JPS5632821A - Tuner - Google Patents

Tuner

Info

Publication number
JPS5632821A
JPS5632821A JP8094079A JP8094079A JPS5632821A JP S5632821 A JPS5632821 A JP S5632821A JP 8094079 A JP8094079 A JP 8094079A JP 8094079 A JP8094079 A JP 8094079A JP S5632821 A JPS5632821 A JP S5632821A
Authority
JP
Japan
Prior art keywords
tuning
low
capacitor
tuning circuit
point
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP8094079A
Other languages
Japanese (ja)
Other versions
JPS5937608B2 (en
Inventor
Mikio Watanabe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Furuno Electric Co Ltd
Original Assignee
Furuno Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Furuno Electric Co Ltd filed Critical Furuno Electric Co Ltd
Priority to JP8094079A priority Critical patent/JPS5937608B2/en
Publication of JPS5632821A publication Critical patent/JPS5632821A/en
Publication of JPS5937608B2 publication Critical patent/JPS5937608B2/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/08—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant using varactors, i.e. voltage variable reactive diodes

Landscapes

  • Channel Selection Circuits, Automatic Tuning Circuits (AREA)

Abstract

PURPOSE:To make it possible to tune a tuner to even a small input signal with accuracy by providing a tuning circuit with two alternate tuning points and then by making comparison between two kinds of output voltages obtained from the tuning circuit. CONSTITUTION:Tuning-detection-signal generator 7 applies varactor diode D with alternate high and low voltages and, at the same time, drives switch 6. With D applied with the high voltage, the tuning point of tuning circuit 2 is high and with the low voltages, the tuning point is low. When the tuning point is high, switch 6 connects the tuning output to the positive input of differential amplifier 10 and capacitor 8 and when low, it is connected to the inverted input and capacitor 9. When the center of the resonance frequency of tuning circuit 2 is higher than a received frequency, differential amplifier 10 generates a negative voltage. As a result, electric motor 11 is so controlled that the capacity of variable capacitor VC will increase.
JP8094079A 1979-06-26 1979-06-26 tuning device Expired JPS5937608B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8094079A JPS5937608B2 (en) 1979-06-26 1979-06-26 tuning device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8094079A JPS5937608B2 (en) 1979-06-26 1979-06-26 tuning device

Publications (2)

Publication Number Publication Date
JPS5632821A true JPS5632821A (en) 1981-04-02
JPS5937608B2 JPS5937608B2 (en) 1984-09-11

Family

ID=13732465

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8094079A Expired JPS5937608B2 (en) 1979-06-26 1979-06-26 tuning device

Country Status (1)

Country Link
JP (1) JPS5937608B2 (en)

Also Published As

Publication number Publication date
JPS5937608B2 (en) 1984-09-11

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