Radio receiver operable in station search mode or station select mode
US4291414A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1980 |
| Grant date | Sep 22, 1981 |
| Priority date | — |
| Expiry date | Apr 30, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J7/28
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A radio receiver comprising a local oscillator, a first counter circuit for computing an algebraic sum of a number corresponding to an oscillating frequency of the local oscillator and a number corresponding to an intermediate frequency, the algebraic sum representing frequency information for a tuned input signal frequency of the receiver, a memory circuit for storing frequency information produced by the counter when the receiver is tuned to a broadcast station in a station search mode, a digital comparator for comparing the frequency information read out of the memory circuit with the frequency information of the counter in a station select mode, and a charge pump and lowpass filter responsive to the digital comparator to control a local oscillator frequency of the local oscillator so that the frequency information of the counter becomes coincident with the frequency information from the memory circuit. A second counter is provided for counting clock pulses in the station search mode. The output signal of the second counter is compared with the output signal of the first counter by the digital comparator. The station frequency information read out of the memory circuit in the st…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.