How is AC electricity made?? I may need BruceB for this one.

[dvandsm64]

Re: How is AC electricity made?? I may need BruceB for this one.

AC is preferred when you want an easy way to step the voltage up and down. This is great when you want to transmit it at high voltage to reduce current and losses then step it down to less dangerous levels for distribution into the home.

However, when you are talking about moving huge amounts of power long distance they use DC. The main power grids in the US and other countries use DC to move the power long distances then convert back to AC for local distribution.
http://en.wikipedia.org/wiki/Electric_power_transmission

???????


don't know where you heard d.c. is ever used for long distance transmission. a.c is what does all our power lines. if d.c were used we would have huge buss bars running along our steets!

 

[1fishbone]

Re: How is AC electricity made?? I may need BruceB for this one.

Okay,
I have taken many courses in electricity from high school to college level, and there is always 1 question I can never find an answer for that satisfies me.
How is AC electricity made?

First let me say that I am comfortabe with DC electricity. I understand chemical reactions. I know about annodes and cathodes. I get free electrons.

However, E is still E, wether it is AC or DC (unless I am missing something) and E is electromotive force. Or, more simply, the flow of electrons.

In DC electricity, I see how electrons are produced. I have done the chemical reaction formulas in school. It all makes sense to me, and I have no quesitons about it.

But what about AC electricity? I know to generate electricity that you need a coil of wire around an iron core, and a magnet to sweep that core in close proximity to it.
But how does it actually all work? Is E in AC still the flow of electrons? I am assuming it is. Where to the electrons come from? Matter can not be created or destroyed, only changed, so what matter is it, and how to the electons form?
It is not chemical, so what specifically happens when a magnet sweeps that iron core? Can anybody here break down what the process is for me?

If anybody answers this... be warned.. I am going to ask about microwave next

I think you should return the money for your education

 

[mscher]

Re: How is AC electricity made?? I may need BruceB for this one.

???????


don't know where you heard d.c. is ever used for long distance transmission. a.c is what does all our power lines. if d.c were used we would have huge buss bars running along our steets!

It looks like it's use is somewhat common, just not in the U.S.

http://en.wikipedia.org/wiki/High-voltage_direct_current

Not sure why one would need to use a buss bar, verses a copper or AL wire. Either would get the job done.

 

[mscher]

Re: How is AC electricity made?? I may need BruceB for this one.

Good catch, 1fishbone.

 

[bruceb58]

Re: How is AC electricity made?? I may need BruceB for this one.

It looks like it's use is somewhat common, just not in the U.S.

http://en.wikipedia.org/wiki/High-voltage_direct_current

They showed a picture of power lines in North Dakota that they state are HVDC in that link.

I too had never heard of it being used but makes sense when you have grids that are not in phase with each other.

 

[jlinder]

Re: How is AC electricity made?? I may need BruceB for this one.

???????


don't know where you heard d.c. is ever used for long distance transmission. a.c is what does all our power lines. if d.c were used we would have huge buss bars running along our steets!

Please take a look at the link. You will see the documentation that while AC is used to get from the regional grids to the home, but HVDC is used to interconnect the regional grids.

You can also google HVDC to find other references.

 

[j_martin]

Re: How is AC electricity made?? I may need BruceB for this one.

???????


don't know where you heard d.c. is ever used for long distance transmission. a.c is what does all our power lines. if d.c were used we would have huge buss bars running along our steets!

It's expensive to convert high voltage DC to AC, but modern silicon electronics has made it feasible. I don't know if any have been built yet, but ultra high voltage DC transmission lines have been proposed for about 15 years or so.

They would have the advantage of much less magnetic loss because the magnetic field about the conductors would not be moving all the time like it is with an AC conductor. In a long line, the difference in power loss would be significant.

(edit) Actually, High Voltage DC transmission has been in use for years. It's about the only way to get much power through a long coaxial power line underground or undersea. The first ones used Mercury switch valves (tubes) and modern setups use silicon thyristors. There are a number of these DC transmission lines in service.

http://en.wikipedia.org/wiki/High-voltage_direct_current

 

[dvandsm64]

Re: How is AC electricity made?? I may need BruceB for this one.

It's expensive to convert high voltage DC to AC, but modern silicon electronics has made it feasible. I don't know if any have been built yet, but ultra high voltage DC transmission lines have been proposed for about 15 years or so.

They would have the advantage of much less magnetic loss because the magnetic field about the conductors would not be moving all the time like it is with an AC conductor. In a long line, the difference in power loss would be significant.

(edit) Actually, High Voltage DC transmission has been in use for years. It's about the only way to get much power through a long coaxial power line underground or undersea. The first ones used Mercury switch valves (tubes) and modern setups use silicon thyristors. There are a number of these DC transmission lines in service.

http://en.wikipedia.org/wiki/High-voltage_direct_current

sorry, i stand corrected.

 

[mike343]

Re: How is AC electricity made?? I may need BruceB for this one.

Okay,
I have taken many courses in electricity from high school to college level, and there is always 1 question I can never find an answer for that satisfies me.
How is AC electricity made?

First let me say that I am comfortabe with DC electricity. I understand chemical reactions. I know about annodes and cathodes. I get free electrons.

However, E is still E, wether it is AC or DC (unless I am missing something) and E is electromotive force. Or, more simply, the flow of electrons.

In DC electricity, I see how electrons are produced. I have done the chemical reaction formulas in school. It all makes sense to me, and I have no quesitons about it.

But what about AC electricity? I know to generate electricity that you need a coil of wire around an iron core, and a magnet to sweep that core in close proximity to it.
But how does it actually all work? Is E in AC still the flow of electrons? I am assuming it is. Where to the electrons come from? Matter can not be created or destroyed, only changed, so what matter is it, and how to the electons form?
It is not chemical, so what specifically happens when a magnet sweeps that iron core? Can anybody here break down what the process is for me?

If anybody answers this... be warned.. I am going to ask about microwave next

Your claim to have taken many electricity courses is suspect. Find one that does a.c. circuits and you will be educated.

 

[tx1961whaler]

Re: How is AC electricity made?? I may need BruceB for this one.

Your claim to have taken many electricity courses is suspect. Find one that does a.c. circuits and you will be educated.

A university AC circuits class will most likely NOT cover how the AC is generated, except in a very general overview.
That would be covered in electromagnetics and/or electromechanical devices class. Also if the particular university does not stress power generation and distribution, you may never see anything in detail about generation.
Let's put it this way: you can get a EE degree and still not know that black is hot and white is neutral in US house wiring, or how to wire a light switch.

 

[mscher]

Re: How is AC electricity made?? I may need BruceB for this one.

A university AC circuits class will most likely NOT cover how the AC is generated, except in a very general overview.
That would be covered in electromagnetics and/or electromechanical devices class. Also if the particular university does not stress power generation and distribution, you may never see anything in detail about generation.
Let's put it this way: you can get a EE degree and still not know that black is hot and white is neutral in US house wiring, or how to wire a light switch.

That's a shame, as knowing how it is generated, determines how/why everything else is configured.

It was covered in great detail, in my USAF basic electronics classes, which lasted about 3 months.

Without knowing the relationship between an electron and a "hole", electrical current flow is only "magic".