Double beep circuit

Discussion in 'General Electronics Chat' started by sebastianpatten, Mar 1, 2011.

  1. sebastianpatten

    Thread Starter New Member

    Nov 28, 2010
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    Hi there I've been looking for a double beep circuit. For example something that would do two beeps quickly, back to back then a pause and repeat.

    Any ideas on where i can start?

    Many thanks!
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    Use a CMOS 555 timer wired as an astable multivibrator for a clock pulse to drive a 4017 5-stage Johnson counter. Use 10k Ohm resistors from the 1st and 3rd outputs to the base of a Darlington transistor that has its' emitter grounded, and connect the buzzer between the collector and +V.
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    Or two 555s, one fast, one slow, both oscillators.
     
  4. sebastianpatten

    Thread Starter New Member

    Nov 28, 2010
    18
    0
    Thanks guys - any diagrams to go with your answers? It would be of great help.
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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    Have a look at the attached. I used a 4093 quad Schmitt trigger NAND instead of a 555 timer; makes for a low parts count. As shown, it gives 2 quick beeps every ~1.5 seconds.

    Power connections to the ICs are not shown, neither are 0.1uF ceramic or poly bypass capacitors, which are required.

    I don't know what kind of buzzer/beeper you'll use. This circuit should be good for one that requires up to 120mA at 12v.
     
  6. sebastianpatten

    Thread Starter New Member

    Nov 28, 2010
    18
    0
    Wicked thank you for taking the time SgtWookie - it really is appreciated. People like you help make the world turn round and be a better place.

    Have a great day!
     
  7. sebastianpatten

    Thread Starter New Member

    Nov 28, 2010
    18
    0
    Cool - I've learned about Schmitt triggers and Decade counters now :)
     
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