PROGRAMMABLE NONNDUPLEX SWITCHING DEVICE

摘要

A non-duplicative switching arrangement for controlling a video or radio frequency switch is used in a cable television system for controlling the application of a distant station signal to the cable system to eliminate duplication in programming. A clock provides an output indicative of the day and time while a timing means, responsive to the output of the clock provides timing signals. Switching is programmed on a transparent matrix disc which has a plurality of concentric circular rows of matrix positions. Each row corresponds to a day of the week and the matrix positions are aligned radially with respect to the disc in columns which correspond to daily time segments. The light transmitting characteristics of selected ones of the matrix positions are altered impermanently in order to program the switching arrangement. A stepping motor is provided for rotating the disc at predetermined times and an optical reader determines the light transmitting characteristics at each successive matrix position. A motor is provided for actuating the switch into one of its switching states in dependence upon the output from the optical reader. Additional switches may be controlled by providing slave switching control units. Each slave unit is substantially the same as the first control unit with the exception that the slave units rely upon the clock and timing means of the first unit.