(under the class definition) Subject matter wherein the amplifier contains in its circuit an impedance element whose impedance value is responsive to the temperature changes therein by reason of the heat generated by the current flow therethrough, or the ambient temperature of the impedance element, or whose impedance value may be changed by separate electrical control means or other heat control means.
(1) Note. Heat responsive impedance elements are species of nonlinear impedance elements and, as such, when appearing in a cathode impedance feedback circuit or generally in the loop path of a feedback amplifier are not in this subclass. Nonlinear impedances, including thermal impedances, in a feedback path which are varied by separate control means are classified elsewhere. Thermally responsive impedance means form a control means and when appearing in the voltage or power supply circuits of a push-pull amplifier are classified elsewhere in this class; and when appearing in the power supply or bias supply circuits, as for example, in the circuit from the voltage power supply to the anode or screen grid or in the bias supply circuit so as to control the bias of a vacuum tube amplifier device, classification is not herein but in the appropriate subclass of this class.
SEE OR SEARCH THIS CLASS, SUBCLASS:
86, for nonlinear impedances, including thermal impedances, in a feedback path which are varied by separate control means. See (1) Note above.
95, and 110, for heat responsive impedance elements when appearing in a cathode impedance feedback circuit or generally in the loop path of a feedback amplifier. See (1) Note above.
123, for thermally responsive impedance means forming a control means and appearing in the voltage or power supply circuits of a push-pull amplifier. 127+, when appearing in the power supply or bias supply circuits, as for example, in the circuit from the voltage power supply to the anode or screen grid or in the bias supply circuit so as to control the bias of a vacuum tube amplifier device. See (1) Note above.
144+, for variable impedance for the signal channel controlled by separate control path.
157+, appropriate subclasses thereunder for amplifier interstage coupling which may include a nonlinear device other than one thermally responsive, particularly subclass 164, for electronic tube or diode, and subclass 174, for electromechanical transducer (e.g., piezo-electric crystal) in the interstage coupling, and subclass 183, for a nonlinear device generally (other than thermally responsive) in a D.C.. interstage coupling circuit.
185+, for nonlinear impedance elements, other than thermally responsive, in amplifier input circuits.
192+, for nonlinear impedance elements, other than thermally responsive, in amplifier output circuits.
256, 272 and 289+, for semiconductor amplifiers with transistor temperature control.
296, and 297, for semiconductor amplifiers involving bias or power supply circuitry.
SEE OR SEARCH CLASS
323, Electricity: Power Supply or Regulation Systems,
294, for thermally responsive impedance means for voltage magnitude control, generally.
336, Inductor Devices, appropriate subclasses for inductor structure particularly
30, for condition responsive inductor adjusting means, including those responsive to thermal conditions.
338, Electrical Resistors,
20+, for resistors whose value is responsive to the current therethrough or the voltage thereacross and subclasses 25+ for resistors whose value varies in response to ambient temperature conditions.
