Circular Motion: The Governor Apparatus. In the Governor Apparatus shown, point A is not free to move up and down. The collar is free to move up and down, and the steel spheres at can swing up and out. As the handle is rotated, the Governor rotates; the spheres rise up and out; the collar at rises up, and the handle at lowers and can be used to regulate other devices.

0:00 This is a mechanical governor, it is used to control speed
0:10 When the speed exceeds a certain value the lever on the right is forced down
0:20 This lever can be used to cut off, for example, gas supply.