| 323 / | HD | ELECTRICITY: POWER SUPPLY OR REGULATION SYSTEMS |
| 234 | DF | OUTPUT LEVEL RESPONSIVE {6} |
| 265 | DF | .~ Using a three or more terminal semiconductive device as the final control device {5} |
| 268 | DF | .~.~ Including plural final control devices {3} |
| 271 | DF | .~.~.~ Switched (e.g., on-off control) {1} |
| 272 | | .~.~.~.~ Parallel connected |