This light activated relay circuit presented here uses the 555 timer IC and a light dependent resistor or LDR to form a light sensitive relay in an intruder alarm system or for switching on a lamp at ...

Looking for a light project to teach young hackers some very basic electronics? Here’s a quick and easy weekend project, a simple metal detector ... and the 555 timer in turn, varies the ...

This motion detector alarm can detect a ... the trigger pin2 of a short duration Monostable timer built around IC NE 555. With the given values of R4 and C2, output of IC1 remains high for two minutes ...