Surface Mount Inductance (smd inductance)

Inductances are radio elements that can form a magnetic field. However, in radio engineering, the main useful property of inductances is that they are capable of passing direct current and not passing alternating current. In addition, they may be part of radio filters. Depending on their task, the requirements for inductances and their designs also change.

As is known from the general course of physics, when an electric current flows through a conductor, a magnetic field is formed around it. On this property are implemented such electronic devices as electromagnets. However, there is an inverse transformation. The magnetic field can cause electrical current in the conductor. More precisely, the electric current will not cause a magnetic field, and its change. The dependence of the emf induced in a conductor by a change in the magnetic flux is written using the following expression:

(one)

Considering that the magnetic field itself is formed by the current flowing, the emf from this magnetic field is induced in the conductor. Such an emf is called a self-induction emf and is written as follows:

(2)

The coefficient of proportionality L in this expression is called the inductance of the conductor. When an alternating current flows through a conductor, its inductance resists the flow of this current. The value of this resistance can be determined by differentiating expression (2):

(3)

From where it is possible to determine the inductance resistance to alternating current:

(four)

The inductance of the wire is quite small. It can be determined by the following formula:

(five)

where L is the inductance of the wire in μH;
l is the length of the wire in cm;
d is the wire diameter in cm;

the simplest inductance is a few turns of wire located in close proximity to each other. The internal structure of the most common type of induction is shown in Figure 1.

Figure 1. Internal smd inductance device

Main scopes:
LCD and plasma displays
Hard disks and optical media readers
DC / DC Converters
Car monitoring and security systems
High EMC devices
Computers