Download Lecture-5 - Dr. Imtiaz Hussain

Electronic workshop
Lecture-5
Inductors and Transformers
Dr. Imtiaz Hussain
email: [email protected]
URL :http://imtiazhussainkalwar.weebly.com/
Inductors
• Generally - coil of conducting wire
– Usually wrapped around a solid core. If no core is
used, then the inductor is said to have an ‘air
core’.
Symbols
Inductors
• Values specified in henries (H), millihenries (mH) and
microhenries (μH).
• Inductor can be fixed value or variable.
Fixed Value Inductor
Variable Inductor
4
Inductor types
Molded inductor & air-wound inductor
Ferrite core toroidal transformer
Adjustable air-wound inductor
Air wound inductor
Iron powder toroidal inductor
5
Inductor ratings
• Wire gauge and physical size of the coil
determine the current handling capacity.
• Core material
dependence.
will
have
a
temperature
• Air is best, followed by iron powder, then
ferrites.
6
Inductor handling
• Inductors are not polarized and may be installed in
either direction.
• Mechanical stress due to lead bending should be
minimized.
• Inductors in timing or frequency determining circuits
should be installed in a mechanically rigid fashion.
7
Color Coding
Inductor Applications
• Speakers
• Solenoid Valves
• Resonant Circuits
Task#1
• An ideal inductor would exhibit zero resistance
but a real inductor has some finite resistance.
• Inductors which have become open will show
infinite resistance, whereas shorted inductors will
show a resistance of zero Ohms.
• Take few resistors and check them for any faults.
Transformers
• A transformer is a device that uses a pair of coils/windings to
manipulate AC voltage and current.
• It uses the principle of mutual induction to either decrease or
increase the voltage/current at its input.
Transformers
Transformers
• The voltage/current at the output of the
transformer is given by the following
equation:
𝑉𝑠 𝑁𝑠 𝐼𝑝
=
=
𝑉𝑝 𝑁𝑝 𝐼𝑠
Task#2
S
N.o
1.
2.
3.
4.
5.
Peak to Peak
Input Voltage
Output Voltage
Turn Ratio
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END OF LECTURE-5