POWER LINE COMMUNICATION CIRCUIT.

摘要

A power line communication circuit (10) comprises a rectifier (20) connected to an a.c. power line utility source (12). The rectifier (20) draws power from the a.c. power source (12) and produces a low-frequency rectified d.c. voltage across its positive and negative output terminals with the negative output terminal (32) being referenced as a circuit ground. The rectified d.c. voltage signal is received by a voltage-to-current converter (38) connected to the positive output terminal (30) of the rectifier. The voltage-to-current converter (38) also receives a high-frequency a.c.-shaped communication input voltage signal from an external high-frequency a.c.-shaped communication signal generator. In response to the two input voltage signals, the voltage-to-current converter (38) generates an output current which contains a low frequency d.c. component from the rectified d.c. input voltage signal and a high frequency a.c.-shaped component from the a.c-shaped high frequency communication input voltage signal. The high frequency a.c.-shaped communication component is superimposed on the low frequency d.c. component to place communication data signals on the a.c. power line.