361 / | HD | ELECTRICITY: ELECTRICAL SYSTEMS AND DEVICES |
139 | DF | CONTROL CIRCUITS FOR ELECTROMAGNETIC DEVICES {7} |
160 | DF | .~ For relays or solenoids {11} |
166 | DF | .~.~ Plural relays or solenoids sequentially operated {2} |
168.1 | DF | .~.~.~ Pulse responsive {1} |
169.1 | .~.~.~.~ Including electronic element |