Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.1 Field representation obtained with iron filings Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 1

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.2 Magnetic lines of force Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 2

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 3 Figure 5.3(a) Effects of placing magnetic material in a magnetic field

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.3(b) Effects of placing magnetic material in a magnetic field 4

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.3(c) Effects of placing magnetic material in a magnetic field 5

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.4 Molecular arrangements in a magnet 6

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.5 Magnetic induction 7

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.6 Rectangular form of magnetic chuck 8

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.7 Magnetic field around a straight conductor 9

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.8 Direction of magnetic fields created around conductors by a current flowing through them 10

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean Figure 5.9 Derivation of current direction symbols 11

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 12 Figure 5.10 Magnetic flux due to an electric current

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 13 Figure 5.11 Right-hand thumb rule for a solenoid

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 14 Figure 5.12(a) Forces exerted by conductors carrying a current

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 15 Figure 5.12(b) Forces exerted by conductors carrying a current

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 16 Figure 5.13 Creating a force with the interaction of two magnetic fields

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 17 Figure 5.14 Magnetisation (B/H) curve for non-magnetic materials

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 18 Figure 5.15 Magnetisation (B/H) and permeability (mr/H) curves for a sample of iron

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 19 Figure 5.16 Comparison of B/H magnetisation curves for ferromagnetic materials

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 20 Figure 5.17 Hysteresis loop for a magnetic material

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 21 Figure 5.18 Comparison of hysteresis loops for two magnetic materials

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 22 Figure 5.19 Magnetic leakage

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 23 Figure 5.20 Magnetic fringing

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 24 Figure 5.21 Typical relay construction

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 25 Figure 5.22 Typical relays. (a) This relay operates several sets of contacts at current ratings of 100 mA. (b) This relay operates only one set of changeover contacts at a current rating of 2 A

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 26 Figure 5.23 Typical reverse- current relay circuit

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 27 Figure 5.24 Illustrating Lenz ’ s law — conductor moving

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 28 Figure 5.25(a) Illustrating Lenz ’ s law — field moving

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 29 Figure 5.25(b) Illustrating Lenz ’ s law — field moving

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 30 Figure 5.26 Inductors (a) Air-cored inductor

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 31 Figure 5.26 Inductors (b) Iron-cored inductor

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 32 Figure 5.27 Relative movement of a conductor in a magnetic field as the current increases

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 33 Figure 5.28 Relative movement of a conductor in a magnetic field as the current decreases

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 34 Figure 5.29 Values and directions of self-induced voltages for different current conditions

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 35 Figure 5.30 Various snubber circuits designed to avoid high transient voltages when switching off inductive circuits

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 36 Figure 5.31 Time constant for an inductive circuit

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 37 Figure 5.32(a) Mutual induction between parallel conductors

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 38 Figure 5.32(b) Mutual induction between parallel conductors

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 39 Figure 5.32(c) Mutual induction between parallel conductors

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 40 Figure 5.33(a) Mutual induction between adjacent coils

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 41 Figure 5.33(b) Mutual induction between adjacent coils

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 42 Figure 5.33(c) Mutual induction between adjacent coils

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 43 Figure 5.34 Basic induction coil

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 44 Figure 5.35 Car ignition system

Copyright  2003 McGraw-Hill Australia Pty Ltd PPTs t/a Electrical Principals for the Electrical Trades 5e by Jenneson Slides prepared by Anne McLean 45 Figure 5.36 Solenoid diagram for exercise 5.3