Light-Beam Alarm For Intrusion Detection Circuit

  
When the light beam that falls in the CDS photocell is interrupted, transistor (EN3904) conducts thereby triggering SCR1 (CI06) and activating alarm bell. SI resets the SCR. The alarm bell should be a self-interrupting electromechanical type.
Light-Beam Alarm For Intrusion Detection Circuit - schematic

Lamp should draw at least 100 mA to sensure SCR1 remaining on during alarm cycle




Leave Comment

characters left:

New Circuits

.