Really Cool Invention Brings Teens Awards (Amazing Kids-Invented What GM Couldn't)

The Salt Lake Tribune ^ | 07/06/2005 | Jessica Ravitz

[coloradan]

An alternator does NOT get harder to turn as the electrical load increases.. You F---king idi-t!

You are very, very mistaken. Why do they build water turbines at the bottom of thousand-foot dams? If a generator were no harder to turn as the electrical load went up, why wouldn't the dribble from a downspout suffice to light up NYC?

Conservation of energy, one of the most fundamental axioms of physics, is at stake.

Cut the attitude, you don't know what you're talking about.

[babyface00]

A couple of points...

It says GM rejected the idea in 1964.

Seems like a lot has changed since then. I wouldn't be surprised if GM has re-evaluated these devices as time goes on.

Also, GM (and other automotive manufacturers) are transistioning from the 12V system to a larger one (48v? - I can't remember).

Using the higher-voltage system may make these devices more practical. GM may be waiting until after the higher-voltage platforms are rolled out to implement this type of cooling device.

[coloradan]

That's because it doesn't take much power to charge a nearly-charged battery, while it takes quite a lot of power to run a compressor, or, more fundamentally, to cool the interior of the vehicle on a hot day. If you had enough Peltier devices to cool the inside, it would draw a hell of a lot more current than trickle-charging a nearly-fully-charged battery - and that would increase the torque necessary to turn the alternator by a corresponding amount.

[longtermmemmory]

but the enviro wackos will be used by the patent owners to mandate its use despite being so inefficient.

(kind of like developers using nature conservancy to control land prices and competition.)

[andyk]

What are the odds that somone in the know might tell the rest of us (me) what a Peltier Chip actually is?

Whatever it is, it's really bad, this is a stupid idea, the kids are nitwits, it'll never work, and everyone here is a freaking rocket scientist.

[myself6]

The cost to charge the battery doesn't change if the battery is charging or not. The cost is paid when the belt turns the pulley that is connected to the rod that holds the windings of conductor.

Once turning, the alternator generates an electrical current. No matter the electrical load you place on the alternator the engine will NOT work harder. If the electrical load becomes to much for the alternator things will simply stop working. but the cost to run that specific alternator will not change (barring wear and tear on the bearings and sh-t like that)

[brownsfan]

"When will Detroit ever learn!"

When the big 3 are all foreign owned and forced to innovate, or seek other employment.

[coloradan]

Again, you are mistaken. Very mistaken.

[P-Marlowe]

And where does this nitwit think the electricity for the Peltier chips comes from? That's right: the engine.

It's a nice story, but in the end I think GM was right. The thermoelectric Chips produce more heat than cold. Where is the heat dissipated to and where is the electricty going to come from? You literally have to create enough energy to heat the one side of the chip 25 degrees in order to cool the other side of the chip 25 degrees and you need to create enough energy to do both. For instance, it requires up to about 50 watts to cool a computer chip. What is it going to take to cool the inside of an SUV? I'd say probably about 5000 watts.

I suspect that you're going to need a generator/alternator that sucks more gas than an air conditioner.

[Nov3]

An alternator does NOT get harder to turn as the electrical load increases.. You F---king idi-t!

Oh really??? Where does the energy come from perchance??? Are you a rocket surgeon or something???

[brownsfan]

"Take a physics class before you embarass yourself anymore."

Wow, go easy. Not everyone is as brilliant as you are.

But I would say, an alternator under load is not nearly as costly to run, in terms of mechanical load, as a running A/C compressor. It's not free energy, but it is low cost.

[longtermmemmory]

had a physics teacher who had a series of regular bulb lights wired onto a generator powered by an exercise bicycle.

One light was not hard. Two lights required more pedaling.

and so on until five lights were lit and it was like going up a steep hill.

It demonstrates load and resistance very very very well.

[norwaypinesavage]

I discussed this device with GM in the 1960's (when I worked there). A co-worker had actually built one in the 1950's. It was invented in the early 1800's.

The problem is that it is very inefficient. It produces far fewer BTU's of cooling for the same amount of engine energy, than a current air conditioner does. Air conditioner requirements include quick, cold air on hot days, and sufficient cold air to cool the vehicle at all speeds in very hot conditions. If a Peltier device was built that met the same requirements, it would use more engine power than the current air conditioner requires.

[Kirkwood]

Huh! You are just repeating what I said. You can't argue that it is an efficient or effective system though, because it simply is not. Do you always turn the faucet on full to fill a glass with water? Do you set your stove burner on full to warm up some soup. Do you accelerate your car to full speed and then slam on the brakes at the next stop light? Of course not, and yet this is how A/C works. How many times have you heard people complain that A/C leaves them either too hot or too cold? It is inefficient if you are using more energy than is actually needed at a given time. The solution has been to run the A/C and add warm air so you avoid the uncomfortable cycling and can zone different parts of living space to specific temperatures. You trade off energy efficiency for comfort.

[myself6]

Because the amount of current needed determines the SIZE generator you need to turn. Once the SIZE of the generator is figured out you determine the "cost" to turn the windings. generators run at a specific RPM , if you need more power you don't turn it faster you bring more generators on line. The cost to run THAT one generator does not change as the electrical load changes.



This isn't that hard to understand...


Im absolutely amazed at peoples lack of understanding on this...

don't they teach this stuff in high school any more?

[brownsfan]

run the calculations and the fossile fules

Wow, good thing they'll be using fossil fuels instead!

BTW, they are rethinking the moniker, fossil fuels. Turns out they're not sure that's how oil was formed, and they're not even sure that oil is a non-renewable resource anymore.

[MarkL]

Hmmm. Something that I wonder about... What about home use? Using solar cells on the roof to generate the power to run the peltier cells (during the day), and using convection water cooling on the peltier cells to help heat water for the home-owners? The peltier cells probably wouldn't be enough to cool the house, but it might help a conventional AC unit. Would this allow a smaller, more efficient AC unit for the home?

Mark

[JAKraig]

DumbA$$...


An alternator does NOT get harder to turn as the electrical load increases.. You F---king idi-t!


(You F---king idi-t!)?

Ok, at this juncture I have to jump in. I'm sorry but unless I don't understand what you are trying to say you are as mistaken as can be.

There is a minimum friction that has to be overcome and an minimum force that has to be overcome to move (spin) the weight of the alternator. Above these minimums the force required to spin the alternator directly increases as the (electrical) load increases. There is also an increase in force required for spinning faster but it is of comparatively little consequence. The vast majority of force needed to spin the alternator is from the power generated by the alternator. The Alternator will try to produce more and more power as required by the load, the regulator however will limit the power output so that the alternator does not overheat and destroy itself. So, there is a maximum of torque required only because of the regulator, without it the torque required will continue to increase with the load until the alternator burns up.

Now what are you trying to say?

[Zeppelin]

---

As the electrical load increases the mechanical load on the engine does not.
Free energy! Get as much electricity as you want from any size engine!

Take a physics class before you embarass yourself anymore.

---

HSE,

Free energy? Nobody claimed that. And it is you that should take a physics class; particularly E&M and/or Machine Elements.

As the alternator spins, it converts mechanical to electrical, we all know that. But any electrical energy above and beyond what the appliances use and the battery is recharged with is wasted. The engine does not allocate less mechanical energy to be converted to electrical as it sees fit. So what the poster above was saying is that as the electrical load increases, it does not rob the engine of power, but is just being more efficient with the electrical energy generated.

You quit embarrassing YOURself.

[from occupied ga]

As the electrical load increases the mechanical load on the engine does not

WRONG! As the electrical load increases it requires more power to turn the alternator. You're describing perpetual motion of the first kind.