Electric Motors

An electric motor is a device that turns electric current flow into mechanical rotation of a spindle, or rotor. The rotation is turned into linear motion in many applications.

There are many variants and options of Electric Motors; for example DC motors – brushed or brushless and AC motors – induction (or asynchronous) and synchronous. The motors can operate at a variety of voltages to suit an application and the supply available.

The operation of a motor relies on two properties of electric current. The first is that an electric current, flowing in a wire or coil, will create a magnetic field.

The second is that a changing current in a conductor, for example from an ac supply, will induce a voltage in the conductor (self-inductance), or in a secondary conductor (mutual-inductance). A current flow in the circuit of a secondary conductor will also produce a magnetic field, as outlined above.

For a magnet, like poles repel and unlike poles attract. In all motors, the construction uses this property to ensure continuous rotation of the rotor.