Transcript Physical Characteristics of Inductors

Physical Characteristics of Inductors
N A
L
l
2
ECE 201 Circuit Theory I
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L = Inductance in Henrys (H)
N = the number of turns
μ = permeability in Henrys/meter (H/m)
A = cross-sectional area in meters (m)
ECE 201 Circuit Theory I
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Winding Resistance, RW
• The resistance of the wire used to make
the coil (winding).
• Most of the time assumed negligible.
ECE 201 Circuit Theory I
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Winding Capacitance, CW
• Stray capacitance due to two conductors
placed side – by – side.
ECE 201 Circuit Theory I
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Faraday’s Law
• Moving a magnet through a coil of wire
induces a voltage across the coil. When a
complete path is provided, the induced
voltage causes an induced current.
• The amount of induced voltage in a coil
is directly proportional to the rate of
change of the magnetic field with
respect to the coil.
ECE 201 Circuit Theory I
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Inducing a Voltage by Moving a Magnet
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• The induced voltage is proportional to the
number of turns, N, of the wire and the
rate of change of the magnetic flux.
d
eN
dt
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Types of Inductors
ECE 201 Circuit Theory I
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