361 / | HD | ELECTRICITY: ELECTRICAL SYSTEMS AND DEVICES |
271 | DF | ELECTROSTATIC CAPACITORS {4} |
277 | DF | .~ Variable {4} |
287 | DF | .~.~ Mechanically variable {5} |
292 | DF | .~.~.~ By varying effective area of electrode {6} |
298.1 | DF | .~.~.~.~ Rotary plates {5} |
298.5 | .~.~.~.~.~ With adjustment means |