Patent ID: 8378810
Filing Date: 2013-02-19
Classification: G01C,G08G,H04H

Abstract:
1. A communication device comprising: a power supply line for supplying electric power; a receiver circuit, connected to the power supply line, for receiving a communication signal from an external site and outputting a reception signal to a signal processing circuit through the power supply line, a set of resistors, connected in series between the power supply line and ground, that divides a power supply voltage of the power supply line thereby producing an offset potential; a power/signal common line connected to the power line; a capacitor connected between the power/signal common line and the set of resistors to produce only an AC component signal of the reception signal, which varies relative to the offset potential; a low pass filter, connected to the capacitor, for passing the noise of the predetermined frequency as a reference signal and cutting off the AC component signal of frequencies higher than the predetermined frequency; and a comparator, provided to receive the AC component signal produced from the capacitor and the reference signal from the low pass filter, for producing an output data signal as a result of a comparison of the reception signal and the reference signal.