Hi, long time no post!
I have a question about a car electrical system.
The alternator has two functions... #1, to provide power to the car's electical system (fans, spark plugs, injectors, ECU...) and #2 to charge the car battery.
What I would like to know is the following:
When an additional high load is placed on the alternator, the engine note changes somewhat to a rumble.
For what reason does this occur? Is it:
1. Because the power to turn the alternator places a higher power load on the engine (due to additional loading on the engine).
2. Because the ECU compensates for a lower charge voltage by increasing the RPM to spin-up the alternator.
In addition to this... are these statements correct:
- The torque required to turn a fully UNLOADED alternator is greater than that required to turn a moderately loaded alternator.
- The torque required to turn a fully LOADED alternator is greater than that required to turn a moderately loaded alternator.
It's for a discussion I'm having on a car website about power savings.
It's said that the engine efficiency drops 6% when the lights are left on during a drive. I'm trying to figure out whether this is a consequence of the ECU compensating for the load, or the alternator causing more resistance.
I have a question about a car electrical system.
The alternator has two functions... #1, to provide power to the car's electical system (fans, spark plugs, injectors, ECU...) and #2 to charge the car battery.
What I would like to know is the following:
When an additional high load is placed on the alternator, the engine note changes somewhat to a rumble.
For what reason does this occur? Is it:
1. Because the power to turn the alternator places a higher power load on the engine (due to additional loading on the engine).
2. Because the ECU compensates for a lower charge voltage by increasing the RPM to spin-up the alternator.
In addition to this... are these statements correct:
- The torque required to turn a fully UNLOADED alternator is greater than that required to turn a moderately loaded alternator.
- The torque required to turn a fully LOADED alternator is greater than that required to turn a moderately loaded alternator.
It's for a discussion I'm having on a car website about power savings.
It's said that the engine efficiency drops 6% when the lights are left on during a drive. I'm trying to figure out whether this is a consequence of the ECU compensating for the load, or the alternator causing more resistance.