PURPOSE: To ignite an air-fuel mixture surely as well as to improve the extent of startability by impressing a high voltage on each spark plug several times in and around a compressive top dead point of each piston, in case of an ignition controller available for an automobile engine.
CONSTITUTION: A microcomputer 10 inputs each signal out of a cylinder internal pressure switch S1, a cooling water temperature switch S2, a starter switch S3, a car speed sensor switch S4 and crank angle sensor switch S5. An arithmetic circuit 13 operates ignition numbers of each spark plug in and around a compressive top dead point of each piston and each individual ignition action. At one- shot timers 14, 15, ignition timing and current-energization start timing calculated by the arithmetic circuit 13 are set each, and these timers output a control signal SOUT. Thus, since high voltage is impressed on each spark plug several times in and around the compressive top dead point of each piston, such an air-fuel mixture is surely ignitable and, what is more, startability is improvable.
SHIBATA AKITO
MARUYAMA NOBUTOSHI
