The trigger wheel rotates with engine RPMs and causes the speed sensor, or pickup oil, to produce triggering voltage pulses that correspond to engine speed and piston position. 觸發(fā)葉輪隨發(fā)動(dòng)機轉速而旋轉,使得轉速傳感器或拾波線(xiàn)圈產(chǎn)生與發(fā)動(dòng)機轉速和活塞位置相對應的觸發(fā)電壓脈沖。