When a machine converts electric energy into mechanical energy ... There are basically two types of motors: alternating-current (ac) motors and direct-current (dc) motors. An ac motor (discussed in ...

but the electric carriages dating to before the dawn of the 20th century—used the simplest style of electric motors, also known as brushed (direct-current) motors. These motors have a wire coil ...

The first electric machines employed a mechanical switch, in the form of a carbon brush/commutator system, to produce this rotating field. While the widespread use of power electronics is making ...