Electric motor
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An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy.
Jedlik's "electromagnetic self-rotor", 1827 (Museum of Applied Arts, Budapest). The historic motor still works perfectly today.
An electric motor presented to Kelvin by James Joule in 1842, Hunterian Museum, Glasgow
Rotor (left) and stator (right)
Three-phase electric power
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Three-phase electric power is a common type of alternating current (AC) used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires and is the most common method used by electrical grids worldwide to transfer power.
Three-phase transformer with four-wire output for 208Y/120 volt service: one wire for neutral, others for A, B and C phases
The first AC motor developed by Italian physicist Galileo Ferraris. This was a two-phase motor and required four wires.
Three-phase electric power transmission lines
Three-phase transformer (Békéscsaba, Hungary): On the left are the primary wires, and on the right are the secondary wires.