The inductance is the element that converts the current into the magnetic field energy, and the inductance value represents the ability of the current to generate the magnetic field. The same current, the wire around the multi-turn coil, you can increase the magnetic field, such as iron wire inside the magnetic material, can greatly increase the magnetic field, therefore, the common inductors are built-in core coil.
Inductor: When the coil through the current, the formation of magnetic field in the coil induction, induction magnetic field will produce induced current to resist the current through the coil. We put this current and the interaction of the coil called the electrical inductance, that is, the inductance, the unit is "Henry" (H). The inductance element can also be made using this property.
The inductance is the ratio of the magnetic flux of the conductor to the current that produces this flux when the AC current is passed through the wire. When the inductor through the DC current, the surrounding only showed a fixed magnetic field lines, does not change with time;
But when the AC current through the coil, the surrounding will show a change over time with the magnetic field lines. According to Faraday's law of electromagnetic induction - magnetic electricity to analyze, changes in the magnetic lines at both ends of the coil will produce the induced potential, the induction potential is equivalent to a "new power." When forming a closed loop, this induced potential will produce an induced current. By the Leng's law to know the induced current generated by the total amount of magnetic field lines to try to prevent the changes in magnetic field lines. Magnetic field line changes from the external alternating power supply changes, so the objective effect, the inductor coil to prevent the AC circuit in the current changes in the characteristics. Inductance coil and mechanical inertia is similar to the characteristics of the electric name named "self-induction", usually in the open knife switch or switch knife switch moment, there will be sparks, this self-induced phenomenon is very High induced potential caused by.
In short, when the inductor coil connected to the AC power supply, the coil inside the magnetic field lines will be alternating with the current and constantly changing, resulting in electromagnetic induction coil. This is due to the current changes in the coil itself caused by the electromotive force, known as "self-induced electromotive force." It can be seen that the inductance is only a parameter associated with the number of turns of the coil, the shape of the shape and the medium, which is the measure of the inertia of the inductor and is independent of the applied current.
Substitution principle: 1, the inductance coil must replace the original value (the same number of turns, the same size).
2, chip inductors can only be the same size can also be used 0 ohm resistance or wire replacement.