Arrangement and method for providing power line communication from an ac power source to a circuit for powering a load, and electronic ballasts therefor

Abstract

An arrangement () and method () for providing power line communication from an AC power source () to a circuit () for supplying power to a load (), as well as electronic ballasts () that operate according to the method (). Method () includes the steps of: providing () an AC power source () that includes hot, neutral, and ground wires () and a control station () for generating a power line carrier control signal; providing () a power supply circuit () having an EMI filter (), power processing circuitry (), and a power line communication (PLC) circuit (); setting () a fundamental frequency of the power line carrier control signal to be about equal to either an effective common-mode resonant frequency of the EMI filter () or a harmonic thereof; injecting () a power line carrier control signal between the neutral and ground wires () of the AC power source (); detecting () the power line carrier control signal by monitoring a current flowing from the ground wire () to a circuit ground (); and directing () the power processing circuitry () to control load power in dependence on the detected power line carrier control signal. Specific preferred embodiments are directed to electronic ballasts () that include various PLC circuits ().