Police Siren

Discussion in 'Circuits' started by Admin, Apr 17, 2013.

  1. Admin

    Admin Administrator Staff Member

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  2. Konrad

    Konrad Member

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    Hi,
    I've just put together this circuit and all I'm getting is a single intermittent note, part of a two tone. Certainly not wailing. Any ideas where I've gone wrong? Made sure all the components are secure and that the circuit is as shown on the schematic. Unable to upload a photo of my circuit constructed on a breadboard, message just said file too large doh!! Any idea moderator why a single photo is too large to upload?
    Konrad :eek:
  3. Justin

    Justin Member

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    I think this forums limit is 50kb. Try uploading it onto a different site and just post the link on the forum. If you're already trying on another site, tell me what the file size of the photo is and I can help you more.
  4. Admin

    Admin Administrator Staff Member

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    Hi Konrad,

    I have just increased the file upload limit. Please try to upload your photo again.

    Regards,
    Admin
  5. Konrad

    Konrad Member

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    Thanks. I have found where I went wrong with this circuit. For some reason I had put two links in between pin 3 of the first ic and pin 5 of the second ic, one with the 10k resistor and the other without, that's why I was only getting the single tone. I've removed the one without, works fine now. I have made a few changes and have come up with a much more realistic sound, not so much the tone but the speed between tones. Substitute the 68k resistor between pins 6 and 7 on the first ic with a 100k resistor and it slows the sequence down just enough to give a very realistic experience. Almost like being back on the fire engine. One other mod I have made is to place a plastic container over the 8 ohm speaker held in place with a 'lacky' band. I will try and post a picture of the set up later on. It would be good if the size could be increased to accept video as well. I'll try it just in case it accepts it. auf wiedersehn,

    Konrad ;)
  6. Konrad

    Konrad Member

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    Police siren on breadboard.

    Konrad :)

    Attached Files:

    Justin and Admin like this.
  7. Justin

    Justin Member

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    That's pretty cool, you said that you managed to change how it sounds. Mind posting a video if its still constructed?
  8. Konrad

    Konrad Member

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    It's still constructed but I'm not sure that it will be of a size acceptable for uploading here. Videos, even short ones take a lot of space. Perhaps the moderator could give us advice on whether or not a short video would be ok.

    Konrad :confused:
  9. Admin

    Admin Administrator Staff Member

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    The best way is to upload the videos to youtube and then embedding them here.
  10. dasari

    dasari New Member

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    Can this circuit work with input of 3.66V ??.
    BecausE I want to attach this to a fire alarm.
  11. Fleck

    Fleck Member

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    Build it and try it, it might be a bit low at 3v so maybe use the voltage doubler circuit? Just an idea.
  12. dasari

    dasari New Member

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    I built it.It is not even giving sound out.
    My bad luck is voltage doubler also needs input of 5V to 15V
  13. Daithi

    Daithi Member

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    Is it possible to substitute a 556 chip for the two 555's?
  14. George

    George Moderator

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    Yes, that is what a 556 is, just 2 555 timers in one 14 pin chip.
  15. Daithi

    Daithi Member

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    Got it to work as shown with the two 555's and also with the 556... Inserted a 1k pot between the second capacitor and the speaker for volume control... Worked great...
  16. Ofa Tilini

    Ofa Tilini New Member

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    sorry admit I tried connecting the circuits according to the schematic diagram but it only gives me a 1 sound not a two sound... can you help me please admin.... I am trying to get this work.. please..
  17. Fleck

    Fleck Member

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    Maybe the breadboard is faulty. I always use veroboard. You can't beat proper solder connections.
  18. MarkoP

    MarkoP New Member

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    Hello to to you all,
    I am quite new as hobbyist to small electronics so please be gentle with comments.
    I have tried to assemble the shown "police siren" circuit with 9V battery (10k, 68k, 1k to bridge the two ne555 and two 1k for second NE555 with 104 and 10 microF) and I have no sound out of speaker.
    Here is my breadboard. I would be trilled if anyone could help me out to solve the problem.

    Attached Files: