20090027175 | Data Transmission Method and Device for A/C Systems - A method for modulating the effective power in one or several power consuming devices disposed in an A/C system in order to transmit data on a power supply line thereof by specifically varying the effective power in the connected device. In order to transmit the data, the momentary value of the effective power is randomly varied (increased or decreased), and the data is impressed into the A/C supply line by a unit (transmitter or modulator) and is evaluated by another unit (receiver or demodulator). | 01-29-2009 |