Help whith Intruder alarm circuit project

Discussion in 'General Electronics Chat' started by Mattia, Feb 6, 2016.

Why isnt my project working???

Poll closed Feb 10, 2016.
  1. Some element is not well positioned

    0 vote(s)
    0.0%
  2. Problem with the cables

    0 vote(s)
    0.0%
Multiple votes are allowed.
  1. Mattia

    Thread Starter New Member

    Feb 6, 2016
    6
    0
    Hello guys!
    Im a student and im having some problems with my electronic project.
    I've followed the step by step instructions for the Intruder alarm but just dont work. I would really aprecciate if you could help me with this project. Then i tried to built it like the persone in the video but still no sound coming out.
    i will paste the link of the elctronic circuit that im using and that i took from the site engineers garage http://www.engineersgarage.com/electronic-circuits/intruderalarm.
    I will post three photos the two with the white background are my project and the third one (the one with the EG logo) is a screenshot of the working project that i took from the explaining video. Thank you and please help me.
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,998
    745
    Post the circuit diagram and we can see what is going on.
     
  3. Mattia

    Thread Starter New Member

    Feb 6, 2016
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    Sorry i forgot
     
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,998
    745
    It will never work, the pnp transistor will short the supply out when the opamp goes low.
    Also the 555 timer is connected wrong, it should be wired as an Astable oscillator.
     
  5. Mattia

    Thread Starter New Member

    Feb 6, 2016
    6
    0
    So how should connect them i tried to connect them like the video guy did because its circuit was working but i dont undersrand how can i fix it
     
  6. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,998
    745
    How do you want to it detect,do you want ant it to buzz when it detects darkness or light?
     
  7. Mattia

    Thread Starter New Member

    Feb 6, 2016
    6
    0
    Yes this is exactly how it supposed to work
     
  8. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    745
  9. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    Here's a circuit that works.
    Capture.JPG
     
  10. Mattia

    Thread Starter New Member

    Feb 6, 2016
    6
    0
    So i should build this on the breadboard?
    Do you have any idea where can i find some photos of a breadboard versione of this circuit diagram that you send to me? I've just started using breadboard and i still dont know how to use it very well
     
  11. Mattia

    Thread Starter New Member

    Feb 6, 2016
    6
    0
    I need the darkness detector but i still have some problema with the breadboard working because i have just started using it.
     
  12. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,998
    745
    You don't need pictures of breadboard, you read the circuit diagram and put the components in their correct positions.

    If you have to look at pictures of how its done, you're clearly not upto it.
     
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