| 摘要 |
PURPOSE:To make it possible to precisely detect smolder and dirt on a spark plug, by extracting the frequency component which is determined by the characteristic of a high voltage generating circuit after termination of spark discharge of the ignition plug, and by determining whether the ignition is inferior or not in accordance with the magnitude of amplitude of the frequency component. CONSTITUTION:The one end of a secondary winding in an ignition coil 10 is connected to an ignition coil 100 and the other end thereof is grounded through a resistor 20 for measuring discharge current. Further, the terminal on the high voltage coil 10 side of the resistor 20 is connected to a current detector 14 whose detection signal i2 is led to a first comparator 16 together with a reference signal iR from a first reference signal generator 15. If i2 >i1, a signal s1 is energized to detect the termination of discharge. Further, the above-mentioned signal s1 is led to a multiplier 17 together with a detection signal (v) from a voltage detector 13, and an output signal (s) from the multiplier 17 is delivered to a second comparator 19 together with a reference signal sR from a second reference signal generator 18. Further, it s>sR, the signal (s) is energized to detect inferior ignition. |
