ELECTRIC POWER LINE RETURN TYPE PROTECTION SYSTEM

摘要

An alarming system using a power line as a signal path includes a number of detecting means (21), a power line supplying AC electricity, an alarming means (20) collecting alarm signals from the detecting means and generating alarm sound, and an alarm sound generating means (22) demodulating the signals modulated in the alarming means. The advantage of this alarming system is that abnormalities can be detected at any place where a power line passes through.