Revealing the secrets of Inductor Coil, do you really understand it?
Publish Time: 2025-04-01
Inductor Coil is an electronic component wound with insulated wire. It uses the principle of electromagnetic induction to store magnetic field energy and suppresses current mutations through self-inductance. It has the characteristics of passing DC and blocking AC. It is often used for filtering, oscillation, voltage conversion (such as transformers), RF circuit matching and sensors, etc. It is a key passive device for processing signals and energy in electronic circuits.From its working principle, when current flows through a wire, a certain electromagnetic field will be generated around the wire, and the wire of this electromagnetic field itself will induce the wire within the range of this electromagnetic field. This electromagnetic induction phenomenon is the basis for the work of Inductor Coil. When current passes through Inductor Coil, due to the effect of electromagnetic induction, the coil will generate self-induced electromotive force to counteract the current change in the coil, thereby achieving the obstruction of AC current. In high-frequency circuits, the blocking effect of Inductor Coil is particularly significant, which can effectively limit the passage of high-frequency current.In practical applications, the role of Inductor Coil is varied. First, it has a choking effect. It can be used to block low-frequency AC in low-frequency circuits, or to form a Π-type filter circuit between two filter capacitors at the output end of the rectifier circuit. In high-frequency circuits, Inductor Coil prevents high-frequency current from flowing to the low-frequency end. Secondly, it has a filtering effect. Inductor Coil can be combined with resistors or capacitors to form high-pass filters, low-pass filters, band-pass filters, and band-stop filters, etc., to achieve the screening and filtering of different frequency signals in the circuit. Finally, it has an oscillation effect. Inductor Coil can complete the process of converting DC into AC. This circuit is called an "oscillator".Inductor Coil also has the function of tuning and frequency selection. When Inductor Coil is connected in parallel with a capacitor, an LC tuning circuit can be formed. When the inherent oscillation frequency of the circuit is equal to the frequency of the non-AC signal, the inductive reactance and capacitive reactance of the circuit are also equal, so the electromagnetic energy oscillates back and forth between the inductor and the capacitor, generating the resonance phenomenon of the LC circuit. This resonance phenomenon makes Inductor Coil have a frequency selection effect, which can filter out signals of a specific frequency. In addition, the Inductor Coil has a certain delay effect on the change of current. This allows the Inductor Coil to provide more stable and accurate performance when processing complex signals.When designing and using the Inductor Coil, some important parameters need to be considered. The first is the inductance L, which is determined by the ripple. The second is the average value of the full-load DC inductor current, which determines the DC operating point of the magnetic core. Finally, the maximum ripple current requirement is the requirement for inductance. In addition, the best core structure, the smallest geometric size, the appropriate number of winding turns, the cross-sectional area of the wire, and the air gap length need to be determined.Inductor Coil is a very important electronic component that plays a key role in many electronic devices. Whether it is filtering and rectification in the power circuit, matching and frequency selection in the RF circuit, or even in some sensors, Inductor Coil plays an irreplaceable role. However, despite the wide application and importance of Inductor Coil, many people do not understand its working principle and characteristics. Therefore, it is of great significance for electronic engineers and enthusiasts to have a deep understanding of the mystery of Inductor Coil.
