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Laser Burglar Alarm -- Need Help

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

  1. john1

    john1 Active Member

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    Briefly,
    the transistor starts in the off position (not conducting)
    until some current through its base will allow it to conduct E to C
    so all is well so far.

    Now to allow it to conduct we will introduce some current through its base.

    Okay ... ?
     
  2. Anonymous321

    Anonymous321 New Member

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    Wait! Not yet, please! Did you see my post from above?
     
  3. john1

    john1 Active Member

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    hard to gauge sizes ...
    will the resistor 33K reach from number 1 terminal
    to number ten terminal ... ?

    Just to touch it on while holding it.
     
  4. dave

    Dave New Member

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  5. john1

    john1 Active Member

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    dont worry,
    battery not on yet ...
     
  6. john1

    john1 Active Member

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    you mean the wattage .. ?
    just use the one with the longest legs.
    i don't think we will be driving it hard.
     
  7. Anonymous321

    Anonymous321 New Member

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    Ok, please hold on while I open the package for the 33k. Sorry for taking so long.
     
  8. john1

    john1 Active Member

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    Thats Ok,
    but its late here, i will have to go to bed after a while.
     
  9. john1

    john1 Active Member

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    you might have to re-position the connections on No 10
    to go on No 6
     
  10. Anonymous321

    Anonymous321 New Member

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    Yeah, I understand. I'm really sorry for keeping you up. Ok, so I have the 33k. Orange, orange, orange, gold stripes.
     
  11. john1

    john1 Active Member

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    will it touch on both No1 and No 10 at the same time,
    with you holding it ?
     
  12. Anonymous321

    Anonymous321 New Member

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    I changed +ve of siren to number 6. And have resistor going from base to +ve of siren (1-6).
     
  13. Anonymous321

    Anonymous321 New Member

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    So you said to introduce some current through its base? How so? Have a wire from +ve of 9V to base?
     
  14. john1

    john1 Active Member

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    And also i hope the battery wire + to No6.
    please remove the resistor,
    as we only want to touch it across from 1 to six,
    briefly, to see what reading we get.

    Will it touch across easily with you holding it ?
     
  15. Anonymous321

    Anonymous321 New Member

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    Yes, it will. But let me get this straight:
    You want me to:
    - have a wire from +ve of 9V to base
    - +ve of 9V to No 6
    - resistor to be able to touch 1 and 6 but not actually fitted in spring
    Is that correct?
     
  16. john1

    john1 Active Member

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    Not Quite.
     
  17. Anonymous321

    Anonymous321 New Member

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    What's the error?
     
  18. Anonymous321

    Anonymous321 New Member

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    John, are you there?
     
  19. john1

    john1 Active Member

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    No error really, just should be same as before,

    pos of 9v to No6,
    pos of siren to No 6,
    Neg of siren to No11,
    Collector to No 2 and across to No 11,
    Emitter to No3 and over to neg of 9v.

    really, same as before, but using 6 instead of 10

    Okay?
    So really no change at all, so far.
     
  20. john1

    john1 Active Member

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    alright so far ?
     
  21. Anonymous321

    Anonymous321 New Member

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    Ok, and what about the Base to 1 and then 1 to +ve of 9V?
     

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