Ignition control apparatus for internal combustion engine

摘要

An ignition control apparatus for an internal combustion engine for preventing ignition control upon occurrence of rotation reversal of the engine includes a rotation sensor ( 3 ) disposed in opposition to projections ( 11, 12 ) of a rotor ( 1 ), and an ignition timing control circuit ( 4 ) for fetching a rotation sensor signal (R) as a reference angular position signal to output a driving signal (P) to the ignition circuit ( 6 ). A retarded ignition control module ( 46 ) of the control circuit ( 4 ) measures a period of a specific interval of the sensor signal (R) while generating a driving signal (P) in dependence on the specific interval period. An arithmetic module ( 46 ) of the retarded ignition control module ( 46 ) sets an expectation period for accepting a succeeding sensor signal on the basis of the specific interval period to validate only the signal inputted during the expectation period.