When a strong on-board magnet is moved relative to a conducting sheet, a circulating eddy current will be induced in the conductor. The eddy current in turn produces a magnetic field, which by Lorentz force law, produces repulsive forces between the two magnetic fields. An experimental study on the electrodynamic suspension system was carried with a 1.5 m diameter rotary type test wheel. Two types of on board magnets are tested. One is a HTSC magnet and the other one is a Halbach-arrayed permanent magnet. The Lorentz forces of the two EDS systems are measured and compared with theoretical and numerical calculations.