It is not negligable. The load on the alternator is perfectly proportional to the electrical load on it. 'Drag', exactly as uglymoney said.Quote:
Originally Posted by Arty50
It has a quite simply measured impact. Gasoline has 12000 Wh/kg energy density. using a 100 W headlight system for 1 hour with a 50% efficient alternator would use 1/60th of a gallon of gas. edit: err, 1/60th of a kg of gas!
The engine rpm would only go up if you had a battery with a relatively small capacity. With a battery in good condition with a large capacity (rated in amp hours) the draw from the lights would be negligible and not cause the alternator to draw the engine down. On the other hand a small battery with corroded connections that has already been drawn down repeatedly may not have enough available amperage to power the lights. The amperage has to come from somewhere, hence the alternator working harder (increased field voltage from the regulator, causing there to be a stronger magnetic field in the alternator).Quote:
Originally Posted by Arty50
Magnetic resistance in the alternator is NOT negligible. The black box monitoring the load is the voltage regulator. The voltage regulator typically has a bulk voltage setting and a float voltage setting. When you start the vehicle the regulator will attempt to bring your system up to the bulk voltage setting. This is usually somewhere around 14.5 volts. The regulator controls the output of the alternator by applying a voltage on to the field wire of the coil. As load increase on the dc system the regulator has to apply a higher voltage on the field wire to increase the available amperage (by increasing voltage). After the voltage regulator has sensed the system (through the voltage sense wire) at the bulk voltage for the set amount of time it will drop to a slightly lower voltage, usually around 13.8. Magnetic resistance is huge. That's why you have to have a 10hp motor just to run a 6000 watt generator.
What would be really neat would be if the auto manufacturers installed a simple system that only engaged the alternator if the accelerator was not depressed (like during braking or coasting), or if the voltage in the dc system dropped below a specific (intentionally low) point. But that would be too easy and it would save gas, and brake pads.
http://www.tetongravity.com/forums/s...&postcount=147Quote:
Originally Posted by doughboyshredder
My new sled deck has expandable/collapsible sides. I'm totally doing my part to help the environment, how about you?Quote:
Originally Posted by BlurredElevens
BTW, if you focus your rearview mirror on the brightest lights possible, the photon energy will propel you without even needing the motor!
Ok, I retract my poppycock and 0BernhardFranz remarks. Extra current load does equal extra magnetic field and extra rotational resistance. I'm embarrassed now, but it's been a long time since E-fundies, and UglyMoney shoud have dropped the science earlier. The extra current from headlights is not a load that I've ever seen require an increase in rpm to compensate for. Perhaps it's just not detectable as the battery provides the instantaneous extra current and slowly dampens the increasing current load on the alternator as it[battery] requires the extra current to stay at the regulated voltage.
New subject, less about electricity:
One theory I've had, and this may be utter poppycock... my Tundra doesn't even whince when you engage the AC compressor. Our Matrix acts like you dropped 3 yards of concrete in the back...very noticeable extra load on the engine.
Obviously we're talking a great difference in horsepower here, like 240 HP vs 118 HP, and difference power bands. The 4 cyl 1.8L engine just isn't as torquey at cruise rpm of ~ 2500 as the 8 cyl 4.7L is at 2100 rpm. An AC compressor I would imagine requires the same power in both vehicles, so the more HP you have available, the less noticeable draw on power required for the compressor. Perhaps if we were screaming flat out in 2nd gear at 4500rpm in the Matrix, the compressor engagement wouldn't feel nearly as draggy as it does at 2500rpm, just from the extra torque available.
Um, wow that's too many words for my drunken mind, but I DID have the thought earlier that since energy cannot be created by moving a vehicle down the road, that the energy for the lights, when the vehicle is operating, has to come from somewhere, via the battery, which is charged by the alternator, which is powered by the movement of the vehicle, which is powered by gas.Quote:
Originally Posted by bio-smear
The question is, does this increase in gas consumption pose a greater detriment to humanity than the safety created by increased visability and the resultant protection of human life it yields? I think not.
Ugly Money says it does (based on what he quoted without crediting the source, of course he might have later, I only read the first couple of pages of this yesterday, fie on me if I am wrong).
From what I read, it seemed that he was damaging what little credibility he had as an unbiased researcher by jumping to one side and only looking at those who sought to deny what is commonly understood by most.
I turn on my headlights as a matter of habit regardless of the time of day or conditions, and as courtesy to other drivers, because I know it's easier for me to see others when their lights are on, and curse those who don't have them on.
I have not heard any convincing reason not to. Motorcyclyclists especially should follow suit, if they know what's good for them, they are hard enough to see WITH their lights on.
Fuck. Who needs lights to see a 2.5 tons pick up truck in day time should not be driving.
DRL are useful to single out something. If everybody use DRL, nobody stands out and DRL are useless. Same shit as before. But brighter.
When glancing into a rearview mirror (or in any direction), the human eye picks up on prominent concentrations of photons, either reflected or generated, the later of which are more concentrated (unless the reflection is the sun off of a higly reflective surface like a windshield, mirror, or water on the road), and so, are far more visable. The contention that headlights somehow create a uniform field of light that makes the source of generated light indistinguishable from reflected light is laughable.Quote:
Originally Posted by philippeR
Bwahahahahaha. See, I just laughed at it.
Uglymoney doesn't sit in front of the computer 24 hours a day, but thanks for the retraction.Quote:
Originally Posted by bio-smear
Wrong. I never said it didn't create drag, but using that for argument sake is fucking retarded. If you want to split hairs arguing about something so negligible, argue these- (btw-your engine speed DOES NOT change while using electric accessories unless you drive a golf cart)Quote:
Originally Posted by runethechamp
-Use a less heavy oil. It takes more gas to pump that heavier viscosity stuff.
-Wash your car. All that dirt and mud on your car leads to drag and less aerodynamics. Think of the Polar Bears!
-That little satellite radio antenna you're using? It's fucking up your gas mileage due to wind resistance. Place it inside the car to save a mile a year!!!
The polar ice caps will benefit.
-Only put 5 gallons or less of gasoline in your tank at any given time. Why put another 15-25 gallons in there? It'll take more gas to carry around all that extra weight. Like snow? Don't ruin it.
-Over inflate your tires, and put concrete in them so you don't lose any rolling ability due to tire sag. Save an iceberg!
-Do not EVER roll down your window while driving. Each time you do, it's like having DRLs on for like an infinity of hours. GLOBAL WARMING!!!!!!
-
Yeah, you're forgetting something though. That 10 hp motor is dedicated to the generator.Quote:
Originally Posted by doughboyshredder
An alternator on a truck like mine is using an engine designed to pull, oh, lets say 10,000 lb loads. You really think a little alternator is going to make a difference on an engine that has so much power? Think again. Negligible.
If this thread has proven anything, it's how little most of you actually know, but more so how much you rely on Google to debate.
One could also argue that the pulley system used in Alternators (they spin 3x faster than the crankshaft) goes both ways, thus decreasing the force enacted on the crank by a factor of 3 (I think.) Also, the flywheel should overcome any temporary reverse-torque caused by the small added resistance, no?
Either way - turn the fucking lights on when warranted. Phillippe - that means rain, drizzle, fog, or dawn/dusk. Just because you can see the other cars does not mean they can see you.
Wow, who would have guessed that a thread that I started in the Padded Room could fill up with 8 pages of douchebaggery? ;)
Quote:
Originally Posted by Shaggy
Thanks for Cherry-picking my answer to sound smart. Maybe you could have commented on the next sentence???? It was an earlier contention by many that current output was constant. I simply stated that if that was true there would have to something to shunt that extra current when it wasn't needed or the battery would blow up. I later said that shunting wouldn't make sense and added that external circuitry is probably how the current is controlled. After that I googled and found ONE explanation that seemed to indicate that there is a feedback loop with the battery which is what??? External circuitry that controls the current -- I don't think I'm wrong here.
Maybe you just read one of my many posts?????????????
Edit: I'm sure you will agree that if there was a feedback loop with the battery and then extra current was required of the battery, which it did not have the charge to support, then the voltage would drop on the battery. This is where the feedback comes in that tells the alternator to supply more current. Of course everyting really runs off the alternator but it sounds like it is actually a voltage drop at the battery that tells the alternator to supply more current.
Well played sir!Quote:
Originally Posted by RootSkier
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Originally Posted by BlurredElevens
12345678Quote:
Originally Posted by BlurredElevens
Quote:
Originally Posted by runethechamp
Yes, still retarded.Quote:
I don't think its ever been proven that they actually save lives + they waste gas with the extra drag they exert on the alternator.
Turn you headlights on and off and you can hear your motor speed increase and decrease as the drag comes and goes.
I just question whether it is worth it, and have considered disconnecting them many times to save fuel. .......using over a days worth of fuel per year on high energy DRL's would have.
Having driven HUNDREDS of different cars, trucks ans vans, I've never had the engine have to adjust for the pull of the alternator.
:rolleyes:
Don't worry, that's real world experience there, you won't find it on google. :rolleyes:
If those HUNDREDS of cars are idling between 600 and 1000 rpm, and you turn the lights on, assuming uglymonkey and the universal laws of physics are true, do you really think you will see the 5-10 rpm change on your tach?Quote:
Originally Posted by BlurredElevens
When I was in school, my professor had this contraption set up with a bike attached to an automotive alternator, connected to 3 light bulbs. The light bulbs were on switches. When you pedaled and the lights were off, it was easy. Every light you turned on it got harder to pedal. Real world experience there too.
cool experience.Quote:
Originally Posted by mcsquared
So you're agreeing with me, eh?Quote:
Originally Posted by mcsquared
Still pretty damn funny if you ask me.Quote:
Originally Posted by uglymonkey
That is what the battery is for dude. The battery acts like a 'buffer' between the engine and electrical system. The additional load on the electrical system is spread out over time by the battery. But just because you don't notice it because the battery does its job, doesn't mean the additional load isn't there.Quote:
Originally Posted by BlurredElevens
:rolleyes2 If that's what you need to trust the laws of physics..., on a four cylinder with a tired battery you can definitely feel the rpm' drop.Quote:
Originally Posted by BlurredElevens
Personal experience.
From what I understand while the engine is running all the accessories are running on the alternator. The battery actually acts like another accessory while the engine is running. It draws power as needed till its fully charged, at which time it no longer draws energy.Quote:
Originally Posted by Powow
As for Blurred not feeling any noticable rpm change, I guess perception is 2/3 of reality. Last night we had to run up north a ways to see old folk and I had plenty of time to fiddle with this. With my Suby in nuetral (its a stick) and all accessories off the idle changes slightly when I flip the lights one. If I flip the lights on along with both of my seat heaters it is quite noticeable and visible on the tack.
I guess the ultimate test is when you charge another car. When you have a (dead)battery with low voltage and jumper to a car battery humming along at 14.5 volts fully charged the car that is running will have a very noticable change in its idle speed and load as the alternator starts pumping out its maximum amperage. This shouldn't be susceptible to the perception/reality baloney that Blurred is playing with.
Listen here you little Google nerd. I said there is a draw, but it's negligible, about like having your side mirrors out while driving.Quote:
Originally Posted by Powow
Have you ever installed an alternator? Seen one? Have any experience other than shit you googled about them?
I used to be a certified car stereo installer, so I think I have a little more REAL WORLD knowledge than your pedantic googlin' self.
I've installed numerous alternators, and I understand the functions of a cars electrical system pretty damn well.
Why don't you hold your breath for a while, and do your part in reducing CO2. :rolleyes: