ac motors

Very smiplist An AC motor runs on alternating current While a DC, which you did not ask-a battery is DC Direct current) With AC Hz is the Frequency that it alternates between positive and negetive magnetic fields- 50Hz in Australia According to many combination of winding in the motors case outer area. and the rotating armature The big heavy cylinder attache to the shaft. has windings that get current induced to them as it is spining. now with the AC connected to the motor with 50 Hz every one second the current alternated +- +- +- +- 50 times in one second as this magnetic field is pulsing the North and South magnetic feilds it's like think back when you had two magnetic one in each hand and when trying to put together if it is North North or South South. They push each other away from each other. IE: with the electric AC motor (By design-dont put higher voltage to a motor thinking it will go faster) only if it is designed for different or varing voltages, currents, or frequency changes) the changes in voltage can change speed and split windings, Also by changing the number of internal windings the speed power direction can be changed I hope this answered your question, if it was not easy to understand let me know I'm trying to change .slightly, my lengthy comments as it has been mentioned I can make it confusing with lengthy writing. have a good day eric

With AC currents, we can reverse field directions without having to use brushes. This is good news, because we can avoid the arcing, the ozone production and the ohmic loss of energy that brushes can entail. Further, because brushes make contact between moving surfaces, they wear out. The first thing to do in an AC motor is to create a rotating field. 'Ordinary' AC from a 2 or 3 pin socket is single phase AC--it has a single sinusoidal potential difference generated between only two wires--the active and neutral. (Note that the Earth wire doesn't carry a current except in the event of electrical faults.) With single phase AC, one can produce a rotating field by generating two currents that are out of phase using for example a capacitor. In the example shown, the two currents are 90° out of phase, so the vertical component of the magnetic field is sinusoidal, while the horizontal is cosusoidal, as shown. This gives a field rotating counterclockwise. (* I've been asked to explain this: from simple AC theory, neither coils nor capacitors have the voltage in phase with the current. In a capacitor, the voltage is a maximum when the charge has finished flowing onto the capacitor, and is about to start flowing off. Thus the voltage is behind the current. In a purely inductive coil, the voltage drop is greatest when the current is changing most rapidly, which is also when the current is zero. The voltage (drop) is ahead of the current. In motor coils, the phase angle is rather less than 90°, because electrical energy is being converted to mechanical energy.)