What is the difference between alternating current motors and dc motors?
Upstairs is a little irrelevant answer, the first people ask is the difference, again is the motor, not the generator! How it works: Dc motor installed a constant magnetic field, after the stator coil zhongtong current is generated electromagnetic force, so they will move, but the direction of the electric current to change, so will generally use brush, contact with the terminal. So the cost is higher. It is commonly used in servo motor, measuring motor and excitation motor. The ac motor has only one winding and the rotor is squirrel-cage. When a single-phase sinusoidal current in the stator winding, the motor can produce an alternating magnetic field, the magnetic field strength and direction interplanting sine law of change at any time, but is fixed on the spatial orientation, say again so the magnetic field is alternation pulse magnetic field. This alternation pulse magnetic field can be decomposed into two at the same speed and direction of rotation are instead of a rotating magnetic field, when the rotor static, the two rotating magnetic field generated in the rotor torque of two equal and opposite, making synthetic torque is zero, so the motor can't rotate.
(2) to construct a copper ring at each end of the alternating current generator coil (slide ring). A copper half ring is called a commutator on both ends of the dc motor coil, which changes the current of each winding to make alternating current direct current. (3) the direction of induced electromotive force of different ac generator is determined, and the right hand rule is determined. The rotation direction of dc motor is determined by the left hand rule. (4) the ability to convert different alternator inputs is mechanical energy, and the output is electrical energy; A rotating motor that converts mechanical energy into electricity. The dc motor is powered by mechanical energy, which converts electrical energy into mechanical energy
1 similarities (1) structure on the same ac generator and dc motor structure is composed of stator, rotor, iron core, coil, magnetic pole, brush, etc. (2) the application of electromagnetic applications is the same as electro-magnetic and magnetoelectric phenomena. (3) the transformation using the same Asynchronous motor, as long as the prime mover drag (such as turbine, diesel engine, etc.), the rotor rotating speed n higher than that of rotating magnetic field of synchronous speed n1, even if the slip S = negative, plus the exciting current, becomes the ac asynchronous generator; Dc motor, if the part of the change of its power to external power rotation, it's on the end of the armature winding and field winding is dc voltage, which means dc motor can also be used as dc generator. (4) to maintain the same operation In the operation of all needs to check its operation, sound and vibration is normal, the ventilation is good, bearing oil, adequacy of stator winding and the temperature of each part is normal, the rotor brush on the presence of abnormal spark, voltage and current is within the scope of the rating, chassis ground zero are in good condition and etc. 2 the difference
The same is true of their principle, which is the use of electromagnetic induction. Different is confidential by dc commutator to change the direction of current. To get a torque, principle, I would say, junior high school. Ac motor is to pass through it into the alternating current to produce a rotating magnetic field in the motor, and then is the law of electromagnetic induction. I wrote it myself, hoping to help the owner.
