| 327 / | HD | MISCELLANEOUS ACTIVE ELECTRICAL NONLINEAR DEVICES, CIRCUITS, AND SYSTEMS |
| 1 | DF | SPECIFIC SIGNAL DISCRIMINATING (E.G., COMPARING, SELECTING, ETC.) WITHOUT SUBSEQUENT CONTROL {11} |
| 50 | DF | .~ By amplitude {9} |
| 51 | DF | .~.~ With sensing amplifier {2} |
| 52 | DF | .~.~.~ Differential amplifier {3} |
| 53 | | .~.~.~.~ Current mirror |