Page 192 - 15 Dangerously Mad Projects for the Evil Genius

Chapter 13 ■ Levitation Machine 169

hand in front of the beam to activate the coil. coil off if there is nothing being levitated. So, to
Afterward, hold the magnet first one way and then activate it, we need to move the bottle up and
the other to find the orientation that attracts the down a bit near the phototransistor.
electromagnet. If all is well, you should feel the electromagnet
A variant on the bottle theme is to take the pull at the bottle as the bottle moves down, and
bottle and cut away just the top section, leaving relax as you move the bottle up. If you get too
enough to attach a ping-pong ball to it. This can close to the electromagnet, you will start to feel the
then be painted to look like a globe. The end result permanent magnet attracted to the steel bolt in the
may look something like Figure 13-16. electromagnet. Therefore, you should keep the
bottle out of this area.
Step 10. Try It Out Try to feel the forces acting on the bottle by
lightly holding it from the bottom. Gradually let
We are now ready to try out the levitation device.
the bottle go and you should feel it being held by
All we need to do is attach the power connector the electromagnetic force (Figure 13-17).
and turn it on. The program that controls the
If there is nowhere near enough force to support
levitation device has a safety feature that turns the
the object, you may need to move the phototransistor

Figure 13-16 A globe for levitation Figure 13-17 Levitation in action