The universal motor is a sturdy yet small electric motor, designed to be ideally suited for portable devices or mainly for home use. An engine with these purposes has its electrical scheme adapted to work with any type of available voltage.
The design and principle of operation of the universal motor are the same as those of the motor in series of DC: when the universal motor is powered by alternating current, the variation of the direction of the current causes variation in the field, both of the rotor and of the stator. In this way, the conjugate continues to rotate in the same initial direction, with no reversal of the direction of rotation.
A higher power universal electric motor can be obtained if modifications are made to your design so that it performs well with DC and AC.
Advantages: low manufacturing cost when produced in large quantities; Speed control according to the need of the application.
Disadvantages: high noise level, both audible and electromagnetic, which produces interference in electronic circuits; Short service life due to brush and switch wear; Are usually made for intermittent or sporadic (drill, blender, mixer), so do not support continuous work.