Use of Frequency Modulation Technique to Improve Security System
A wireless fire alarm and other passive circuit elements has been designed and implemented. The designed alarm circuit could detect any kind of smoke and generate an alarm signal that would be sent to the control room by frequency modulation technique. The designed transmitter could operate around 100 MHz. A monopole antenna has been used for transmitting the signal carrying the information in the free space. An antenna length of 41cm has been used for the design convenience. The transmitting signal has been successfully received at a distance of 53 feet without any disturbance by FM receiver.