Electricity and Common Urban Myths

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J

JorgensenSteam

Guest
There is a thread going on about a nice little generator/motor, and some interesting ideas have been presented in that thread.

In order to keep from getting off-thread, I will post this information here, but it is relevant to any generator/motor thread, especially when you start trying to figure out how your motor/generator works, and how much power it uses/generates.

But in a general sense, there is a great deal of confusion about electricity and how it works, and this often leads to urban myths about electricity. You cannot begin to work with electricity without understanding what is myth and what is reality, so I offer a few generalities about these for those who really want to know and understand.

Myth No.1:
You can make an electrical device that will create more energy than it uses.
Of course this statement is false, but why is the idea so pervasive in urban lore?
If someone sold you an automobile, and told you that as you drive the car, the engine creates gasoline and adds it to the gas tank, you would immediately know something is amiss. Since you can control and measure what goes into the tank, and what comes out of the tank, then you can quickly find out that engines don't put gas back into the tank.
With electricity, since few understand how it is used and measured, then it is easy for the general public to get fooled with the "free energy" theories. But if you understand how to use electrical instruments correctly, then you can easily measure what energy goes in, and what energy comes out.

People want to believe good things, and often the argument is used that look at what has been created by people who were told it was not possible. Anything is possible as long as it follows the laws of physics. All things that have been made by man all adhere to the same laws of physics. When people say "it can't be done", what that really means is that they don't have knowledge of a method that can be used functionally, but their lack of knowledge does not mean that what works does not follow the fundamental laws of physics. Very important distinction, and a mistaken argument that is often heard.

Myth No.2:
Scientists try to suppress new ideas about free-energy.
I have heard this argument many times, but you don't need to be a rocket scientist to debunk free-energy machines, you only need to know how to correctly use a ammeter, voltmeter, and oscilloscope. Anyone can learn to use these items correctly, it is not difficult. A "red flag" on the free energy ideas is that you will never see these instruments during presentations. Accurately measuring what is happening with an electrical device is not what the "free energy" folks want, they prefer the smoke-and-mirrors approach, or the argument that this is something new that people don't understand. Measure accurately first, and then make claims, not vice-versa.

If you transfer X amount of energy into an electrical device such as a motor, you will convert some of the electrical energy into waste heat by heating the wires, which act as heat-generating resistors, by hysteresis and eddy current losses in magnetic cores, frictional losses in bearing, which generates heat, etc.
So if you transmit 100 watts of energy to a motor, the motor will not produce 100 watts of work, but will produce a portion of that amount in heat, and then produce less than 100 watts of mechanical work.

For a generator, if your prime mover is inputting 100 watts of mechanical energy into a generator, the generator will not output 100 watts of generated electrical power, but will produce less than 100 watts, because of the losses mentioned above.

A coreless design may prevent cogging, but I don't see any large scale devices that do not use laminated iron cores. Solid iron cores can be used, but the laminated cores minimize hysteresis and eddy current losses, and so are used almost exclusively in power devices of any size, such as transformers or motors.

Why are most power systems in use today 3-phase.
3-phase systems are just three 1-phase systems connected together, no big deal there. They originally experimented with 6-phase, 12-phase, and other phase systems, but settled on the 3-phase system due to its efficiency, and the fact that 3-phase motors produce constant torque (ie: very low vibration).

For very long distance power transmission, very high voltage DC systems are used, with a converter from AC to DC at either end of the line. These systems use a single wire, with the earth used as the second conductor. But 3-phase AC systems are used for power distribution because you have to convert lots of bulk power up and down in voltage, and the power transformer works with AC only.

Do I know everything about electricity?
Absolutely not, I will never know everything about electricity.

Do I understand electricity well enough to predict what motors, generators, and free-energy devices will do and how much power they will use?
Absolutely yes. It is as simple as knowing how much gasoline I put in my car, and how far I drive at what gas mileage.

Will people create more efficient electrical equipment in the future?
Absolutely yes.

Will people create electrical devices that "create" energy in the future?
Not on this earth, maybe in the center of some giant black hole, but I doubt it.

These things are relevant when you start measuring the input/output of your motor/generator on these threads though, so I mention them.
I don't know it all, but I wasn't born yesterday either.
 
Hello Pat, perhaps it would be a benefit if you went back and reviewed your understanding of basic electricity, at least in terms of high tension transmission is concerned. For one, the 'earth' as you are calling it is not used as one 'side' of any given circuit, it is used as a reference only. A common mistake. That reference could be any positive or negative component of the AC voltage being generated. I'm certain what prompted your initial response, but please use the proper terms when attempting to explain the concepts of power transmission to a certified electrician. Thank you.

BC1
Jim
 
I do not want to muck up Manfred's generator thread so I will post here.

Rare earth magnets are being used for the newest designs of large wind turbines and hybrid cars. They are in all sorts of small stuff like hard drives small motors etc. The price increase of the magnets by China the largest producer has a lot of industry scrambling for new sources of magnets.

This was new to me also but checking the internet ever so often for new advances in engineering designs is one of the reasons I read this forum.
http://www.technologyreview.com/energy/25188/

Dan
 
Bearcar,
Your reference to earth is correct for all but what Jim mentioned - those ultra high DC transmission lines have only one insulated strand and an "earth" cable that runs in the ground from tower to tower (as well a some underground co-ax systems).
DC is a more efficient way of moving bulk power (like Cahora Bassa Dam) long distances and doesn't suffer from capacitive inter strand connection losses, induction loss etc.

http://en.wikipedia.org/wiki/Cahora_Bassa_(HVDC)

Clearly a single strand. The upper earth strand is for lightning protection only.

Some HT DC transmission systems use bipolar transmission lines and others use two for redundancy with an "earth", also for ballancing the mechanical loading on the towers.

Ken
 
Gee's

All I thought it was is V=IR and W=VI. :p

where V = volts = pressure
I = amps = flow
R = resistance = restrictions to flow
W = power

Best Regards
Bob
 
Bob,
W=VA Cos psi (more correctly W=EI)

cos psi being the cosine of the angle that the current waveform leads or lags the voltage waveform in AC circuits - this is the "power factor". For DC it is 1.0 so your formula holds there.

For a purely inductive or capacative load the power factor is zero so its entirely possible (nearly) to have voltage and current but no Wattage - sometimes refered to as "Wattless Current"

All rather confusing really.

As regards ANY claims of getting more energy out than you put in means someone has made a discovery that shatters all the existing laws of physics - we would have heard about it.

So forgive us scientific types for being blunt but that's why we say "it isn't possible" and switch off - I for one won't waste my time listening to the drivel that is invariably trotted out with such claims.

I've had family members accuse me of having a closed mind on this issue.

Ken
 
There is something else nobody used to think off. When you buy a motor, no matter what brand, the specified power in W or KW is measured at the shaft. When you compare electrical consumption that's where you see the difference. Cheaper motors on constant use will "gulp" the difference in acquisition cost to more efficient ones in a matter of months.
Some big companies, when a older motor burns out, they usually exchange it with a more efficient one.
 
So where's Nikola Tesla when we need him?
Lets not get into high frequency and the wireless transmission of power. ::)
 
For people unwilling or unable to learn any science, the most compelling argument that over-unity devices can't exist is the economic one. If such devices existed, every facet of advertising media would already be hired to the task of trying to sell you one. [ The faithful will argue that these devices are being suppressed by big business, etc.. However, see Baloney Detection below.]

Most technical university physics departments receive so many claims of over-unity devices invented that they have standard form letters refusing to examine the suggested ideas.

If you're interested in learning how to detect junk science, a good start is the "Baloney Detection Collection"...

http://www.physics.smu.edu/~pseudo/baloney.html
 
bearcar1 said:
Hello Pat, perhaps it would be a benefit if you went back and reviewed your understanding of basic electricity, at least in terms of high tension transmission is concerned. For one, the 'earth' as you are calling it is not used as one 'side' of any given circuit, it is used as a reference only. A common mistake. That reference could be any positive or negative component of the AC voltage being generated. I'm certain what prompted your initial response, but please use the proper terms when attempting to explain the concepts of power transmission to a certified electrician. Thank you.

BC1
Jim

Jim-

The earth is indeed used as one side of the electrical circuit for high voltage DC transmission lines. Only one current carrying conductor is on a DC trasmission pole, the other conductor is the earth. No mistake here. Don't take my word for it, reseach it on the internet. It is common knowledge.

Pat J
 
A quick Google search revealed this information:

Monopole and earth return
Block diagram of a monopole system with earth returnIn a common configuration, called monopole, one of the terminals of the rectifier is connected to earth ground. The other terminal, at a potential high above or below ground, is connected to a transmission line.

Current flows in the earth between the earth electrodes at the two stations. Therefore it is a type of single wire earth return.
 
I remember a funny thing about power factor.

I was baffled for years about the meaning of power factor, and finally one day it all clicked in my small brain.

I was so excited that I wanted to tell someone immediately about my great discovery.

My Mom and Dad were leaving to go on vacation, and were in the car and backing out of the driveway. I ran up to the car, and banged on the window, and yelled loudly "MOM, DAD, I FIGURED OUT POWER FACTOR, STOP THE CAR".

My dad very wisely cracked the window very slightly, and said "That's nice........see you in two weeks", without ever slowing down the car. They quickly sped off down the street, and thus were spared the dreaded "power factor" lecture.
Such is the appreciation of parents when great scientific understanding is reached.

A common equation for electricity is V=I*R*cos(thesa)
where "cos(theta)" is the power factor.

For DC circuits, cos(theta) is always equal to 1.
For AC circuits, the power factor can be leading or lagging.

Modern AC motors generally have a power factor in excess of 85% or more.
Older motors can have a power factor of 50% or less.

Inductors and capacitors have a power factor of zero, ie: they use a lot of electrical current, but produce no electrical work.

Resistive loads always have a power factor of 1.

If you have a low power factor in your manufacturing plant, you can add capacitors at each motor, or at a group location at the electrical service entrance, or you can install some synchronous motors, and adjust the field for a leading power factor on the synchronous motor, and thus improve the power factor of the entire facility.

Pat J
 
I want every one to know that it was not my intension to disrupt Mansfred's tread I do apologize for that. I had simply posted that his motor was just like John Bedini's motor and it started from there again my apology.
Pat that was an excellent coarse in electricity. There is only one thing I would add is that the biggest contributor of losses from converting from mechanic to electricity is because of Lenz's Law. And I do agree with you about the ground and High voltage.

One great thing about every one being different is that we all see and understand things in our own way. We have our own views of things how they work and how to apply them. If we were all closed minded, we would not be where we are today. My father did not believe they went to the moon or man could go to space but yet they did. None of us are smarter there the next person, we my know more about different subjects but that does't make us smarter. With that being said my apology again.

kind regards Don
 
Don,
It is easy to fix the off topic drift on Manfred's generator thread. You can simply remove the posts you made that went off topic. I removed the response post I made and the other responses were made by global moderators who know how to edit or remove posts.

I am a big fan of Nikola Tesla. His main rival was Edison and I want to point out that there is a unit named for Tesla http://en.wikipedia.org/wiki/Tesla_(unit) and Edison never received that honor.

He demonstrated a radio controlled boat in 1898 in the hopes of interesting the US Navy but they saw no use for the device. That was some serious dumbness on the part of the upper brass.

Dan
 
OK relax everyone. I don't like editing threads unless it goes WAY pear shaped. I not convinced it did in this case either.

Arnold and I can discuss a change there, but I doubt it. And I wouldn't in any case unless I talked to Manfred first...

Though Marv and Ken, as an Engineer, I understand EXACTLY where your coming from....

Deep breath in....let it out slow. ;D.

It's a hobby right?..... ::) Let's leave it be.

Dave
 
Well that is why I jumped over to the Break Room, where we could just blog about stuff, and not get too far off topic.

But we are in the Break Room, and this is where we all kick back and have all sorts of converstations, share and learn.

I learn something everytime I post, so I enjoy posting.

And as a matter of fact, I actually enjoy the posts were everyone does not agree, because then it makes me dig around and learn and study, and find out more about the topic.

Manfred's posts are a perfect example of spawning lots of thoughts and learning, and I am enjoying them very much, as well as the posts that are just somewhat related.

But we are in the Break Room, so I say lets blog and chat, and have fun.

That is what the Break Room is for.

Pat J
 
Sorry Dave,
Engineering is like oxygen to some of us.

The mention of John Bedini did lead me to a partial list of perpetual motion patents that have been granted through the years. It seams like patent lawyers should take a few engineering courses. http://www.lhup.edu/~dsimanek/museum/patents.htm

Dan
 
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