| 摘要 |
PURPOSE:To improve the noise resistance by generating a control signal for the maximum/minimum spark advance position through a hysteretic rectangular wave shaping circuit by means of rotating a rotor which has angular information data contrary to each other at intervals corresponding to the spark advance width. CONSTITUTION:The signal of a sensor 2, which comes from the rotation of a magnetic rotor 20 with a protrusion 21 corresponding to the spark advance width, is level-converted at a constant voltage Vr, which is made as a set signal through a comparator 103 and an inverter 104. Through a hysteretic rectangular wave shaping circuit 30, it is shaped into rectangular pulses at intervals of an angular space corresponding to the spark advance width, and further, through an integrating circuit 40, it is converted into operational waves with the prescribed inclination which is reset once per rotation of the rotor. And a point where it intersects the threshold value Vth of a comparator 112 is the ignition point, generating an ignition signal J. In this way, a signal sensor can detect the maximum/minimum spark advance position, and the noise resistance can be considarably improved by the hysteretic action. |
