Inductor principle 

Inductance is the ratio of the magnetic flux of the wire to the current that produces the alternating flux in and around the wire when an alternating current is passed through the wire.

When DC current passes through the inductor, there are only fixed magnetic force lines around it, which do not change with time. But when an alternating current is passed through the coil, the magnetic field lines around it change with time. According to Faraday's law of electromagnetic induction - magneto-electricity analysis, the changing line of magnetic force at both ends of the coil will generate an induced potential, which is equivalent to a "new power source". This induced potential generates an induced current when a closed loop is formed. According to Lenz's law, the total number of magnetic field lines generated by induced current should try to prevent the original magnetic field lines from changing. Since the original magnetic field line change comes from the change of external alternating power supply, the inductor coil can prevent the current change in AC circuit from the objective effect. Inductor coil has similar characteristics to inertia in mechanics, which is called "self-induction" in electricity. Usually, when the knife switch is opened or switched on, sparks will occur. This is caused by the phenomenon of self-induction which produces a high inductive potential.

In short, when the inductor is connected to the AC power supply, the magnetic field lines inside the coil will change with the alternating current, resulting in continuous electromagnetic induction of the coil. This electromotive force caused by the change in the current of the coil itself is called "self-induced electromotive force".

It can be seen that inductance is only a parameter related to coil number, size, shape and medium. It is a measure of inductance coil inertia and has nothing to do with the applied current.

Shenzhen YLZ Technology Co., Ltd. specializes in the design and production of various types of high-frequency transformer, low-frequency (pulse, isolation) transformer, inductor coil.