what are the differences between ac and dc generating motors?
I think you are talking about electric generators rather than motors, although the problems are similar. AC generators are more simple ----they have a rotor coil rotating inside a stator coil which generates a magnetic field. The voltages induced in the rotating rotor coil is fed out via a brush commutator to outside wires. The DC generator is similar except that the commutator is more complex. It reverses the positive-negative polarity as needed to keep one output wire positive and the other negative. This involves reversing the connection to the rotor as needed during rotation. The AC voltage from an AC generator can also be converted to DC with a diode rectifier, which in most cases is preferred (less cost, more reliable --less wear). A car uses an AC generator (alternator) for this reason.
motors are not designed for generation of electricity, they are less efficient! DC generators are old technology alternators use dioded and are much more efficient = better conversion mechanical to electrical energy. alternators produce alternating current D
