A comparator circuit compares two voltages and outputs either a 1 (the voltage at the plus side) or a 0 (the voltage at the negative side) to indicate which is lager. Comparators are often used for example to check whether an input has reached some predetermined value. In most cases a comparator is implemented using a dedicated comparator IC, but op-amps may be used as an alternative. Comparators consist of various types which include; mechanical comparator, mechanical- optical comparator, Reed type comparator, electrical-electronic comparator and pneumatic comparators. A comparator helps to identify when a given value is zero, it helps to detects each an AC pulse changes polarity, it helps to build a relaxation oscillator, it helps to identify if a voltage is above or below a given threshold. Smart light benefits are increasing day in day out. It renders a lot of benefits ranging from in-home activity for the elderly people, enhancing sleep quality and saving energy consumption as well as indoor navigation. A smart light should be used in homes were elderly people are living since it aids indoor navigation.