossed with yours,
    and i thought for a minute you were going to pull it apart!

    When i edited, i saw you noted my post before i edited !
     
  20. Anonymous321

    Anonymous321 New Member

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    The closest one I have is 33k. Should it be 1/4 or 1/8 watt?
     
  21. Anonymous321

    Anonymous321 New Member

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    Haha yeah. Instant messaging.
     

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