These two facts, in addition to the cheaper price of a permanent magnet motor with respect to a standard DC motor (as a matter of fact only the rotor coils need to be winded), are the main reasons why armature controlled motors are widely used. However, several disadvantages arise from this control technique, of which major is the flow of large currents during transients. For example when started speed ω is zero initially hence back EMF (Electromotive Force) governed by the following relation, would be zero.