Simple Light Sensor Alarm circuit with NE555


Posted on Feb 7, 2014

This circuit sent out an alarm when its LDR sensor is exposed to light by sun or lamp. A 555 astable multivibrator was used here which sent signal a tone of about 1kHz upon detecting light. The sensor when exposed by light completes the circuit and makes the 555 oscillate at about 1kHz with transistor to drive current. Sensitivity can be adjust wit


Simple Light Sensor Alarm circuit with NE555
Click here to download the full size of the above Circuit.

h P1. This makes the sun light to flow through it to the ground and prevents the alarm from going on due to the stored light on the sensor.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Digital-ProfiLab 4.0
    Rain alarm-door bell
    Optical-ttl-coupler
    Digital-frequency-window
    Visual Target Tracking Sysyem
    Inverter/Charger relay
    40V dual power supply
    AVR Interrupts and binary counter
    Solid State Relay Required Only 50uA Drive Current
    Heart-rate And Ekg Monitor Using The Msp430fg439
    Oscillators
    Crosswalk Pedestrian Signal and Homemade Controller



    Top