SCMaglev (SuperConductingMaglev), formerly known as the MLU, is a maglev system developed by JR Central and the Railway Technical Research Institute (RTRI) based on the principles of magnetic repulsion between the track and cars.
The trains use electrodynamic repulsion as their method of operation; superconducting magnets are installed in the train's bogies, with the guideway containing two sets of metal coils. The current system used on the Yamanashi Test Track has the series of coils wound into a "figure 8" shape along both walls of said guideway. As the train accelerates, the magnetic fields of the superconducting magnets induce a current into said coils due to the magnetic field induction effect. At low speeds, however, the trains use rubber wheels to run along the guideways; these wheels fold up into the chassis à la an airplane's landing gear on reaching 150 km/h (93 mph) due to there being enough current to lift the train off the guideway.
If the train was centered with the coils, the electrical potential would be balanced and no currents would be induced; while the rubber wheels are being used, the magnetic field is positioned below the center of the coils which causes the electric potential to be unbalanced. This creates a reactive magnetic field which opposes the superconducting magnet's pole and a pole above that attracts it. The coils don't just serve to accelerate the cars; the coils also help to guide and stabilize the cars. Due to their "figure 8" configuration, currents are induced into the connections to correct the train's configuration if it ever moves off-center.
