Quieting receiver during power interruption

Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

455343, H04N 563

Patent

active

051444410

ABSTRACT:
A receiver comprises a tuner circuit for detecting a selected input signal and an audio circuit for reproducing the audio content in the detected signal. The tuner circuit includes a local oscillator, a prescaler, a phase detector and an integrator, and has a tendency to uncontrollably detune during AC power interruption responsive to a spurious tuning control signal generated in the tuner circuit and generate audible noise during the detuning. The audible noise is introduced into the audio content of the detected signal. An AC power interruption detector monitors a run power supply and generates a power loss control signal when the run supply falls below a predetermined threshold. A control circuit responsive to the power loss control signal, absent a user command, first disables normal operation of the tuner circuit and then disables the audio circuit, thereby reducing the audible noise. The tuner circuit may be disabled by decoupling the output of the phase detector from the input to the integrator, enabling the input to float. In the absence of a corrective signal from the phase detector, which may be the spurious tuning control signal, the integrator maintains a substantially constant output tuning voltage and prevents sudden detuning.

REFERENCES:
patent: 3882400 (1975-05-01), Hamada
patent: 4031549 (1977-06-01), Rast et al.
patent: 4110693 (1978-08-01), Evans
patent: 4207530 (1980-06-01), Gallagher
patent: 4227257 (1980-10-01), Sato
patent: 4355422 (1982-10-01), Paschen
patent: 4405947 (1983-09-01), Tults et al.
patent: 4532457 (1985-07-01), Haferl
patent: 4546388 (1985-10-01), Williams, Jr.
patent: 4641064 (1987-03-01), Testin et al.
patent: 4641190 (1987-03-01), Testin et al.
patent: 4656399 (1987-04-01), Testin et al.
patent: 4716463 (1987-12-01), Stacy et al.
patent: 4743864 (1988-05-01), Nakagawa et al.
patent: 4750040 (1988-06-01), Hakamada
patent: 4763195 (1988-08-01), Tults
CTC 140 Color TV Chassis Technical Training Manual, first published by GE Consumer Electronics, pp. 34-39, 1987.
SL-HF750 Operation Manual, published by Sony, Aug., 1986, pp. 127-131.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Quieting receiver during power interruption does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Quieting receiver during power interruption, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quieting receiver during power interruption will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-772382

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.