Communicating over power lines

摘要

An audiofrequency signal is applied to a power amplifier having an output impedance of considerably less than an ohm that is coupled through a network comprising at least a capacitor that presents a low impedance to this audiofrequency signal and much higher impedance to energy at the 60 Hz power frequency to a power line to provide an amplified signal that is transmitted to a receiver separated from the transmitter by at least one distribution transformer and having a high pass filter for rejecting the 60 Hz power frequency and a number of harmonics thereof while transmitting the audiofrequency signal. The system is especially advantageous for using ordinary power lines for transmitting information in connection with automatic meter reading.