|
The "Top
Secret" consists of a spinning top with a radially oriented
magnetic field and an associated base that houses a conductive
coil. When the top spins past the center of the base,
its changing magnetic field induces a current in the coil which
momentarily opens the switch to the battery resulting in powering
up the electromagnet. The electromagnet then delivers enough
torque to the spinning top to allow it to speed up and spin away
from the center. Since the electromagnet is
only engaged when the top crosses near the center of the base, one
9 volt battery can last for over a week of continual use! |
