This sub-class deals only with modulation, keying, or interruption of sinusoidal oscillations or electromagnetic waves, the modulating signal having any desired waveform.
In this sub-class, circuits usable both as modulator and demodulator are classified in the group dealing with the type of modulator involved.
This sub-class deals only with (a) demodulation or transference of signals modulated on a sinusoidal carrier or on electromagnetic waves, and (b) comparing phase or frequency of two mutually-independent oscillations.
This sub-class deals with (a) linear amplification, there being linear relationship between the amplitudes of input and output, and the output having substantially the same waveform as the input, (b) dielectric amplifiers, magnetic amplifiers, and parametric amplifiers when used as oscillators or frequency-changers, and (c) constructions of active elements of dielectric amplifiers and parametric amplifiers for which no provision exists elsewhere.
This sub-class deals with (a) control of gain of amplifiers or frequency-changers, (b) control of frequency range of amplifiers, and (c) limiting amplitude or rate of change of amplitude.
This sub-class deals with (a) networks comprising lumped impedance elements, (b) networks comprising distributed impedance elements together with lumped impedance elements, (c) networks comprising electromechanical or electro-acoustic devices, (d) networks simulating reactances and comprising discharge tubes or semiconductor devices, and (e) constructions of electromechanical resonators.
In this sub-class, the term "passive elements" refers to resistors, capacitors, inductors, mutual inductors, or diodes. [3]
Main groups with a higher number take precedence. [3]
This sub-class also covers the control of tuning, including the combined control of tuning and other functions, e.g. combinations of tuning control and volume control, combinations of control of local oscillator and of supplementary resonant circuits. [3]
This sub-class deals with (a) methods, circuits, devices, or apparatus using active elements operating in a discontinuous or switching manner for generating, counting, amplifying, shaping, modulating, demodulating, coding, decoding, or otherwise manipulating signals, (b) electronic switching not involving contact-making and braking, and (c) logic circuits handling electric pulses.
In this sub-class, an "active element" is understood to exercise control over the conversion of input energy into an oscillation or a discontinuous flow of energy.
AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (of dynamo-electric generators Fulltext... Hierarchy... Expanded...H02P) [3]
H03L
Note(s)
This sub-class includes automatic control circuits for generators of electronic oscillations or pulses and also includes starting, synchronisation, or stabilisation circuits for generators where the type of generator is irrelevant or unspecified. Stabilisation or starting circuits specially adapted to only one specific type of generator are classified with the generator in the relevant sub-group of sub-classes Fulltext... Hierarchy... Expanded...H03B, Fulltext... Hierarchy... Expanded...H03K. [3]
The term "automatic control" includes only closed loop systems. [3]