| 摘要 |
A programmable timing device includes a plurality of rotatable discs, three of which are concentrically rotatable about a common axis, one of which is eccentrically rotatable about another axis, and three light sources. Opaque portions of the four discs periodically mask and expose the three light sources whereby detectors activate and deactivate the timing device and activate a machine function in a programmed sequence of two time intervals at two dissimilar power levels. The two power levels are determined by independently moving two of the light sources in horizontal directions whereby one of the four rotating discs periodically exposes each light source for variably controllable time periods during each of the programmed time intervals. The exposure of the horizontally movable light sources is further controlled by the rotation of another one of the four rotating discs by determining which of the light sources is exposed to the detector for actuating the machine function during each time interval.
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