With a low load the armature rotates more slowly, reducing the induced voltage and allowing a greater current to slide in the armature. The DC electric motor can thus receive more electrical power from the source, Coupon codes for electric motors providing and doing more mechanical work. The speed that runs an electric motor of direct current depends on the intensity of the magnetic field that acts on the armature, as well as of the current of this one. The stronger the field, the lower the degree of rotation required to generate a sufficient induced voltage to replicate to the applied voltage. For this reason, the speed of the DC motors can be controlled by varying the field current.

When the armature is stopped it does not truly have resistance, and applies the normal operating voltage, in that it will produce a large current, which could damage the commutator and the coils of the armature. The normal means of preventing such damages is the use of a combustion resistor connected in series to the armature to decrease the current before the motor develops the appropriate induced voltage. When the electric motor accelerates, the resistance decreases manually or automatically, gradually.