The speeds of universal motors normally exceed 3500 RPM and their speeds on AC supply are lower than when they run on DC supply, with the same voltage. This is due to a drop in reactance voltage that exists in AC but not in DC. When the universal motor receives a DC power supply, it acts as a series electric DC motor.
Universal motors can be classified as two types:Compensated type/Uncompensated type
Motor manufacturing is done at Teco Electric Co. Ltd. which has a range of products that have been specially designed and produced. They have over 30 years’ experience in the field and manufacture all kinds of motors like coreless motors, flat motors, precision motors, gearless motors, brushless motors and the like.
Construction of a Universal Motor
The construction of a universal motor is almost the same as an electric DC motor. There is a stator, the stationary part, which has the field poles mounted on it with wound field coils. The entire magnetic path including the stator field circuit and rotor or armature is laminated to reduce eddy currents. This is only when the motor operated on AC supply.
As in the electric DC motor, the rotary armature is wound with slots that are either straight or skewed. It also has a commutator with brushes. The brushes in an AC motor have high resistance because the current in the coils reduce the commutation on AC, as compared to an electric DC motor.