Abstract: The present invention concerns an intelligent electric switching device designed to secure electric energy distribution systems; the device is characterized in that it includes, in a single physical unit: an electric switch through which an electric power network passes; a measurement means assembly including one or more measurement means; a network communication means, connected to a communication network; a memory storage means permitting storing all the measurements conducted on the electric switching device an the data coming from the communication network means; a decision means analyzing the stored and controlling the electric switch; decision means being connected to electric switch, to measurement means, to communication network means and to memory-storage means.

Abstract: An echo canceller is used to cancel an echo signal occurring in the receive path of a data transmission modem in response to the signal appearing in the transmit path. This echo canceller comprises a controllable digital filter connected to the transmit path and adjusted by means of a control circuit, a difference circuit producing a residual signal resulting from the difference between the signal in the receive path and the synthetic echo signal supplied by the filter and an analog-to-digital converter which converts the residual signal into a digital control signal for the control circuit. In order to have the echo canceller function in a homochronous transmission system with an analog-to-digital converter having a reduced number of bits, the converter is controllable and is adjusted by the output signal of an attenuation circuit connected to the output of a circuit which detects the peak value of the residual signal.