| 摘要 |
An electronic tuning system for radio receivers, with digital memorization of the signal frequencies. A manual control generates a first control voltage. A clock pulse generator applies pulses to a counter, the output of which is connected to a digital-to-analog converter to supply a second control voltage, indicative of the number of clock pulses counted by the counter, to electronic tuning circuitry of an electronically tuned radio receiver. A voltage comparator receives the digital-to-analog converter output and the output from the manual control. The output of the voltage comparator is applied to a gate circuit which controls application of the clock pulse signals to the counter so that these signals are discontinued when the output signal from the digital-to-analog converter is substantially equal to the output from the manual control. A digital memory couples the counter output to the input of the digital-to-analog converter and is arranged to digitally store clock pulse count signals corresponding to control frequencies associated with tuning frequencies of selected radio broadcasting stations. |
