| 摘要 |
A method and apparatus for levitating objects in a magnetic field, comprising disposing at least one electromagnet having a centrally disposed core with at least one end positioned adjacent an outer surface of the electromagnet, connecting the electromagnet to a switchable electrical power source, and mounting at least one magnet on the object to be levitated. At least one magnetic field sensor is disposed adjacent the core end for providing an output signal indicative of a magnetic field level and orientation. A reference source is used for generating a variable reference signal which is applied to one input of a comparison element which is in turn connected to the sensor at a second input. The comparison element is used for comparing the respective voltages generated by each source, sensor and reference, and for providing an output signal indicative of a relative status of the two. The output signal is applied to a field strength controller connected to the comparison element and in series with the power source for adjusting electrical power delivered to the electromagnet in response to changes in the comparison output signal.
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