Briefly describe the application range of inductors, structures, and types.

Reference encyclopedia main types 1. Small fixed inductors: small fixed inductors are usually made of enameled wire directly wound on the core, mainly used in filtering, oscillation, notch, delay and other circuits, it has sealed and unsealed two packaging forms, and both forms have vertical and horizontal shape structures.

1 Vertical Sealed Fixed Inductor Vertical Sealed Fixed Inductor adopts the same direction pin, and there are series of inductors such as LG and LG2 in China, and the inductance range is directly marked on the shell), the rated working current is, and the error range is 5%-10%. There are TDK series color-coded inductors imported, and their inductance is marked on the surface of the inductor with color points.

2 Horizontal sealed fixed inductor Horizontal sealed fixed inductor adopts axial pins, and there are LG1, LGA, LGX and other series in China. The inductance range of LG1 series inductors is directly marked on the housing) and the rated operating current is 5%-10%. The LGA series inductors have an ultra-small structure and are similar in shape to 1 2W color ring resistors, with an inductance range marked on the case with a color ring) and a rated current.

The LGX series color-coded inductors are also available in small packages, with inductance ranging from 50mA, 150mA, 300mA and four sizes.

2. The tunable inductors commonly used in adjustable inductors include oscillating coils for semiconductor radios, oscillating coils for televisions, linear coils, intermediate frequency notch coils, frequency compensation coils for audio, and wave-blocking coils. Structural inductors are generally composed of skeletons, windings, shields, packaging materials, magnetic inductance coils, cores or cores, etc.

Small inductors are used in mobile phones, digital set-top boxes, Bluetooth headsets, LCD TVs, automotive electronics, and industrial control.

Inductors Small inductors are widely used in mobile phones, digital set-top boxes, Bluetooth headsets, LCD TVs, automotive electronics, industrial control and other fields, and there is a huge market potential. In terms of chip inductors alone, the market demand in 2007 reached more than 300 billion units, worth about 30 billion yuan.

As the market continues to be segmented, a variety of small inductors for specific applications are gradually emerging. In data systems and industrial electronics applications, the demand for point-of-load power supplies has increased dramatically, creating opportunities for high-power, small-size inductors.

TDKMLK1005S3N9S, MLF1608A100KT and other types of multilayer inductors are widely used in high-frequency environments, and the market sales are good; The TDKHHM1517 and HHM1520, which are used in Bluetooth headsets, band-pass filters such as wireless network cards, and balanced balunistic transformers, also have broad market prospects.

Search: Briefly describe the application scope, structure, and type of inductors.

There are three types of inductive sensors: self-inductive sensors that change the δ of the air gap thickness and dispersion bonds, that is, variable gap inductive sensing; a self-inductive sensor that changes the air gap cross-section S, i.e., a variable-cross-section inductive sensor; A self-inductive sensor that changes the air gap thickness δ and the air gap cross-section s at the same time, i.e., a solenoid inductive sensor.

1. Variable gap inductance sensor, the air gap δ of this sensor changes with the change of being measured, thereby changing the magnetic resistance. Its sensitivity and nonlinearity decrease as the air gap increases, so it is often necessary to consider both δ generally in the millimeter.

2. Change the area type inductance sensor, the relative coverage area between the core and the armature of this sensor (i.e., the flux cross-section) changes with the change of being measured, and the state match changes the magnetic resistance Its sensitivity is constant, and the linearity is also very good. Solenoid plug-in inductive sensor. It consists of a solenoid coil and a cylindrical armature connected to the object to be measured.

3. Solenoid plug-in inductive sensor, which is composed of solenoid coil and cylindrical armature connected to the measured object. Its working principle is based on the change in magnetic resistance in the leakage path of the coil's magnetic field lines. The armature changes the amount of inductance of the coil as it moves with the object being measured.

This kind of sensor has a large range, low sensitivity, simple structure, and is easy to manufacture.

There are generally three types of inductive sensors: variable reluctance sensor, self-inductive type, differential transformer sensor, mutual inductance, and eddy-current sensor.

How it works: An inductive sensor is composed of three parts. When a metal object is sensed by this magnetic field, eddy currents are generated. This will lead to a weakening of **.

Advantages: The inductive sensor has no active electric shock, so it works reliably and has a long service life. High sensitivity and resolution. Good reproducibility. The linearity is good in a certain range.

Application: The inductive sensor has the outstanding advantages of simple structure, fast dynamic response, easy to achieve non-contact measurement, etc., and is especially suitable for acid, alkali, chloride, organic solvent, liquid CO2, ammonia, PVC powder, ash, oil-water interface and other liquid level measurement, and is currently widely used in metallurgy, petroleum, chemical, coal, cement, grain and other industries.

According to the different signal forms, the speed sensor can be divided into two types: analog and digital.

A sensor that converts the rotational speed of a rotating object into an electrical output. Rotational speed sensors are indirect measuring devices that can be manufactured using mechanical, electrical, magnetic, optical, and hybrid methods.

The output signal value of the former is a linear function of the rotational speed, and the output signal frequency of the latter is directly proportional to the rotational speed, or its signal peak interval is inversely proportional to the rotational speed.

The open-circuit speed sensor (Fig. 4a) has a relatively simple structure and a small output signal, so it is not suitable for use in situations with severe vibration. A closed-circuit speed sensor consists of an external gear, an internal gear, a coil, and a permanent magnet mounted on a rotating shaft (Fig. 4b).

It can be categorized as:

1. Variable reluctance sensor - self-inductive.

2. Differential transformer sensor - mutual inductance.

3. Eddy-current sensor - eddy-current type.

There are three types of inductive sensors: self-sensing sensors that vary the thickness of the air gap by δ, i.e., variable gap inductive sensing; a self-inductive sensor that changes the air gap cross-section S, i.e., a variable-cross-section inductive sensor; A self-inductive sensor that changes the air gap thickness δ and the air gap cross-section s at the same time, i.e., a solenoid inductive sensor.

1. Variable gap type inductance sensor.

The air gap δ of such a sensor varies with the measurement and thus the magnetic resistance. Both its sensitivity and nonlinearity decrease as the air gap increases, so it is often necessary to consider both. δ is generally taken in the millimeter.

2. Change the area type inductance sensor.

The relative coverage area between the core and the armature (i.e., the flux cross-section) of such a sensor changes with the measurement and thus the magnetic resistance.

Its sensitivity is constant and the linearity is good. Solenoid plug-in inductive sensor. It consists of a solenoid coil and a cylindrical armature connected to the object to be measured.

Its working principle is based on the change in magnetic resistance in the leakage path of the coil's magnetic field lines. The armature changes the amount of inductance of the coil as it moves with the object being measured. This kind of sensor has a large range, low sensitivity, simple structure, and is easy to manufacture.

3. Solenoid plug-in iron inductive sensor.

It consists of a solenoid coil and a cylindrical armature connected to the object to be measured.

Its working principle is based on the change in magnetic resistance in the leakage path of the coil's magnetic field lines. The armature changes the amount of inductance of the coil as it moves with the object being measured. This kind of sensor has a large range, low sensitivity, simple structure, and is easy to manufacture.

An inductive sensor consists of an iron core and a coil that converts linear or angular displacement into a sensor, an inductive displacement sensor. The number of turns of the coil and the permeability of the material are determined, and the change in inductance is caused by the change in the geometry of the coil's magnetic circuit caused by the displacement input. When the coil is connected to the measurement circuit and connected to the excitation power supply, a voltage or current output proportional to the displacement input is obtained.

Commonly used inductive sensors are variable gap type, variable area type, and spiral type. In practice, the three sensors are made into different types of sensors, which improves linearity and reduces additional errors caused by electromagnetic forces.

Variable Gap Inductive Sensor:

The change in the air gap of a variable gap inductive sensor varies with the measurement. The sensitivity and nonlinearity of the air gap increase as the air gap increases. The delta is generally between millimeters and millimeters.

Variable Area Inductive Sensors:

The relative coverage area between the core and the armature (i.e., the flux part) of the variable region type inductive sensor varies with the measurement, thus changing the magnetic resistance. Its sensitivity is constant and the linearity is good.

Spiral Tube Plug-in Inductive Sensor:

The attached spiral tube is an iron inductive sensor consisting of an electromagnetic coil and a cylindrical armature object. How magnetoresistive-based leakage path replacement coils work. The armature of the inductance coil is changed with the measured object when moving.

The sensor has the advantages of large measurement range, low sensitivity, simple structure and convenient manufacturing.

It is divided into three categories: variable reluctance sensors, differential transformer sensors, and eddy current sensors (1) variable reluctance sensors - self-inductive.

The structure is simple, and the sensor has no active electrical contacts, so it works reliably and has a long life;

High sensitivity and resolution, can detect micron displacement changes. The output signal of the sensor is strong, and the voltage sensitivity is generally up to hundreds of millivolts per millimeter of displacement;

The linearity and repeatability are relatively good, and the nonlinear error of the sensor can be reached within a positioning range (tens of microns to several millimeters). At the same time, this sensor can realize the long-distance transmission, recording, display and control of information, and it is widely used in industrial automatic control systems. However, it has the disadvantages of low frequency response and unsuitable for fast dynamic measurement and control.

2. Differential transformer sensor - mutual inductance.

Advantages: high measurement accuracy, high sensitivity, simple structure, reliable performance (3) eddy-current sensor - eddy-current type.

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