logical circuit to command a cultural of solid state switches

摘要

A logic circuit is described for controlling a plurality of solid state switches in a wired broadcasting system. The circuit is arranged to distinguish between dialling and reset pulse signals applied to an input, and has a plurality of outputs to which the solid state switches are connected. The circuit sequentially switches the condition of the outputs in response to dial pulse signals, and resets the outputs to a datum condition in response to the reset pulse signal.