Structure And Characteristics Of Inductance Coil


Components of inductance: generally, it is composed of magnetic core or iron core, skeleton, winding group, shielding cover, packaging material, etc.


1. The frame generally refers to the bracket for winding copper wire coils. large volume of fixed inductance or adjustable inductance (such as oscillation coil, resistance coil, etc.), most of the enameled wire (or gauze wire) is directly wound on the skeleton, and then the core or copper core, iron core, etc., into the inner cavity of the skeleton, in order to improve the inductance. The skeleton is usually made of plastic, bakelite, ceramic, according to the actual needs that can be made into different shapes.


Small inductor coils (such as color ring inductors) generally do not use a skeleton, but wrap enameled wire directly around the core.


The hollow inductor coil (also known as the tire coil or hollow coil, mostly used in high-frequency circuits) does not need the core, skeleton and shielding cover, but is wound on the mold first and then removed, and the coil is separated from each other to a certain distance.


2. Winding refers to a set of coils with specified functions, which is the basic component of the inductor coil.


Windings can be divided into single layer and multiple layers. The single-layer winding has two forms: close winding (winding wire a circle to a circle) and between winding (winding wire each circle are separated by a certain distance); multilayer winding has layering winding, disorderly winding, honeycomb winding method and so on.


3. Magnetic cores and rods Magnetic cores and rods are generally made of nickel-zinc ferrite or Mn-zinc ferrite and other materials, which are I-shaped, cylindrical, cap shaped, "E" shaped, tank shaped, annular and other shapes.


4. The core material mainly includes silicon steel sheet, permalloy and so on, and its shape is mostly "E" type.

5. Shielding cover In order to prevent the magnetic field generated by some inductor coils from affecting the normal operation of other circuits and components, a metal screen cover (such as the oscillating coil of a semiconductor radio, etc.) is added to it. The inductor with a shield will increase the loss of the coil and reduce the Q value.


6. Encapsulation material After some inductors (such as color ring inductors, etc.) are wound, the coil and core are sealed with encapsulation material. Encapsulation materials are plastic or epoxy resin.


(2) Small fixed inductor



A small fixed inductor coil is usually made of enameled wire wound directly on the core, which is mainly used in filtering, oscillation, notch, delay and other circuits. It has sealed and non-sealed packaging forms, and both forms have vertical and horizontal configuration.


1. Vertical seal fixed inductor Vertical seal fixed inductor with the same type of pin, its inductance range is 0.1~2200 μh, rated working current is 0.05~1.6A, error range is ±5%~±10%. The color ring inductor whose inductance is marked on the surface of the inductor with a color dot.


2. Horizontal seal fixed inductors Horizontal seal fixed inductors use axial pins.


The inductance range of LGA series color ring inductor is 0.1~ 22000μh (directly marked on the housing), the rated working current is 0.05~1.6A, the error range is ±5%~±10%.


(3) Adjustable inductor


Commonly used adjustable inductors include oscillating coil for semiconductor radio, oscillating coil for television, linear coil, IF notch coil, frequency compensation coil for audio, and resistance coil, etc.