I was wondering if electrons can flow in opposite directions along the same wire, and it seems to me they can. See my schematic to further understand, If you make the center wire that connects both motors to each battery separate, and watch the motor speed of each motor separately, then reconnect them so that the middle wire is only a single wire such as in the schematic, you will notice no speed change either way in the motors showing each motor is only being powered by a single battery, and that the electrons are taking the path of least resistance . And that also shows in the middle wire on the schematic connecting to both motors we have opposite electron flow along the same wire at the same time!
Read this.
http://amasci.com/amateur/elecdir.html
Quote from: stevensrd1 on September 20, 2010, 08:23:46 PM
I was wondering if electrons can flow in opposite directions along the same wire, ...
Along the common wire there is no potential difference thus there is no current.
Remove this wire and you will understand what is going on: the current flows along the external circuit only.
If I remove the middle wire that goes up and down, in the center, there is a change in motor speed, a very noticeable change, thus showing that there is flow in the middle wire, the electron path follows the path drawn, if it did not follow the path drawn and if the middle wire going up and down where electrons flow in both directions had no flow, there would be no change in any motor speed if it was removed. It would be the same as if it did nothing. The electrons are taking the path of least resistance, as drawn,,and that shows that electrons can flow in opposite directions along the same wire at the same time.
Quote from: exnihiloest on September 21, 2010, 02:22:53 AM
Along the common wire there is no potential difference thus there is no current.
Remove this wire and you will understand what is going on: the current flows along the external circuit only.
There is no net current in the common wire, but it is a way for charges to find a quicker, less resistive path to the back end of a battery.
If you consider that each individual charge effectively traces its own electric circuit, you will find the circuit presented is really a summation of innumerable electrical circuits overlapping each other - as many circuits as there are electrons in there. If you treat it that way, each electron moving through that common wire certainly undergoes a voltage drop. Now not all the electrons will move through that common wire. After all, electrons can and do gain and lose energy by transferring energy between themselves, allowing a bit of them to go through the longer path that includes both motors (at the top of the diagram).
the common or middle wire is the path of least resistance,,electrons always take the path of least resistance, the shortest distance to ground, for each battery the path of least resistance is the middle or common wire. Its just what they teach when you learn about electronics and electron flow, is it not lol.
Try looking at it this way: it's a standard bipolar or dual power supply. The middle wire is GND or common. Many op-amp circuits require dual supplies, as does the power amplifier in your stereo.
This is not strange, it just may look that way. See the link below of a dual supply from the mains. It's the same thing essentially.
Dual supply diagram (http://www.dibsplace.com/design/CIRCATS/opamp-ps.pdf)
.99
Yes I see what you are saying, but this is different. I still think I am correct, its what is taught, unless what is taught is incorrect. It is taught electrons always take the path of least resistance, which for both batteries would be the center wire. There is electron flow there, if you remove it there is motor speed change, if the wire had no flow there would be no change in motor speed if it was removed. Each motor spins at the speed it would if it was a separate circuit with only one motor and one battery. Neither motor is spinning faster as it would if it was a separate circuit with one motor and two batteries in series powering it, as that would increase the speed of a motor. So this explains it all I think. I dont think what they teach is incorrect in this respect, and they do teach electron flow takes the path of least resistance, which is the middle wire for each battery, after going through a motor. Now if we remove the middle wire,,then and only then the electrons only have one path to follow,,that would be through both batteries, as that would then be the path of least resistance, and that would speed one motor up as it would then be powered by the two batteries in series.
Simplifiying the loads using resistors and redrawing the circuit can help understand what happens in two different scenarios. A current sense resistor (CSR1) of 0.01Ohm is added to probe actual current in the conductor in question.
The gnd_path_balanced.gif illustrates your circuit if both motors represent loads that are identical. Each load has 1A of electron flow. In this case the voltage probe will measure 0V and therefore no net electron flow in CSR1. This conductor can be removed with no effect to the current in each load.
The gnd_path_unbalanced.gif illustrates your circuit with one motor being half the resistance (double the load) than the other. In this case the voltage probe will measure about -77mV indicating a net electron flow of about 770mA. You should notice that the current through R2 is the sum of the currents through R1 and CSR1. This holds for all cases.
Familiarize yourself with Kirchoff's Current Law here:
http://www.facstaff.bucknell.edu/mastascu/elessonshtml/Basic/Basic4Ki.html
.99
So your saying the path of least resistance is incorrect? Then why do they teach it, why do they say it like its a law that electrons take the path of least resistance, Im not sure I understand why they would teach something that is incorrect, when its obvious in my schematic what is the path of least resistance, I still dont buy it, look at the next schematic I will post.
See if the wire showing electron flow in both directions was not there, as in we remove the wire from point A and point B then all three batteries combined as an external path is not enough power to run the led and the motor. However with the wire from A and B in place the motor runs at the speed that one battery would give it and the leds brightness is the brightness of two batteries. So to me it still seems we have electron flow going in both directions at the same time on the same wire, from point A and point B. Electrons always take the path of least resistance, its the taught law. And even if this is incorrect, if electrons take all paths, and not the path of least resistance, then we still have electron flow along the same wire at the same time, going in opposite directions, as all paths taken would mean this.
I will try to make this as simple as I can.
When you connect to the center of the two batteries, that junction becomes 0-Volts, AKA ground or earth, in respect to the other two poles, the far left pole becomes -1.5V and the far right +1.5V. You should also notice, if you have connected both motors correctly, that the two motors spin in different directions (I think but I may be wrong), this is because the polarity at one end is mirror image to the other. You should also notice that each motor is only receiving 1.5-Volts.
Disconnect the vertical center green wire, then both motors should spin in the same direction, this is because now the far right positive end is 3-Volts, in respect to the far left negative. With that wire disconnected, one motor will speed up if the other one is labored or stalled, very handy for a differential effect in a model car or robot.
That kind of circuit is simply a voltage splitter, very handy for reversible speed control circuits.
Thank you all very much,,I will certainly put forward some thought into this.
hm
Quote from: stevensrd1 on September 21, 2010, 05:46:38 AM
If I remove the middle wire that goes up and down, in the center, there is a change in motor speed, a very noticeable change,
...
Either your batteries or your motors are not perfectly identical or their rotation are not a synchronized. In this last case, there is probably an AC current in the common wire (check the current with an oscilloscope)
The electrons flow because they are submitted to a force F=q.E where E in the electric field in the wire. The direction of the force is the same for all electrons and all electrons are identical thus there is no crossed flux of electrons.
Quote from: Bulbz on September 21, 2010, 02:32:13 PM
I will try to make this as simple as I can.
When you connect to the center of the two batteries, that junction becomes 0-Volts, AKA ground or earth, in respect to the other two poles, the far left pole becomes -1.5V and the far right +1.5V. You should also notice, if you have connected both motors correctly, that the two motors spin in different directions (I think but I may be wrong), this is because the polarity at one end is mirror image to the other. You should also notice that each motor is only receiving 1.5-Volts.
Disconnect the vertical center green wire, then both motors should spin in the same direction, this is because now the far right positive end is 3-Volts, in respect to the far left negative. With that wire disconnected, one motor will speed up if the other one is labored or stalled, very handy for a differential effect in a model car or robot.
That kind of circuit is simply a voltage splitter, very handy for reversible speed control circuits.
How can you have current going out of the positive on one side and current out of the negative in the other? Batteries don't work like that.
What do you think would happen if you had two rectangular circuits, each with a motor and a battery operating, and
then decided to connect a little wire between the hot side of the first one and the cold side of the second one? Would one motor reverse direction? I think not. I understand that is not actually the same circuit, but you could take four plates of copper and arranged them like an H like you have in my example and some how build it so you could then rearrange them like H tilted over like in your diagram, then would the motor reverse? Never. Not in a million years.
The ability for the battery on the left to power that motor directly is largely dependent on the size of the conductor relative to your current. If you use very wide conductor plates, it would easy for the opposing currents to be split, but if they were so thin, then it would be more like attaching a meter across with high impedance, and you basically get nothing going through there. Somewhere in between those two situations you would have something like a ground that is 1.5V less than the rest of the circuit.
Your diagram below:
Quote from: poynt99 on September 21, 2010, 08:52:32 AM
... This is not strange, it just may look that way. See the link below of a dual supply from the mains. It's the same thing essentially.
Dual supply diagram (http://www.dibsplace.com/design/CIRCATS/opamp-ps.pdf)
.99
.99 may have a point. An astable multivibrator using a push-pull inverter can do the same thing as the diodes in the schematic.
http://upload.wikimedia.org/wikipedia/commons/3/39/Astable_multivibrator.png
--Lee
Quote from: kmarinas86 on September 22, 2010, 08:41:51 AM
How can you have current going out of the positive on one side and current out of the negative in the other? Batteries don't work like that.
I never said that, I said the junction where the batteries meet act as a ground. I think you misunderstood me.
Get yourself two batteries, and one motor, connect the two batteries in series and connect a wire to the point where the batteries meet (the center). Connect that wire to on side of the motor, then connect the other side of the motor to one of the open ends of the battery assembly. The motor will obviously spin and if you connect it to the other end of the battery assembly, it will spin the opposite direction.
I know that is right, I was taught it in college yonks ago. It is also the configuration that is used in a push-pull amplifier.
Quote from: Bulbz on September 22, 2010, 03:22:35 PM
I never said that, I said the junction where the batteries meet act as a ground. I think you misunderstood me.
Get yourself two batteries, and one motor, connect the two batteries in series and connect a wire to the point where the batteries meet (the center). Connect that wire to on side of the motor, then connect the other side of the motor to one of the open ends of the battery assembly. The motor will obviously spin and if you connect it to the other end of the battery assembly, it will spin the opposite direction.
I know that is right, I was taught it in college yonks ago. It is also the configuration that is used in a push-pull amplifier.
Where is the AC in the diagram?
With batteries, wires, and nothing else, those motors cannot be AC and be made to run properly.
For the motor on the left to run the opposite direction, you're asking the direct current from the other side of the battery to power the motor.
Your diagram:
Quote from: kmarinas86 on September 22, 2010, 06:36:27 PM
Where is the AC in the diagram?
With batteries, wires, and nothing else, those motors cannot be AC and be made to run properly.
For the motor on the left to run the opposite direction, you're asking the direct current from the other side of the battery to power the motor.
Your diagram:
AC ?, there is no AC and the motors aren't either. I was simply trying to describe as simply as I can that current doesn't run in both directions in the center wire. The circuit is simply a voltage divider !
[me]Bangs head against wall[/me]
assume both batteries are the same and both motors are the same.
there will be no voltage between the battery junction and the motor junction
the motors act as a voltage divider, the batteries are center tapped.
without voltage there can be no currant in the cross link.
no indication on the diagram of motor polarity so no way to say what direction they turn but the polarity of the applied voltage on the motors will not change with or without the cross link.
fritznien
I will simply quote what I said earlier:
Quote from: kmarinas86The ability for the battery on the left to power that motor directly is largely dependent on the size of the conductor relative to your current. If you use very wide conductor plates, it would easy for the opposing currents to be split, but if they were so thin, then it would be more like attaching a meter across with high impedance, and you basically get nothing going through there. Somewhere in between those two situations you would have something like a ground that is 1.5V less than the rest of the circuit.
Quote from: fritznien on September 22, 2010, 08:51:16 PMthe polarity of the applied voltage on the motors will not change with or without the cross link.
fritznien
Exactly.
Quote from: Bulbz on September 22, 2010, 08:30:16 PM
AC ?, there is no AC and the motors aren't either. I was simply trying to describe as simply as I can that current doesn't run in both directions in the center wire. The circuit is simply a voltage divider !
Not at all.
As the motors do not draw the same current at each moment of time during each turn, due to the switching connections and the variable coupling between coils and magnets, it is obvious that there is an AC current (with a frequency depending on the number of turns/s and on the number of coils, + harmonics).
Quote from: exnihiloest on September 23, 2010, 09:54:12 AM
Not at all.
As the motors do not draw the same current at each moment of time during each turn, due to the switching connections and the variable coupling between coils and magnets, it is obvious that there is an AC current (with a frequency depending on the number of turns/s and on the number of coils, + harmonics).
What if you swapped the motors for light bulbs, there shouldn't be any AC fluctuation and those bulbs will still light up.
Quote from: exnihiloest on September 23, 2010, 09:54:12 AM
Not at all.
As the motors do not draw the same current at each moment of time during each turn, due to the switching connections and the variable coupling between coils and magnets, it is obvious that there is an AC current (with a frequency depending on the number of turns/s and on the number of coils, + harmonics).
Yes this is true, however this is not the question of the topic. The question is not whether a current
can flow in the common (because I have shown that it can under certain conditions), but whether it
has to based on the notion that it
appears to be the path of least resistance.
The issue has very little to do with which path has the least resistance, and quite a lot to do with Kirchoff's current law, and mesh currents. The only thing that determines if there is current in the common lead is if the loads are unbalanced or balanced. With a perfectly balanced load, the common lead can be removed and the circuit will operate the same. There will be no potential at the common node where the loads connect, and therefore no current in the common leg.
.99
With high frequency ac the current can flow in two directions at the same time. It's a well known fact in some circles. I'm thinking a transmission line that is long (longer than 1/2 wave length) or if the frequency is very high (since I just read a book on it). In one part of the wire the current is going one way and in another part the current is going another.
What really puzzles me is when you have a transmission line or antenna and the wave is reflected off the end and it comes back and is supper imposed over the next wave traveling in the opposite direction. At that instant it there would be no voltage on the line and no magnetic field surrounding it.
How in the world does the wave know to continue?! There is no difference in potential. It's like it just bleeps out of existence and then comes right back. There wouldn't be any momentum because the electrons would be standing still.
I still don't get it. It seems kind of freaky to me!
If the frequency is high enough, then you could have an AC current on the skin of the wire and a DC current in the entire cross-section, including the skin.
It still comes down to the net potential across the wire, and for one half of the AC cycle the AC and DC currents will add, and in the other half they will subtract. The two currents are not mutually exclusive of one another (i.e. electrons never pass each other going opposite directions).
So there are not two currents running in opposite directions. The current will run either one way or the other, depending on the net potential across the ends of the wire at any instant of time.
Take as an example two current sources connected to a wire: one sources 10mA DC, and the other sources 1mA AC sine-wave at 500MHz. Now if you utilize your 10GHz Hall effect current probe (good luck finding one) to measure the current in that single wire, you will see a current fluctuating between 9mA and 11mA at a sine frequency of 500MHz.
.99
Quote from: angryScientist on September 23, 2010, 05:59:49 PM
What really puzzles me is when you have a transmission line or antenna and the wave is reflected off the end and it comes back and is supper imposed over the next wave traveling in the opposite direction. At that instant it there would be no voltage on the line and no magnetic field surrounding it.
That depends on whether the reflection is the same (open circuit) or opposite (short circuit) polarity as the incoming wave or pulse.
Quote
How in the world does the wave know to continue?! There is no difference in potential. It's like it just bleeps out of existence and then comes right back. There wouldn't be any momentum because the electrons would be standing still.
I still don't get it. It seems kind of freaky to me!
Transmission lines (TL) exhibit a local effect. A pulse sufficiently short to be small in comparison to the length of the transmission line will propagate along at some fraction of c, but until that pulse reaches the end, the "end" is not even aware of the pulse. If the end is not terminated in the characteristic Z of the TL, there will be a reflection, and if there are sequential pulses, the reflected pulse will intersect the next advancing one. What happens there is the same as what happens on a single wire; the two currents mesh. Either they add or subtract locally. They continue to propagate past each other because the TL is made up of a series of storage elements, and the energy in them can not be destroyed.
.99
First half, poignant. It's what I've read. I like. For sure.
Second, I'm still not seeing it. If they add together and nullify each other then where is the energy. Which dimension is the energy contained in? Not in the electric or magnetic or even mass.
I still don't comprehend...
Quote from: stevensrd1 on September 21, 2010, 05:46:38 AM
If I remove the middle wire that goes up and down, in the center, there is a change in motor speed, a very noticeable change, thus showing that there is flow in the middle wire, the electron path follows the path drawn, if it did not follow the path drawn and if the middle wire going up and down where electrons flow in both directions had no flow, there would be no change in any motor speed if it was removed. It would be the same as if it did nothing. The electrons are taking the path of least resistance, as drawn,,and that shows that electrons can flow in opposite directions along the same wire at the same time.
You are right about the motor speed. If you keep the verical wire, you got two separate circuits, and a parallell circuit between the battery cell and the motor. If you remove the vertical wire the motors are now connected in series, and a slight difference between those motors (It could be friction, efficiency, anything), you might end up with one stalled motor and one running.
I made a new video,concerning electron flow,this time I think I got it right.http://www.youtube.com/watch?v=b8eUbyWa-cY (http://www.youtube.com/watch?v=b8eUbyWa-cY)
Quote from: stevensrd1 on May 01, 2011, 09:03:09 AM
I made a new video,concerning electron flow,this time I think I got it right.http://www.youtube.com/watch?v=b8eUbyWa-cY (http://www.youtube.com/watch?v=b8eUbyWa-cY)
Steven,
Have you drawn your circuit out and examined the loops?
I just did myself. If you do, you'll find when both batteries are connected as you showed, virtually no current flows in the single battery, and the power for both motors is supplied by the two batteries in series. You'll also see that current flow is in one direction.
.99
Batteries are another example of non-electron or "ionic" conductors. When you connect a lightbulb to a battery, you form a complete circuit, and the path of the flowing charge is through the inside of the battery, as well as through the light bulb filament. Battery electrolyte is very conductive. Down inside the battery, within the wet chemicals between the plates, the amperes of flashlight current appears as a flow of both positive and negative atoms. There is a powerful flow of electric charge going through the battery, yet no individual electrons flow through the battery at all. So, while the current is between the two plates of the battery, what's its real direction? Not right to left, not left to right, but in both directions at once. About half of the charge-flow is composed of positive atoms, and the remaining portion is composed of negative atoms flowing backwards. Of course in metal wires outside the battery, the real particle flow is only from negative to positive. But inside the battery's wet electrolyte, the charge-flow goes in two opposite directions at the same time. And if we built a circuit from hoses full of salt water, with no metal conductors used, then all the current would be bi-directional.)
http://amasci.com/amateur/elecdir.html
If the particle flow is from the neg/South magnetic pole,to the pos/North magnetic pole,then the two like poles are going to repel the particle or current flow giveing you zero.
I could debate over this but I wont,much,, what is is right. And you know or you dont. Either way you will believe what you want,,and thats ok we all do. I will mention however that I did disconnect each motors power input in the video, showing neither changed speed when that happened, and that one motor spins faster and has more torque which is the one powered by the two batteries in series where as the other motor,,the one with the purple paper propeller on it spins slower and has little torque since it is powered by only one battery. But Ill not debate it further, take it as it is,,if you can use it,,then do,,or discard it. Worst case Im wrong, its still a very handy concept to ponder I think. Best wishes steve....
Quote from: stevensrd1 on May 01, 2011, 09:03:09 AM
I made a new video,concerning electron flow,this time I think I got it right.http://www.youtube.com/watch?v=b8eUbyWa-cY (http://www.youtube.com/watch?v=b8eUbyWa-cY)
Please, could you add diode to this short wire where electrons are flowing both directions in such direction to allow only one of this flow. I'm very curious about this but can't check it.Thank you.
I'm not sure this is real relevant but I had a handheld radio transceiver that had a coax cable coming out of it to go to the antenna. It transmits RF (high frequency AC) out the antenna. That SAME coax (two wires as in a center wire and a shield as the second wire) was used to feed DC power in to the transceiver. This was a mod with a diode to save having two separate cables (or 4 wires) going to the radio. So you had DC going in on the same wire that AC was going out when it transmitted. In that configuration it did not use any internal batteries. It worked fine.
Quote from: e2matrix on May 01, 2011, 01:11:41 PM
I'm not sure this is real relevant but I had a handheld radio transceiver that had a coax cable coming out of it to go to the antenna. It transmits RF (high frequency AC) out the antenna. That SAME coax (two wires as in a center wire and a shield as the second wire) was used to feed DC power in to the transceiver. This was a mod with a diode to save having two separate cables (or 4 wires) going to the radio. So you had DC going in on the same wire that AC was going out when it transmitted. In that configuration it did not use any internal batteries. It worked fine.
Reminds me of some solar panel experiments I have did in the past, and found out rf can power a solar cell, believe it or not its true. Also many solar cells use the non visible spectrum of light for energy conversion, all tho most would assume its the visible spectrum they use. For example I took my roomba ir virtual wall. It simply shines a light not in the visible spectrum,,that the roomba can see and so it avoids that area. Anyway the virtual wall ir light can actually be seen as visible light when viewed in a digital camera. So I took the virtual wall and in a dark room turned it on with its Ir led facing the solar panel,,the panel was connected to a meter,,and you can see how each time the virtual wall is turned on the meter shows voltage from the solar cell and that reading goes off soon as you turn the virtual wall off or face it another way..Very interesting I thought..
QuoteWorst case Im wrong, its still a very handy concept to ponder I think. Best wishes steve....
If you think you may be right you need to keep pondering it. I still think there is more going on than meets the eye. I will say this. Ive taken two aaa batterys and put the same polarity's together and measured the voltage. With the positve the voltage reads over 100 millivolts with the pos sign. The neg polarity's read exactly the same but with the neg sign. The amps were .2 microamps. Not even close to being one microamp.
This is still very interesting.
Electron's have, and always will travel in opposing directions on the same conductor, period.
That said, put two diodes in parallel ,
on facing one way,
the second the opposite.
Place this bi-directional gate into the center (green) wire
then measure the voltage drop across both diodes and see.
better yet, use an oscilloscope,
and watch current flow in BOTH directions simultatiously...
Please note, in a perfect world, and a perfect resistive network,
as in poynt99's textbook example above, no currunt will flow.
All respect meant there .99, but this example isn't
a "Static" purely resisitive experiment however.
Nice nick BTW, good word-play:
http://en.wikipedia.org/wiki/Poynting's_theorem
But in the real world these motors will draw and release (BEMF) current
in both directions in that center-tap green wire that can be observed.
This is most notibly used in the RF field with many items
that need to be remotely powered from a distance,
but use the same conductor as the RF return path as well,
like mast-mount antenna preamps, many marine products too,
such as the very common mod e2matrix observed.
The DC rides the core to to the preamp,
the RF rides the skin-effect back to the decoupler.
Can electrons flow in opposite directions on the same wire ?
YES, 8) off course, 2 years ago I have reproduced radiant energy experiement something like "Imhotep Radiant Oscillator" using a battery oscillating transistor ignition coil and some CFL and flourescent tube... Whith the skin effect while DC or low frequency flow from battery and at the same times light on the CFL in every connection of the circuit (even on the same polarity !!!)... Curious RF phenomena :o