electrical circuit to notify the kanalwahl in a abstimmbaren receiver

摘要

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.