Floating Ring Stabilization System

The necessity of magnetically levitating a superconducting, current carrying ring without mechanical supports requires an electrical stabilizing system. The ring, when supported, has only one equilibrium position and this position is one of unstable equilibrium. The ring is free to move with up to six degrees of freedom. Two degrees are dictated by the ability of the ring to move in any direction in the plane of the ring. Additionally, the ring can be tilted requiring three more reference points to determine a new plane. The sixth degree of freedom is the ability of the ring to rotate upon its own axis, but because external forces tending to cause this rotation can, in principal, be eliminated, a restoring supply is not provided. Each of the five identical stabilizing supplies in this system has a feedback loop composed of the following segments. The position detector element is an optical head which sends a light beam across an optical edge on the ring, the reflection of which is sensed on a photo diode. This diode voltage signal, proportional to the ring position, is the input to an amplifier whose output is a signal proportional to position, velocity and ring acceleration. A 50 volt, 100 ampere, bidirectional dc transistor power supply is activated from this signal which in turn powers the appropriate stabilizing coil located near the floating current carrying ring.