quote Originally posted by Falcon4: Nice job totally missing the point. You'd do great in Iraq - that is, if you can dodge bullets just as well as you dodge the point... plus you fit John Kerry's model as well. No use trying to reason with you... wonder if anyone else wants to give it a shot?

I simply love how you cant put 2 and 2 together. And since you still insist on me answering your weak arguement, I shall:

quote A college degree doesn't give you experience. A college degree gives you the peace of mind that you successfully memorized a book of charts and figures - but gives you no real understanding of what goes on underneath to do what you learned happens. Basically all you did is spout out a bunch of words and equations from the book that says how motors work. You don't have experience with both, you haven't heard about both, you haven't taken apart and understood -- not just analyzed -- how each work. You just say what's in the book and you don't even know if it applies.

So because the textbook is not a motor, but instead tells me about how the physical universe treats a motor, my point is invalid? Until you have thrown both an AC and DC motor into a bomb caloriometer, your notion of "experience" is completely baseless. Not to mention the sweeping generalizations about someone who actually IS an electrical engineer...

quote In this instance you're telling me that a motor which can only spin at a fixed speed is more appropriate for an electric vehicle than a DC motor. In a DC brush motor, energy is almost directly converted to motion, in much the same way as gas to fire and heat. The power drives the rotating electromagnets that oppose the fixed magnets, and spin the shaft and the commutator, switching polarity, so on and so forth. If the motor is stopped or stalled, the current applied to the electromagnets increases (according to the voltage provided) and the motor pushes harder. If it were capable of applying constant torque across all RPMs, well... it'd spin up to an infinite speed and fly apart

Since I am an EE, I know that oscillators can change frequency. This particular paragraph makes me doubt you even understand how the driver for an AC motor actually works. The driver is not a fixed frequency machine.

quote not "smoke screen" terms that one EE says to another to increase the size of their ego.

Sorry, thats second semester physics. Lots of majors take that course and its exceptionally easy. I dont suppose one that doesnt quite understand how an AC driver works should be lecturing me on the supposed advantages of DC mtors at high RPMs. Next youll tell me that our good ol' Duke maintains its efficiency when run at 20kRPM like a Formula 1 engine....

Wake up, bud. "Real world terms" dont explain effieiency any more than two rednecks pissing on each other over Ford vs Chevy. If you dont understand the sine function or function in general, thats fine... alot of American graduates dont either. But dont force into throwing away an arguement simply because my point includes a word you probably needed to get a dictionary to know the definition.

Happy now? Pride tends to get the better of us, so I dont expect you turning your opinion, despite coming up with more support than your rhetoric.

[This message has been edited by AP2k (edited 11-07-2006).]

Batteries produce DC and only DC. There is no such thing as an AC battery.

There is also no such thing as an AC "driver" -- unless you count the capacitor. Or unless you're talking about servo or stepping motors, which also operate on their own kind of AC current. That's a completely different topic which -- AFAIK -- we're not talking about.

So let's see here.

Battery -> Very high current DC/AC inverter -> Single speed AC motor.
Power lost in DC/AC inverter. Current lost in complicated layout of AC motor. Extremely high current DC/AC inverter needed to make up for startup surge of AC motor.

Side note: You don't see lights dim when a DC motor starts up. Don't even try to compare the two.

DC motor...
Battery -> Motor.

Tough **** to work with here!

------------------

'87 Fiero GT, Automatic, 153k miles, stock everything, just trying to make it all work again. :D

quote There is also no such thing as an AC "driver" -- unless you count the capacitor. Or unless you're talking about servo or stepping motors, which also operate on their own kind of AC current. That's a completely different topic which -- AFAIK -- we're not talking about.

I'm about done with this. Seeing as though you dont seem to understand the concept of an amplified sine wave driving a motor, your pretty bad off for a discussion of electric motors. Should I drag the "dodging of topic" offshoot of yours into this post? Naa, just adds cement over your coffin. Not likely you will walk among the living, aye?

quote Battery -> Very high current DC/AC inverter -> Single speed AC motor. Power lost in DC/AC inverter. Current lost in complicated layout of AC motor. Extremely high current DC/AC inverter needed to make up for startup surge of AC motor.

The driver is rated for upwards of 200kW. Nothing much can be said for inefficiencies except to say the tired cliche "inverter being ineffieicnt" is not valid here because its not subject to stringent cost/benefit economy, and your run of the mill inverter isnt even a sine wave, so you still have it wasting %141 more energy than a true sine wave inverter of the same power. And dont lie to our readers. The site you posted earlier gives the advantage of design to the AC motor....

quote DC motor... Battery -> Motor.

Lest we forget that the RPM of the motor is directly proportional to the applied voltage. And since the impedance of the motor does not change, power lost to heat is exponentially proprtional to voltage.

Unlike the AC motor whose input current can be stepped down while maintaining necessary drive voltage.

Ooops, there I go with those damned physics again!

Build me an electric car with an AC motor from a washing machine then. I'd love to see it.

Run, Kerry. Run!

Well you're so damn confident you can convert the DC from a battery into AC while still keeping it more efficient than a DC motor... which is like trying to write a .NET (C#) application that's as efficient as its C++ counterpart... just ain't gonna work. But I'd love to hear you keep spinning your wheels...

quote Originally posted by Falcon4: Dude, your math is way, way off. Battery chargers do not have a 15% efficiency - not even close. I'd actually say my charger has about an 80% efficiency - I can calculate that nearly everything that went out on the last drive (60 amps acceleration / 30 amps cruising) came back into the batteries with the charge, with just slightly more going back in with the trickle charge to make up for the lost energy. It also doesn't take 11 kilowatts to move a car at 55 miles an hour. My charger puts out 11 amps at 48 volts DC, and that takes 900-1000 AC watts. Triple that for a cruising speed of 30 miles an hour - that's 3KW. Basically we could add 2.5KW more, plus some for additional drag, and that's 6KW -- charging -- at 55. Apparently you never owned an electric vehicle. xD (edit: and all these numbers were gathered not using label specs, but using a clamp meter for the amps and a wattmeter for the watts)

EDITED IN ITS ENTIRETY:

That doesn't make sense to me. You're saying that your battery charger is more efficient because it charges your batteries well?

When I am talking about efficiency, I am talking about the amount of power the charger uses versus the amount of power actually stored in the battery. I don't care and am not interested in power expended while driving versus the power returned during the charge cycle.

Ed

EDIT 2:
You do realize that 48 volts times 11 amps is only 528 watts? That would mean that your charger only supplies a bit less than 53% of its input power to the battery, which is considerably less than 80% efficient.

[This message has been edited by edhering (edited 11-07-2006).]

While I don't disagree with you Ryan, HERE our powerplants are 1)Nuke and 2) Natural Gas. That makes them much cleaner than the cleanest coal. I also pay 7.49 cents per KWH for my electricity here and that's up from 6.9 cents average from last year.

Not splitting hairs, just pointing out that different regions can vary widely when you're looking at the side effects/costs/unintended consequences.

John Stricker

quote Originally posted by ryan.hess: By the time you burn the coal, heat the water, spit steam through a turbine, convert the mechanical energy into electricity, heat the miles of wires, and step down the voltage to power your car........... I bet you'll have made 4x the pollution (CO2, what have you) and wasted 2x the energy than a gasoline engine. You're pulling a Rube.

As far as electric engines.... why couldnt an alternator be hooked up to feed a inverter to recharge as it drives... that way it would be pretty much self sucficient and rarely need a charge unless your starting system goes..

Same as a car, you dont need to plug a car in every night to charge the battery..

Or do like the flintstones.. Foot power!!!! no gas, no oil, no asbestous brakes,etc... just passenger power!!! Imagine how "happy inside" a guy would feel if his "dreaded mother in law" came along for the drive and he looked in the rearview mirror to see the old hag working her way up thaat step hill you "acccidently" made a wrong turn on?

AC vs DC motors
I have little to say here. AC motors have a nice advanatge in that the AC frequency is directly applied to the motor's RPM. you can have a low power "cruise". AC is the way to go for "cruise". DC motors have MUCH better direct power. but, the power drops off as the RPM's increase. you can adjust the "timing" on a DC motor to compensate for some of power loss at increased RPM's, or use a controller, much like the AC. and, AC motors also have power loss with increased RPM's. the power loss is due to less time exposed to the opposing magnets/attracting magnet, and the time it takes to build the magnetic field. so, the only real difference is if you want the off the line power of the DC or the low power "cruise" of the AC. also - with a decent controller - a DC motor can have a decent low power cruise also. overall - I say the DC motor is the way to go.

quote Originally posted by isthiswhereiputausername?: As far as electric engines.... why couldnt an alternator be hooked up to feed a inverter to recharge as it drives... that way it would be pretty much self sucficient and rarely need a charge unless your starting system goes..

It's a nice thought, but I don't believe that anyone has yet demonstrated a genuine perpetual motion machine, let alone a machine which produces more energy than it consumes.

quote Originally posted by dguy: It's a nice thought, but I don't believe that anyone has yet demonstrated a genuine perpetual motion machine, let alone a machine which produces more energy than it consumes.

Keanu Reeves did it.....

I have recently become interested in EVs half because of an article I read on a super capacitor being designed mainly for EV use (Google EEStors) and half because it would fit my life style well. Electric Vehicles have a lot of promise in my opinion. With the idea that we can get away from using as much oil as we do and it being cheaper and cleaner is a big plus. I plan on building an EV for myself when I can afford it and over time if energy storage gets better it will be easy to upgrade. If this super capacitor works out than there could be a significant change towards purely electric cars. A quick run down of proposed performance from the super capacitor:

-Light weight 1/10 the weight of lead acid batteries.
-contains no harmful chemicals
-500 miles to the charge
-lots of power (they said think of regular sedans with ferrari type acceleration now I say think for Fieros with that kind of power)
-the ability to charge fully within 5 minutes (mind you this is not from any 110 outlet it would be from a speciality charger but it would make cross country trips feasible)
-reasonably priced (they said around $6000 per unit but it's a one time buy kind of thing because it's been tested over one million cycles - Lit-Ion packs are between twenty and thirty thousand dollars.)

Just my two cents. Regardless I will build an EV using Lead/Acid batteries unless some other technology that's not gas blows me away and is affordable.
Daniel

quote Originally posted by Pyrthian: AC vs DC motors I have little to say here. AC motors have a nice advanatge in that the AC frequency is directly applied to the motor's RPM. you can have a low power "cruise". AC is the way to go for "cruise". DC motors have MUCH better direct power. but, the power drops off as the RPM's increase. you can adjust the "timing" on a DC motor to compensate for some of power loss at increased RPM's, or use a controller, much like the AC. and, AC motors also have power loss with increased RPM's. the power loss is due to less time exposed to the opposing magnets/attracting magnet, and the time it takes to build the magnetic field. so, the only real difference is if you want the off the line power of the DC or the low power "cruise" of the AC. also - with a decent controller - a DC motor can have a decent low power cruise also. overall - I say the DC motor is the way to go.

I wonder why the Tesla boys didnt go with a DC motor?....

You cant get any more power out of a DC motor than at full duty cycle. The point of a DC driver is to NOT have %100 duty cycle. So your not going to get any power improvements using a driver (you CAN get efficiency improvements, however). Adjusting the timing of a DC motor isnt the way to go, either. You will get even less peak power out of it and it will only be useful at high RPMs.

If I ever were to see a DC motor with positive timing I will laugh my ass off when you start it one day and it throws itself into reverse because you started it at the wrong phase angle.

They didn't go with an "AC motor", Einstein. Is that like saying the words "AC motors are more cost effective" means "AC motors are more efficient"?

edit: Your blatant and ignorant misuse of the word "Your" is a plain sign of your intelligence level, too. God, just get out of this topic.

[This message has been edited by Falcon4 (edited 11-08-2006).]

quote Originally posted by Falcon4: They didn't go with an "AC motor", Einstein. Is that like saying the words "AC motors are more cost effective" means "AC motors are more efficient"? edit: Your blatant and ignorant misuse of the word "Your" is a plain sign of your intelligence level, too. God, just get out of this topic.

Yay for off-topicness! And kudos for the blatant misrepresentation of all my prior posts in making the strange leap from cost effection to pure efficiency, when I did not.

quote Type designation 3-phase, 4-pole electric motor

From teslamotors.com

Last I checked my EE books, DC doesnt come in three phases. Either the current alternates or it doesnt. If its not DC, then it must be AC.

That makes it a SERVO motor. **** man, don't you know a damn thing about anything other than angle this and phase that? You don't even know what kind of motor you're talking about, FFS!!!

My scooter runs on a servo motor with what I believe are 2 phases (three wires). It has a controller that steps it through the different motions in sequence. That controller is extremely complicated and eats up about 1/8 the power used to drive the motor. Taken to a person that custom builds electric vehicles, I was told that the amount of battery power I carry around should take me at least 50 miles at 40MPH on a charge given a straight DC brush motor. However, with this complicated controller and servo motor, I'm left with a 20 mile range at 30MPH (computer controlled) on a good day. However, when the controller used to go haywire and reverse regeneration and acceleration, I could get up to 45MPH. That was fun.

But back to the topic at hand. AC MOTORS RUN ON 60HZ. AN ALTERNATING INPUT DOES NOT MAKE IT AN AC MOTOR. Get the hell out of this topic - you're not contributing ANYTHING at all but some useless drivel!

Wow... just wow.... Honestly I have no clue where to begin....

quote That makes it a SERVO motor. **** man, don't you know a damn thing about anything other than angle this and phase that? You don't even know what kind of motor you're talking about, FFS!!!

I'm slapping myself in the head right now trying to comprehend this. Why cant you come to face the fact that the Tesla car has an AC motor in it? Because you run around on your Vespa that uses a servo driver and that all you know of? Isnt this like "This is the way I dun it my whole life, and the way my daddy dun it his whole life, etc..."?

quote That makes it a SERVO motor. **** man, don't you know a damn thing about anything other than angle this and phase that? You don't even know what kind of motor you're talking about, FFS!!! My scooter runs on a servo motor with what I believe

And you talk about ME not knowing what kind of motor I'm talking about....

And the icing on the cake:

quote AC MOTORS RUN ON 60HZ. AN ALTERNATING INPUT DOES NOT MAKE IT AN AC MOTOR

I wonder how people in Europe get by with their mtors seeing as their AC runs at 50Hz?... Saying AC motors must run at 60Hz is beyond ridiculous. And yes, a waveform having symmetrical alternations of voltages with respect to time constitutes an alternating signal.

The more I point out your glaring misconceptions the more hilarious your replies. Shall I keep going?

[This message has been edited by AP2k (edited 11-08-2006).]

Just go away.

quote Originally posted by AP2k: You cant get any more power out of a DC motor than at full duty cycle. The point of a DC driver is to NOT have %100 duty cycle. So your not going to get any power improvements using a driver (you CAN get efficiency improvements, however). Adjusting the timing of a DC motor isnt the way to go, either. You will get even less peak power out of it and it will only be useful at high RPMs. If I ever were to see a DC motor with positive timing I will laugh my ass off when you start it one day and it throws itself into reverse because you started it at the wrong phase angle.

Tesla also built a magnetic building destroyer which was no larger than home PC
but, dont see anyone useing that either, do you?
as awesome as Tesla's stuff was - not all of it was right.

same goes for AC.
AC is not magic, its just nice because you can control the RPM thru the fequiency of the sine wave - that is it.
AC still has the same limitations as DC on timing & field building & field collapsing.

DC has more power. AC power is roughly 70% of its peak - DC is peak.
I agree 100% that the RPM control is WAAAAY better on a AC motor, which makes for a much much more efficent cruising motor choice.
so, it becomes more a choice on what you plan on doing with the vehicle on what should be your choice.
anyone looking for the maximum power output to the wheels will go DC
anyone looking to drive 100 miles a day will want AC

Pyrthian You know anything about a radio "skip" atmospheric or magnetic?

quote Originally posted by Butter: Pyrthian You know anything about a radio "skip" atmospheric or magnetic?

I'll go solar/atmospheric, being it happens at night

What about the daytime happenings?

quote Originally posted by Butter: What about the daytime happenings?

not sure - never picked up any. just AM, at night, way back in the 70's, when I was a kid. I could occasionaly pick up some WAY far away stations. Kentucky was the furthest.
of course there could be many other reasons - this is just observation from when I was a kid. could be I was to busy playing outside during the day

quote Originally posted by Pyrthian: not sure - never picked up any. just AM, at night, way back in the 70's, when I was a kid. I could occasionaly pick up some WAY far away stations. Kentucky was the furthest. of course there could be many other reasons - this is just observation from when I was a kid. could be I was to busy playing outside during the day

I'd bet Nikola Tesla was playing something different than you during the day.

I had a SW radio that pidked up foreign languages and I thought that was one hella of a radio till an old Navy radio man enlightened me. Which brings me to the point I wanted to make. I've had many questions and doubts about Tesla's claims and such. After reading and pondering over him I have come to the conclusion he didn't think on the same level as most electrical engineers. In fact it is my belief the electrical part of him was the smaller part of what he knew in the world of physics. It is in this light that the so called majical things he accomplished has real possibilities.

well, that is the whole point of shortwave radio.
yes, Tesla had great ideas. he also had some bad ones.

either way - electric vehicles are a good way to go - escpecailly hybrids with electrical storage

whether AC or DC - that depends on use. much like gas vs deisel or HP vs Tq. or V8 vs SC. right tool for the job.

Yeah I think electric vehicle will be a great way to go too. I feel we may need to go the hybrid way till we learn some things that Tesla probally took to the grave with him though.

quote Originally posted by AP2k: The DC motor in cars needs to be buried next to Edison's grave. In no way can they be viable as performance and economy engines.

This cracked me up...I agree but for a different reason. I am a huge fan of Tesla, (the man). He worked for Edison and eventually quit because he didn't agree with using DC to power the grid...(he was right).

AC motors are NOT DC motors with extra crap on them to handle AC power. Just the opposite, Tesla invented the Induction AC motor and it's the simplest thing in the world. No brushes or commutator bars, the motor just runs based on the phase of the power.

In my opinion the biggest flaw in electric cars is not the batteries, (even though they do suck really bad)...the flaw is that our energy infrastructure is not designed to replace all the gasoline consumed with any other energy source, including electricity. If we had magical batteries that could store the equivalent of a gasoline car the grid would collaspe from the load. The only way it would work is ive we built hundreds of nuclear powe plants. Are the environmentalists going to back that plan??