ABSTRACT
The technology of power line communication with carrier has two kinds, one is the narrow-band communication with the carrier, the other one is a broadband communication with the carrier, and low-voltage power line communication adopts the narrow-band communication with the carrier. Easy-installation and cheap-price of Power Line result in the wide application of Low-Voltage Power Line Carrier Communication Technology, but the interference of noise is great, for example harmonic signal, so the efficiency of power line carrier communication is affected and the device of power line carrier communication is damaged. Power line communication release information transferred by using the power line available. The price is cheaper than others, so the power line communication is widely applied to lowvoltage reading device. The low-voltage power line communication is applied, but the device in the circuit is damaged during the applying. The circuit is reliably protected by the combination of two dereliably protected by the combination of devices.
