The present invention relates to a power line communication apparatus, standby power saving for minimizing the consumption of standby power in the present application relates to a power line communication apparatus of a synchronous communication using the cross-point zero which is the minimum attenuation of communication noise and signal.
And a coupling circuit which, according to an embodiment of the present invention, and a power supply circuit for supplying the external power source through a transformer, to remove the power supply frequency (60Hz) and the communication frequency (carrier) receives the communication data, the communication noise (Noise) and the ZCP (zero cross point) circuit for detecting a minimum, at which point the attenuation of communication signals, in a power line communication device comprising a communication module for transmitting and receiving a data signal and converted by the coupling circuit and ZCP circuit, the ZCP circuitry in the communications module is connected to the secondary side of the transformer, the ZCP circuitry when low (low) voltage is applied from the photocoupler and the photo-coupler operating in the zero-cross point (zero cross point) point of the AC power supply and that comprises a bipolar transistor for transmitting a pulse signal to a base.
Thus, the present invention is ZCP circuit is connected to the secondary side of the transformer is external power reduced pressure. Therefore, since the ability to change the resistance of removing the resistor connected to the input terminal is relatively low, or the size of the ZCP circuit to minimize power consumption due to the resistance it is possible to reduce the standby power.