This type of motor can work with both DC and AC power. A true DC electric motor does not accept AC power, as this will reverse the current every half cycle and this would only cause the shaking. In the same way, best prices for alemite a true AC motor does not accept DC power and this will not offer the appropriate changes of the direction of the current for the correct operation of the motor.
When we replace the permanent magnets of the stators of the DC motors with electromagnets and we connect in series these electromagnets in the same circuit of the rotor and switch, we will have a universal motor. This motor will ‘rotate’ correctly when powered by either direct current or alternating current. The remarkable difference between universal motor and DC motor is that if you power the universal motor with DC source, it will not reverse the direction of rotation if you reverse the polarity of the source (as with the DC motor) will always continue to rotate in the same sense. If you really want to reverse the direction of rotation of a universal motor you should reverse the connections on the stator electromagnets to reverse their poles.