Ed Leedskalnin's Magnetic Current. Illustrations and Research.
PMD demonstration with one coil
This is a great example of ED's research that once you start the magnets flowing in this device they will continue to circulate until the the bar is removed. Notice how only one terminal of the battery is connected and the other is only tapped. This shows that only a small amount passed into the PMD holder and it has the ability to hold it.