327 / | HD | MISCELLANEOUS ACTIVE ELECTRICAL NONLINEAR DEVICES, CIRCUITS, AND SYSTEMS |
100 | DF | SIGNAL CONVERTING, SHAPING, OR GENERATING {29} |
141 | DF | .~ Synchronizing {7} |
155 | DF | .~.~ With feedback {1} |
156 | DF | .~.~.~ Phase lock loop {3} |
158 | .~.~.~.~ With variable delay means |