Abstract: In a remote control system which generates a remote control signal by a temporary short-circuit on the secondary side of a transformer during an influencing period or time span about a zero point transition of the alternating-current mains voltage, a considerable improvement in the receiver-side recognition or detection of the remote control signal can be accomplished by a different determination, in relation to the prior art, of the receiver-side comparison period as concerns its start and duration. There is correlated the comparison period to the course of the receiver-side alternating-current mains voltage before the mains voltage zero transition to be monitorerd. This system may be used in remote control technology using signal transmission on a power supply network.

Abstract: A method of, and apparatus for, the remote transmission of signals over a line, especially via an electrical energy supply network, wherein at the transmitter there is formed from a first auxiliary frequency delivered to the transmitter a signal frequency which is in a predetermined first relationship to the first auxiliary frequency, an auxiliary signal characteristic of the first auxiliary frequency and the signal frequency are transmitted via the same transmission channel or via different transmission channels to at least one receiver, and at the location of the receiver there is formed from the signal characteristic of the first auxiliary frequency a second auxiliary frequency which is in a predetermined second relationship to the first auxiliary frequency, and such second auxiliary frequency is delivered to a sampling filter for controlling its throughpassage characteristics.