In order to protect the wires, circuits and coils from external magnetic fields and to attenuate the interference of electromagnetic fields generated by the circuit on other components, magnetic shielding or electromagnetic shielding is usually used.
Features: Reduce the electromagnetic interference of the inductor to the outside world.
The inductor mainly plays the role of filtering, oscillation, delay, trapping, etc. in the circuit, as well as screening signals, filtering noise, stabilizing current and suppressing electromagnetic interference. The most common function of the inductor in the circuit is to form an LC filter circuit together with the capacitor. The capacitor has the characteristics of "resistance to DC, AC", while the inductor has the function of "DC, DC". If the DC current with many interference signals is passed through the LC filter circuit, the AC interference signal will be consumed by the inductor into heat energy; when the relatively pure DC current passes through the inductor, the AC interference signal is also turned into a magnetic sense. And thermal energy, the higher the frequency is the most easily inductive impedance, which can suppress higher frequency interference signals.
The inductor has the characteristic of preventing the passage of the alternating current and allowing the direct current to pass smoothly. The higher the frequency, the larger the impedance of the coil. Therefore, the main function of the inductor is to isolate, filter or form a resonant circuit with a capacitor or a resistor.
The characteristics of the inductor are exactly opposite to those of the capacitor. It has the characteristic of preventing the passage of alternating current and allowing the direct current to pass smoothly. When the DC signal passes through the coil, the resistance of the wire itself is small. When the AC signal passes through the coil, the self-induced electromotive force will be generated at both ends of the coil. The direction of the self-induced electromotive force is opposite to the applied voltage, which hinders the passage of AC. Therefore, the characteristics of the inductor are DC and resistance AC. The higher the frequency, the larger the coil impedance. The inductor often works with the capacitor in the circuit to form an LC filter, an LC oscillator, and the like. In addition, people also use the characteristics of the inductor to manufacture chokes, transformers, relays and so on.
