| 摘要 |
PURPOSE:To provide an ignition timing controlling apparatus for an automotive engine, which is capable of controlling the engine noise always at a level lower than a predetermined value, by delaying the ignition timing of the engine when engine noise or vibration higher than a predetermined level is detected. CONSTITUTION:When the levels of engine noise and vibration are raised, output of a sensor 10 is also raised and it is amplified at an amplifier circuit 11. Then, only relevant components of the signal are taken out in a band-pass filter 12 and its effective value within a predetermined time interval is calculated in an effective value calculating unit 13. The effective value thus obtained is compared with a reference value Vr in a comparator 14. Here, if the effective value exceeds a tolerable value, the comparator 14 produces an H-signal and controls a delay circuit 16 for switching the same to delay mode. This causes a lag of 0.5 deg. of ignition signals produced by a signal generator 6 and the signals thus lagged 0.5 deg. are supplied to a power transistor 5. Thus, the delay circuit 16 continues to delay the ignition timing until the noise level becomes lower than a tolerable value. |
