Timing laser for small 2-stroke motors

摘要

This circuit illuminates the timing marks (usually on the flywheel) at the firing of cylinder 1 in a 2-stroke motor. It should also work on cars.The pick-up is made by winding about 150 turns of enamelled copper wire through a split toroid sleeve (eg, Jaycar LF1290) - see diagram. This is placed over the spark plug lead and the signal developed in the coil is used to trigger a 555 timer (IC1) which is wired as a monostable pulse generator. The laser diode is driven directly from pin 3 of ICl and the pulse width is adjusted by trimpot VR1.