1. ECE 201 Circuit Theory I1 Physical Characteristics of Inductors

2. ECE 201 Circuit Theory I2 L = Inductance in Henrys (H) N = the number of turns μ = permeability in Henrys/meter (H/m) A = cross-sectional area in meters (m)

3. ECE 201 Circuit Theory I3 Winding Resistance, R W The resistance of the wire used to make the coil (winding). Most of the time assumed negligible.

4. ECE 201 Circuit Theory I4 Winding Capacitance, C W Stray capacitance due to two conductors placed side – by – side.

5. ECE 201 Circuit Theory I5 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.

6. ECE 201 Circuit Theory I6 Inducing a Voltage by Moving a Magnet

7. ECE 201 Circuit Theory I7 The induced voltage is proportional to the number of turns, N, of the wire and the rate of change of the magnetic flux.

8. ECE 201 Circuit Theory I8 Types of Inductors