Several timing methods are in used, for example, using a stroboscopiclight or a piston-position gauge.
可使用的正时方法有几种，例如可使用频闪灯或活塞位置仪。
2
A disc lit by a stroboscopiclight rotates. The disc is covered with a series of pictures which move in a spiral from the outer edge to the centre.
一张由频闪观测仪旋转照亮的光盘，光盘本身被一系列图片覆盖，由外部边缘向中心螺旋式旋转。
3
The stroboscopiclight source made of high-power LEDs (higher than 5w) not only can replace the mercury stroboscopiclight source, but also can greatly simplify the drive circuit.