Automatic turn-off apparatus for a radio or television receiver
US4241450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1979 |
| Grant date | Dec 23, 1980 |
| Priority date | — |
| Expiry date | Aug 27, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J7/065
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A television receiver includes a tuning system comprising a phase locked loop (PLL) configuration and an automatic fine tuning (AFT) configuration which are selectively enabled to operate in response to respective levels of a MODE signal to tune standard and nonstandard frequency RF carriers. In the absence of the RF carrier for a selected channel, the operations of PLL and AFT configurations are alternately enabled and the level of the MODE signal changes accordingly. The MODE signal is applied to a capacitor which develops a control voltage for turning the receiver "off" after the MODE signal has changed levels for a predetermined time because of the absence of a RF carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.