Abstract: A wafer switch includes a printed circuit board having etched thereon a common ring and a desired number of contacts having parallel sides at an angle to a radius of the common ring, and includes a rotor. The rotor has mounted on one side a blade that bridges between a contact and the common ring accomplishing a switching function. The switch further includes a spacer ring and a wave washer that establish a bearing distance between the rotor and the printed circuit board. Finally, the improved wafer switch includes a snap-in bushing intended to pass through an aperture in the board and an aperture in the rotor. The aperture in the rotor is smaller in diameter than the bushing so that the bushing is frictionally mounted within the aperture.

Abstract: A system for automatically monitoring the programs broadcast by network affiliated broadcasting stations includes a plurality of remote monitoring sites and a central office for periodically interrogating the remote monitoring sites. Each remote monitoring site contains apparatus for monitoring time varying program identifying data, and for storing the data in a change format when the time varying data changes in an unexpected manner. An elapsed time clock in each remote monitoring unit generates a record of the elapsed time between the unexpected changes.Each remote unit includes a minicomputer having a read-only memory and a random-access memory. The data in the read-only memory serves to establish communications with the central office and permits the central office to access the random-access memory. After the random-access memory has been accessed, it may be reprogrammed to alter the operation of the remote monitoring unit to accommodate different data formats or different information.

Abstract: A system for monitoring the channel to which a remotely located voltage tunable receiver or converter is tuned includes a comparator for comparing the magnitude of the tuning voltage with an internally generated reference voltage to determine the channel number. The reference voltage is generated by a counter driving a linear digital-to-analog converter. The output of the digital-to-analog converter is modified with an analog function generator to provide a piecewise linear approximation of the receiver tuning voltage versus channel number characteristic. A window comparator is utilized to compare the output of the function generator with the tuning voltage and to stop the counter and transfer the contents of the counter to an output circuit when the magnitude of the reference voltage approaches that of the tuning voltage. The contents of the counter at the time the counter is interrupted is indicative of the channel number of the station being received.