US 2006/0214507 A1 · Power line terminating circuit and method, and power line relay device

Abstract

The present invention provides a power line terminating circuit and method and a power line relay device for setting indoor power lines to a state adapted to communications by making impedances match each other irrespective of a device connected, thereby enabling noise entering from an electric device to the power lines to be reduced. By a capacitor (33) provided between connection ends (35A) and (35B) and an inductor (34) provided between a termination (32A) of an indoor power line (1A) and the connection end (35A), a series resonance circuit having a series resonance point in a frequency band which is higher than a frequency of a power source voltage and is lower than a communication frequency band is configured. A resistor (31) having a resistance value corresponding to a characteristic impedance of the indoor power line (1A) and an indoor power line (1B) is provided in parallel with the inductor (34). Irrespective of the presence or absence and the kind of a load (electric device (5)), an input impedance of a power line terminating circuit (30U) is made constant in the communication frequency band and reflection caused by impedance mismatching at the terminations of the power lines can be prevented. Thus, communication quality of the power line communication can be maintained.

Claims22

Dependent claims

A power line terminating circuit provided at terminations of a pair of indoor power lines where a high frequency signal in a communication frequency band is superimposed on an AC power source voltage, comprising:

a first capacitor provided between the pair of indoor power lines to suppress fluctuations of a capacitive load in an electric device connected to the terminations of the indoor power lines;
one or more inductors provided on the indoor power lines and configuring a series resonance circuit in cooperation with the first capacitor;
and
one or more resistors respectively provided in parallel with each of the inductors,
wherein the series resonance circuit has a series resonance point in a frequency band which is higher than a frequency of the AC power source voltage and is lower than the communication frequency band.

2 more elements

A power line relay device for relaying between terminations of a pair of indoor power lines where a high frequency signal in a communication frequency band is superimposed on an AC power source voltage and an electric device which is supplied with power from the indoor power lines, comprising:

a pair of connection plugs connectable to the terminations of the pair of indoor power lines;
a pair of electric-device-connection sockets to which a power source plug of the electric device can be plugged in;
a first capacitor provided between the pair of electric-device-connection sockets to suppress fluctuations of a capacitive load in the electric device;
one or more inductors provided between the connection plug and the electric-device-connection socket and configuring a series resonance circuit in cooperation with the first capacitor;
and
one or more resistors provided in parallel with each of the inductors,
wherein the series resonance circuit has a series resonance point in a frequency band which is higher than a frequency of the AC power source voltage and is lower than the communication frequency band.

4 more elements

Dependencies are inferred from the claim text.

Power line terminating circuit and method, and power line relay device

Life of this patent

Power line terminating circuit and method, and power line relay device

Life of this patent

Abstract

Claims22