I hate that my car has daytime running lights.

[woodie1]

Originally posted by: MrPickins

Originally posted by: nakedfrog
I mostly like being able to decide whether my lights are on or off. That way if I'm pulling up to the house late, I can shut the lights off at the last minute and not bother anyone.

Exactly why I dislike my wife's car with DRL's

I'd rather not flash the neighbors house at 2 am.

I think if you turn off the headlights but leave the parking lights on the DRLs will stay off.

 

[Eli]

Originally posted by: foghorn67

Originally posted by: jagec

Originally posted by: foghorn67
No, it isn't.
You have a belt that goes around an alternator pulley. The alternator uses the rotation to transfer energy, yada yada. Depending on the power you need, it does not regulate it mechanically. It uses a voltage regulator.
Other devices are mechanically controlled, like your A/C. The A/C compressor has a clutch that engages and draws an increased load. Your alternator just spins happily whenever your motor is running, despite the power.

Thermodynamics 101...even though the pulley's spinning the whole time, it takes more horsepower to KEEP it spinning if you're drawing more power from the alternator. Since it always takes a bit of power to keep the engine running, this is more efficient than using the 100% on/100% off mechanical method of the AC compressor, but make no mistake, increased electrical demand WILL burn more fuel.

OP will never know the difference, in fact, there isn't even an environment controlled enough to see the difference in mpg.

Nonsense.

If you knew all of the numbers, it wouldn't be hard to figure out exactly how much fuel the electrical system of a car is using.

And it would be a hell of a lot more than 0.

Seriously people, this isn't a hard concept. Energy is energy. If you turn a lightbulb on, it's using energy. Since the source of power is ultimately the engine, the engine must burn more fuel to maintain operation.

Like I said, in older carbed cars, the idle RPM drop when you flick the headlights on is quite noticable, as is the overall power decrease.

 

[sandorski]

DRL increases your cars visibility to other Drivers significantly. Perhaps you think that's to give those with deficient eyesight some help in seeing you, but you'd be wrong. Even You have trouble seeing certain colours under certain lighting conditions. DRL are mandatory based on simple Biology common to Humans, not to a small subset of Humans with some type of "problem".

 

[nweaver]

Originally posted by: Eli

Originally posted by: jagec

Originally posted by: nweaver

that's just bad engineering then. My 1988 VW cuts the headlights (when they are on) when you engage the starter. of course, the Germans have figured out cars a lot better then most countries, I think.

Wait...you say that, and you had a VW?:laugh:

I snickered at that too.. :laugh:

Take a look at my 100% mechanical fuel injected 1988, and lots of things they did make sense. Much more sense then some craptastic ideas on an american car even 10 years later. 160K on the clock, with a water pump and a timing belt, still kicking along and getting nearly 40MPG.

 

[foghorn67]

Originally posted by: Eli

Originally posted by: foghorn67

Originally posted by: jagec

Originally posted by: foghorn67
No, it isn't.
You have a belt that goes around an alternator pulley. The alternator uses the rotation to transfer energy, yada yada. Depending on the power you need, it does not regulate it mechanically. It uses a voltage regulator.
Other devices are mechanically controlled, like your A/C. The A/C compressor has a clutch that engages and draws an increased load. Your alternator just spins happily whenever your motor is running, despite the power.

Thermodynamics 101...even though the pulley's spinning the whole time, it takes more horsepower to KEEP it spinning if you're drawing more power from the alternator. Since it always takes a bit of power to keep the engine running, this is more efficient than using the 100% on/100% off mechanical method of the AC compressor, but make no mistake, increased electrical demand WILL burn more fuel.

OP will never know the difference, in fact, there isn't even an environment controlled enough to see the difference in mpg.

Nonsense.

If you knew all of the numbers, it wouldn't be hard to figure out exactly how much fuel the electrical system of a car is using.

And it would be a hell of a lot more than 0.

Seriously people, this isn't a hard concept. Energy is energy. If you turn a lightbulb on, it's using energy. Since the source of power is ultimately the engine, the engine must burn more fuel to maintain operation.

Like I said, in older carbed cars, the idle RPM drop when you flick the headlights on is quite noticable, as is the overall power decrease.

Gah, the alternator is always on, it regulates power OUTPUT non-mechanically.
It generates power mechanically. Turn on a car, cruise at anywhere from 10-100mph, stick it on cruise control, and turn on lights, stereo, whatevers...do rpm's increase at all to maintain speed?
lightbulb, bad example. AC power, from generators. A million ways this is different.

 

[woodie1]

I thought by now someone would have mentioned the fact that when your headlights are on they are at full voltage. The sidemarker lights, tail lights and dash lights are on too. Together you are talking 30-50 amps. When on, DRLs are usually the high beams at a reduced voltage with no other current draw. Sure the DRLs reduce your mpg but it can't be by much. Surely nothing like driving with the headlights, tail lights and dash lights on as some seem to think.

 

[jagec]

Originally posted by: foghorn67
Gah, the alternator is always on, it regulates power OUTPUT non-mechanically.
It generates power mechanically. Turn on a car, cruise at anywhere from 10-100mph, stick it on cruise control, and turn on lights, stereo, whatevers...do rpm's increase at all to maintain speed?
lightbulb, bad example. AC power, from generators. A million ways this is different.

You never took thermo, did you?

There was a demo that I once saw in a museum. They had a generator hooked up to a hand crank, and the wires were connected to an electrical motor. Spin the generator, and the motor started spinning. Grab the motor's shaft to provide a load, and suddenly the generator was much harder to keep cranking. Same deal with the alternator...it's spinning the whole time, but when a greater load is placed on it, it gets harder to turn and thus the engine has to burn more gas to get the same output to the wheels.

 

[GuitarDaddy]

I have DRL's but I can turn them off by turning the knob to the left. Yours should also have some way to turn them off.

 

[foghorn67]

Originally posted by: jagec

Originally posted by: foghorn67
Gah, the alternator is always on, it regulates power OUTPUT non-mechanically.
It generates power mechanically. Turn on a car, cruise at anywhere from 10-100mph, stick it on cruise control, and turn on lights, stereo, whatevers...do rpm's increase at all to maintain speed?
lightbulb, bad example. AC power, from generators. A million ways this is different.

You never took thermo, did you?

There was a demo that I once saw in a museum. They had a generator hooked up to a hand crank, and the wires were connected to an electrical motor. Spin the generator, and the motor started spinning. Grab the motor's shaft to provide a load, and suddenly the generator was much harder to keep cranking. Same deal with the alternator...it's spinning the whole time, but when a greater load is placed on it, it gets harder to turn and thus the engine has to burn more gas to get the same output to the wheels.

Here is the problem with cute little comparisons, you miss things important to what is at hand.

One...the alternator is not a generator, it throws much of what offers resistance when a load is placed on it simply because it operates differently. Simplistic view, sure they can be one in the same.
Two...alternators aren't spinning at the same speed as the engine.
You never took autoshop?
They are going at 2x or more of engine speed. At idle, they should be providing ample potential output to make up for any parasitic lose for any loads.
This is why your lights might dim if your engine dips below idle (running rough, near stalling, etc.)
Any sort of throttle input will also make that minuscule parasitic loss even tinier.
So, OP is insisting that he can measure MPG loss. I say BS.

And for the record, I think DRL's suck. But for other reasons besides MPG pooey talk.

 

[jagec]

Originally posted by: foghorn67
One...the alternator is not a generator, it throws much of what offers resistance when a load is placed on it simply because it operates differently. Simplistic view, sure they can be one in the same.
Two...alternators aren't spinning at the same speed as the engine.
You never took autoshop?
They are going at 2x or more of engine speed. At idle, they should be providing ample potential output to make up for any parasitic lose for any loads.
This is why your lights might dim if your engine dips below idle (running rough, near stalling, etc.)
Any sort of throttle input will also make that minuscule parasitic loss even tinier.

An alternator is simply a generator that provides alternating current, no more, no less.

All I said was that the alternator was powered by the engine, I made no claim to the relative speed, nor is it material to the discussion. I further claim that the alternator's load on the engine varies based on its power output. So as not to violate thermodynamics, the maximum load would have to be the maximum output of the alternator divided by its efficiency (about 50% for a car alternator), and the minimum load would be based on frictional losses and whatever power is needed to keep the car running.

Let's say I mosey on down to my favorite auto parts store and pick out a nice 200 amp alternator, just for overkill. So, if I were to use this thing to peak capacity, it would produce a current of 200 amps at 14 volts (for easy calculation), thus conferring some 2800 W of power. Certainly nothing to sneeze at. At an efficiency of 50%, this would require 5600 watts of power from the engine.

Now this is all very well and good when I'm trying to run a welder, but if I'm just driving around town that's a LOT of surplus power. If the alternator is actually producing peak power at all times, as you claim, we now have a lot of unaccounted-for energy. Where's it going?

 

[foghorn67]

Originally posted by: jagec

An alternator is simply a generator that provides alternating current, no more, no less.

In order to generate alternating current, what does it do differently?
Yes, something was eliminated from the generator days of yore that amounted to a degree of parasitic loss.

All I said was that the alternator was powered by the engine, I made no claim to the relative speed, nor is it material to the discussion.

Umm, yes it is. If you can't get pass that, I don't know what to tell you.

I further claim that the alternator's load on the engine varies based on its power output.

Further claim? It's an interweb forum, not Law & Order. Sorry, that statement always makes me chuckle for some random reason.
And I said it's downright almost a moot point. OP will never notice the damn difference.

So as not to violate thermodynamics,

Would I argue, thermodynamic law?
It is relevant, but you are applying it the wrong way in this argument.

the maximum load would have to be the maximum output of the alternator divided by its efficiency (about 50% for a car alternator), and the minimum load would be based on frictional losses and whatever power is needed to keep the car running.

Let's say I mosey on down to my favorite auto parts store and pick out a nice 200 amp alternator, just for overkill. So, if I were to use this thing to peak capacity, it would produce a current of 200 amps at 14 volts (for easy calculation), thus conferring some 2800 W of power. Certainly nothing to sneeze at. At an efficiency of 50%, this would require 5600 watts of power from the engine.

Now this is all very well and good when I'm trying to run a welder, but if I'm just driving around town that's a LOT of surplus power. If the alternator is actually producing peak power at all times, as you claim, we now have a lot of unaccounted-for energy. Where's it going?

I said nothing MECHANICALLY is being loaded when increasing loaded on the alternator.
The resistance does increase due to the induction, but this is MINIMAL compared to any average engine that's spinning it.
The alternator's amazing efficiency (well not really, but compared to an automotive generator) won't do much to get in the engine's way.
I was trying to imply that this can't be measured as easily like an A/C clutch.
But once again, someone with a student or recent grad mentality tries to trump practicality, with crappy trivial arguing and thus missing the meaning of the original statement.
And no, OP won't notice any fuel gains with a disconnected DRL hack.

 

[jagec]

Originally posted by: foghorn67

An alternator is simply a generator that provides alternating current, no more, no less.

In order to generate alternating current, what does it do differently?
Yes, something was eliminated from the generator days of yore that amounted to a degree of parasitic loss.

The old "generators" were a type of generator. The new "alternators" are a type of generator. The confusion results from the usage of a very general term to describe a specific auto part that was used back in the day...sort of like how SUVs and sedans are both "cars", but only one of them is considered the "car" when they are side by side.

All I said was that the alternator was powered by the engine, I made no claim to the relative speed, nor is it material to the discussion.

Umm, yes it is. If you can't get pass that, I don't know what to tell you.

You must be confusing my arguments with someone else's. This one baffles me.

I said nothing MECHANICALLY is being loaded when increasing loaded on the alternator.
The resistance does increase due to the induction, but this is MINIMAL compared to any average engine that's spinning it.
The alternator's amazing efficiency (well not really, but compared to an automotive generator) won't do much to get in the engine's way.
I was trying to imply that this can't be measured as easily like an A/C clutch.
But once again, someone with a student or recent grad mentality tries to trump practicality, with crappy trivial arguing and thus missing the meaning of the original statement.
And no, OP won't notice any fuel gains with a disconnected DRL hack.

There we go...what was alarming to me was that you seemed to be claiming that the alternator took just as much power to run when you had everything on as it did when you had everything off. I agree that the difference in fuel usage with DRL on or off is minimal, but the difference between a completely unloaded alternator and one that's being used at peak capacity is not.

FWIW I work at a lab, and here we find it very impractical to operate under erroneous scientific understanding, even if it may seen trivial to you.

 

[MrPickins]

Originally posted by: Fenixgoon

Originally posted by: MrPickins

Originally posted by: nakedfrog
I mostly like being able to decide whether my lights are on or off. That way if I'm pulling up to the house late, I can shut the lights off at the last minute and not bother anyone.

Exactly why I dislike my wife's car with DRL's

I'd rather not flash the neighbors house at 2 am.

how close are your houses to your neighbors'? and why dont they close their shades?

I live in a suburban neighborhood, so they're too close.

And sure, they close their blinds, but unless you have blackout curtains (like my bedroom ) light gets through.

 

[MrPickins]

Originally posted by: woodie1

Originally posted by: MrPickins

Originally posted by: nakedfrog
I mostly like being able to decide whether my lights are on or off. That way if I'm pulling up to the house late, I can shut the lights off at the last minute and not bother anyone.

Exactly why I dislike my wife's car with DRL's

I'd rather not flash the neighbors house at 2 am.

I think if you turn off the headlights but leave the parking lights on the DRLs will stay off.

On her Corolla, you have to have the car in park and have the emergency brake up to get them to turn off, IIRC.

 

[foghorn67]

Originally posted by: jagec
FWIW I work at a lab, and here we find it very impractical to operate under erroneous scientific understanding, even if it may seen trivial to you.

lol. Seriously? I don't have an erroneous scientific understanding. You might since, lab findings can be different from real world...and you don't seem to understand that. (not saying you do, but your arguments say otherwise.

 

[jagec]

Originally posted by: foghorn67

Originally posted by: jagec
FWIW I work at a lab, and here we find it very impractical to operate under erroneous scientific understanding, even if it may seen trivial to you.

lol. Seriously? I don't have an erroneous scientific understanding. You might since, lab findings can be different from real world...and you don't seem to understand that. (not saying you do, but your arguments say otherwise.

Which? My argument that it takes engine power to run the alternator, or that the laws of thermodynamics hold even in the "real world"? You're really going to dispute that?

Because I'm not one of the people claiming that you can see a real-world MPG difference.

 

[foghorn67]

Originally posted by: jagec
Because I'm not one of the people claiming that you can see a real-world MPG difference.

well then, that ummmm, *looks down, shuffles feet....hmmmmm, so we are on the same page?

 

[jagec]

Originally posted by: foghorn67

Originally posted by: jagec
Because I'm not one of the people claiming that you can see a real-world MPG difference.

well then, that ummmm, *looks down, shuffles feet....hmmmmm, so we are on the same page?

Apparently so.

This forum is such a collossal waste of time...

 

[Zorba]

I hate DRL also. There are just sometimes you don't want lights on. Driving though a Christmas lights display, for example. Making out with your girlfriend in front of her house with her dad home, etc. Playing car hide and seek.

 

[BUTCH1]

Thank god mine can be switched off at the stalk, I hate 'em too..

 

[Eli]

I can't believe we're still arguing about the alternator thing. Get a clue.

There is no kinetic energy fairy. If I took my 140A alternator and hooked it up to a 2.5HP Briggs engine, and loaded it with 140A, the engine would stop because it doesn't have enough power to run such a load. If you unhooked the load, the alternator and engine would happily spin along.

I don't understand where the confusion is arising. If you think it doesn't require engine power to spin the alternator, you are just plain ignorant.

Have you ever used an emergency generator? What happens when you hook a load up? The engine's RPM drop momentarily as the governor corrects and brings them back up. Same RPM. More throttle, more fuel used. Same basic concept. The only reason you're having trouble with it is because of the scale. Yes, an automobile engine produces three-digit horsepower. That doesn't mean it has no effect. Every single milliamp, bit of friction, etc... robs power from the wheels. Period.

Edit: Oh, and there is no way to turn them off.. Or I wouldn't be bitching. In the manual, it says its an option whether you can turn the DRL off via the headlight switch. It's not present, though.

Edit2: I never claimed that I could measure MPG loss with the DRL on. I even stated as such, it's not practically measurable.. there's too much margin of error in the fill tank divided by miles driven method of MPG computation.

That doesn't mean that I don't acknowledge the loss is there, though.

I burn through 220 gallons of gasoline a month. I need every 0.01mpg I can get.

 

[Gillbot]

Originally posted by: Eli
here is no kinetic energy fairy. If I took my 140A alternator and hooked it up to a 2.5HP Briggs engine, and loaded it with 140A, the engine would stop because it doesn't have enough power to run such a load. If you unhooked the load, the alternator and engine would happily spin along.

I know for a fact that you can't spin a 100 amp alternator with a 4hp briggs motor without it stalling the motor or burning off generic small belts.

Here's a good link: http://myweb.cableone.net/rschell/TIG.htm

One that uses car power: http://www.geocities.com/damonfg/obweld.html

Here's one that uses an AC motor instead: http://classicbroncos.com/homemade-welder.shtml

Here's the best page though, http://myweb.cableone.net/rschell/TIG_Power.htm

A engine/motor driven welder requires the following energy requirements:

1 Horse Power = 745 Watts

Alternators are in the range of 70-90% efficient with most "regular"
alternators coming in around 75%.

So for a 17V arc @ 160A output = 2720W @ 75% = 3600W = 4.9HP input power

Electric motors are generally more efficient and run about 80-95% efficient.
The average low horse power models 5-10HP generally fall around 84-91%
efficient. Let's go with the low end to get an outside number.

4.9HP output @ 84% = 5.8HP = 4300W @ 240Vrms = 18Arms

So, you need an 240V electric motor that can produce about 5HP output at around
3450 RPM (1700 RPM motors would double the pulley ratio requirements). Most motors above 3HP are 240V.

For those wishing to design a portable design, a 12-HP gasoline engine is roughly equal to a 5-HP electric motor.

This theory applies to EVERY electrical load, not just welding so any load on the alternator will consume power produced by the motor.

 

[foghorn67]

Originally posted by: Gillbot

Originally posted by: Eli
here is no kinetic energy fairy. If I took my 140A alternator and hooked it up to a 2.5HP Briggs engine, and loaded it with 140A, the engine would stop because it doesn't have enough power to run such a load. If you unhooked the load, the alternator and engine would happily spin along.

I know for a fact that you can't spin a 100 amp alternator with a 4hp briggs motor without it stalling the motor or burning off generic small belts.

Here's a good link: http://myweb.cableone.net/rschell/TIG.htm

One that uses car power: http://www.geocities.com/damonfg/obweld.html

Here's one that uses an AC motor instead: http://classicbroncos.com/homemade-welder.shtml

Here's the best page though, http://myweb.cableone.net/rschell/TIG_Power.htm

A engine/motor driven welder requires the following energy requirements:

1 Horse Power = 745 Watts

Alternators are in the range of 70-90% efficient with most "regular"
alternators coming in around 75%.

So for a 17V arc @ 160A output = 2720W @ 75% = 3600W = 4.9HP input power

Electric motors are generally more efficient and run about 80-95% efficient.
The average low horse power models 5-10HP generally fall around 84-91%
efficient. Let's go with the low end to get an outside number.

4.9HP output @ 84% = 5.8HP = 4300W @ 240Vrms = 18Arms

So, you need an 240V electric motor that can produce about 5HP output at around
3450 RPM (1700 RPM motors would double the pulley ratio requirements). Most motors above 3HP are 240V.

For those wishing to design a portable design, a 12-HP gasoline engine is roughly equal to a 5-HP electric motor.

This theory applies to EVERY electrical load, not just welding so any load on the alternator will consume power produced by the motor.

You're about a day late.

 

[jagec]

Originally posted by: Gillbot

Here's one that uses an AC motor instead: http://classicbroncos.com/homemade-welder.shtml

Here's the best page though, http://myweb.cableone.net/rschell/TIG_Power.htm

A engine/motor driven welder requires the following energy requirements:

1 Horse Power = 745 Watts

Alternators are in the range of 70-90% efficient with most "regular"
alternators coming in around 75%.

So for a 17V arc @ 160A output = 2720W @ 75% = 3600W = 4.9HP input power

Electric motors are generally more efficient and run about 80-95% efficient.
The average low horse power models 5-10HP generally fall around 84-91%
efficient. Let's go with the low end to get an outside number.

4.9HP output @ 84% = 5.8HP = 4300W @ 240Vrms = 18Arms

So, you need an 240V electric motor that can produce about 5HP output at around
3450 RPM (1700 RPM motors would double the pulley ratio requirements). Most motors above 3HP are 240V.

For those wishing to design a portable design, a 12-HP gasoline engine is roughly equal to a 5-HP electric motor.

This theory applies to EVERY electrical load, not just welding so any load on the alternator will consume power produced by the motor.

wait, they're using a 240V electric motor...to power an alternator...to produce electricity for a welder?

Doesn't, well, just about every small-scale welder on the planet run on 240V in the first place?

 

[Gillbot]

Originally posted by: jagec

Originally posted by: Gillbot

Here's one that uses an AC motor instead: http://classicbroncos.com/homemade-welder.shtml

Here's the best page though, http://myweb.cableone.net/rschell/TIG_Power.htm

A engine/motor driven welder requires the following energy requirements:

1 Horse Power = 745 Watts

Alternators are in the range of 70-90% efficient with most "regular"
alternators coming in around 75%.

So for a 17V arc @ 160A output = 2720W @ 75% = 3600W = 4.9HP input power

Electric motors are generally more efficient and run about 80-95% efficient.
The average low horse power models 5-10HP generally fall around 84-91%
efficient. Let's go with the low end to get an outside number.

4.9HP output @ 84% = 5.8HP = 4300W @ 240Vrms = 18Arms

So, you need an 240V electric motor that can produce about 5HP output at around
3450 RPM (1700 RPM motors would double the pulley ratio requirements). Most motors above 3HP are 240V.

For those wishing to design a portable design, a 12-HP gasoline engine is roughly equal to a 5-HP electric motor.

This theory applies to EVERY electrical load, not just welding so any load on the alternator will consume power produced by the motor.

wait, they're using a 240V electric motor...to power an alternator...to produce electricity for a welder?

Doesn't, well, just about every small-scale welder on the planet run on 240V in the first place?

No, they can range from 120v up to 480v for AC power. The thing you are missing is they are using 240v AC to turn an alternator to get high current DC for welding. It's easier (and cheaper) as a DIYer to use the alternator for variable current welding by adjusting the field volts as opposed to make a variable tap AC circuit with a rectifier to allow adjustable current for welding from straight AC.