(under subclass 508) Subject matter in which the impedance device is of the type in which the impedance of the device inherently changes appreciably in magnitude (e.g., with mere lapse of time, change in potential applied thereto or current flowing therethrough, change in temperature or physical pressure applied thereto, etc.).
(1) Note. Impedances such as reactors and condensers whose value of impedance changes in consequence merely of a change in the frequency of the electric energy supplied thereto are not included herein. Should the impedance of these devices change inherently, however, with the frequency remaining constant, classification is herein.
SEE OR SEARCH THIS CLASS, SUBCLASS:
767, for motor systems having inherently variable impedance devices in the primary circuit of an induction motor. See particularly subclasses 788, 796, 797, 804, 815, and 892.
821, for motor systems having a inherently variable impedance device in the secondary circuit of an induction motor.
SEE OR SEARCH CLASS 323, Electricity: Power Supply or Regulation Systems,
364, for miscellaneous impedance systems.
336, Inductor Devices,
30, for adjustable induction apparatus designed to have its impedance automatically controlled in response to a condition, and subclass 155 for the structure of inductive regulators (of the saturable or high leakage reactance type) having no movable adjustable feature.
338, Electrical Resistors,
2, for strain gauge type electrical resistors, and subclass 13 for electrical resistors whose value changes in response to a condition.
