The working principle and function of inductor
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- publisher
- Gordon
- Issue Time
- Jan 14,2021
Summary
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 only hinders the change of current. Inductors are also called chokes, reactors, and dynamic reactors.
Introduction of Inductor
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.