8 | inductor
What is inductor?
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it.
An inductor consists of a wire loop or coil. The inductance is directly proportional to the number ofturns in the coil.
The symbol for inductance, in honor of the physicist Heinrich Lenz. In the SI system, the unit of inductance is the Henry (H), which is the amount of inductance that causes a voltage of one volt, when the current is changing at a rate of one ampere per second.
Figure 1 inductor
Figure 2 symbol
Inductor Principles
Basically, it uses a conductor that is wound into a coil, and when electricity flows into the coil from the left to the right, this will generate a magnetic field in the clockwise direction.
Figure 1 inductor
Inductor Operations and characteristics
Types of Inductors
Air Core
Iron Core
Ferrite Core
Iron Powder
Laminated Core
Bobbin based
Toroidal
Multi-layer Ceramic
Figure 4 symbol in circuits
Inductor applications
Inductors have various uses in electrical transmissions based on their requirements.
Inductors are used in tuning circuits.
These are used as sensors.
It is also used to store energy in a device.
Inductors are used in induction motors.
It is used as transformers.
Inductors are used as filters.
Uses of inductors in chokes
Inductors in Series
Inductors can be connected together in a series connection when the are daisy chained together sharing a common electrical current.
The current, ( I ) that flows through the first inductor, L1 has no other way to go but pass through the second inductor and the third and so on. Then, series inductors have a common current flowing through them.
Total current , ILt = IL1 = IL2 = IL3
Total inductance, Lt = IL1 + IL2 + IL3
Figure 5 Inductor in series
Source > https://www.electronics-tutorials.ws/inductor/series-inductors.html
Inductors in Parallel
When inductors are connected together in parallel so that the magnetic field of one links with the other, the effect of mutual inductance either increases or decreases the total inductance depending upon the amount of magnetic coupling that exists between the coils.
The voltage drop across all of the inductors in parallel will be the same.
Then, Inductors in Parallel have a common voltage across them.
Total inductance voltage, VLt = VL1 = VL2 = VL3
Total inductance,
Lt = 1 ÷ ((1÷ L1) + (1÷ L2) + (1÷ L3))
Figure 6 inductor in parallel
Source > https://www.electronics-tutorials.ws/inductor/parallel-inductors.html
Inductor in AC - Inductive Reactance
Like resistance, reactance is measured in Ohm's but is given the symbol “X” to distinguish it from a purely resistive “R” value and as the component in question is an inductor, the reactance of an inductor is called Inductive Reactance, ( XL ) and is measured in Ohms. Its value can be found from the formula.
Formula:
XL ( Ω ) = 2 x π x Freq x L
where;
π (pi) = 3.14
Freq - supply frequency
L - inductor value in unit henry (H)
Example calculation
Example 1 : Inductor in series
Three loads connected in series with the value of L1=0.5, L2=0.25, L3=0.8 find the following value.
Find the total inductance Lt ? L t = L1 + L2 + L3
Answer solutions : Lt = 0.5 + 0.25 + 0.8 = 1.55 H (or henry)
Example 2 : Inductor in parallel
Three loads connected in series with the value of L1=0.15, L2=0.25, L3=0.4 find the following value.
Find the total inductance Lt ? L t = 1÷ ((1/L1) + (1/L2) + (1/L3))
Answer solutions : Lt = 1 ÷ ((1÷0.15) + (1÷0.25) + (1÷0.4)) = 0.075 H (or henry)
Example 3 : Inductive reactance calculation
Given the value of F=50Hz, L=0.35H, calculate the inductive reactance.
Solution : XL ( Ω ) = 2 x π x Freq x L
= 2 x 3.14 x 50hz x 0.35H = 109.9 Ω