| 摘要 |
991, 674. Electric selective signalling systems. PERKIN-ELMER CORPORATION. Nov. 1, 1962 [Nov. 8, 1961], No. 41401/62. Heading G4H. In a shaft-position encoder a single brush 20, Fig. 2, moves over 1000 contacts 001, 002 &c. connected together in 18 groups-these being indicated by the circled numbers-and each group is connected via conductors 1, 2 . . . 18, Fig. 1, to two of a set of 12 triggers 23, 24... 35, constructed from transistors, Fig. 3 not shown, which, via relays and weighted resistors, control ammeters 78, 80 and 81, the arrangement being such that (i) as the brush moves over the contacts the markings produced on the 18 group conductors indicate which triggers are to change their states so that the ammeters indicate the shaft position and (ii) the 12 triggers are brought into phase, or registration, with the shaft position from any initial combination of states once the brush has passed over 10 contacts. This second property of the circuit is made possible by using a monophylic-binary coded monophylic-decimal arrangement for the 12 triggers. Thus normally, when registration has been achieved, only one trigger changes its state for each incremental displacement of the shaft, so that, normally of the two connections made to the triggers from each group conductor, one is redundant. However, these redundant connections are so chosen, the theory being given in the Specification, that after the shaft has turned through 10 incremental positions, all of the triggers will have been set in registration with the shaft. |
