Development of snooping phone system / Nor Hisham Abbas

This thesis describes the development of a snooper phone system for security purposes. This device is intended to be implemented as intrusion detection and listening device for checking home, office and etc. It may also be used to trigger other electrical devices in the premise via a switching relay or other electrical apparatus to perform the same function. Making a call to the telephone line activates the device. The caller will be able to listen to the signal generated by the intruder. For testing purposes, the output obtained is fed to a speaker via matching transformer such that any intrusion will produce audio signal. In normal use, the audio signals that were being picked up will be transmitted through the telephone line. The operating frequency range is 200 Hz up to 30 kHz. The system has been tested in the laboratory for the performance identification and discovered that this system is possible to be implemented in real world application with the incorporation of a hybrid component prior to the actual telephone line.