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#127038 - 03/30/01 06:28 AM Current Flow Discussion [finally!]  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Hi all!!

I have finally compiled a message that covers current flows, which is not too extreme.
I have decided to limit everything to a general area, whereas before I wanted to include a multitude of related stuff. This resulted in several separate messages that were each very long!!
Therefore, I have come up with the following message. Sure hope it is cool!!

Let me know what you think!!

Sorry to disappoint everyone - it just became apparent that if I posted the message the way I was planning at first, it would have been so difficult to follow, no one would have gained anything from it.

Good Luck!! I am sure that you will enjoy it anyway!!


Current Flows-
An in-depth look at the simple basics which result from complex methods.

We shall look at the actual flows of current in a common circuit, and relate to the flow of Electrons primarily, rather than discuss both flows of charges, in order to keep things simple. Just remember to the flow of Electrons in one direction, there will be a corresponding flow of Positive Charges in the opposite direction.
This is due to the Positive Charge created on an Atom when an Electron in the outer shell [valence] is lossed, due to it being transferred to another Atom. The result is the Atom that gave up the Electron becomes Positive, and the Atom that received the Electron becomes Negative.

There will be a heavy reliance to commonly used concepts in Electrophysics - like Capacitance, Voltage, Etc. - so a firm understanding of them will benefit greatly.

Now, on to the flow theory!

Many things happen prior to a current flow in a simple circuit, which are done regardless to if the currents are AC or DC, if the circuit is open or closed, or if there's a physical connection or not. These primary functions must occur in order to get a current to flow from a supply to a load.

In the example of a simple closed circuit, comprising of a battery power supply, a fixed Resistor for the load, and metallic insulated conductors which connect all the elements together, we will discuss the full events.

When the circuit becomes closed, the first thing that happens is the power supply needs to "pump" the conductors and the load with charges. This is accomplished by a level of charge in the conductors themselves, in the load and on external portions of the circuit and load.

First off, a column of Electrons flows out of the power supply from the Negative side, through the central part of the conductors and the load. Once the Electrons have returned back to the supply [at the Positive side], they allow the supply to build up a pressure on them. This pressure causes these Electrons to be pushed away from the center of the conductors, and towards the outer circumferences of the conductors.
When they get pushed away, the original column in the center gets re-established until they can once again make the supply create a pressure on them. This continues until the entire conductor becomes "Pumped full of Electrons", which is the first step necessary to having currents flow.

Next steps include external charging [AKA Line Charging, or Permittance and Admittance].

Since there's some level of potential differences between the circuit's conductors, the + and - polarity of the supply, and over different areas in series across the complete paths, there will be a resulting flow of charges external to the circuit.
Primarily, the parallel charge paths are forms of simple Capacitance, but there is a level of Conductance that exists.
The separation of conductors at different potentials, via a Dielectric [the conductors' insulation and the air between the wires], creates a level of Capacitance. The semiconductive properties of the Dielectrics also create a certain ability to flow, resulting in a Resistance Value between the conductors.
These flows will exhibit the same characteristics as any other flow - each flow will have an Inductance created from the flow of current [the magnetic fields produced by flowing currents].

Since these external circuits exist, they need to be "Charged" in the same fashion as the conductors' them selves do. Since they are directly connected to the circuits, they will need to be charged to the level of the circuit before any currents can flow.

The same applies to series charging as would to the parallel charging. The entire circuit will need to be charged to the level of the supply and to fill the conductors plus other paths, at the same level, before currents will flow in the known fashion of "Electrical Currents".

The conductors will exhibit a series Capacitance that causes the supply to charge the conductors to a specific level. Electrons are pushed towards the outer portions of the conductor due to internal Capacitance, but mostly from the supplies' pressure pushing electrons against impurities in the conductor.

When the entire circuit is charged enough, a current will begin to flow. As this flows, the circuit will re-charge all points to the levels according to the overall changes in the complete circuit, until the levels become stable. Any changes in flow levels or pressure [voltage] causes an overall circuit charge change.

The currents flowing in the conductors will find the most effective paths for high concentrations to flow in the outermost layers of the conductors, so the higher levels will flow easier in the outer layers of the conductors, but the charge levels remain somewhat stable in the central points.
The supply continues to deliver charges under pressure to the central points of the conductors, where they are forced to the outermost layers by factors like the resistance from impurities, skin effect and such. If not for the difficulty for charges to flow in the center of the conductors, they would not be subjected to concentrations in the outermost layers.
In addition, when they flow in the outermost layers, they have more trouble when they encounter impurities in the conductors. When the charges have to give up some power to these impurities, they create heat in the conductors - which results in the structures becoming more distant from each other. This all results in the charge flows not being in uniform straight line fashion. Rather, they bounce around within the conductor and have to take longer and different paths, in order to get around the obstructions.
This causes the effective conductive area to be lowered. In addition, since the furthermost layer has the lowest energy level, the impurities can easily accumulate there.

Now, when the flows go through the load Resistor, they tend to do the opposite as they did in the conductors.
In this case, it is easier for them to occupy as little space as possible, so the concentration of flows is through the central parts of the load, with minimal flows happening on the outermost layers.

When the charges flow through the load, they lose nearly all their potential energy - the combination of the level of charges flowing and the pressures pushing them through the load - to the load it's self. The energy is transferred to the load via conduction, convection and some levels of radiation.

Free Electrons in the load elements can, and do, get dislodged from the element and placed into the charge flow stream. Under normal circumstances, the resulting Positive Charge allows another free electron to take its place.

Some level of energy transfer will be external to the load device, so it will cause the load device itself to lose mass over time.

To sum things up;
We have many separate paths for charges to flow inside and external to any circuit. If a difference in potential exists, then a current will flow. Before a current can flow, the entire circuit must be charged to a certain level. After currents flow, the entire circuitry will be naturally recharged to the value at that instance - so all circuits will be constantly re-charging them selves.
Since there's a parallel circuitry connected to any circuit, there is a loss of energy to it. When we change the directions of flows in rapid sequences [use AC], they are constantly undergoing change. When the frequency becomes, or exceeds 10,000 Hz, the charges will easily leave the conductor and radiate outward in much higher concentration levels than before. This is Radio Frequency Emissions.

The conductors' themselves cannot keep the flow concentrations themselves contained exclusively in the centers of the conductors, due to inherent losses and other mechanisms.
If it was possible to remove that problem - resulting in the charges flowing in a single central column through the conductors and the load, we could [in theory] just get the flows moving, then they would naturally continue to move on their own until something changed. This is the theory of Superconduction.
Dynamic [Kinetic] Inertia causes an object to remain in motion until acted upon by another object. When that occurs, the results will equal the total energy delivered to both objects.
Static Inertia causes a body at rest to remain at rest until acted upon by another force, whereas dynamic Inertia [the opposite], causes a body in motion to remain in motion until acted upon by another force.

If the charges could flow inside the complete circuitry and the power supply without being subjected to some oppositions, the Dynamic Inertia on the flows would make them continue to flow continuously after they get moving at a certain energy level, which doesn't require a continuously supplied energy source.
We are not creating energy from thin air, nor are we destroying it - just observing it's basic concepts.

When the required energy level increases, temporary energy input is required, until once again the flows are set to a steady energy level.

To stop the energy flows, the flows of charges will need to be submitted to an element that resembles commonly used circuitry.

This is similar to taking a Bowling Ball into outer space and throwing it. The Ball will never stop moving until it hits a planet, moon, comet, black hole, asteroid or such. If it never does, it will never stop moving - ever!! When and if it hits something, it will transfer its energy to that body.

I wanted to really go in-depth here, but that would have been bad. This message is the results of pruning and editing of the original messages!!

A very basic look at the Atoms used for current flow would be:
Free Electrons are electrons in the outer layers, or shells, of an element. Metals usually have free electrons, whereas gases have some type of equality.
An abundance of electrons means that there are more electrons than the total size of the Kernel [Nucleus]. If the Kernel has 25 Protons and Neutrons, and there's 25 Electrons combined in the shells, the element is balanced - or is said to have no free electrons [this doesn't mean the electrons on the outer shells can't be moved, though!!].
If there's 25 Protons and Neutrons in the Kernel, and 26 Electrons in the shells, there is a free electron.
Moving an electron out of a shell results in a Positive Charge being placed on that element [Atom].
Electrons in the outermost shells are at a lower power level than the ones closest to the Kernel, so it does not require too much energy to move electrons that exist in the outermost layer of multiple layered elements.

Electrons will be attracted to Positive charges, so when an atom becomes positively charged, the natural thing for an electron to do is to "Fall Into The Hole" created by the Positive Charge. In this fashion, one could see how charges transfer in two directions at one time during conduction. The - charges migrate towards the + potentials, and the + charges migrate towards the - potentials.

Pressures are built up when a certain level of charges are restricted by a load's resistance [in this case, the term resistance will mean any opposition to flows of charges]. At the load[s], the power supply will need to push the charges through there, by building up a level of pressure. The two levels result in an energy transferred to the load.

Sure hope everyone has enjoyed this message!!

Feel free to ask more questions, or elaborate a little more on certain areas of this message.

Scott SET


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

Tools for Electricians:

#127039 - 03/30/01 08:13 AM Re: Current Flow Discussion [finally!]  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,306
Thanks Scott!
this isn't so deep as to have me at a total loss.
one Q..
All these atoms loose their electrons right?, the electrons go and do their thing...
What kind of atoms do these electrons originate from?? Do the escaped electrons seek similar atoms with opposite charges ? Or are these free electrons less discriminate.
Would these all be lead atoms in my car battery???

[Linked Image]


#127040 - 03/30/01 09:27 AM Re: Current Flow Discussion [finally!]  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Hey Steve,
Glad to see that the message was understandable - you should have seen what it was built from [Linked Image]

Simply, Electrons will "Jump" into any "Hole" available. If there's a Positive Charge available, an Electron will naturally jump into it. This is not limited to exact elements - it occurs in any element or compound.

If this wasn't true, there would be no way to create new compounds [Molecules], or even complex elements [Atoms].
No Chemical reactions would occur, nor would simple things like Static Electricity or even Lightning be able to function.

Hope this clears everything up!!

Scott SET


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

#127041 - 03/30/01 01:25 PM Re: Current Flow Discussion [finally!]  
sparky66wv  Offline
Member
Joined: Nov 2000
Posts: 2,236
West Virginia
Ever consider writing a book?

Electrical Theory for Dummies

[Linked Image]

How come the UBB underline didn't work?

[This message has been edited by sparky66wv (edited 03-30-2001).]


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

#127042 - 03/31/01 02:28 AM Re: Current Flow Discussion [finally!]  
old Appy  Offline
Member
Joined: Mar 2001
Posts: 118
Auckland, New Zealand
that was great!
thanks Scott, I'd buy the book!!!!


#127043 - 03/31/01 09:05 AM Re: Current Flow Discussion [finally!]  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,878
NY, USA
Haven't had a chance to get through the Current flow explanation yet. Just wanted to mention to sparky66wv that Underline does not seem to be supported under UBB code as yet.

FYI for all: Sparky66wv is referring to the special formatting codes that this forum recognizes. It allows things like live email links, quotes and pictures to be shown in messages. If anyone does decide to try including a picture, please watch the size. A large picture (dimension) can really stretch out things and a large File size can really slow things down for those with slower modem connections.
https://www.electrical-contractor.net/ubb/ubbcode.html

Bill


#127044 - 03/31/01 08:34 PM Re: Current Flow Discussion [finally!]  
sparky66wv  Offline
Member
Joined: Nov 2000
Posts: 2,236
West Virginia
I found UBB codes here and thought would work since it's listed.
http://www.nintendigital.com/forums/ubbhtml/ubbcode.html


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

#127045 - 03/31/01 08:54 PM Re: Current Flow Discussion [finally!]  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,878
NY, USA
Hmm,

I don't know why? It's not listed on our page?? I see colors there too. There are many addons and modifications We could do here, but prefer to keep it simple. There is an upgrade that's out that We might try sometime. Maybe that will have underline.

Bill



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