Practical Electronics/Inductors
Inductor[edit]
This device generates a magnetic field as current passes through it similar to the magnetic field of a magnet. An inductor stores electrical energy in the form of a magnetic field.
Inductor's Symbol[edit]
The symbol for inductance is L and is measured in Henry which has the symbol H.
Inductor's Construction[edit]
An inductor is a device made from a wire conductor with several turns that has the dimensiion permability, length of inductor, and number of turns and inversely proportional to crosssectional area.
 = μN^2
Characteristics[edit]
Inductance[edit]
Inductance is the ability to generartes Magnetic Field B for a given Current
Magnetic Field[edit]
When a voltage is applied across the inductor, current generates Electric Field . Change of Electric Field in the turns generates Magnetic Field perpendicular to Electric Field
 B = I L
Voltage[edit]
Current[edit]
Reactance[edit]
Reactance is defined as the ratio of Voltage over current
Impedance[edit]
Impedance is defined as the sum of Reactance and Resistance of Inductor . Since all conductor has Resistance
Frequency Respond[edit]
Inductor is a device depends on frequency
 , Inductor Closed circuit, I ≠ 0
 , Inductor Opened circuit, I = 0
 ,
 Z_L = [(R_{L}]⅓</math> ,
With the value of I at three frequency points ω = 0, , 1 / CR_{C} I  f curve can be drawn to give a picture of current in the inductor over time
Phase Angle[edit]
When a Voltage is applied across inductor , current generates magnetic field . Change in curent generate change in magnetic field which generate voltage across inductor . Therefore, current will lead voltage
For ideal losses inductor which has no internal resistance, Current will lead Voltage an angle 90 . For Non  Ideal inductor which has an internal resistance, Current will lead Voltage an angle θ

 Tanθ = = 2π f
Phase angle relates to time frequecy or time and the value of R and L . When there is a change in phase angle Time and frequency also change
Induced Voltage[edit]
Induced Voltage is defined as the voltage of the turns which oppose the current flow

 ξ = where Φ = NB
Từ Dung[edit]
Từ Dung là tính chất Vật lý của Cuộn Từ đại diện cho Từ Lượng sinh ra bởi một Dòng Điện trên Cuộn Từ . Từ Dung đo bằng đơn vị Henry H và có ký hiệu mạch điện L
Cuộn Từ tạo từ một cộng dây dẩn điện có kích thứớc Chiều dài , l , Điện tích , A , với vài vòng quấn N . Khi mắc với điện
Độ Dẩn Từ của vật liệu
Construction  Formula  Dimensions 

Cylyndrical Coil ^{[1]} 


Straight wire conductor 




Short aircore cylindrical coil 


Multilayer aircore coil 


Flat spiral aircore coil 




Toroidal core (circular crosssection) 

Network[edit]
Inductors can be connected in series to increase inductance or in parallel to decrease inductance
Parallel Connection[edit]
Series Connection[edit]
References[edit]
 ↑ ^{a} ^{b} Nagaoka, Hantaro. The Inductance Coefficients of Solenoids[1]. 27. Journal of the College of Science, Imperial University, Tokyo, Japan. p. 18.