Engine fuel injection system - has digital computer to correct multivibrator output signals

摘要

Signals corresponding to engine speed and air intake are fed to a multivibrator unit. The air intake volume is divided by the engine speed signals to produce a pulse length proportional to the combustion air on each induction stroke. The multivibrator output is fed to a multiplication stage a battery tension correcting circuit, a distributor logic and a final amplifier stage to excite the injector windings. The multivibrator stage is a hybrid computer, working partly as a digital unit containing a forwards and backwards counter. The counter receives the output from the multivibrator and a correcting frequency from a fixed value storage bank (read only memory). The main counter finishes when the multivibrator pulse gap appears. The air volume frequency is counted back until a nil condition is reached to form an injector pulse.