Room Noise Detector Circuit Schematic


Posted on Feb 5, 2014

This circuit is intended to signal, through a flashing LED, the exceeding of a fixed threshold in room noise, chosen from three fixed levels, namely 50, 70 & 85 dB. Two Op-amps provide the necessary circuit gain for sounds picked-up by a miniature electret microphone to drive a LED. With SW1 in the first position the circuit is off. Second, third


Room Noise Detector Circuit Schematic
Click here to download the full size of the above Circuit.

and fourth positions power the circuit and set the input sensitivity threshold to 85, 70 & 50 dB respectively. Current drawing is 1mA with LED off and 12-15mA when the LED is steady on. The 50 dB setting is provided to monitor the noise in the bedroom at night. If the LED is steady on, or flashes bright often, then your bedroom is inadequate and too noisy for sleep.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Phone Bill Calculator
    100W 420-450Mhz push-pull linear amplifier
    Make this Astable Multivibrator Blinker Circuit Using NAND Gates
    charging small nimh battery from air by
    Simple AM radio
    The signal processing circuit



    Top