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#171288 - 11/24/07 10:56 AM Alternating current Fundementals Sixth Edition  
Angel_Electric  Offline
Member
Joined: Jun 2007
Posts: 20
Fl.
I'm currently reading this book.I would like to discuss some of the theory and its applications with our trade, so if perhaps anyone can identify some of the materials and share its use within our trade ,I would greatly appreciate the consult.


Tools for Electricians:

#171290 - 11/24/07 12:02 PM Re: Alternating current Fundementals Sixth Edition [Re: Angel_Electric]  
Angel_Electric  Offline
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Joined: Jun 2007
Posts: 20
Fl.
Perhaps someone might know of a similar reference, I could use as a checks and balances source.


#171293 - 11/24/07 01:23 PM Re: Alternating current Fundementals Sixth Edition [Re: Angel_Electric]  
renosteinke  Offline
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Joined: Jan 2005
Posts: 5,316
Blue Collar Country
While I do not know the specific book you reference, I can make two general notes:

1) It's basic science. As such, the 'facts' can't change, just the presentation; and,

2) It's simply not possible to completely understand alternating current unless you already understand calculus. The expression 'dx/dy' better mean something to you. This becomes critical, especially in understanding such things as impedance, harmonics, and power factor.

For 99% of the time, the simpler models used by electricians, based upon algebra, are adequate.

The fact remains that electricity, much like light, is still not completely explained by any existing model. We do know enough, though, to leave those puzzles to the ivory tower crowd.


#171295 - 11/24/07 01:27 PM Re: Alternating current Fundementals Sixth Edition [Re: renosteinke]  
SP4RX  Offline
Member
Joined: Oct 2007
Posts: 56
Edmonton, Alberta, Canada...eh
Google is your friend.

You could probably learn most, if not all, of what you're interested in by reading online. You'll need to break out the scientific calculator if you really want to understand the material though.


#171314 - 11/25/07 04:03 AM Re: Alternating current Fundementals Sixth Edition [Re: SP4RX]  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,708
Anaheim, CA. USA
Angel_Electric

Glad to hear that you wish to expand your knowledge base! Good for you, even better to come here (ECN) with queries.

As "renosteinke " says, AC is basic science, but very complex; plus the formulas for basic figures are performed via Algebra & Calculus.

Here is an easy example - showing the same Series RL Circuit's total value (opposition) for both DC and AC supplies:

***** DC Supply *****:

3 Ohm Inductor in series with a 4 Ohm Resistor.

Circuit = 7 Ohms Resistance

3 Ohm + 4 Ohm = 7 Ohms - total opposition to the DC Current Flow.

Connect this Circuit to a DC Source with a Potential Difference of 7 Volts, and the result is 1 Ampere flowing through the Circuit.

***** AC Supply *****:


3 Ohm Inductor ("X") in series with a 4 Ohm Resistor ("Y").

Circuit = 5 Ohms Impedance ("Z").

Formula uses the Pythagorean Theorem (Right Triangle Formula), as follows:
(Substitute "X" with "A", "Y" with "B", and "Z" with "C")

C = sq. root of A + B
or:
C² = A² + B²

Looks like this:

3² = 9
4² = 16
9 + 16 = 25
Square Root of 25 = 5
So, "C" = 5, which is the total opposition to the Alternating Current - expressed in "Z", for Impedance.

Connect this Circuit to an AC Supply with a Potential Difference of 5 Volts across the output terminals, and 1 Ampere will flow through the Circuit.

These values would be the "RMS" values. There are "Average" and "Peak" values coexisting in this example.

Along with these basic figures, there are several others to deal with:

1: True Power - in Wattage - VS "Apparent Power - in Volt Amps.
In the DC example, the "True Power" (Wattage) drawn from the Generating Source, may be found simply by multiplying the Voltage (E) and Amperage (I).
The Wattage (P) would be 7 Watts drawn from the supply.

In the AC example, the E x I = Volt Amps (VA).
Within the "Volt Amps Package" is:
* True Power (Wattage), or "P"
and
* Reactive Power (Volt amps Reactive), or "VAR"

Depending on the "Power Factor" of the Circuit - in this case, it's mostly dependent on the Power Factor of the Inductor, the Circuit may draw from 1 Watt to 5 Watts.

Consequentially, the VARs may be from 1 to 5 VARs.

This is also found with the Right Triangle formula, as follows:
(I will be using very simple + basic values here again - the numbers "3", "4" and "5" - as these do not result in any decimals remaining)...

Figure the Circuit has 3 VARs + 4 Watts, equaling 5 VA.
This is an 80% (0.8) Power factor.

As you can see, there are quite a few calculations involved with just a basic example circuit's value.

Nevertheless, do not be discouraged by this, and keep up the quest to broaden your knowledge base.

Try searching the Web, and this site, for assistance.

Not sure of any specific Text Books to suggest, - try your local Library's reference section out. check out 3 books covering the same "areas" each time, then when you return those, find 3 more which are a bit more advanced.

Soon you will see that there is a HUUUUGGGGEEE complex world behind the theories of AC; one which may keep you on a never ending quest.

Good luck, and let us all know when you see the "relationship" between AC and Light!!! This will come in time, around the time when "Charges Fall Into Holes"
wink
Scott


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#171315 - 11/25/07 04:12 AM Re: Alternating current Fundementals Sixth Edition [Re: Scott35]  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,708
Anaheim, CA. USA
It looks like we all forgot to ask Angel Electric a simple question:

Would You Like To Begin With An Example To Discuss?

Toss something out for us all to discuss.
May be simple, may be complex.

Let's get some dialog going here!!! smile

If you are unsure, we could elaborate on the above examples.

Pick something from the Manual you have quoted, and let's discuss it.

p.s. How well written is this manual?

Scott


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#171527 - 11/30/07 01:39 AM Re: Alternating current Fundementals Sixth Edition [Re: Scott35]  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,708
Anaheim, CA. USA
Just bumping this topic up again.

Angel, have you reviewed this thread yet?

Scott


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!


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