Electronic tuner

Abstract

Abstract PURPOSE: To make channel selection possible through general variation in tuning voltage by changing inductances of tuning coils by a voltage sensing switch which turns ON-OFF depending upon the variation in turning voltage. CONSTITUTION: Switching direct-current voltage 12 to be applied to switching diode 3 is supplied through voltage sensing switch 13 which turns ON-OFF on receiving a tuning voltage. Centering its operation point, this switch 13 changes in state from OFF to ON at a certain value of voltage 7 to apply voltage 12 to diode 3. On being applied with this voltage 12, diode 3 shorts tuning coil 11 through capacitor 5 in terms of a high frequency. Then, a reception frequency is determined by the inductance of tuning coil 10 and the value of varactor diode 6 depending upon voltage 7 at that time. A frequency band from a low channel to a high channel can be covered by turning voltages of a low value to high value. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Kiichi Yamamoto

Bibliographic Details