Sound-activated-switch


Posted on Oct 27, 2012

Al and A2 are two sections of a quad comparator. The first, Al, functions as an amplifier and detector. Resistors R~and R6 set the gain at 100; the output of Al is an open collector to negative-peak-rectify the output with a decay time constant determined by R9 and C3. This de output is then compared with the reference level selected by RB.


Sound-activated-switch
Click here to download the full size of the above Circuit.

A2 triggers switch Ql, and an LED inserted in the base drive of Ql gives visual indication of switch closure. The standby battery drain is 2 mA. Use potentiometer R8 to select the desired sensitivity.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Filter Wiz PRO
    Hi-Fi stereo Preamplifier with tone controls
    Fast Symmetrical Zener Clipper
    0-24VDC Digital PIC Power Supply circuit diagram
    555 Voltage Doubler Relay Driver
    solar charge
    clk3 binary alarm clock
    phone busy circuit
    vhfuhf tv modulator
    Flashflex Microcontroller Control Of Character Lcd Module
    Dual AC radio remote control switch circuit diagram
    Source suspended programmable instrumentation amplifier PGA203
    XTR105 RCV420 composed of 12V power transmission reception circuit diagram of the ring



    Top