Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

electrical charging and cranking > charging systems and controlls > Flashcards

charging systems and controlls Flashcards

1
Q

purpose of a charging system

A

to provide the electrical current required to operate the system and charge the battery when necessary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

the charging system converts

A

mechanical energy into electrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

12 volt open circuit voltage

A

12.6 v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

24 volt open circuit voltage

A

25.2 v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

alternator must

A

produce enough electric current to operate all of the units electrical loads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

battery group must

A

assist in the supply of electrical current when idling and when electrical accessory load is high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

voltage regulator

A

when battery voltage drops to a set level the voltage regulator (electric switch) turns on the alternator and current is produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

regulator may start and stop a alternator field circuit as many as

A

6000 times per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

maximum voltage setting for a 24 volt system

A

29.6 volts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

maximum voltage setting for 12 volt system

A

14.8 volts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

if charging exceeds the maximum voltage setting for the system

A

damage to the battery group or other electrical components could be caused

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

alternator induces voltage by

A

rotating a magnetic field (rotor) inside a fixed conductor (stator)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

alternators can be belt driven and

A

gear or coupler driven

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

the greatest induced voltage occurs when

A

the rotors magnetic field is at 90 degrees to the stator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the field circuit

A

delivers current to the alternators field windings creating a magnetic field inside the alternator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

output circuit

A

sends electrical current to the battery group and electrical loads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

alternating current

A

switches from positive to negative flow in a circuit moving one direction then the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

AC voltage is also called

A

sine wave voltage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

single phase voltage

A

caused by one revolution of the rotor across one conductor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

because batteries can only carry DC current AC current must be

A

rectified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

alternator brushes

A

carbon brushes slide on the contact surface of the slip rings only carry small current required to induce the magnetic field in the rotor core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

why is alternator rotation considered bi directional

A

because because the stators direction changes multiple times every rotation is dose not matter witch way it is rotated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

methods for controlling heat in an alternator

A

heat sinks and cooling fans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Heat sink

A

finned block of aluminum that absorbs and moves heat away from sensitive components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
cooling fans
pulls cool air from the back of the alternator past internal components and out the front
26
what is a limiting factor in maximum current output for an alternator
the design of the stator
27
Rotor
carries the alternators magnetic field | is a coil of wire surrounded by two pole pieces
28
pole pieces
are interfacing fingers that will take on either north or south pole when magnitized
29
typical field circuit range is
2-10 amps
30
stator
is made up of three conductors wound onto a cylindrical laminated iron core
31
why do you laminate the iron stator core
to reduce heat build up from eddy currents in the core material
32
eddy currents
are localized circular current flows developed in the confines of the stator core by alternating electromagnetic fields eddy currents change the mechanical input energy into unwanted heat
33
three phase current
is three evenly spaced overlapping single phase ac voltage waves
34
two types of stators
wye and delta
35
delta type stator
stator windings are connected end to end shaped like a triangle used in alternators with high current output demands
36
diodes
act as a one way electrical check valve | used in the rectification of ac voltage
37
half wave rectification
only half of a ac singe wave is allowed through a diode creating pulsating dc current
38
alternator housing
made of two piece cast aluminium because it is lightweight transfers heat well and is nonmagnetic
39
drive end housing
holds the bearing for the end of the rotor shaft where the drive pulley is mounted
40
rear housing
holds the diodes heat sinks brushes and electrical terminal connections also holds the bearing for the slip ring end of the rotor shaft
41
alternator terminals
because the alternator is bolted directly to the engine it becomes part of the ground circuit any positive diodes or terminals that must be insulated must be carefully insulated form the alternator case
42
alternator capacitors
are installed between the positive diodes output terminal and the negative diodes ground circuit case mount protects the electronic components from transient voltage spikes and reduces radio frequency interference
43
how are capacitors rated
by there capacitance measured in farads
44
what is a diode bridge
a group of negative or positive diodes connected into a heat sink positive diodes need to be insulated from the alternators ground circuit negative diodes don't
45
filter capacitor
used to smooth out ac voltage fluctuations and protect the diodes in the system from to much reverse bias voltage also
46
RFI
radio frequency interference
47
how is a wye type stator connected
one of each ends of the stator windings is connected to a junction the free end is then connected to a positive and a negative diode the stator used when a high voltage output is needed at low alternator speeds
48
how are delta type stators connected
by joining each stator winding end to end and then connected to a positive and negative diode produce more current output total then why stator but will have less voltage total at low speeds
49
maximum allowable ac ripple from 12 and 24 volt systems
12 volt = .5 volts | 24 volt = 1 volts
50
residual magnetism
is the magnetism left in the electromagnetic iron core after the vehicle is shut off some times the core needs to be excited by the batteries to produce a voltage in the stator windings
51
full fielded condition of an alternator
when the alternator is at maximum current flow | alternator will be naturally governed by the counter electromotive force that happens in the stator windings
52
Brushless alternators
the field winding will not rotate with the rotor | it is held stationary while the rotor rotates around it in close proximity to keep the magnetic field strong
53
A-circuit construction
voltage regulator process the current flow after it passes through the rotor windings
54
B-circuit construction
voltage regulator processes the current flow before it pass through the rotor windings
55
two types of cooling classes for alternators
open or closed
56
open cooling to an alternator
has holes and a fan allowing passing air to cool internal alternator parts
57
closed alternator cooling
have long service life and are internally cooled bye engine oil or air
58
R or STA auxiliary terminals can be used for
running a tachometer, hour meter or relay | also can be used to excite the field coil if residual magnetism has become weak in rotor
59
Charging system indicators
ammeter voltmeter indicator lamp
60
ammeter indicator
measures current flow in or out of the battery group
61
voltmeter indicator
measures indicated voltage of the alternator or the battery group which ever is greater
62
indicator lamp
will illuminate if there is an unequal voltage on either side

electrical charging and cranking (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions