US PATENT SUBCLASS 331 / 20
.~.~ T.V. sync type


Current as of: June, 1999
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331 /   HD   OSCILLATORS

1 R  DF  AUTOMATIC FREQUENCY STABILIZATION USING A PHASE OR FREQUENCY SENSING MEANS {16}
18  DF  .~ With reference oscillator or source {5}
20.~.~ T.V. sync type {1}
21  DF  .~.~.~> Lock to power line


DEFINITION

Classification: 331/20

(under subclass 18) Subject matter wherein the oscillator system is of the type peculiarly adapted for use in television systems (e.g., vertical or horizontal sweep generators), the reference source comprising synchronizing pulses (usually of short duration) which pulses are compared with signals representative of the generated waves of the controlled oscillator in a phase comparison means, the resulting control or error signal from the comparison means being utilized to adjust the frequency of the controlled oscillator to restore it to the desired relationship with reference frequency.

SEE OR SEARCH THIS CLASS, SUBCLASS:

143+, for relaxation oscillators in general, especially indented subclass 145, for multivibrators with synchronizing, triggering or pulsing circuit, indented subclass 149, for blocking oscillators with synchronizing, triggering or pulsing circuit and indented subclass 153, for relaxation oscillators in general with synchronizing, triggering or pulsing circuit.

SEE OR SEARCH CLASS

315, Electric Lamp and Discharge Devices: Systems,

1+, for cathode-ray tube circuits, especially indented subclasses 378, 379+ and 391+ for cathode ray sweep circuits which may utilize sweep generators with A.F.S. control combined with significant cathode ray control means or cathode-ray tube structure, e.g., deflecting plates, deflecting coils, etc.

348, Television,

536+, for automatic frequency stabilizing systems as an element of a more comprehensive system, e.g., controlled oscillator combined with sync separator.

375, Pulse or Digital Communications,

354+, for synchronizers in general.