Principle inductor - inductor works
Inductance within the lead through the exchange of current in the wire around the inside of the alternating magnetic flux, current ratio of this flux of magnetic flux and produce wire.
     When the DC current through the inductor, showing only around a fixed magnetic field lines, do not change over time; but when the alternating current through the coil, which will appear around the change over time of the magnetic field lines. According to Faraday's law of electromagnetic induction --- magnetic raw power to analyze changes in the magnetic field lines across the coil will produce EMF, the EMF equivalent of a "new power." When forming a closed loop, this EMF would generate an induced current. Lenz's law to know the total amount of magnetic field lines generated by the induced current to be trying to prevent the change of the magnetic field lines. Plus the change in the magnetic field lines vary from alternating power supply, so from an objective effect, the inductor AC circuit changes have prevented the current characteristics. Inductance coil has the mechanics of inertia similar characteristics, named electrically as "self-induced" usually pull the knife blade switch or momentary switch is turned on, a spark occurs, this phenomenon is the self-inductance high EMF caused.
      In short, when the inductor coil connected to an AC power source, the magnetic field lines inside the coil with alternating current and always changing, so that electromagnetic induction coil. This coil itself due to changes in the electromotive force generated by the current, known as "self-induced emf."
      Thus, the inductance is a parameter associated with a number of turns, size, shape and medium coil, which is independent of the applied current measure inductance coil inertia.
 
1 of the inductor.
Inductor choke effect: inductor coil self-induced emf is always changing and the coil current anti. AC inductor currents hinder, impede the role of the size of said inductive reactance XL, ohms. Its relationship with the inductance L and the AC frequency f is XL = 2πfL, inductors can be divided into high-frequency and low-frequency choke coil choke coil.
 
2 of the inductor.
Tuning and frequency selection function: inductors and capacitors in parallel can be composed of LC tuning circuit. I.e., with non-natural oscillation frequency f0 frequency f AC signal circuit are equal, the loop inductance and capacitance are equal, then the electromagnetic energy in the inductance, capacitance oscillate back and forth, this LC circuit resonance phenomenon. Resonant inductance and capacitance equivalent circuit and reverse, loop inductance total current minimum, maximum amount of current (ie f = "f0" AC signal), LC resonant circuit has the effect of frequency selection, can a AC signal of a selected frequency f.
 
3 of the inductor.
There inductor filter signal, filtering noise, constant current and electromagnetic interference suppression effect.
 
4 of the inductor.
In electronic devices, often we see a ring 2 is shown, these small things which effect? ​​This ring and connecting cables constitute an inductor (cable conductors on magnetic inductance coil around a few times). It is commonly used in anti-jamming electronic circuit components, high-frequency noise has a good shielding effect, it is called absorption ring, usually using ferrite material, also known as the ferrite bead (the ring) . In Figure 2, the top one-piece ring, the ring with mounting clip. Ring at different frequencies have different impedance special offerings. Low impedance at low frequencies, when the signal frequency is increased dramatically increases the impedance of the magnetic ring.
We all know that the higher the frequency of the signal, the more radiation out, and the signal lines are not shielded layer signal lines it would be a good antenna to receive all kinds of clutter surrounding environment of high-frequency signals, and these signals superimposed on the signal transmission, even change the useful signal transmission, seriously interfere with the normal operation of the electronic equipment, electronic equipment to reduce electromagnetic interference (EM) has been considered a problem. In ring action, even if the normal useful signal can pass through, but also a good to suppress high frequency interference signals, and low cost.