Security is the most important area for any civilization. When technology mixed up with our daily life and makes our life easier, a need arises to involve the technology for security purpose.
In this digital era, everything tends to electronic. Electronics arrangements are cheap, more efficient and have smart applications. As a consequence, an electronic security system is more reliable than electro-mechanical system.
In this project our mission is to design such a system which enables a LED or an alarm when any sound (especially human voice) is detected by sound detection technique.
We use a voice condenser as a receiver of voice signal (human voice) and an Op-Amp for amplification purpose.
The Op-Amp is the brain of the system because the comparator configuration of the Op-Amp is mainly responsible for activation of LED or alarm.
The system requires a filter, a peak detector and a predefine resistance – capacitance arrangement. The reference voltage of the comparator is the most important parameter of the system.