A chained selsyn keeps this motion picture projection in step with its mate for 1-D projection. Manufactured by the General Electric Company, the low-priced selsyn generator is linked to the projector motor by chain and sprockets shown here being inspected by a projectionist. The GE selsyns are powered by an ac wall plug and are interconnect between the cameras by wall or floor mounted wires. Changing from 3-D to standard feature projection is accomplished by merely snapping a wall switch.

General Electric Company1953-03-30