| 摘要 |
PURPOSE:To improve safety in detecting the turning speed of an internal combustion engine, by using turning angle detectors which detect different turning angles, finding a speed during a fault on the basis of a normal signal, and then using another rotation detecting means when all detectors are faulty. CONSTITUTION:Sensor 2 detects projections 1a provided at 120-degree intervlas on a disk 1 which rotates synchronizing with an engine, and sensors 3 and 4 detect teeth 1b arranged at 2-degree intervals alternately. Therefore, since the outputs of he sensors 3 and 4 are ANDed to obtain a signal of every degree, a fault discriminating circuit 5 counts the pulses from the sensors 3 and 4 and if the 120-degree signal of the sensor 2 is not generated when its counts up to 60, the sensor 2 is judged to be normal, thereby controlling the engine by a control circuit 6. If even one of them is normal, its signal is used to find the signal of a faulty sensor. When all of them are faulty, a wheel speed signal 7 and a variable speed gear signal 8 are used to obtain information. |
