CHAPTER Magnetism and Electromagnetism 11 Copyright © 2016 by Pearson Education, Inc. All Rights...

CHAPTER

Magnetism andElectromagnetism

11

Copyright © 2016 by Pearson Education, Inc.All Rights Reserved

Automotive Electrical and Engine Performance, 7eJames D. Halderman

AUTOMOTIVE ELECTRICAL AND AUTOMOTIVE ELECTRICAL AND ENGINE PERFORMANCEENGINE PERFORMANCE



Figure 11.1 Figure 11.1 A freely suspended natural magnet A freely suspended natural magnet (lodestone) will point toward the magnetic north pole.(lodestone) will point toward the magnetic north pole.



Figure 11.2 Figure 11.2 If a magnet breaks or is cracked,If a magnet breaks or is cracked, it becomes two weaker magnets. it becomes two weaker magnets.



Figure 11.3 Figure 11.3 Magnetic lines of force leave the northMagnetic lines of force leave the north pole and return to the south pole of a bar magnet. pole and return to the south pole of a bar magnet.



Figure 11.4 Figure 11.4 Iron filings and a compass can be usedIron filings and a compass can be used to observe the magnetic lines of force. to observe the magnetic lines of force.



Figure 11.5 Figure 11.5 Magnetic poles behave like electrically Magnetic poles behave like electrically charged particles—unlike poles attract and like poles charged particles—unlike poles attract and like poles

repel.repel.



Figure 11.6 Figure 11.6 A crankshaft position sensor and reluctor A crankshaft position sensor and reluctor (notched wheel).(notched wheel).



Figure 11.7 Figure 11.7 A magnetic field surrounds a straight, A magnetic field surrounds a straight, current- carrying conductor.current- carrying conductor.



Figure 11.8 Figure 11.8 The left-hand rule for magnetic field The left-hand rule for magnetic field direction is used with the electron flow theory.direction is used with the electron flow theory.



Figure 11.9 Figure 11.9 The right-hand rule for magnetic field The right-hand rule for magnetic field direction is used with the conventional theory of direction is used with the conventional theory of

electron flow.electron flow.



Figure 11.10 Figure 11.10 Conductors with opposing magneticConductors with opposing magnetic fields will move apart into weaker fields. fields will move apart into weaker fields.



Figure 11.11 Figure 11.11 Electric motors use the interactionElectric motors use the interaction of magnetic fields to produce mechanical energy. of magnetic fields to produce mechanical energy.



Figure 11.12 Figure 11.12 The magnetic lines of flux surroundingThe magnetic lines of flux surrounding a coil look similar to those surrounding a bar magnet. a coil look similar to those surrounding a bar magnet.



Figure 11.13 Figure 11.13 The left-hand rule for coils is shown.The left-hand rule for coils is shown.



Figure 11.14 Figure 11.14 An iron core concentrates the magnetic An iron core concentrates the magnetic lines of force surrounding a coil.lines of force surrounding a coil.



Figure 11.15 Figure 11.15 An electromagnetic switch that has An electromagnetic switch that has a movable arm is referred to as a relay.a movable arm is referred to as a relay.



Figure 11.16AFigure 11.16A A starter with attached solenoid. A starter with attached solenoid.



Figure 11.16BFigure 11.16B A relay is designed to carry lower A relay is designed to carry lower current compared to a solenoid and uses a movable arm.current compared to a solenoid and uses a movable arm.



Figure 11.17 Figure 11.17 Voltage can be induced by the relative Voltage can be induced by the relative motion between a conductor and magnetic lines of force.motion between a conductor and magnetic lines of force.



Figure 11.18 Figure 11.18 Maximum voltage is induced when Maximum voltage is induced when conductors cut across the magnetic lines of force (flux conductors cut across the magnetic lines of force (flux

lines) at a 90 degree angle.lines) at a 90 degree angle.



Figure 11.19 Figure 11.19 Mutual induction occurs when the Mutual induction occurs when the expansion or collapse of a magnetic field around expansion or collapse of a magnetic field around

one coil induces a voltage in a second coil.one coil induces a voltage in a second coil.



Figure 11.20 Figure 11.20 Some ignition coils are electrically Some ignition coils are electrically connected, called “married” (top figure), whereas connected, called “married” (top figure), whereas

others use separated primary and secondary windings, others use separated primary and secondary windings, called “divorced” (lower figure).called “divorced” (lower figure).



Figure 11.21 Figure 11.21 A GM waste-spark ignition coil showing the A GM waste-spark ignition coil showing the section of laminations that is shaped like the letter E.section of laminations that is shaped like the letter E.



Figure 11.22 Figure 11.22 The coil-on-plug (COP) design typically The coil-on-plug (COP) design typically uses a bobbin-type coil.uses a bobbin-type coil.



Figure 11.23 Figure 11.23 To help prevent underhood To help prevent underhood electromagnetic devices from interfering with the electromagnetic devices from interfering with the antenna input, it is important that all ground wires, antenna input, it is important that all ground wires,

including the one from this power antenna, be including the one from this power antenna, be properly grounded.properly grounded.

CHAPTER Magnetism and Electromagnetism 11 Copyright © 2016 by Pearson Education, Inc. All Rights...

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