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

    VHF remote control
    Remote on-off switch
    Frost Detector Temperature Sensor Circuit
    Long Range FM Transmitter
    DMX Controlled Theatrical Phone Ringer
    2001 monte carlo: no wipers noturn signals none of the dash lights
    POWER MOSFET INVERTER
    Audio Monitoring System
    Three phase torque motor speed control circuit



    Top