Re: Hey do you know your car's alternator only outputs 7-10% while it'srunning?

[[email protected]]

The old generators in cars required high rpms to function efficiently.

Alternators were designed and incorporated into cars specifically
because they do NOT require a high rpm to have efficient output, so you
are wrong about the 2k rpm minimum.

He is NOT wrong. At curb idle the average alternator is not capable of
producing nameplate power. Curb idle of 750RPM spins most alternators
at roughly 2100 RPM due to the pulley ratio. The BIG advantage of
alternators is that belted at 3:1, at 6000 rmp engine speed (18000 rpm
alternator speed) the rotor does not unwind itself - there is no
catastrophic separation of the commutator, and all the other nasty
stuff that happened to generators at high speeds.

Also, idiot, and wind turbine (ALL in fact) gear the blade speed up to
drive the alternator at a higher rpm. It would be no problem to convert
blade rotation into a higher rpm shaft drive.

And most definitely not all wind turbines gear up the alternator. Most
of the BIG commercial units do have a gearbox - in many cases
incorporating a governor.

I do agree with you though that richardson is a dopey dumbfuck.

Something like that - yes.

 

[[email protected]]

I didn't mean to imply that that was not possible, but in an
automotive environment, it is not desirable. Changing output voltage
(to a limited extent) can be as simply as implementing the external
voltage sense line found on many alternators, and sticking a diode in
series.

With today's switch mode power supply technology there really is no
reason an alternator cannot produce higher voltage and have it
electronically converted to clean, regulated power of whatever voltage
is desired for battery charging and accessory power use.

That is already done on most hybrids.

 

[Archimedes' Lever]

At curb idle the average alternator is not capable of
producing nameplate power.

No shit. Did you spend your entire life coming to that conclusion, or
did someone just hit you upside da haed with a common sense stick?

It certainly does not require 2000 rpms either.

 

[Archimedes' Lever]

And most definitely not all wind turbines gear up the alternator. Most
of the BIG commercial units do have a gearbox - in many cases
incorporating a governor.

Wrong. ALL wind turbines gear up the rotational ratio to the driven
shaft. ALL of them. The governor is for the blades, NOT the alternator.

 

[Archimedes' Lever]

[snip]

No, power is NEVER measured in amps. Current is measured in amps.
Power is in Watts, Joules, Calories, BTUs or horsepower. (or volt-amps
or foot-lbs per unit time)

When did the Joule, calorie, and BTU become a unit of power?

Bob

Unit of ENERGY are often confused with, and/or substituted for power
units. That doesn't make it correct, but it does happen often.

 

[Jamie]

And why cars now run 12 instad of 6 volts.

Actually, the voltage was raised to save on copper, weight and space.

Which is the reason, 48 volt electrical systems in car's was once a
subject and may still happen one day.

 

[Paul Keinanen]

Wrong. ALL wind turbines gear up the rotational ratio to the driven
shaft. ALL of them. The governor is for the blades, NOT the alternator.

Apparently you have never heard of direct drive wind turbines ?

When building variable speed wind turbines, you are going to need some
power electronics to convert the variable frequency power from the
generator to the fixed 50/60 Hz mains frequency. When the power
electronic is needed, why not let the generator operate at a low RPM,
generate very low frequency electricity for the inverter and skip the
failure prone gearbox.

In practice, direct drive wind turbines use permanent magnet
generators, which tend to have a large diameter, often requiring a
large nacelle.

For instance Enercon makes direct drive wind turbines in the 2 MW
category.

Paul

 

[Paul Keinanen]

We're not talking about automotive generator,
we are talking about WIND GENERATOR stupid.
Look up there, see the word "Energy homwpower"
You got a set of broken eyes or what?

Where did get that from ?

Subject: Re: Hey do you know your car's alternator only outputs 7-10% while it's running?

This would strongly suggest that automotive generators are discussed.

From the cross posting list one might guess that this might also be
relevant to wind generators, since car parts are sometimes used in
miniature wind turbines.

Paul

 

[Paul Keinanen]

Actually, the voltage was raised to save on copper, weight and space.

Which is the reason, 48 volt electrical systems in car's was once a
subject and may still happen one day.

When was the 48 V system discussed ?

The 42 V (3 x 14 V) system was a hot debate subject in the beginning
of this century.

Paul

 

[Archimedes' Lever]

Got a small wind turbine here... with a straight shaft, blades to armature,
no gearing/belting.
Nelson

Home hobbyist retard projects do not count.

 

[RoyLFuchs]

We're not talking about automotive generator, we are talking about WIND GENERATOR stupid. Look up there, see the word "Energy homwpower" You got a set of broken eyes or what?

Cars have not used generators in nearly 40 years. They all use
alternators. Have for decades.

I told you once before, you retarded twit, LINE LENGTH IN USENET IS 72
CHARACTERS.

 

[Kai]

I admire the old American fathers, they are great and well educated but their youngsters are terrible.

You are a clueless, retarded bastard that doesn't know anything about
either.

 

[Archimedes' Lever]

Apparently you have never heard of direct drive wind turbines ?

When building variable speed wind turbines, you are going to need some
power electronics to convert the variable frequency power from the
generator to the fixed 50/60 Hz mains frequency. When the power
electronic is needed, why not let the generator operate at a low RPM,
generate very low frequency electricity for the inverter and skip the
failure prone gearbox.

In practice, direct drive wind turbines use permanent magnet
generators, which tend to have a large diameter, often requiring a
large nacelle.

For instance Enercon makes direct drive wind turbines in the 2 MW
category.

Paul

Permanent magnet. Would that not then be a generator, not an
alternator?

Anyway, the show I saw had shots of some pretty big gearbox hardware.
I figured that everyone followed that. Just shows that no matter what
gets invented, the rest of the world improves on it.

I think we should us elevated water reservoirs and use the turbines to
pump water up from the water table, and up into the reservoir to be used
with water driven turbines that are much more efficient.

It would be like going back to the old days with the lever on the back
of the shaft, drawing water up from the well.

 

[Archimedes' Lever]

Of course when it's made by junky American nerds.

What country are you from, retard boy?

 

[RoyLFuchs]

you're the man of helucination,

Nicetry, richardson, you fucking retard.

The word is hallucination.

 

[daestrom]

It's easy to call people trolls by the stupid American jerk who doesn't know shit about electronic or car's alternator. Even for a fixed voltage (14V) in automobile you are still wrong, Power is measured in AMP but in WATT no matter where in car or in your house of assholes. No wonder why you flunked comparing to other nation's education.

You get so flustered you can't even write what you mean. "Power is
measured in AMP but in watt" ??? funny. I doubt that's what you meant,
but with you, one can never be sure.

If you keep the voltage fixed, you have to increase the current to get
more power, even a troll like you should agree to that. Unless you want
to shift the whole discussion to AC power transmission, but I don't
think you have the background to carry on a discussion about
torque-angles and power factor so we'll just keep to DC for your sake.

As to what I know about electrical machinery and electronics, you have
no idea what you're talking about. I was re-wiring motors and fixing
the regulators for the old-style DC generators for marine engines while
your mama was still wiping your poop of your butt.

daestrom

 

[Johnny B Good]

The message <[email protected]>
from "Richardson" <[email protected]> contains these words:

====snip====

No you guys are the real dumbfucked assholes of the world. You don't
know shit about 1 phase and 3 phase generator/alternator in general, in
industries and in automobile. 1 phase uses high RPM, 3 phase uses low
RPM because you can squeeze 3 impulse into 1 second window. Man!
you people are really stupid and real jerks.

For a conventional AC machine where the field rotates, the number of
poles on the rotor (always an even number) decides the cycles per rev,
the stator decides how many phases are generated (in practice 1 or 3,
but others are possible, such as 2 or more).

Both a single phase and a 3 phase generator with a 2 pole rotor produce
60Hz when spun at 3,600rpm.

I'm tired of teaching you the right thing. Go on calling other people
stupid,
you're blind in every aspect. From War to technologies...Wow! you
amazed me.

I'm afraid it is you who seems to have the wrong end of the stick in
this matter. The only time you'll see a tripling of frequency due to
using a 3 phase generator over a single phase one is when the output of
all phases are immediately fed to a fullwave rectifier pack, as in the
case of an automobile alternator. This triples the ripple frequency of
the rectified output compared to its single phase cousin.

Perhaps it was this effect you were thinking of?

HTH & HAND

 

[daestrom]

The old generators in cars required high rpms to function efficiently.

Alternators were designed and incorporated into cars specifically
because they do NOT require a high rpm to have efficient output, so you
are wrong about the 2k rpm minimum.

As others have pointed out to you, you got it wrong.

In order to get a useful voltage out of an old DC generator, you had to
rev up the engine slightly. This was simply because they were belted to
run at a slower RPM. This was necessary because when the engine was
turning at 3k-4k, you couldn't have the generator spinning much faster
than 4k itself or it would disintegrate from the centrifugal forces.
(unless you want to spend the $ on a variable-ratio belt drive for just
the DC generator).

Alternators are connected to the engine with a belt drive that steps-up
the RPM so that when the engine is idling, the alternator is spinning
much faster. Thus, it is able to produce a usable voltage even with the
engine idling. The mechanical design of the alternator uses two strong
metal pieces with interlocking 'fingers' to hold the winding and can
withstand much higher speeds than a conventional DC generator rotor.

Also, idiot, and wind turbine (ALL in fact) gear the blade speed up to
drive the alternator at a higher rpm. It would be no problem to convert
blade rotation into a higher rpm shaft drive.

Another gross generalization based on thin air.

daestrom

 

[Fred Abse]

The old generators in cars required high rpms to function efficiently.

Really, to function at all. Even so, at idling speed, output was
effectively zero, since the voltage at maximum excitation was lower than
system voltage, and the cutout operated. Imagine that in today's
stop-start city driving conditions.

A DC generator is limited by how fast it can be run without the armature
disintegrating. Automotive alternators' rotors are wound coaxially to the
shaft with shaped "wrap around" pole pieces and can inherently be run
faster.

DC generators were usually run at not much more than engine RPM (if even
that), alternators much faster, witnessed by the respective ratios of
pulley diameters, alternators having much smaller driven pulleys.

Alternators were designed and incorporated into cars specifically
because they do NOT require a high rpm to have efficient output, so you
are wrong about the 2k rpm minimum.

One of the selling points was their still giving useful output at idling
speed.

In fact, alternators are run much faster than 2000RPM. A 6" pulley on the
crankshaft and a 2" pulley on the alternator with an engine that redlines
at over 6000 RPM says it all. He should take a look under the hood (if he
can find it ;-)).

Also, idiot, and wind turbine (ALL in fact) gear the blade speed up to
drive the alternator at a higher rpm. It would be no problem to convert
blade rotation into a higher rpm shaft drive.

I do agree with you though that richardson is a dopey dumbfuck.

I plonked him ages ago. Patience exhausted.

 

[Fred Abse]

At curb idle the average alternator is not capable of
producing nameplate power. Curb idle of 750RPM spins most alternators
at roughly 2100 RPM

Still *some* power, though.

Take a look at: http://lees.mit.edu/lees/posters/RU2d_Caliskan.pdf for an idea
of what automotive alternator characteristics look like.

That document also describes the use of switched mode rectification to optimize
output power, and postulates an expression for output power which is a reasonable
fit to experimental data.