The Motion Sensor for Security Light system uses Passive infrared sensor. These sensors are capable of sensing the presence of human being and post the same to the compar ator IC. Now the micro comparator takes the responsibility of processing and judges the status of individual appliances and there by controls them using switches like relay, TRIAC. The most important thing to be noticed here is the system is aimed for industrial, home, firm needs. So, there may be very high voltage devices like ACS and very low voltage devices like High intensity LEDS. Due to the presence of different appliances of different power ratings the design of the interfacing circuit should be done with utmost care.