What is power inductor?
An inductor is an element that can convert electrical energy into magnetic energy and store it. The structure of the inductor is similar to that of a transformer, but there is only one winding. The inductor has a certain inductance, which only hinders the change of current. If the inductor is in the state of no current, it will try to prevent the current from flowing through it when the circuit is connected; If the inductor is in a state of current flow, it will try to keep the current constant when the circuit is disconnected. Inductor is also called choke, reactor and dynamic reactor.Metal Composite Power Inductors
Inductors can be divided into several categories?
Self sensor
When a current passes through the coil, a magnetic field will be generated around the coil. When the current in the coil changes, the magnetic field around it also changes accordingly. The changed magnetic field can make the coil produce induced electromotive force (induced electromotive force) (electromotive force is used to represent the terminal voltage of the ideal power supply of the active element), which is self induction.
Electronic components, which are wound with wires and have a certain number of turns and can produce a certain amount of self inductance or mutual inductance, are often called inductive coils. In order to increase inductance, improve quality factor and reduce volume, iron core or magnetic core made of ferromagnetic material is often added. The basic parameters of inductor include inductance, quality factor, inherent capacitance, stability, passing current and service frequency. The inductor composed of a single coil is called self inductor, and its self inductance is also called self inductance coefficient.
Transformer
When two inductance coils are close to each other, the magnetic field change of one inductance coil will affect the other inductance coil, which is mutual inductance. The size of mutual inductance depends on the degree of coupling between the self inductance of the inductance coil and the two inductance coils. The element made by using this principle is called mutual inductor.
How to judge the inductance?
1. Inductance measurement: turn the multimeter to the buzzer diode, put the lead on the two pins and watch the reading of the multimeter.
2. Good or bad judgment: the reading of the chip inductance should be zero at this time. If the reading of the multimeter is too large or infinite, it indicates that the inductance is damaged.
For inductance coils with many turns and thin wire diameter, the reading will reach tens to hundreds. Generally, the DC resistance of the coil is only a few ohms. The damage is hot or the inductive magnetic ring is obviously damaged. If the inductive coil is not seriously damaged and cannot be determined, the inductance can be measured with an inductance meter or judged by the replacement method.
matters needing attention
1、 For inductive components, the iron core and winding are easy to change due to the temperature rise effect. It should be noted that the body temperature must be within the use specification range.
2、 The winding of inductor is easy to form electromagnetic field after the current passes through. When placing the components, pay attention to keep the adjacent inductors away from each other, or the winding groups at right angles to each other, so as to reduce the induction between each other.
3、 The gap capacity will also be generated between the winding layers of the inductor, especially multiple turns of thin wires, resulting in high-frequency signal bypass and reducing the actual filtering effect of the inductor.
4、 When testing the inductance value and Q value with the instrument, in order to obtain the correct data.
