How does the interlock work in Laserworld projectors?

The interlock is a safety option in laser projectors to provide a proper option to connect a safety shut-off button to the laser. The connector used with all Laserworld systems is a D-sub (DE-9) standard connector, with a quite simple pinout:

If pin 1 and 2 are linked, the laser output is active. If there is no connection between pin 1 and 2, the output is interrupted.

All projectors have a bridging plug for the interlock connector included in delivery. This is necessary to operate the laser if there is no safety shut-off button connected (if you don't want to use a Safety shut off button or if you do a mains shut-off in emergency).

You can also connect the interlock to any other switching device, e.g. a light barrier or key switch