Action and reaction:

In practice, both the engine and generator at the same time the impact site.
Current through a conductor in a magnetic field effect of the region pass through the line, but once moving conductor, it starts a generator to make one step in the opposite direction of the pipe through the existing application current. Thus, head movement "back EMF" which opposes the use of EMF creates.
In contrast, a conductor through the escalator area which in turn present the current through conductor exerts force against the force applies.
Is given by the current flowing in the pipe:
I = (V - E)
R
Where V is the applied voltage, e back-EMF, is a research and conductor's resistance.
Load balancing action under For action "and reaction load effect" An important automatic self described above - both AC and DC motors in applications for feedback mechanisms adapt to changes. As engine load increases, the slow, low back EMF will do. This in turn increased to a maximum torque generated to load current allows optimization.
Magnetic field:

Made available through the motor's magnetic field stator and the above example, stator, a permanent magnet, but in the majority of power machines, stator poles are wound around the magnetic field provided by electric coils. In the field and motor windings stator windings that are the "enlightened box. Generally, an iron core wrapped in a rotor to improve the efficiency of the machine's magnetic circuit. Magnetic circuit In the case of electrical machinery, air gap of magnetic circuit through the body by the magnetic stator flow path through rotor and back through the stator air gap. The path length L mean magnetic path length is known MMPI The maximum possible flow of magnetic circuit production and air gap between rotor and stator in focus through the coils are ready step. Flow measured in Webers F Flux density B and field measured in tesla unit defined as A. The magnetic flux per F, B = F / A, which is one area through which the river flows.
Above equation it is clear that the electric motor or generator directly by the torque generated by EMF to generate electromagnetic flux density in the area around the conductor, the proportional and efficient machines for the B, B as high as possible should be.
Magnetomotive MMF () Magnetic flux from one magnetic circuit magnetomotive force (MMF) is proportional to it. For an electromagnet, MMF energizing coil current in amperes measured in effect, and is NI, as mentioned, the actual number present in the horoscope is multiplied by N is I. Thus, MMF = NI = FXR where R is the resistance of the magnetic circuit. Founder of the magnetic circuit magnetic flow reserve through content that is inherent resistance. (Iron is too low for the wind to stop.'s Too much) The equation for the magnetic flux circuit in accordance with law for the OM, which electric circuit current: Where R is the resistance circuit EMF = IXR. In the air gap between rotor and Stator reluctance view is too high, small as possible in order amperes required to make desirable as the air gap flux density should reduce. Magnetic force (H) and magnetic field strength H magnetic field strength per unit length of a magnetic circuit is MMF.

Then:
H NI = L
Is due to magnetic field effects magnetic force Magnetomotive strength.
Flux density (B) and magnetic permeability μ () Bound for uniform fields, magnetic flux density with strength and is proportional to the power sector is given by:
B μ0μrH = Where is known as continuous or μ0 magnetic permeability of free space.
magnetic materials μr is the relative permeability.
Unfortunately, relationships as non-flux density and magnetic material is saturated linear increase. Flow through the increase in magnetic field from outside and is used to enhance and permeability μr relaitive 0 production is continuing.

Saturation:
What can not be seen from these causes a magnetic circuit that increases applied MMF (ampere) flows through the circuit increases, but as the magnetic flux density that the iron content may be, a limit if the content should be saturated. Before that date, became more and more flow is required less MMF. In other words, patience is growing rapidly penetrating the material.
For maximum efficiency, electric machines designed for work in general, just below the beginning of saturation.

Magnetic pole:

Electrical machines can be multiple pole pairs. Usually more efficient magnetic circuit pole multiple machines and provide smooth torque characteristics.

Commutation:
Conversion Basic machine runs on Horoscope above the carbon brush slip rings, one at each end of the show with a pair of wire was connected.
If the machine is used as a generator, the current direction every half cycle as generated Horoscope hand, unlike the opposite poles in a row. When a current is required Unidirectional slip rings and connected between the electric wires apportioned that each half is made of alternative parts. As a commutator switch system easy.
Even if a DC motor is used as a machine, switching DC power supply to the ring half of each cycle power switchboard in order to achieve Unidirectional rotation.
Thus, all wound rotor DC machines, two motors and generators, AC and the DC current in rotor windings of input or output communicator is enabled. Although there are some notable exceptions. World's first motors and generators invented by Faraday unipolar or homopolar machines that were currently flowing in Unidirectional conductor. A laboratory curiosity with no practical applications Faraday motor, but its so-called "Faraday disk dynamo was able to generate electricity.
For over 100 years of mechanical conversion, only practical way is an adaptation of the direction of current flow, however, has since the 1970s, the availability of high power semiconductors electronic commutation is enabled.
AC machine, the complexity of conversion, a direct correlation between entry and windings rotating with the stator windings transformer action current induced in the rotor windings, so no need to be avoided as should be. See Induction.
As rocker is basically a mechanical switch, to create a fast and high current circuit, sparking switches and radio frequency interface (RFI), the generation that this region may disrupt the operation of other electronic circuits are likely.
In very large engines, "Inter poles" in addition to or contrary to Poland "could be through sparking the trend" of the main stator poles at half-way between the narrow end would help. These are connected in series with the rotor MMF and the closing one is equal and opposite rotor MMF so making effective flow between the main poles is zero. Between positive and negative half cycles when current subsidized through zero are moments in design, and it occurs when the rotor is in between the main pillars. Flow in this region by passive, sparking is less likely.