How do Universal Motors work ?

Universal Motors they are capable of running under both DC and AC power supply this unique feature makes them preferable for many special types of applications a universal motor is a specially constructed DC series motor let's consider a simplified series motor when connected to a DC power source they work just like a DC motor with the help of commutator rings a unidirectional current is always made to flow through the left and right side of the coil thus the torque action is always unidirectional and the rotor continues to rotate let's see what happens when the same motor is connected to an AC power source since the field coil and rotor coils are connected in series the same phase of electricity passes through them always it is obvious that in this case the electricity flow through the left and right part of the coil is never unidirectional but along with the change in direction of this current direction of magnetic flux also changes as the same electricity flow through field and rotor coils this simple trick will make sure that the torque action is always unidirectional here are the different scenarios that could occur during the motor rotation it is clear that irrespective of speed of the rotor and frequency of electricity the torque action is always in the same direction as a result the rotor will continue to rotate even under an AC power source but if you connect an ordinary DC series motor with an AC power supply it won't perform well you have to make some modifications on it since the AC power produces a fluctuating magnetic field any current loss in the core will be heavy for this reason the core layers should be laminated for a universal motor during the AC operation the transformer action induces an EMF and extra sparking at the brush contact thus the contact brushes of a universal motor have to be of high resistance we help you had a nice introduction on the working of Universal Motors thank you for watching the video

Channel: Lesics

Views: 1,042,042

Keywords: Electric Motor (Engine Category), Universal Motor, Electrical machines

Id: 0PDRJKz-mqE

Length: 3min 0sec (180 seconds)

Published: Thu Oct 16 2014