Clap switch not working properly

Discussion in 'The Projects Forum' started by Ishan Jain, Jul 19, 2017.

  1. Ishan Jain

    Thread Starter Member

    Nov 12, 2016
    100
    1
    Hello Folks! I am making a clap switch activated relay circuit in which the bulb will glow on first clap and will shut off on the second clap. The circuit is working but in order to make it work I have to clap very hard as well as close to the condenser mic which makes it unsuitable to use for any application. So please let me know how can I increase the sensitivity of the circuit? Whether by using any other condenser mic of higher range and sensitivity or amplifying the output of the condenser mic and then feeding it to the 555 Timer. The circuit diagram is attached.
     
  2. JohnInTX

    Moderator

    Jun 26, 2012
    3,323
    1,665
    Search AAC for 'clap switch' . We have several threads on the subject. If you still have questions, ask them in this thread.
     
  3. dl324

    AAC Fanatic!

    Mar 30, 2015
    6,958
    1,609
    We need information on your condenser mic. You could try a darlington transistor configuration, but I'd replace the transistor with a comparator which would make it easier to set sensitivity.

    I'd also do something about the supply voltage or the flip flop. 74S won't tolerate VCC=9V well. You should also use a current limiting resistor with the LED because the outputs don't like low resistance loads.

    There are a lot of questionable schematics on the internet; this is one of them. At least the author didn't embarrass himself by putting his name on it.
     
    JohnInTX likes this.
  4. Ishan Jain

    Thread Starter Member

    Nov 12, 2016
    100
    1
    Thanks for your suggestion but the main concern here is increasing the sensitivity of the condenser mic so that it works on slow claps despite of this circuit is working fine and at the output of 74S, I am connecting relay as I want to actuate it using the clap sound. The condenser mic which I am using is electret microphone and the image is attached.
     
  5. jjw

    Member

    Dec 24, 2013
    236
    34
    It is a bad circuit.
    The transistor is always saturated.
    The mic is biased at Vbe of the transistor, about 0.7V, which is too low.
    It is wonder, if you get any response from the circuit.
    Search for a condenser mic amplifier.
     
  6. Ishan Jain

    Thread Starter Member

    Nov 12, 2016
    100
    1
    if the transistor is always saturated what can I do to correct this and can you provide a simple circuit for condenser mic amplifier.
    Thank you
     
    Last edited: Jul 19, 2017
  7. jjw

    Member

    Dec 24, 2013
    236
    34
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