LED VU Meter

Posted on Feb 5, 2014

The circuit below uses two quad voltage comparators (LM339) to illuminate a series of 8 LEDs indicating volume level. Each of the 8 comparators is biased at increasing voltages set by the voltage divider so that the lower right LED comes on first when the input is about 400 millivolts or about 22 milliwatts peak in an 8 ohm system

LED VU Meter
Click here to download the full size of the above Circuit.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Car Speed limit Alarm
    Astable oscillator
    Flip-Flop Independent Lamp Driver
    Production of automatic re-set timer for crime prevention buzzer that uses PIC
    STHS Computer Technology
    power supply variable with lm338
    usb 5v to 12v dc dc step up converter
    120 vac lamp dimmer
    Tilt Sensor Alarm Circuit
    Speed Alarm For Cars
    Temperature-Controlled Soldering Iron
    Open Source USB Generic HID devices based on the PIC18F and Windows
    AC motor integrated Hall element off the circuit diagram
    Pure CL B amplifier circuit