(under subclass 17) Subject matter in which the electromagnetic operator is provided with a linkage device for connecting the operator to a variable tuning unit of a resonant circuit and a control means for automatically operating the electromagnetic operator so as to tune the resonant circuit to its optimum operating point and to
maintain the circuit at that point by regulating the adjustment of the variable tuning unit to compensate for variations in the tuned circuit or in the frequency of the signal wave to which the circuit is tuned.
SEE OR SEARCH THIS CLASS, SUBCLASS:
13, for automatic frequency controlled saturable core type tuning elements.
16, for automatic frequency centering circuits of the reactance tube type.
SEE OR SEARCH CLASS
318, Electricity: Motive Power Systems, 445+, for automatic motor starting and/or stopping means.
322, Electricity: Single Generator Systems,
32, for dynamoelectric generator systems with frequency responsive devices or networks for automatically maintaining the frequency of the generator wave constant.
331, Oscillators,
1+, for oscillators having automatic frequency stabilization using a phase or frequency sensing means.
332, Modulators,
123+, for controlling an average condition in a frequency modulator and subclasses 155+ and 159+ for controlling an average condition in an amplitude modulator.
455, Telecommunications,
125, for radio transmitters which may utilize a.f.c. circuits and subclasses 257+ for receivers with a.f.c. circuits.
