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US 3,940,702 AGranted
Automatically presetting channel selecting system
AssigneeAlps Electric Co., Ltd.
InventorsJun'Ichi Yoshimura, Tatsumi Watabe
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AssigneeAlps Electric Co., Ltd.
InventorsJun'Ichi Yoshimura, Tatsumi Watabe
Estimating the term…
A channel selecting system for use in a receiver having a voltage controlled tuning element which has an automatic channel presetting function which utilizes a pulse generator and a binary counter connected to the generator to count the pulses and to generate a binary coded output in accordance with the sum of the pulses. A digital-to-analog converter changes the binary coded output into a linearly increasing tuning sweep voltage which in turn conditions the voltage controlled tuning element to scan the frequency range of the tuner as the tuning voltage increases. As the frequencies are scanned, a detector, connected to the tuning element, senses the presence of a broadcast channel. When a channel is detected, the scan is interrupted and a binary memory is utilized to store the binary coded output which corresponds to the frequency of the detected broadcast channel. A control gate signal generator driven by the detector controls the pulse generator and memory such that the scan is continued until the entire frequency range has been scanned. Channel selection is accomplished by switch means actuatable to address the memory to read out a selected binary code output corresponding to the channel desired which causes the converter to generate a voltage to condition the tuning element to tune to the desired frequency. The voltage control tuning element may comprise several different elements, one for each of a plurality of different frequency ranges. Means are provided for selecting an appropriate tuner such that channels from any of the frequency ranges may be selected.
A channel selecting system for use in a receiver or the like having a first voltage controlled tuning element capable of tuning in a first frequency range and a second voltage control tuning element capable of tuning in a second frequency range, said system comprising means for detecting the presence of a broadcast signal at a selected frequency, means for generating a first data signal corresponding to the voltage level necessary to condition one of said elements to tune said frequency, storage means, control means operably connected to said detecting means and said storage means for actuating said storage means to store said first data signal, means for generating a voltage in accordance with said first data signal, a selected one of said tuning elements being conditionable by said voltage to select a frequency in accordance therewith, a read-only memory having stored therein second data signals corresponding to voltages capable of conditioning each of said first and second tuning elements to the upper and lower limits of their respective frequency ranges, means for comparing said first data signals with said second data signals and for generating an equality signal in the event said signals are equal and means for selecting one of said first and said second tuning elements in accordance with said equality signal.
Dependencies are inferred from the claim text.