| 摘要 |
PURPOSE:To allow maintaining, even at the abnormal time, ignition functions similar to those at normal time by monitoring abnormality of a control computer and issuing back-up signals with the fixed pulse duration instead of ignition signal from the control computer when abnormality occurs. CONSTITUTION:An ignition control device is equipped with MPU4 for entering output signals from the reference angle sensor 1 and angle sensor 2 after their wave-form rectification, calculates optimum ignition timing and electrifying time on the basis of output signals from individual operational state sensors 5 and issues ignition signal 4A. In this case, a monitoring circuit 7 for monitoring abnormality of MPU and a back-up signal generation circuit 6 including a counter 21 for counting generation case number of angle signal 3B after the entry of reference angle signal 3A and issuing back-up signal 6A with the pulse duration lasting from the time when the counted value becomes a fixed value to the time when the next angle signal 3A is entered are formed. And at the time of MPU4 abnormality, back-up signal 6A is put out through a selection change-over circuit 8.
|
