| 摘要 |
PURPOSE:To enable ignition timing to be certainly controlled nearby the most suitable knock limit by discriminating the noise by a sensor signal so as to eliminate it at a pulse count circuit and to judge the size of knocking precisely, in the case of noise occurring in an engine. CONSTITUTION:When noise occurrs due to the secular change or the like an engine, a wave shape with swell is output. In a comparator 33, a judging level made in a judging level making circuit 32 and a knock sensor 2 signal are compared with each other, and pulse is successively output by being devided into the first and the second half (not described in the diagram). Therefore, in a monostable circuit 34, the count is once reset, and a signal is produced again after s signal occurrs in the successive pulse of the first half. In a judging section setting circuit 35, the count is reset by getting down of the signal of the first half, and the state of reset continues until the next ignition. In a pulse count circuit 36, only the number of the successive pulse of the first half is counted, and a signal of pulse width depending on the size of knocking is output. In this way, the most suitable ignition timing can surely be controlled constantly nearby the knock limit. |
