The control principles and the design of a fuel injection system, developed by F.A.F Schmidt, are described. In this system, injection time and injection pressure are controlled independent of each other. The injection time is controlled by two rotating discs having slots, which are turnable to each other and which are turned by the influence of a centrifugal governor in connection with a three-dimensional cam. With the three-dimensional cam, a punctiform scanning of engine characteristics can be realized.
Some results obtained with this injection system are shown, for example, fuel quantity characteristic, CO and n-hexane characteristic of a 4-cyl 4-stroke engine, injection pressure distribution dependent on crank angle, and consumption loops for injection and carburetor operation.