| 摘要 |
PURPOSE:To discriminate occurrence of a knock and abnormality of a knock sensor, by providing a fail-safe circuit, in which abnormality of the knock sensor is detected, and detecting the knock and abnormality of the knock sensor through an output signal from said knock sensor. CONSTITUTION:Output from a comparator 101, if a knock is detected, decreases to LOW, and is reset to change to a HIGH level by a signal from Id, for instance, an ignition signal or other interruption signal. While comparators 36, 37 output a LOW signal only when abnormality of disconnection or short-circuit is caused in a knock sensor 1, and hold the LOW signal during the time for the knock sensor 1 in an abnormal state. When either output from this knock detector circuit or output from a fail-safe circuit is LOW, a LOW level signal is input to an input/output device 534 of a microcomputer. |
