Sony Corporation

Kaoru Umeda

Hideo Harada

Yoshinori Nishimura

Tuning indicator apparatus is provided for use with a frequency synthesizer tuner of the type having a phase-locked loop including a reference oscillator, a variable frequency oscillator to produce a local oscillating signal, a programmable frequency divider coupled to the variable frequency oscillator for dividing the frequency of the local oscillating signal by a variable dividing ratio to produce a frequency-divided oscillating signal, a phase comparator for comparing the frequency-divided oscillating signal to the output of the reference oscillator to produce an error signal, and a feedback circuit for feeding back the error signal from the phase comparator to the variable frequency oscillator to adjust the frequency of the local oscillating signal and thereby establish a tuning condition of the tuner. The tuning indicator apparatus includes a counter for counting counter pulses supplied thereto, the count of this counter determining the dividing ratio of the programmable frequency divider. An indicating circuit is responsive to a change in at least a predetermined value of the count of this counter to indicate that the count has changed and, thus, that the tuning condition of the tuner has changed. In a preferred embodiment, a sound generator is provided to generate an audible indication of a change in the tuning condition.

Tuning indicator apparatus for a frequency synthesizer tuner

Tuning control apparatus is provided for use with a frequency synthesizer tuner of the type having a phase-locked loop including a reference oscillator, a variable frequency oscillator to produce a local oscillating signal, a programmable frequency divider coupled to the variable frequency oscillator for dividing the frequency of the local oscillating signal by a variable dividing ratio to produce a frequency-divided oscillating signal, a phase comparator for comparing the frequency-divided oscillating signal to the output of the reference oscillator to produce an error signal, and a feedback circuit for feeding back the error signal from the phase comparator to the variable frequency oscillator to adjust the frequency of the local oscillating signal and thereby establish a tuning condition of the tuner. The tuning control apparatus includes a counter for counting control pulses supplied thereto, the count of this counter determining the dividing ratio of the programmable frequency divider. A control pulse generator supplies control pulses to the counter. An adjusting circuit is operable to adjust the rate at which the control pulses are supplied to the counter for adjusting the speed at which the count of the counter and the dividing ratio of the programmable frequency divider changes. In one embodiment of this invention, a switching circuit is provided to be selectively operable to supply only a predetermined number of the control pulses to the counter so as to change the count of the latter, and thus the dividing ratio of the programmable frequency divider, by a predetermined step. Thus, the tuning condition of the frequency synthesizer tuner can be changed at a variable rate or, alternatively, in a stepwise manner.

Tuning control apparatus for a frequency synthesizer tuner

A radio signal receiver having a demodulator circuit with a variable local oscillator is provided with a station selector including a record medium for storing frequency selection information at spaced locations thereon, a conversion circuit for reading the frequency selection information at a selected location by aligning that location with a reading assembly and converting the respective information into a signal for determining the output frequency of the local oscillator, and a signal generating circuit responsive to a lack of alignment of the reading assembly with a location at which frequency selection information is recorded for generating a signal indicating that such lack of alignment exists and which may be effective to cause muting of the output of the demodulator circuit.

Radio receiver with frequency selection and muting

A control circuit includes two full-wave rectifiers connected to an AC power source to produce two rectified outputs having different phases with respect to each other, a combining circuit for combining the two rectified outputs to produce a composite output, and a switching means controlled by the composite output. The switching means generates a control signal nearly at the same time that the AC power supply is switched on or off. The control signal is used to energize a device at a delayed time after the AC power supply is switched on, and to de-energize the device substantially at the same time that the AC power supply is switched off.

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Kawasaki, Japan

Kaoru Umeda