초록 ▼

In a system for communicating information over a power line network, connection of power loads is interrupted in the vicinity of zero crossings of the A.C. power line waveform to provide a high impedance condition during which the transmitters and receivers of the power line communication carrier sy

In a system for communicating information over a power line network, connection of power loads is interrupted in the vicinity of zero crossings of the A.C. power line waveform to provide a high impedance condition during which the transmitters and receivers of the power line communication carrier system can be efficiently coupled to power network transformer secondary windings in order to improve communications reliability. The communications apparatus is coupled to the secondary winding through a capacitance, chosen to substantially series-resinate the leakage inductance presented by transformer secondary winding. Each load is connected through an interruption device to the secondary winding, with the interruption device interrupting the flow of current from the secondary winding to the associated load, responsive to both detection of each zero crossing of a power distribution network voltage waveform and to the presence of the power line carrier communications signal.

대표청구항 ▼

Apparatus for use in a power line carrier communications system having at least one load connected through a transformer to a power distribution network having a periodic network waveform voltage thereon, comprising: at least one means for selectively interrupting current flow to an associated power

Apparatus for use in a power line carrier communications system having at least one load connected through a transformer to a power distribution network having a periodic network waveform voltage thereon, comprising: at least one means for selectively interrupting current flow to an associated power-consuming load, responsive to an interruption signal; means for detecting zero crossing of the network waveform voltage to provide an output signal to said interrupting means as said interruption signal to cause said interrupting means to interrupt current flow to said associated load for a time interval of predetermined duration in the vacinity of each network waveform zero crossing; communications means associated with at least one of said at least one load for transmitting and/or receiving power line carrier communications signals to and/or from said network when said interrupting means has interrupted current flow to said associated load; and an impedance element connected in series between said communications means and said transformer, said impedance element having a reactance selected to neutralize at least a portion of the leakage inductive reactance of said transformer to which said element is connected, at the carrier frequency of said power line communications signal.