Permanent magnet system, control device and control method

Abstract

The permanent electromagnet system (16) includes a permanent electromagnet (10) and a control device (14); the permanent electromagnet has a first permanent magnet (20), a second permanent magnet (22) whose magnetization direction can be changed, and a coil (24); the control device has an energizing control unit (50), which makes the permanent electromagnet in a deactivated state by passing a first current (I1) of a first magnitude (Ie) to the coil, and makes the permanent electromagnet in an attracted state by passing a second current (I2) of a second magnitude (If) opposite to the first current to the first current to the coil, wherein the first magnitude is smaller than the second magnitude. A permanent magnet system (16) includes a permanent magnet (10) and a control device (14). The permanent magnet includes: a first permanent magnet (20); a second permanent magnet (22) changeable in magnetization direction; and a coil (24). having a second magnitude (If) to the coil in a direction opposite to the first electrical current, where the first magnitude is smaller than the second magnitude.

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