The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 16, 1980
Filed:
Dec. 11, 1978
Masanori Kamiya, Yokohama, JP;
Hitachi, Ltd., , JP;
Abstract
A channel selection voltage generator comprises a tuning voltage generator circuit having a capacitor for supplying a tuning voltage to an electronic tuner, a first constant current source for constantly discharging the capacitor at a first constant current and a second constant current source adapted to be rendered selectively in an operative state and in an inoperative state for selectively charging the capacitor at a second constant current which is higher than the first constant current, a frequency discrimination circuit for producing a discrimination signal representative of the amount of frequency deviation when a tuning voltage deviates from a receiving frequency, a buffer circuit for producing a binary '1' level signal when the discrimination signal is higher than a predetermined value and producing a binary '0' level signal when the discrimination signal is lower than the predetermined value, and a control circuit for causing the second constant current source to assume the inoperative state when the binary signal is at '0' level and causing the second constant current source to assume the operative state when the binary signal is at '0' level, the control circuit serving to maintain the second constant current source in the operative state or the inoperative state irrespective of the level of the binary signal during the frequency sweep.