In a circuit does the current remain unchanged? ie how is i possible to remove an electron or loose one. Does that mean the current entering a circuit is equal to the current leaving a circuit.
I can understand how the Voltage or EMF can lower due to resistance. But am a little confused about the relationship current and voltage loss

http://www.sciencejoywagon.com/physicszone/lesson/07electr/kirchoff/index.html



Appy, these are just basics, poke around here and find some of Scott's responses...

Sparky,

Good Stuff!


Bill

Old Appy,

I'm a little unclear on that also. I'm wondering where the Energy comes from that is released as Heat or Light etc. as current passes through it. It seems like something should be depleted somewhere. I don't think electrons get 'lost' but they may give up their energy and stop flowing. Or, what I'm thinking is that some of them may pass their energy, say to electrons in a Lightbulb filament which in turn give off Light and Heat.

Less Electrons flowing means lower voltage. (I = E/R) So in the case of a set amount of pressure (voltage) as in a Battery, Current and Voltage will eventually drop off.

Anyone, Does this seem right?

Be kind....

Bill

well....i've read Scott's responses in the thread below
" an anology of electrical power transfer" a number of times.

i'm starting to realize that a lot of our trade is somewhat programed, spoon fed, or simply given the ten cent tour of theory.

i suppose we need not major in the physics of electricty to do our trade, but it certainly evokes more thought to have a grasp on such things during any given installation.

i can only answer a Q with a Q here.

if energy can't be destroyed, and a light fixtures byproduct is heat, would the tranfer to heat be "loosing" electrons?

Does a more efficent light give more electrons to light that to heat?



If we hook up a mile of wire to your battery, we will see a difference at either end, all due to R factor?

Sparky,

I'm out on a limb with a chainsaw here!
Keep in mind this is in 'Bills' World' and may prove no resemblance to things in the real world.

Once upon a time...

I would say that what you are losing is Free electrons from your flow. Those are the ones that have the energy to jump from atom to atom as part of your current flow. They're either giving up their 'juice' to the atoms in the filament or decide to leave your group and join the 'Resistance' (I didn't plan that it just happened )

So these Electrons in the Filament are stirring things up and the result of the increased activity is Heat. The amount of light emitted and its' color depend on the temperature of the Filament.

What do you think?

Bill

well my volt-tic's gotta be catchin' something so i guess i'd go along with that.

filament temp, or heat vs. visible spectrum is interesting, we do use that K # system, it might be kelvin....

so i guess i'm on the limb with ya Bill, i got a feelin' an EE's gonna crank up the chipper machine though...

Sparky,

That's right, Color temperature is measured in degrees Kelvin, (Black Body Temperature I think it's called)

I'm waitin for the Chipper...


Bill

Althought Kirchhoffs Current Law states "Electrical charge is neither created nor destroyed in ordinary circuit operation..."
This i take too mean Electrons Flow ?

The energy to move the electrons is transfered. The electrons moving are just a transfer of that energy.

Imagine if you will, you could move a magnet with your hand and arm across a coil of wire to generate voltage and current flow. The energy comes from the food you ate to make your hand and arm move not the electrons of the conductor.

Or, you are in bumper to bumper traffic(literally) and the last car rams into the car in front of it. The gas being burned made the car move and cause one car after another to "move". The movement of the first car in line will equal the energy of the gas being burned. Even if the brakes are on (resistance) the heat produced by brake pads etc. will be an equal transfer of power. Power is not created or destroyed.

I think this is a simplistic explanation but gets the point across about electrons being "lost"

Well, I can explain this stuff if you guys want me to, but it's gonna be some extreme "Twilight Zone" stuff

There's a message I posted in the Theory Section, which can briefly explain the fundamentals behind energy transfer [power transfer]. Look for a message called "Power Transmission Analogy" or something like that.

To be honest, almost all charges leaving the power supply return back in the closed circuit and normal flow. However, the detailed physics of how electrical circuits function requires "Conductor Charging", plus allows multiple branched circuits, so not every charge "Pumped" into the conductor gets "Pushed" through the load, then back to the power supply.
To complicate things even more, throw in Quantum Physics and the Theory of Light [Electro-Magnetic Radiation]. This would have Photons being produced from the load, either in the form of heat [infrared light], or in visible white light, which would require the loss / atraction of some mass for the Photons to be generated.
That loss would be primarily in the load element it's self, but would also apply to normal conductors - especially using AC, as they would produce Electro-Magnetic Radiation, in the form of extremely low frequency waves, which will be "Thrown" away from the conductors.
At, or around 10,000 Hz, the volume of stuff leaving the conductors becomes real excessive - thus the conductor produces Radio Frequency [the dreaded source of RFI!!].

If you guys want me to write up something about this baloney, let me know. I will have to make the message long, as usual, in order to explain things fully - however I will not go beyond the limits of Practical Electrophysics [stay in the basics of the theory for Electrical Circuitry only - no Quantum stuff, no major physics either].

Having a firm understanding of Atomic structures is needed, in order to grasp this stuff. Understanding the consepts of energy is also needed [should go hand in hand with the Atomic Structures knowledge]. If you have any books that describe Semiconductor principles, these would be the best way to visualize the flows, as this theory is a great aid for basic circuit flows.

If you do want this message [may be clear that you have Nerd-Like tendecies ], then I'll type one out in a word processor, then Copy/Paste it to the Theory section.

A quick note to the original Q is that nearly all charges flow out from the power supply, then through the load - where the energy induced into the electrical circuitry is transduced into another form of energy, then the charges return to the power supply.
While Electrons - or Charge Carriers - are flowing from the polarity with the higher negative potential towards the polarity with the higher Positive Potential [or a lower Negative Potential], there is an equal, but opposite flow of Positive Charges from the polarity with the higher Positive Potential, to the polarity with the higher Negative potential [or lower Positive potential]. Each flows through the circuit and the load.
Picture this first, then apply it to the charge transfer breakdowns that will be explained later.

With a fixed Resistance value, Lower pressures [voltages, or Electro-Motive Forces "EMF"] will push fewer charges through that load, with a resulting lower power transfered.
Example, if a fixed Resistor has a value of 100 ohms, and a power supply that has a voltage of 100 volts was applied to it, the level of current that can be pushed through that resistor at 100 volts would be 1.0 Amps, with a power dissipated [and required to be put into the power supply] of 100 watts.
If this same resistor, with the value of 100 ohms resistance, was connected to a power supply that has a voltage of 200 volts, the level of current that can now be pushed through the resistor is 2.0 Amps, with a power dissipated [and required to be put into the power supply] of 400 watts.
Linear loads respond to the amount of power that the supply is delivering to the load, so the same resistor varies drammatically according to the voltage present.
In a round about way, the energy transfered to the load is a result of X amount of charges pushed through it at X level of pressure.

If you can grasp this bunch of baloney, then you will easily understand the extreme geek stuff that I will post later [if you guys really want it ]

As far as the Color Temerature thing, that would need to be a separate message - it doesn't relate to the current flow at all.
This relates to what has been determined to fall into a temperature, using the Kelvin Scale, that responds to a level of color in the combined white light spectrum.
A certain Fundamental Frequency of light will have a color temperature of X degrees Kelvin. Mixed tones [like "pink noise" in sound] will have a fundamental which is distorted by lower and upper tones - very similar to harmonic distortion. This new "semitone" of light will have a K temp that corresponds to it's fundamental Hz, along with the distortions from the "Side Bands".

As with any other Electro-Magnetic Radiation, Visible white light [plus the seven basic fundamental colors it's comprised of] have Resonant Frequencies.
Applying these to a "Black Body" determins their Color Temperature [I think it works that way Let me double check that].
The Color Temp will also coorespond in the power dissipated according to the wave length.
With EMR above Infrared, it's easier to figure wave length [Angstroms], rather than frequency.

I can add another message on this stuff to the Theory area if you guys want. Let me know.

I do want to point out that you guys have a very good understanding of this stuff, as I have seen in this thread.
It's something that will never be applied to day to day trade related installations, plus is never even applied to Electrical Engineering designs of projects [a small exception exists, though].
Nevertheless, it's great to see such an interest from you guys in this area. It is something nice to know, just so the stuff you install is not so "mysterious".

Scott SET

I just had to write another message to tell you guys how impressive it is to see the messages in this thread that point to a load's heat output characteristics!!
Relizing this simple, yet complex key point is the step away from basic theory to advanced areas!!

Very cool!!

This is the reason that Incandescent lamps will eventually fail - no matter if they claim to "run forever".
Also applies to discharge lighting, and many other things.
The load device discharges energy in the form of moving matter [E=MC2], so the load device will lose matter over time.

Steve [Sparky] has taken this a step higher with the efficency of lighting, as to the heat generated.
The majority of energy used in the creation of visible white light in an Incandescent Lamp is plain old heat - Infrared Light and just plain old heat energy. A very small amount is actually converted into usable and visible white light.

Discharge lighting has a higher transfer to visible light in the white light spectrum, which makes it more efficient per input watt to output lumens in the visible spectrum.

With this in mind, apply it to what happens to conductors when there is a large voltage drop in them. This also becomes an energy transfer issue!

To sum it up, the electrical power is knocking free electrons out of the load element [kind of ]. This is a simple way to view it.

The closest one can come to producing an output level of light, without a rapid deterioration of the load device it's self, would be the LED.
Most of the light produced from an Electron falling into a hole after passing the PN junction, is just simply the release of the energy required to get the electron across the PN junction. Very little Semiconductor matter is dislodged during this joining of charge to hole [hole being the Positive Charge]. Eventually, there will be enough matter dislodged from the junctions of the diode, so it will also fail.

FYI: Due to this type of energy transfer / discharge, all Semiconductor devices produce light. Mostly in the form of heat and HF radio waves.

Scott SET

P.S.: Who is "The Chipper" ?? or whom would "The Chipper" be run from??

Sure hope it's not me!
Chippers are, and should only, be used on me, not by me.

Scott,

So, what are you saying happens to the Electrons?

For simplicity, consider a simple circuit with a Battery at full charge a switch and a Light Bulb, circuit conductors having negligible resistance.

The switch is closed and current begins to flow. What happens next? Generally speaking, what happens to the values and amounts of voltage and current flow over time and why?

Does any part of 'Bills' World' above resemble the facts?

Bill

Bill,
I'll go ahead and type up the document that covers this stuff, then paste it to this discussion area.
I'll call it something like "Electrical Charge Flows" or such.
This would be the best way for me to fully explain [if I have the ability], all the stuff involved.

Sure hope it will be of help and interest to all.

Scott SET

Scott,

Go for it!

Give it your best shot. Hey, you're bringing back some old memories there with your mention of Holes! I'm gonna sleep tonight dreaming of Semiconductor Theory, and it's NPNs' and PNPs' ... probably learned from some old Radio Shack Books. I can almost see the diagrams.

Bill

Scott;
Do please , expand on these items. We were hoping to lure you in, sorry about the chipper crack, not meant to offend!

Yeppers i'd like to see that

Hi all,

I have been compiling that discussion message over the weekend, but the thing is - it's turning out to be so darn huge, it makes my other messages look like leafletts

Let me go through it and prune the contents, then I'll be glad to post it. Look for topic:
Current Flow Analogy.

To assist in the basic theory stuff related to the in-depth current flow principles, I'll post another message that contains this, prior to posting the current flow message. Look for topic:
Flow analogy-Basics.

This thread of discussions should be of great interest to everyone. Not only that, it would help explain some points, such as how Volt-Tick testers can work, what happens to all the current flowing in circuits and loads, effects of voltage drops in conductors, how the total current flows in and around circuits, line charging, capacitive coupling, inductive coupling, EMI/RFI, Arcing faults, Superconductivity, on and on and on.

I'm sure that after reading this message, you will have a different look at Electrical Circuits

Please pardon the "lag" in time on my part.
Just want to get these items compiled into the most concise message[s] as possible.
Might take a few more days to do this

Scott SET