The principle of the rotating beacon light knowledge

Rotating beacon light can rotary lamp: LED fluorescent lamp into the bracket, LED fluorescent lamp rotating beacon light  direction can be rotated to change the LED fluorescent lamp.
LED fluorescent lamp is not rotatable lamp: LED fluorescent lamp into the bracket, LED fluorescent light emitted by the light direction is fixed, can not adjust.
The knowledge related to the beacon strobe light  knowledge in high school, rotating beacon light of the shaft end should have a coil around a few times, due to magnetic flux changes resulting in coil current occurs inside the structure, then I do not know, estimation is a bit like the electric fan, but just knowing to produce warning signal light  current, then the problem is still a good solution.
Rotating beacon light the reason that the magnetic flux will change, because we usually electric, are used in alternating current. If the DC, do not know is not to make the rotating lights turn up with a magnet to.