US PATENT SUBCLASS 333 / 177
.~.~ Transformer coupled

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use


333 /   HD   WAVE TRANSMISSION LINES AND NETWORKS

24 R  DF  COUPLING NETWORKS {15}
167  DF  .~ Frequency domain filters utilizing only lumped parameters {10}
177.~.~ Transformer coupled {3}
178  DF  .~.~.~> Including bandwidth adjusting, shaping, or stabilization means
179  DF  .~.~.~> With permeability tuning means
180  DF  .~.~.~> With variable coupling means

DEFINITION

Classification: 333/177

Transformer coupled:

(under subclass 167) Subject matter which include a mutual inductance link of the lumped type between the input and output of the filter.

(1) Note. The filters in this subclass are usually of the band-pass type, wherein the band-pass effect is due to the coupling between resonant circuits (e.g., intermediate frequency transformer systems with more than critical coupling between tuned primary and secondary circuits). The mutual inductance link need not be between the resonant circuits of the filter but may constitute the input or output coupling, the coupling between the resonant circuits being capacitive.

(2) Note. Wave filters wherein the mutual inductance link is of the long line type are not in this subclass but will be found in subclasses 125+ for branched circuit impedance matching networks; subclass 26 for balanced to unbalanced circuit conversion; subclasses 33+ for impedance matching networks; and subclasses 202+ for wave filters.

SEE OR SEARCH THIS CLASS, SUBCLASS:

197+, for electromechanical transducer-type filters involving transformer coupling.

SEE OR SEARCH CLASS

323, Electricity: Power Supply or Regulation Systems,

247, 301, 305, 328, and 355 for current and/or voltage magnitude control systems including transformers, and for miscellaneous transformer systems. 330, Amplifiers,

154, 165+, 188+, and 195+ for amplifiers having transformer coupling.

336, Inductor Devices, appropriate subclasses for transformers which are not designed to be frequency responsive.

379, Telephonic Communications,

443+, for induction coils combined with the structure of

telephone instruments.