Inductance - inductance classification: SMD inductance, color ring inductance, choke inductance, common mode inductance
Inductance is something that has a long history. People have known for a long time that when a wire passes an electric current, it creates a magnetic field around the wire. If you wrap it around the iron, it makes the iron magnetic.
If change, can eliminate the magnetic iron, also found that when broken that moment, can produce a lot of back emf, later found out that the conductor in magnetic field produces current cutting lines of magnetic force exercise (soon invented the generator), inductance and use it the magnetic energy substation power - the power of magnetic energy principle.
1. Symbol of inductance
The sign of inductance is in international and domestic standard law is same, but kind is more, want to understand carefully only, discovery is much the same.In addition, the transformer can also be called inductance, but no one calls it that, it is two mutual coupling inductance.
2. The unit of inductance
The basic unit of inductance is H (H), which, like capacitance, is a large unit of measurement.The relationship between them is 1,000 times greater.1H = 1000mH = 1000000 mu H
3. Types of inductance (inductor coil, color ring inductor, power inductor, inductor, color code inductor, inductor package, filter inductor, common mode inductor)
As mentioned above, there are many types of inductance, but they can be roughly divided into the following types, which have different functions, not to mention who is superior and who is inferior.
Hollow inductance: as the name implies, is the wire wound in the non-magnetic conductor, the inductance of small, no memory, but it is difficult to achieve magnetic saturation (so-called magnetic saturation is the surrounding magnetic field to reach a certain saturation, and the magnetic force no longer increase, no longer work in the linear interval.
Sound is often output from the amplifier to the speaker, in the amplifier output stage after a string of inductance, it is hollow inductance.
Ferrite inductance: ferrite is a kind of magnetic conductor, but it is not pure iron, but the oxide of iron, mainly Fe3O4 and Fe2O3 and some other materials.
It is generally made into a regular body and then wound on the wire, it became a ferrite inductance, the advantages of the inductance is large, high frequency, small size, high efficiency.
The disadvantage is magnetic saturation.Some of the radios that we use, some of the bpers that we use are antennas that are made with coils on the ferrite, in fact it's an inductance, just one way.
4. The role of inductance
The function of inductance seems to be somewhat opposite. We have said that capacitance is dc resistance, while the function of inductance is dc resistance.
Direct current through the inductance of the magnetic field generated by the magnitude of the same direction, does not change.And alternating current (ac) is of positive and negative change, so the magnetic field will also change, because from the positive (negative) to negative (positive) is a very short period of time, the first assumption is potential and rising, so the magnetic field around the inductor increases, it is the largest, when to the potential then began to decline, due to the presence of magnetic field around, the magnetic field around the inductor when will put into electricity, electricity can maintain for a period of time, on the other hand, through which prevents an alternating current.
Post time: Oct-22-2019