Light control alarm circuit diagram

Published:2011/4/14 21:01:00 Author:Ecco | Keyword: Light control, alarm circuit | From:SeekIC

As a photoresistor, CL5M4 has a high sensitivity to the reducing of light exposure. Usually, the light from the street lights can provide enough ambient illumination. If there was an activity to steal the window in 3.1m of the device, the light would be weakened, the resistance of photosensitive resistor and SCR controlling pulse amplitude would increase. Then the SCR starts regenerative amplification, the relay pulls in, the sound alarm warns. The SCR in the circuit is not used as a switching element. Potentiometer R4 is used to control sensitivity, adjust the R4, to make SCR receive the positive pulse from the AC power, but the pulse amplitude could not make the SCR produce renewable effects. If S2 turns off, the alarm will stop the warning when the light will not change any more. If S2 is closed, the alarm is in self-locking state, the alarm stops warning by cuting off S1.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Switch_Control/Light_control_alarm_circuit_diagram.html

Print this Page | Comments | Reading(3)