American AI is usually American Airlines, and usually appears because of a baggage fee paid at the airport, or a purchase made during a flight. posted 09/11/2012 Helpful (4)
Electric motors are in general, a lot more efficient that internal combustion engines. An average combustion engine has about 18â20%. A formula one engine, has about 50% of an efficiency.
DC and AC motors have differing means of speed control. While DC motors are controlled by varying the armature winding's current, AC motors simply vary the frequency. An induction motor and a synchronous motor are two types of AC motors. An induction motor uses a magnetic field on a rotor that is created by an induced current. A synchronous motor is powered by a current through slip rings or a permanent magnet. Synchronous motors usually run much faster than induction motors because of the presence of slip rings. DC electric motor repair is much more expensive than AC electric motor repair. Paper producing machines and steel mill rolling machines are a few examples of a DC electric motor.