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You are here: Home / Topics / Intruder Alarm

Intruder Alarm

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Electronics › Electronics › Intruder Alarm

  • This topic has 9 replies, 3 voices, and was last updated 10 years, 4 months ago by Ashutosh Bhatt.
Viewing 10 posts - 1 through 10 (of 10 total)
  • Author
    Posts
  • December 16, 2014 at 4:45 pm #3353
    Karthick Pandy
    Participant

    http://www.engineersgarage.com/electronic-circuits/intruderalarm

    What is the voltage of the capacitor(100 uF) they have used here?

    In the circuit diagram they have given capacitor(100 uF) goes with 3rd pin of 555timer. But in the video C-100uF is connected to 6th pin of 555timer. plz explain. .?

    December 17, 2014 at 6:31 pm #12425
    Ashutosh Bhatt
    Participant

    i think there is some mistake in the circuit diagram

    the IC is configured in monostable mode. so at pin 6-7 there must be a capacitor connected

    December 26, 2014 at 2:18 pm #12462
    Karthick Pandy
    Participant

    I tried both the ways. But still it doesn’t work properly. Any suggestion on the changes in circuit configuration?

    December 29, 2014 at 6:02 am #12469
    AJISH ALFRED
    Participant

    Remove the end of capacitor from pin3 and connected that end of capacitor to pin6, it should work. If you still have confusion please refer any monostable circuit based on 555.

    December 31, 2014 at 6:50 am #12476
    Karthick Pandy
    Participant

    Buzzer just simply goes on without any intruder, when I use in monostable based model.

    December 31, 2014 at 11:05 am #12478
    Ashutosh Bhatt
    Participant

    there may be some other problem. its very simple and streight forward circuit

    check voltage at pin no 2 of IC. it will be always low

    January 1, 2015 at 7:48 am #12486
    AJISH ALFRED
    Participant

    Hi Karthick,

    Lets fix it !! There is a short circuit shown between the emitter or transistor and 5V. Replace that short circuit path with a resistor of 330ohms or 1Kohms. 

    January 1, 2015 at 1:12 pm #12488
    Karthick Pandy
    Participant

    I tried all possible methods you have suggested! It doesn’t work. I have attached a image, just check it and give your opinion. Thank u all in advance!

    wysiwyg_imageupload:14228:

    January 2, 2015 at 11:07 am #12492
    AJISH ALFRED
    Participant

    Hi,

    In previous posts I mentioned to connect a resistor 1K from emitter of transistor to VCC, it is not connected in the image. The positive pin of the capacitor should be connected to pin6 of 555 and the negative pin should be connected to the ground.

    January 10, 2015 at 11:04 am #12513
    Ashutosh Bhatt
    Participant

    this is very easy and streight forward circuit to build-run and test. this should not create such big problem. if you just go through basics of IC555 you can easily build your own circuit. 

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