page_title: Homopolar motor
hierarchical_section_title: Homopolar motor
caption_attribution_description: Construction of a simple homopolar electric motor. A neodymium disk magnet is attched to a ferromagnetic screw that is suspended (by magnetic attraction) to one end of an alkaline cell. A wire connects the other terminal of the battery to the edge of the magnet, completing the circuit.
context_page_description: A homopolar motor is a direct current electric motor with two magnetic poles, the conductors of which always cut unidirectional lines of magnetic flux by rotating a conductor around a fixed axis so that the conductor is at right angles to a static magnetic field. The resulting force being continuous in one direction, the homopolar motor needs no commutator but still requires slip rings. The name homopolar indicates that the electrical polarity of the conductor and the magnetic field poles do not change.
context_section_description: A homopolar motor is a direct current electric motor with two magnetic poles, the conductors of which always cut unidirectional lines of magnetic flux by rotating a conductor around a fixed axis so that the conductor is at right angles to a static magnetic field.  The resulting force being continuous in one direction, the homopolar motor needs no commutator but still requires slip rings. The name homopolar indicates that the electrical polarity of the conductor and the magnetic field poles do not change (i.e., that it does not require commutation).
caption: DIY simple homopolar motor made with a drywall screw, a battery cell, a wire, and a disk magnet. The magnet is on the screw head. The screw and magnet make contact with the bottom of the battery cell and are held together by the magnet's attraction. The screw and magnet spin, with the screw tip acting as a bearing.
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