(under the class definition) Oscillators systems comprising a feedback amplifier having a predetermined phase shift between the input and output voltages thereof, the feedback path including a passive phase shifting network for providing a phase shift of such amount to cause the oscillator system to generate sustained oscillations.
(1) Note. Oscillator systems in this subclass rely on achieving proper phase shift between input and output voltages of the system by a nonresonant passive phase shifting network to produce oscillations and should be distinguished from those oscillators, classified elsewhere in this class, whose frequency is determined by the resonant properties of an LC type resonator.
SEE OR SEARCH CLASS
323, Electricity: Power Supply or Regulation Systems,
212, 219 for phase angle control circuits effective at a single frequency.
332, Modulators, particularly 140, and 142+ for oscillator systems which may be similar to those classified in Class 331, subclasses 135+.
333, Wave Transmission Lines and Networks,
138+, for delay networks, per se, for retarding wave energy a predetermined period of time over a range of frequencies.
