Automotive Electrical & Electronic Systems Classroom Manual

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Gauges, Warning Devices, and Driver Information System Operation

Vacuum Fluorescent Display (VFD) This is the most commonly used display for automotive electronic instruments, primarily because of its durability and bright display qualities. The vacuum fluorescent display (VFD) generates light similar to a television picture tube, with free electrons from a heated filament striking phosphor material that emits a blue-green light (Figure 13-31). The anode segments are coated with a fluorescent material such as phosphorous. The filament is resistance wire, heated by electrical current. The filament coating produces free electrons, which are accelerated by the electric field generated by the voltage on the accelerating grid. High voltage is applied only to the anode of those segments required to form the characters to be displayed. Since the anode is at a higher voltage than the fine wire-mesh grid, the electrons pass through the grid. The phosphors on the segment anodes impressed with high voltage glow very brightly when struck by electrons; those receiving no voltage do not glow. The instrument computer determines the segments necessary to emit light for any given message and applies the correct sequences of voltage at the anodes. VFD displays are extremely bright, and their intensity must be controlled for night viewing. This can be done by varying the voltage on the accelerating grid: the higher the voltage, the brighter the display. Intensity can also be controlled by pulse-width dimming, or turning the display on and off very rapidly while controlling the duration of on-time. This is similar to the pulse-width modulation of a carburetor mixture

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control solenoid or a fuel injector. The on-off action occurs so rapidly that it cannot be detected by the human eye. Cathode Ray Tube (CRT) Another display device used in automotive instrumentation was the cathode-ray tube (CRT), as used in the 1986–1996 Buick Riviera Buick Reatta. The CRT is essentially the same as the display used in an oscilloscope or a television set. CRTs function with an electron beam generated by an electron gun located at the rear of the tube. The CRT consists of a cathode that emits electrons and an anode that attracts them. Electrons are “shot” in a thin beam from the back of the tube. Permanent magnets around the outside neck of the tube and plates grouped around the beam on the inside of the tube shape the beam. A tube-shaped anode that surrounds the beam accelerates it as it leaves the electron gun. The beam has so much momentum that the electrons pass through the anode and strike a coating of phosphorus on the screen, causing the screen to glow at these points. The control plates are used to move the beam back and forth on the screen, causing different parts of it to illuminate. The result is a display (oscilloscope) or a picture (television). The automotive CRT has a touch-sensitive Mylar switch panel installed over its screen. This panel contains ultra-thin wires, which are coded by row and column. Touching the screen in designated places blocks a light beam and triggers certain switches in the panel, according to the display mode desired. The switches in turn send a signal to the control circuitry, which responds by displaying the requested information on the CRT screen. In principle, this type of instrumentation combines two personal computer attributes: It has touch-screen control and is

menu driven.

HEAD-UP DISPLAY (HUD) Figure 13-31. In a vacuum fluorescent display, voltage applied selectively to segment anodes makes the fluorescent material glow. (DaimlerChrysler Corporation)

The head-up display (HUD) is a secondary display system that projects video images onto the windshield. It is an electronic instrumentation system (Figure 13-32) that consists of a special windshield, a HUD unit containing a computer module, and a system-specific dimmer switch.


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Summary

4min
page 363

Cruise Control Systems

3min
pages 357-358

Review Questions

3min
pages 364-366

Radios and Entertainment Systems

6min
pages 337-339

Theft Deterrent Systems

7min
pages 353-356

Heated Seats

6min
pages 343-345

Power Seats

2min
pages 341-342

Power Door Locks, Trunk Latches, and Seat- Back Releases

2min
page 346

Heating and Air-Conditioning Systems

12min
pages 328-334

Class 2 IPM-Controlled HVAC Systems

2min
pages 335-336

Review Questions

1min
page 326

Summary

1min
page 325

Windshield Wipers and Washers

10min
pages 319-324

Summary

1min
page 314

Review Questions

2min
pages 315-316

Head-Up Display (HUD

5min
pages 311-313

Electromagnetic Instrument Circuits

11min
pages 296-300

Review Questions

2min
pages 293-294

Malfunction Indicator Lamp (MIL

5min
pages 301-303

Summary

1min
page 292

Instrument Panel and Interior Lamp Circuits

4min
pages 289-291

Circuits

1min
page 288

Backup Lamp Circuits Side Marker and Clearance Lamp

1min
page 287

Circuits

2min
page 286

Stop Lamp and Turn Signal Circuits Hazard Warning Lamp (Emergency Flasher)

6min
pages 282-285

Taillamp, License Plate Lamp, and Parking Lamp Circuits

1min
page 281

Common Automotive Bulbs

1min
page 280

Headlamp Circuits

16min
pages 270-279

Summary

1min
page 267

Review Questions

1min
page 268

Spark Plug Construction

4min
pages 264-266

Distributor Cap and Rotor

3min
pages 259-261

Primary and Secondary Circuits

1min
page 248

Voltages

4min
pages 246-247

Basic Circuits and Current

1min
page 241

Silicon-Controlled Rectifiers (SCRs

1min
page 233

Review Questions

2min
pages 236-238

Summary

1min
page 235

Transistors

9min
pages 229-232

Rectifier Circuits

2min
page 228

Semiconductors

7min
pages 222-224

Photonic Semiconductors

2min
page 227

Review Questions

3min
pages 218-220

Starter Motor and Drive Types

8min
pages 210-214

DC Starter Motor Operation

5min
pages 206-208

Summary

2min
pages 216-217

Overrunning Clutch

1min
page 215

Specific Starting Systems

6min
pages 200-203

Summary

2min
pages 191-192

Differences

13min
pages 183-190

Review Questions

3min
pages 193-194

Charge/Voltage/Current Indicators

3min
pages 180-181

Solid-state Regulators

9min
pages 175-179

Electromagnetic Regulators

1min
page 174

Voltage Regulation

2min
page 173

Current Production in an AC Generator

9min
pages 168-172

Diode Rectification

3min
pages 162-163

AC Generator (Alternator) Components

7min
pages 164-167

Review Questions

4min
pages 157-158

Battery Installations

4min
pages 150-151

Battery Installation Components

2min
pages 152-153

Summary

2min
page 156

Battery Life and Performance Factors

5min
pages 154-155

State-of-Charge Indicators Wet-Charged and Dry-Charged

2min
page 147

Battery Electrolyte

2min
page 146

Electrochemical Action

8min
pages 142-145

Review Questions

3min
pages 138-140

Wire Color Coding

2min
pages 121-122

Multiplex Circuits

8min
pages 112-114

Ground Paths

2min
page 111

Connectors and Terminals

5min
pages 108-110

Wire Size

6min
pages 105-107

Wire Types and Materials

2min
page 104

Wiring and Harnesses

2min
pages 102-103

Review Questions

4min
pages 97-100

Parallel Circuit Voltage Drops Calculating Series Circuit Total

1min
page 87

Series and Parallel Circuit Faults

3min
pages 94-95

Series-Parallel Circuits

4min
pages 91-93

Review Questions

2min
page 82

Summary

3min
pages 80-81

Electromagnetism

9min
pages 67-71

Electromagnetic Induction

11min
pages 72-76

Magnetism

2min
page 66

Power

2min
page 56

Capacitance

8min
pages 57-60

Review Questions

2min
pages 62-64

Summary

1min
page 61

Complete Electrical Circuit

3min
pages 52-53

Summary

2min
page 43

Historical Figures in Electricity

2min
page 42

Fire Extinguishers

1min
page 31

Safety Tips for Technicians

2min
pages 25-26

Nuts

1min
page 15

Review Questions

2min
pages 44-46

Electrical Cord Safety

1min
pages 29-30

Safety in Lifting (Hoisting) a Vehicle

2min
pages 27-28
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