Dark-activated LED or Lamp Flasher


Posted on May 11, 2012

This circuit adopts the rather unusual Bowes/White emitter coupled multivibrator circuit. The oscillation frequency is about 1Hz and is set by C1 value. The LED starts flashing when the photo resistor is scarcely illuminated. The onset of flashing can be set by trimming R2.


Dark-activated LED or Lamp Flasher
Click here to download the full size of the above Circuit.

* Best results in flashing frequency can be obtained using for C1 a value in the 100 - 1000µF range. * To drive a filament lamp make the following changes: Use a 2.2 to 3V, 250-300mA bulb in place of the LED R2 = 10K 1/2W T




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Nocturnal Animals Whisker
    Audio Detector switch
    H-bridge circuit using NPN transistors
    LED Drivers/LCD Bias
    microcontroller Generate a reset signal from a falling edge trigger
    audio preamplifier
    control of remote domestic system
    Modular Burglar Alarm
    PERIOD TO VOLTAGE CONVERTER
    MC1411 series of Darlington Drive current internal structure



    Top