Inductance is the ratio of the magnetic flux of the conductor to the current producing the alternating magnetic flux generated in and around the conductor, when the alternating current passes through the conductor.
When DC current passes through the inductor, only fixed magnetic lines of force appear around it, which does not change with time; However, when AC current passes through the coil, there will be magnetic lines of force around it that change with time. According to Faraday's law of electromagnetic induction - magnetoelectricity, the changing magnetic line of force will produce an induced potential at both ends of the coil, which is equivalent to a "new power supply".
When the inductance coil is connected to the AC power supply, the magnetic line of force inside the coil will change with the alternating current, resulting in the continuous electromagnetic induction of the coil. This electromotive force generated by the change of the current of the coil itself is called "self induced electromotive force".
Here are the precautions for the use of inductors:
1. Occasion of inductance
Attention should be paid to humidity and dryness, ambient temperature, high-frequency or low-frequency environment, whether the inductance is inductive or impedance characteristics.
2. Frequency characteristic of inductance
At low frequency, the inductance generally presents inductance characteristics, which only stores energy and filters high frequency.
But at high frequency, its impedance characteristics are very obvious. There are phenomena such as energy consumption, heating and reduction of inductive effects. The high frequency characteristics of different inductors are different.
