Power line communication apparatus, and method and apparatus for controlling electric devices
A power line communication apparatus, device control apparatus, and device control method are disclosed. By controlling the phase of AC power with reference to a zero cross point during power line communication, the power line communication apparatus enables not only data to be transmitted and received in a manner robust against noise and impedance but also the receiving end to be miniaturized. The power and operation of household devices can be controlled through the power line communication apparatus, thereby eliminating the need for separate communication networks when a remote control system is built in the home.
1. A device control apparatus for controlling devices connected to a power line, comprising:
a power control unit generating a control message to control a device connected to a power line according to a user selection, and generating a power control message including device address information and a control command by controlling a phase of AC power carried by the power line; and
a plurality of devices, each performing an operation according to the control command of the power control message in response to the power control message addressed thereto,
wherein the power control unit generates the power control message by controlling the phase of the AC power by turning off the AC power between 1/16 and ¼ of at least one of a positive-polarity half cycle and a negative-polarity half cycle of the AC power to cut the phase of the AC power; and
the device connected to the power line comprises:
a delayer delaying the phase of the AC power carried by the power line;
a comparator comparing the phase-delayed AC power to a normal-phase AC power; and
a controller analyzing an output from the comparator to detect the power control message and controlling an operation of the device according to the control command of the power control message in response to the device address information of the detected power control message addressed to the device.
2. The device control apparatus according to claim 1 , wherein the power control unit comprises:
a zero-crossing detector detecting a zero cross point of the AC power;
a controller analyzing the control message and outputting a power control signal in a manner synchronized with an output of the zero-crossing detector, the power control signal comprising device selection information for power control and operation control information for a selected device; and
a phase controller controlling the phase of the AC power carried by the power line according to the power control signal to output the power control message to the power line.
3. The device control apparatus according to claim 1 , wherein the power control message comprises:
start information indicating an initiation of the power control message;
device address information indicating the device to be controlled;
a control command controlling an operation of the device to be controlled; and
end information indicating an end of the power control message.
4. A method of controlling devices connected to a power line, comprising:
generating a control message to control a device connected to a power line according to a user selection;
generating a power control message including device address information and a control command by analyzing the control message and controlling a phase of AC power carried by the power line, wherein the controlling of the phase of AC power comprises turning off the AC power between 1/16 and ¼ of at least one of a positive-polarity half cycle and a negative-polarity half cycle of the AC power to cut the phase of the AC power;
analyzing the power control message in a plurality of devices connected to the power line; and
controlling at least one of the devices to perform an operation according to the control command of the power control message in response to the device address information of the power control message addressed thereto;
wherein the analyzing of the power control message comprises:
delaying the phase of the AC power carried by the power line;
comparing the phase-delayed AC power to a normal-phase AC power; and
determining whether the power control message has been generated through analysis of the comparison result, followed by performing the operation by the associated device according to the control command of the power control message in response to the device address information of the power control message addressed thereto.
5. The method according to claim 4 , wherein the generating of the power control message comprises:
analyzing the control message and synchronizing a power control signal with a zero-cross detection signal, the power control signal comprising device selection information for power control and control information for a selected device; and
outputting the power control message to the power line by controlling the phase of the AC power carried by the power line according to the power control signal.
6. The method according to claim 4 , wherein the power control message comprises:
start information indicating an initiation of the power control message;
device address information indicating the device to be controlled;
a control command controlling an operation of the device to be controlled; and
end information indicating an end of the power control message.