POWER LINE COUPLING CIRCUIT AND POWER LINE CARRIER COMMUNICATION ADAPTER

摘要

PROBLEM TO BE SOLVED: To provide a power line coupling circuit and a power line carrier communication adapter in which power line carrier communication can be stably performed even on an light cable generating the noise of large amplitude in a specific frequency band. SOLUTION: A power line coupling circuit 10 is provided with an insulating transformer 11 for electrically insulating a commercial lighting wire and a power line carrier MODEM, a capacitor 12 connected between a primary winding of the insulating transformer 11 and the commercial lighting cable while having operation for passing only a high frequency signal by cutting a commercial frequency component, an amplitude limiting element 13 connected parallel to the primary winding of the insulating transformer 11 while having operation for absorbing an excessive noise voltage, and an impedance circuit 14 connected parallel to the primary winding of the insulating transformer 11. The impedance characteristics of the impedance circuit 14 are set so that impedance can be reduced in the frequency band range with noises mostly generated from electrical equipment in domestic use.