Charging Systems Part 1

Question 1

Which explosive gas do car batteries produce?

Answer 1

Hydrogen

Question 2

True or False: You should never disconnect the battery while the engine runs.

Answer 2

True

Question 3

True or False: You should disconnect the positive cable first and reconnect it last.

Answer 3

False: You should disconnect the negative cable first and reconnect it last.

Question 4

What is the purpose of the charging system?

Answer 4

Recharges the battery and supplies power to electrical devices after engine start-up

Question 5

What are the two major parts of the charging system?

Answer 5

Alternator and Voltage regulator

Question 6

What is the purpose of the alternator?

Answer 6

It is the heart or electrical pump of the system. It converts the kinetic energy from the drive belt into electrical energy.

Question 7

What does a generator use to create an AC voltage?

Answer 7

Electromagnetic Induction

Question 8

What is electromagnetic Induction?

Answer 8

When a magnetic field cuts through a wire, it induces a voltage into the wire

Question 9

What is ACV?

Answer 9

Alternating Current Voltage: It causes current to flow first in one direction and then in the opposite direction

Question 10

What are the two main parts of an AC generator?

Answer 10

1. The stator

2. The rotor (a spinning magnet)

Question 11

What are the 3 ways to increase the voltage induced in a conductor?

Answer 11

1. Spin the rotor faster
2. Make the roto’s magnetic field stronger
3. Add more coils

Question 12

How do you calculate the amount of voltage induced in a generator?

Answer 12

Multiply the the voltage for each coil by the number of coils

Question 13

True or False: In a generator that produces 3-phase AC voltage, the voltage can equal zero.

Answer 13

False: The voltages of each conductor are out of sync with each other and will never equal zero

Question 14

What is a stator made up of?

Answer 14

3 conductors fitted into an iron frame

Question 15

True of False: The stator does not move

Answer 15

True: The stator is held stationary while the rotor spins inside

Question 16

What type of voltage does a vehicle require?

Answer 16

Constant DC voltage

Question 17

Since the generator produces 3-phase AC and a vehicle needs constant DC voltage, what converts the ACV to DCV?

Answer 17

The Rectifier

Question 18

How many diodes are needed to convert ACV to DCV?

Answer 18

6

Question 19

Why does a rectifier require two heat sinks?

Answer 19

Because the rectifier gets very hot it needs two aluminum heat sinks to conduct heat away from the diodes.

Question 20

What is a rotor?

Answer 20

A spinning electromagnet

Question 21

What controls the amount of voltage a rotor induces into the stator?

Answer 21

The strength of the rotor’s magnetic field

Question 22

What makes the magnetic field in a rotor?

Answer 22

The field winding (coil) inside it

Question 23

What does the voltage regulator control?

Answer 23

Rotor field current

Question 24

What are the three functions of the capacitor?

Answer 24

1. helps stabilize the output voltage
2. protects the rectifier from voltage spikes
3. reduces RFI

Question 25

_______________ are used on diesel and luxury vehicles. The clutch prevents the rotor from stopping abruptly when the engine shuts down.

Answer 25

Over-running alternator pulleys

Question 26

What is a benefit of an over-running alternator pulley?

Answer 26

Reduction of belt noise and wear

Question 27

What are the three circuits in a charging system?

Answer 27

1. The output circuit 2. The field circuit 3. The charge indicator circuit

Question 28

Generator output current flows through 10-gauge wire. This circuit is protected by either a _________ or a ___________.

Answer 28

Fusible wire (fuse link) or maxi-fuse

Question 29

What is the purpose of the field circuit?

Answer 29

supplies current to the field winding

Question 30

Which circuit is the voltage regulator a part of?

Answer 30

Field circuit

Question 31

What is the purpose of the voltage regulator?

Answer 31

Measures charging system voltage and varies field current as required

Question 32

What does the BCM monitor?

Answer 32

Battery current, battery charging voltage and the generator field duty cycle

Question 33

The _____ controls the voltage regulator by a PWMed signal

Answer 33

ECM

Question 34

What does the BCM use to measure the battery charge and discharge rates?

Answer 34

Hall effect type battery current sensor

Question 35

The hall effect battery current sensor operates at ____Hz

Answer 35

128 Hz

Question 36

The ECM uses circuit 23 to monitor the generator field circuit. If there is a problem, the ECM sends a network message to the ______ to illuminate the charge lamp.

Answer 36

IPC

Question 37

What can the BCM do if it detects an undercharge condition?

Answer 37

Shed electrical loads and/or command the ECM to boost idle speed

Question 38

Where is the charging gauge (voltmeter) located

Answer 38

In the IPC

Question 39

What does the voltmeter measure?

Answer 39

Electrical system voltage

Question 40

When is the charging gauge active?

Answer 40

When the ignition switch is on