Greetings: There is so much good stuff on RF Cafe that there is no way to list or link to
all of it here. Please use the Search box or the Site Map
to find what you want - there is a good chance I have it. Thanks!
University of Maryland 30-Ton Metal Sphere Spins for Magnetic Field Investigation Videos for Engineers
Get ready to flip the dial on your compass by 180° soon. Well not real soon, but indications point to another
reversal of the Earth's magnetic field reversal in as little as
1,500 years. To more
accurately investigate the phenomenon, researchers at the U. of MD have constructed a 30-ton sphere that spins at
more than 90 mph to generate magnetic fields. The 10-ft sphere is filled with 13.5 tons of liquid sodium to mimic
the Earth’s liquid-iron center core. A 3.3-ft sphere counterrotates inside the larger one. Both spheres are driven
by 350-hp electric motors. At full speed the outer sphere spins at 240 rpm. The inner sphere reaches 960 rpm.