The series motor is a kind of DC electric motor in which the armature and the debuted or excitation inductor are connected in series. That is why the excitation or inductor current is also the induced current absorbed by the motor.
This type of DC motor is also called a series-excitation motor. The constitution of the electric motor in series is to have all the elements of the circuit in series, induced windings and inductors. The series motor is characterized by having a high torque at startup and its highly variable speed depending on the load, making it an unstable motor.
This is the type of motor used in applications where high torque is required.
Characteristics of the series motor
The main features of the standard electric motor are:
When operating under vacuum, there is a danger of packing because the speed of a DC motor increases or decreases with the flux of the inductor and, in a series motor, it decreases with increasing speed, since the current in the inductor is the same as the uninduced one.
The power is almost constant for any speed.
Sudden variations in the supply voltage affect it very little, because an increase in it causes an increase in intensity and, therefore, in flux and electromotive force, stabilizing the absorbed intensity.
What are series motors used for? Uses and applications
Due to its characteristics, the series motor is used in cases where a large torque is required: trams, locomotives... and its use in electric traction is very practical.
A drill could not have a series motor, because when finishing making the hole in the piece, the machine would be empty (no load) and the speed of the drill would increase so much that the machine would become dangerous for the user.
