US PATENT SUBCLASS 379 / 390
.~.~ With amplification or attenuation level control

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

Internet Version by PATENTEC © 1999      Terms of Use


379 /   HD   TELEPHONIC COMMUNICATIONS

387  DF  SUBSTATION OR TERMINAL CIRCUITRY {7}
388  DF  .~ For loudspeaking terminal {2}
390.~.~ With amplification or attenuation level control

DEFINITION

Classification: 379/390

With amplification or attenuation level control:

(under subclass 388) Subject matter having a circuit for adjusting or maintaining the level of signal strength.

SEE OR SEARCH THIS CLASS, SUBCLASS:

347, for amplification or attenuation control in a telephone repeater.

SEE OR SEARCH CLASS

381, Electrical Audio Signal Processing Systems and Devices,

104+, for amplitude or volume control for an audio system.