A white halogen bulb is mounted within a cylindrical fresnel lens--larger versions of which are used in lighthouses--and set at an angle on a tripod. A small motor moves the lens back and forth, varying the angle of the emitted light. This is concentrated in a narrow beam and projected onto the walls of a circular room. The beam moves up and down in a wave-like manner.
|Wood, fresnel lens, halogen bulb, tripod, motor|