IGNITION APPARATUS FOR AN INTERNAL COMBUSTION ENGINE

摘要

An ignition apparatus for an internal combustion engine is provided which is simple in the circuit arrangement and highly reliable in operation. An electromagnetic pickup coil generates an ignition signal having a magnitude proportional to the number of revolutions per minute of the engine in synchrony with the rotation thereof for controlling an ignition coil. A waveform shaper in the form of a comparator shapes the ignition signal from the pickup coil into a signal containing a pulse having a rising edge and a falling edge. An integrator integrates the ignition signal from the pickup coil to provide a rpm voltage representative of the number of revolutions per minute of the engine. A signal level controller controls the voltage level of the ignition signal based on the rpm voltage generated by the integrator. A current absorber absorbs from the ignition signal a current in accordance with the voltage of a power supply which powers the ignition coil. A switch turns off the current absorber when the shaped signal generated by the waveform shaper rises. A current-absorption suppressor suppresses a current to be absorbed by the current absorber in accordance with the rpm voltage generated by the integrator.