Automatic ignition advance as function of IC engine speed control - uses variable slope sawtooth voltage which is compared with reference voltage

摘要

Starting from a reference voltage a saw-tooth voltage with constant slope is generated. It is compared with a number of threshold voltages and converted into a voltage with variable slope. Its slope changes and points of change are in accordance with a required ignition advance characteristic for comparison of the variable slope voltage with the reference voltage. The variable slope voltage is corrected as a function of a logic circuit which controls the instant of ignition spark release when the reference voltage coincides with the variable slope voltage.