Electronic control circuit for carburettor slow running jet - compares instantaneous with averaged changes of engine speed

摘要

An input circuit generates a signal proportional to engine speed from metal studs on a rotating part. It is passed through a tachometer which feeds an integrator. The integrator drives a saw tooth generator whose output is compared with a reference signal. The difference is fed into a memory. The initiating signal is passed through a frequency divider which triggers the memory output once for every cylinder working stroke. This output passes through a rectifier to a comparator which is also fed directly from the tachometer. The output of this comparator energises the solenoid of a slow running fuel valve in the carburettor which is thus controlled by the difference between instantaneous and average change in speed.