Patent ID: 7110236
Filing Date: 2006-09-19
Classification: H02N

Abstract:
1. An apparatus for supporting an object by balancing gravitational force against magnetic forces such that there are no physical supports provided to the object, comprising: a frame constituting an upper station and a structure to support the upper station, a permanent magnet, an electromagnet and a sensor system all contained in the upper station, and an object containing a permanent magnet, the object being movable between a theoretical balance point where the gravitational force on the object is balanced by the attraction between the permanent magnet on the object and the permanent magnet on the upper station of the frame, and a dynamic balance point, below the theoretical balance point, where the attraction between the permanent magnet on the object and the permanent magnet on the upper station is weaker than at the theoretical balance point, and for which the electromagnet in the upper station is capable of compensating by providing a magnetic force, the apparatus further comprising a feedback circuit comprising the sensor system and a controller to control electrical current to the electromagnet, provided by a power supply, to urge the object towards the dynamic balance point whenever the object is not at the dynamic balance point, wherein the apparatus further comprises a second circuit for detecting a loss of supplied power, the feedback circuit and/or second circuit being capable of responding to any sensed loss of power by providing sufficient current to the electromagnet to pull the object upwards, above the theoretical balance point, such that should the power fail completely, the object will come to rest in the proximity of the upper station.