CHAPTER Electronic Fundamentals 12 Copyright © 2016 by Pearson Education, Inc. All Rights Reserved...

CHAPTER

ElectronicFundamentals

12

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

AUTOMOTIVE ELECTRICAL AND AUTOMOTIVE ELECTRICAL AND ENGINE PERFORMANCEENGINE PERFORMANCE

Automotive Electrical and Engine Performance, 7eJames D. Halderman



Figure 12.1 Figure 12.1 N-type material. Silicon (Si) doped with a N-type material. Silicon (Si) doped with a material (such as phosphorus) with five electrons in the material (such as phosphorus) with five electrons in the

outer orbit results in an extra free electron.outer orbit results in an extra free electron.



Figure 12.2 Figure 12.2 P-type material. Silicon (Si) doped with a P-type material. Silicon (Si) doped with a material, such as boron (B), with three electrons in the material, such as boron (B), with three electrons in the

outer orbit results in a hole capable of attracting an outer orbit results in a hole capable of attracting an electron.electron.



Figure 12.3 Figure 12.3 Unlike charges attract and the current Unlike charges attract and the current carriers (electrons and holes) move toward the junction.carriers (electrons and holes) move toward the junction.



Figure 12.4 Figure 12.4 A diode is a component with P-type and A diode is a component with P-type and N-type materials together. The negative electrode is N-type materials together. The negative electrode is

called the cathode and the positive electrode is called called the cathode and the positive electrode is called the anode.the anode.



Figure 12.5 Figure 12.5 Diode connected to a battery with correct Diode connected to a battery with correct polarity (battery positive to P type and battery negative to polarity (battery positive to P type and battery negative to N type). Current flows through the diode. This condition is N type). Current flows through the diode. This condition is

called forward bias.called forward bias.



Figure 12.6 Figure 12.6 Diode connected with reversed polarity. No Diode connected with reversed polarity. No current flows across the junction between the P-type and current flows across the junction between the P-type and N-type materials. This connection is called reverse bias.N-type materials. This connection is called reverse bias.



Figure 12.7 Figure 12.7 Diode symbol and electrode names. The Diode symbol and electrode names. The stripe on one end of a diode represents the cathode stripe on one end of a diode represents the cathode

end of the diode.end of the diode.



Figure 12.8 Figure 12.8 A zener diode blocks current flow until a A zener diode blocks current flow until a certain voltage is reached, then it permits current to flow.certain voltage is reached, then it permits current to flow.



Figure 12.9 Figure 12.9 (a) Notice that when the coil is being (a) Notice that when the coil is being energized, the diode is reverse biased and the current energized, the diode is reverse biased and the current is blocked from passing through the diode. is blocked from passing through the diode. (b) When (b) When the switch is opened, the magnetic field surrounding the switch is opened, the magnetic field surrounding the coil collapses, producing a high-voltage surge in the coil collapses, producing a high-voltage surge in

the reverse polarity of the applied voltage.the reverse polarity of the applied voltage.



Figure 12.10 Figure 12.10 A diode connected to both terminals of A diode connected to both terminals of the air-conditioning compressor clutch used to reduce the air-conditioning compressor clutch used to reduce

the highvoltage spike that results when a coil (compressor the highvoltage spike that results when a coil (compressor clutch coil) is de-energized.clutch coil) is de-energized.



Figure 12.11 Figure 12.11 Spike protection diodes are commonly Spike protection diodes are commonly used in computer-controlled circuits to prevent damaging used in computer-controlled circuits to prevent damaging

highvoltage surges that occur any time current flowing highvoltage surges that occur any time current flowing through a coil is stopped.through a coil is stopped.



Figure 12.12 Figure 12.12 A zener diode is commonly used inside A zener diode is commonly used inside automotive computers to protect delicate electronic automotive computers to protect delicate electronic

circuits from high-voltage spikes.circuits from high-voltage spikes.



Figure 12.13 Figure 12.13 A despiking resistor is used in many A despiking resistor is used in many automotive applications to help prevent harmful automotive applications to help prevent harmful high-voltage surges from being created when the high-voltage surges from being created when the

magnetic field surrounding a coil collapses when the magnetic field surrounding a coil collapses when the coil circuit is opened.coil circuit is opened.



Figure 12.14 Figure 12.14 A typical light-emitting diode (LED). This A typical light-emitting diode (LED). This particular LED is designed with a built-in resistor so that particular LED is designed with a built-in resistor so that 12 volts DC may be applied directly to the leads without 12 volts DC may be applied directly to the leads without

an external resistor.an external resistor.



Figure 12.15 Figure 12.15 Typical photodiodes. They are usually Typical photodiodes. They are usually built into a plastic housing so that the photodiode itself built into a plastic housing so that the photodiode itself

may not be visible.may not be visible.



Figure 12.16 Figure 12.16 Symbol for a photodiode. The arrows Symbol for a photodiode. The arrows represent light striking the P-N junction of the photodiode.represent light striking the P-N junction of the photodiode.



Figure 12.17 Figure 12.17 Either symbol may be used to represent Either symbol may be used to represent a photoresistor.a photoresistor.



Figure 12.18 Figure 12.18 Symbol and terminal identification Symbol and terminal identification of an SCR.of an SCR.



Figure 12.19 Figure 12.19 Wiring diagram for a center high-mounted Wiring diagram for a center high-mounted stoplight (CHMSL) using SCRs.stoplight (CHMSL) using SCRs.



Figure 12.20 Figure 12.20 Symbols used to represent a thermistor.Symbols used to represent a thermistor.



Figure 12.21 Figure 12.21 This rectifier bridge contains six diodes; This rectifier bridge contains six diodes; the three on each side are mounted in an aluminum-the three on each side are mounted in an aluminum-

finned unit to help keep the diode cool during alternator finned unit to help keep the diode cool during alternator operation.operation.



Figure 12.22 Figure 12.22 Basic transistor operation. A small current Basic transistor operation. A small current flowing through the base and emitter of the transistor flowing through the base and emitter of the transistor turns on the transistor and permits a higher amperage turns on the transistor and permits a higher amperage

current to flow from the collector and the emitter.current to flow from the collector and the emitter.



Figure 12.23 Figure 12.23 Basic transistor operation. A small current Basic transistor operation. A small current flowing through the base and emitter of the transistor flowing through the base and emitter of the transistor turns on the transistor and permits a higher amperage turns on the transistor and permits a higher amperage

current to flow from the collector and the emitter.current to flow from the collector and the emitter.



Figure 12.24 Figure 12.24 The three terminals of a field-effect The three terminals of a field-effect transistor (FET) are called the source, gate, and drain.transistor (FET) are called the source, gate, and drain.



Figure 12.25 Figure 12.25 A Darlington pair consists of two A Darlington pair consists of two transistors wired together, allowing for a very small transistors wired together, allowing for a very small

current to control a larger current flow circuit.current to control a larger current flow circuit.



Figure 12.26 Figure 12.26 Symbols for a phototransistor. (a) This Symbols for a phototransistor. (a) This symbol uses the line for the base; (b) this symbol symbol uses the line for the base; (b) this symbol

does not.does not.



Figure 12.27 Figure 12.27 A typical automotive computer with the A typical automotive computer with the case removed to show all of the various electronic case removed to show all of the various electronic

devices and integrated circuits (ICs).devices and integrated circuits (ICs).



Figure 12.28 Figure 12.28 Typical transistor AND gate circuit using Typical transistor AND gate circuit using two transistors. The emitter is always the line with the two transistors. The emitter is always the line with the

arrow. arrow.



Figure 12.29 Figure 12.29 Symbol for an operational amplifier Symbol for an operational amplifier (op-amp).(op-amp).



Figure 12.30 Figure 12.30 Schematic for a blinking LED theft Schematic for a blinking LED theft deterrent.deterrent.



Figure 12.31 Figure 12.31 To check a diode, select “diode check” on To check a diode, select “diode check” on a digital multimeter. The display will indicate the voltage a digital multimeter. The display will indicate the voltage

drop (difference) between the meter leads. drop (difference) between the meter leads.



Figure 12.32 Figure 12.32 If the red (positive) lead of the ohmmeter If the red (positive) lead of the ohmmeter (or a multimeter set to diode check) is touched to the (or a multimeter set to diode check) is touched to the center and the black (negative lead) touched to either center and the black (negative lead) touched to either

end of the electrode, the meter should forward bias the end of the electrode, the meter should forward bias the P-N junction.P-N junction.



Figure 12.33 Figure 12.33 A DC to DC converter is built into A DC to DC converter is built into most powertrain control modules (PCMs) and is used most powertrain control modules (PCMs) and is used

to supply the 5 volt reference called V-ref to many to supply the 5 volt reference called V-ref to many sensors used to control the internal combustion engine.sensors used to control the internal combustion engine.



Figure 12.34 Figure 12.34 This DC-DC converter is designed to This DC-DC converter is designed to convert 42 volts to 14 volts, to provide 14 volts power convert 42 volts to 14 volts, to provide 14 volts power to accessories on a hybrid electric vehicle operating to accessories on a hybrid electric vehicle operating

with a 42 volt electrical system.with a 42 volt electrical system.



Figure 12.35 Figure 12.35 A typical circuit for an inverter designed A typical circuit for an inverter designed to change direct current from a battery to alternating to change direct current from a battery to alternating current for use by the electric motors used in a hybrid current for use by the electric motors used in a hybrid

electric vehicle.electric vehicle.



Figure 12.36 Figure 12.36 The switching (pulsing) MOSFETs create The switching (pulsing) MOSFETs create a waveform called a modified sine wave (solid lines) a waveform called a modified sine wave (solid lines)

compared to a true sine wave (dotted lines).compared to a true sine wave (dotted lines).

CHAPTER Electronic Fundamentals 12 Copyright © 2016 by Pearson Education, Inc. All Rights Reserved...

Documents

Transcript of CHAPTER Electronic Fundamentals 12 Copyright © 2016 by Pearson Education, Inc. All Rights Reserved...