Device for sending and receiving data through power distribution transformers

摘要

A powerline communication system including a transmitter having a pair of terminals for connection to the power lines. The transmitter comprises a carrier frequency generator for generating a carrier frequency modulated by the data signal and a switching circuit connected to the carrier frequency generator for being switched by the carrier frequency generator for generating a carrier signal having the carrier frequency. The switching circuit is connected to the terminals for providing the generated carrier signal thereto. The switching circuit comprises at least one storage means for storing energy when generating a portion of a cycle of the carrier signal and providing the stored energy when generating another portion of the cycle of the carrier signal. The system also comprises a receiver coupled to the power lines. The receiver includes a filter means for filtering the carrier signal from the power line signal and a demodulator connected to the filter means for extracting the data signal from the carrier signal. Both the transmitter and receiver may utilize a digital algorithm in a computing device to synchronize the carrier signal to the power line frequency to adaptively track changes in the power line frequency to minimize interference with power line harmonics and provide accurate frequency alignment between the transmitter and receiver.