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The working principle and function of inductor

The working principle and function of inductor

Jan 14,2021

Introduction of Inductor

Inductor is an element that can convert electrical energy into magnetic energy and store it. The structure of an inductor is like a transformer, but it has only one winding. The inductor has a certain inductance, it only hinders the change of current. If the inductor is in a state where no current is flowing, it will try to block the current from flowing through it when the circuit is on; if the inductor is in a state where current is flowing, it will try to maintain the current when the circuit is off. Inductors are also called chokes, reactors, and dynamic reactors.

The Function of Inductor

The role of inductor: filtering, oscillation, delay, notch; a vivid statement: "connect DC, block AC"

DC connection: The so-called DC connection means that in a DC circuit, the inductor acts as a wire and does not have any effect.

 

Resistance to AC: In an AC circuit, the inductor will have impedance, that is, XL, and the current in the entire circuit will become smaller, which will hinder AC to a certain extent.

 

The blocking effect of inductor: The self-induced electromotive force in the inductor coil always changes with the current in the coil.

 

Inductor tuning and frequency selection: the inductor coil and the capacitor in parallel can form an LC tuning circuit.

 

Inductor also has the functions of filtering signals, filtering noise, stabilizing current and suppressing electromagnetic interference.

The Function of Chip Inductor

Chip inductors are electromagnetic induction components wound with insulated wires. Belongs to commonly used inductive components. The function of the chip inductor: It is simple to say that it can isolate and filter the AC signal or form a resonant circuit with capacitors, resistors, etc. Tuning and frequency selection inductors: the inductor coil and the capacitor can be connected in parallel to form an LC Tuning the circuit. Any current of the chip inductor in the circuit will generate a magnetic field, and the magnetic flux of the magnetic field will act on the circuit.

 

When the current passing through the chip inductor changes, the DC voltage potential generated in the chip inductor will prevent the current from changing. When the current passing through the inductor coil increases, the self-induced electromotive force generated by the inductor coil is opposite to the direction of the current, preventing the increase of the current, and at the same time converting part of the electric energy into magnetic field energy and storing in the inductor; when the current passing through the inductor coil decreases, The self-induced electromotive force is in the same direction as the current, preventing the current from decreasing, and at the same time releasing the stored energy to compensate for the current decrease. Therefore, after inductance filtering, not only the pulsation of load current and voltage is reduced, the waveform becomes smooth, and the conduction angle of the rectifier diode increases.

The role of inductor:

 

1, The color circle coil (color ring) has a blocking effect: the copper core in the color circle coil is always resistant to the current change in the coil. The color ring has an obstructive effect on the alternating current used in the circuit. The magnitude of the obstructive effect is called inductive reactance XL, and the unit is ohm. The relationship between it and the inductance L and alternating current frequency f is XL=2πfL, and the color ring can be divided into high-frequency choke coils and low-frequency choke coils.

 

2, The color ring has tuning and frequency selection: the color ring and the electrolytic capacitor can be connected in parallel to form an LC tuning circuit. When the color ring is at resonance, the inductance and capacitive reactance of the circuit are equal and reversed. That is, the natural oscillation frequency f0 of the circuit is equal to the frequency f of the non-AC signal, and the inductance and capacitive reactance of the loop are also equal. It is not very high. The color ring used in the circuit is generally more stable.

 

3, The main purpose of color ring is to filter signals, filter noise, stabilize current and suppress electromagnetic interference. The basic function of the color ring is charging and discharging, but many circuit phenomena extended by this basic charging and discharging effect make the color rings have a variety of different uses. Nowadays, color rings have been used by customers, but the role played by small inductors is not underestimated.

 

The working principle of inductor

 

Inductor is the ratio of the alternating magnetic flux generated around the inside of the wire when an alternating current pass through the wire, and the ratio of the magnetic flux of the wire to the current that produces this magnetic flux. When a DC current passes through the inductor, only fixed magnetic lines of force appear around it, which does not change with time; but when an alternating current pass through the coil, the surroundings will show magnetic lines of force that change with time.

 

According to Faraday's law of electromagnetic induction---magnetism generates electricity, the changing magnetic field lines will generate induced electric potential at both ends of the coil, which is equivalent to a "new power source". When a closed loop is formed, this induced potential will produce induced current. It is known from Lenz's law that the total amount of magnetic field lines produced by the induced current is to try to prevent the change of magnetic field lines. The change of the magnetic field line comes from the change of the external alternating power supply, so from the objective effect, the inductor coil has the characteristic of preventing the current change in the alternating current circuit. Inductor coils have characteristics like the inertia in mechanics. They are named “self-induction” in electricity. Usually, sparks will occur now when the knife switch is opened or the knife switch is turned on. Caused by high induced potential.

 

The inductor has the characteristic of preventing the passage of alternating current and allowing direct current to pass smoothly. The higher the frequency, the greater the coil impedance. Therefore, the main function of the inductor is to isolate and filter the AC signal or form a resonant circuit with capacitors, resistors, etc.