Charging Systems Part 1 Flashcards
Which explosive gas do car batteries produce?
Hydrogen
True or False: You should never disconnect the battery while the engine runs.
True
True or False: You should disconnect the positive cable first and reconnect it last.
False: You should disconnect the negative cable first and reconnect it last.
What is the purpose of the charging system?
Recharges the battery and supplies power to electrical devices after engine start-up
What are the two major parts of the charging system?
Alternator and Voltage regulator
What is the purpose of the alternator?
It is the heart or electrical pump of the system. It converts the kinetic energy from the drive belt into electrical energy.
What does a generator use to create an AC voltage?
Electromagnetic Induction
What is electromagnetic Induction?
When a magnetic field cuts through a wire, it induces a voltage into the wire
What is ACV?
Alternating Current Voltage: It causes current to flow first in one direction and then in the opposite direction
What are the two main parts of an AC generator?
- The stator
2. The rotor (a spinning magnet)
What are the 3 ways to increase the voltage induced in a conductor?
- Spin the rotor faster
- Make the roto’s magnetic field stronger
- Add more coils
How do you calculate the amount of voltage induced in a generator?
Multiply the the voltage for each coil by the number of coils
True or False: In a generator that produces 3-phase AC voltage, the voltage can equal zero.
False: The voltages of each conductor are out of sync with each other and will never equal zero
What is a stator made up of?
3 conductors fitted into an iron frame
True of False: The stator does not move
True: The stator is held stationary while the rotor spins inside
What type of voltage does a vehicle require?
Constant DC voltage
Since the generator produces 3-phase AC and a vehicle needs constant DC voltage, what converts the ACV to DCV?
The Rectifier
How many diodes are needed to convert ACV to DCV?
6
Why does a rectifier require two heat sinks?
Because the rectifier gets very hot it needs two aluminum heat sinks to conduct heat away from the diodes.
What is a rotor?
A spinning electromagnet
What controls the amount of voltage a rotor induces into the stator?
The strength of the rotor’s magnetic field
What makes the magnetic field in a rotor?
The field winding (coil) inside it
What does the voltage regulator control?
Rotor field current
What are the three functions of the capacitor?
- helps stabilize the output voltage
- protects the rectifier from voltage spikes
- reduces RFI
_______________ are used on diesel and luxury vehicles. The clutch prevents the rotor from stopping abruptly when the engine shuts down.
Over-running alternator pulleys
What is a benefit of an over-running alternator pulley?
Reduction of belt noise and wear
What are the three circuits in a charging system?
- The output circuit
- The field circuit
- The charge indicator circuit
Generator output current flows through 10-gauge wire. This circuit is protected by either a _________ or a ___________.
Fusible wire (fuse link) or maxi-fuse
What is the purpose of the field circuit?
supplies current to the field winding
Which circuit is the voltage regulator a part of?
Field circuit
What is the purpose of the voltage regulator?
Measures charging system voltage and varies field current as required
What does the BCM monitor?
Battery current, battery charging voltage and the generator field duty cycle
The _____ controls the voltage regulator by a PWMed signal
ECM
What does the BCM use to measure the battery charge and discharge rates?
Hall effect type battery current sensor
The hall effect battery current sensor operates at ____Hz
128 Hz
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.
IPC
What can the BCM do if it detects an undercharge condition?
Shed electrical loads and/or command the ECM to boost idle speed
Where is the charging gauge (voltmeter) located
In the IPC
What does the voltmeter measure?
Electrical system voltage
When is the charging gauge active?
When the ignition switch is on