|
Jim Kelley wrote:
Cecil Moore wrote: Don't you realize that if current is flowing out of the '+' terminal of a battery, that same current is flowing into the '-' terminal? Everybody realizes that Cecil. You don't need to explain. You need to understand. Your attitude toward AC tells me that you don't realize that, Jim. An AC source is like a battery that changes its '+' terminal to a '-' terminal every 1/2 cycle in accordance with a sinusoidal magnitude. Just because you use a Sharpie pen to mark one terminal of an AC source as the '+' terminal, doesn't mean the current out of that terminal is always positive. Good Grief - half the time it's negative! -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote:
Just because you use a Sharpie pen to mark one terminal of an AC source as the '+' terminal, doesn't mean the current out of that terminal is always positive. Hey, you're the one who told the story about the 'hot wire' being the one that the AC comes out of, not me. :-) 73 de ac6xg |
Yuri Blanarovich wrote: So when I plug my toaster into the AC outlet the current doesn't go into one end? Have you got standing waves on your toaster, Yuri? 73, Jim AC6XG It's always standing. Sometimes I use laying on the side if I want warm up pizza slice. That would make laying waves? So when waves are standing, they don't go to antenna? Antenna don't radiate? Cool dude! Yuri |
Yuri Blanarovich wrote:
It's always standing. Sometimes I use laying on the side if I want warm up pizza slice. That would make laying waves? So when waves are standing, they don't go to antenna? Antenna don't radiate? Cool dude! Yuri See how easy it is to get the flow of current mixed up with the flow of energy? That's what Cecil's been doing. Anyway, I enjoy your sense of humor, Yuri. 73, Jim AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: Just because you use a Sharpie pen to mark one terminal of an AC source as the '+' terminal, doesn't mean the current out of that terminal is always positive. Hey, you're the one who told the story about the 'hot wire' being the one that the AC comes out of, not me. You apparently would be surprised to know that the "hot wire" in your house has a negative voltage on it half the time. Current flows out of the "hot wire" half the time and flows into the "hot wire" half the time. That's simply the nature of AC. There's no "hot wire" in a balanced RF transmission line. *--------------------------------*-----------* | | | | | | | *-----| |-----------------* | | | | | voltmeter Ammeter | | | | | | | | Load *-----| |----/\/\/\/\/----* | | | ccw ^ cw | | | | | *----------------*-----------* There are two batteries and a potentiometer hooked up as shown. With the pot in the fully ccw position, what does the voltmeter read? Which way is the current flowing? With the pot in the fully cw position, what does the voltmeter read? Why way is the current flowing? It doesn't take a genius to see that if the pot is turned in a certain repetitive way, the voltage across the load could be sinusoidal with the current reversing its direction every 1/2 cycle. There's only two DC batteries and a magnitude pot. Where's the phase? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
See how easy it is to get the flow of current mixed up with the flow of energy? That's what Cecil's been doing. Anyway, I enjoy your sense of humor, Yuri. 73, Jim AC6XG Applying for further education: so what is flowing energy, no current flowing? This is series! (As freepers would say) double BUm |
Yuri Blanarovich wrote:
See how easy it is to get the flow of current mixed up with the flow of energy? That's what Cecil's been doing. Jim must have just realized that is what he has been doing wrong and is now blaming me for it. Energy moves from an RF source to an RF load. Current moves back and forth through the source. Current moves back and forth through the load. The electrons are not lost from the system. They just move back and forth coherent with the RF frequency. Electrons possess charge. Current is the time derivative of that charge. When the movement of charge changes direction, so does the current. Applying for further education: so what is flowing energy, no current flowing? If AC current always flows toward the load in one wire of a balanced transmission line, which way is the current flowing in the other wire? :-) If it is also flowing toward the load, it is common-mode current, not differential. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote in message ...
Dr. Slick wrote: I think every so often, it's important to point out how full of sh** Cecil Moore really is... When you cannot present a rational argument, mount an ad hominem attack? What is it that you disagree with me about? Do you think AC current doesn't reverse direction every 1/2 cycle? I think you reverse your argument every 1/2 cycle! S. |
Dr. Slick wrote:
Cecil Moore wrote: I think you reverse your argument every 1/2 cycle! Must be your comprehension going into reverse every 1/2 cycle. I have been perfectly consistent. Most people just don't understand that AC current reverses direction every 1/2 cycle and flows backwards just as often as it flows forward. All they have ever seen is an RMS current arrow pointing away from the source toward the load. The RMS model for AC has seduced a whole generation of engineers into feeling the RMS model dictates reality. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Fri, 13 Feb 2004 08:36:44 -0600, Cecil Moore
wrote: Most people just don't understand What a mission of salvation inhabits you. |
Richard Clark wrote:
wrote: Most people just don't understand What a mission of salvation inhabits you. Good to know that you understand everything, Richard. Maybe you could tell us if supersymetry is valid? -- 73, Cecil, W5DXP |
On Fri, 13 Feb 2004 12:03:11 -0600, Cecil Moore
wrote: Most people just don't understand Good to know that you understand everything, Richard. Bipolar now? Which cycle are you cresting on? |
Is there, was there ever, a point to all this drivel?
It might appear that the discussion is, had been, about current flow direction vs. energy flow direction. Unfortunately, the main message the rest of the readers of this group see is one of immaturity. I think the point of contention may have something to do with the fact that current on a t-line can be reversing direction in time and be different directions at different locations on the t-line. Then, there may be some relation to the energy which can be flowing in one direction. So is the nature of waves. But one sure can't tell by reading these posts.Why do I? "Dr. Slick" wrote in message om... Cecil Moore wrote in message ... Dr. Slick wrote: Kinda like how you imagine you are saying something important or intelligent! Makes one wonder why something so unimportant is worth the energy you expend in arguing about it. :-) Sure seems to me that dQ/dt is negative for 1/2 half of an AC cycle. I think every so often, it's important to point out how full of sh** Cecil Moore really is... S. |
On Fri, 13 Feb 2004 13:36:26 -0600, "Steve Nosko"
wrote: Is there, was there ever, a point to all this drivel? Hi Steve, Reference the Subject header. Any expectations above and beyond that promise are a fantasy. But one sure can't tell by reading these posts.Why do I? Boredom? If you perceive a topic worth discussing, start a thread with a more structured enquiry. [This is no guarantor of increased accuracy, coherency, or merit that will follow from such effort.] 73's Richard Clark, KB7QHC |
DUH! I shoulda' known... Gotcha, Rich(ard)
I usually look for a subject line that is either - something I want to know about, or something asked, that I can answer in a simple, straightforward way. [done a lot, seen a lot, know a lot--have a bone in my head - makes me want to help others to understand...no wise cracks invited] I know everything except how to be humble. 73, Steve K:9:D:C:I "Richard Clark" wrote in message ... On Fri, 13 Feb 2004 13:36:26 -0600, "Steve Nosko" wrote: Is there, was there ever, a point to all this drivel? Hi Steve, Reference the Subject header. Any expectations above and beyond that promise are a fantasy. But one sure can't tell by reading these posts.Why do I? Boredom? If you perceive a topic worth discussing, start a thread with a more structured enquiry. [This is no guarantor of increased accuracy, coherency, or merit that will follow from such effort.] 73's Richard Clark, KB7QHC |
Yuri Blanarovich wrote:
Applying for further education: so what is flowing energy, no current flowing? As far as you know, apparently. |
Richard Clark wrote in message . ..
On Fri, 13 Feb 2004 12:03:11 -0600, Cecil Moore wrote: Most people just don't understand Good to know that you understand everything, Richard. Bipolar now? Which cycle are you cresting on? Cecil is on the Bull**** cycle at the moment. The other cycle is sort of a lobotomized euphoria. Slick |
Dr. Slick wrote:
Cecil is on the Bull**** cycle at the moment. The other cycle is sort of a lobotomized euphoria. More ad hominem stuff. That tells me you can't defend your assertion that current sloshes back and forth trapped between voltage nodes. Your assertion would also have to be true of light where the interference energy in the bright rings is trapped between the dark rings. But we know that light does somehow escape that interference pattern and keeps traveling in a straight line unaffected by the other light beam. Similarly, in a constant Z0 environment, the forward current is unaffected by the reflected current and vice versa. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Fri, 13 Feb 2004 22:34:48 -0600, Cecil Moore
wrote: we know that light does somehow escape that interference pattern and keeps traveling in a straight line unaffected by the other light beam. Hi All, How to hold two mutually exclusive thoughts in one idea: If it escapes there never was any notion of affectation; If there was never any notion of affectation, there was nothing to escape. And "somehow?" This adverb presumes odds for which there were never any chance to offer odds for in the first place. At least such statements are consistent with the topic (you keeping notes Steve?). 73's Richard Clark, KB7QHC |
Jim Kelley wrote:
There is no convention describing unidirectional flow of alternating current. That is what you've been trying to say, i.e. current into one end of a coil. When the instantaneous voltage across a resistor is '+' on one end and '-' on the other, instantaneous current is flowing into the '+' end and out the '-' end, by convention. What do you mean there is no convention describing instantaneous current flow for AC? How could we possibly be in the 21st Century without such a convention? From _University_Physics_ by Young and Freedman, 9th edition: "i = I cos(wt) where 'i' is the instantaneous current ..." "But if we pass a sinusoidal current through a d'Arsonval meter, the torque on the moving coil varies sinusoidally, WITH ONE DIRECTION HALF THE TIME AND THE *OPPOSITE* DIRECTION THE OTHER HALF." (emphasis mine so you won't miss it) Instantaneous AC current "is represented by the projection (of a phasor) onto a horizontal axis ...". A '+' sign for the cos(wt) term represents one direction and a '-' sign represents the opposite direction. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote: Jim Kelley wrote: There is no convention describing unidirectional flow of alternating current. That is what you've been trying to say, i.e. current into one end of a coil. What do you mean there is no convention describing instantaneous current flow for AC? What do *you* mean by it? I never said anything like that. From _University_Physics_ by Young and Freedman, 9th edition: "i = I cos(wt) where 'i' is the instantaneous current ..." Yes, you'll also find that in one of my earlier posts in this thread. Cecil, why don't you wait until you've finished learning this stuff before you begin lecturing to me about it. I learned it a long time ago. 73, Jim AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: Jim Kelley wrote: There is no convention describing unidirectional flow of alternating current. That is what you've been trying to say, i.e. current into one end of a coil. What do you mean there is no convention describing instantaneous current flow for AC? What do *you* mean by it? I never said anything like that. There is indeed a convention for describing unidirectional flow of alternating current during 1/2 of the AC cycle. And RMS is exactly a convention, adopted from DC, of describing an equivalent unidirectional flow of AC current. That is what has been confusing you all along. Once again, AC current changes direction every 1/2 cycle and the sign of the cos(phase) function determines which of two, and only two directions, it flows. Current is NOT a vector. Current is a phasor with two and only two directions in a wire. Your phasor current "phase" is only an imaginary math function, a crutch to make the math easier. One amp at 90 degrees exists in your head, not in the real world.. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote:
That is what has been confusing you all along. No confusion here, Cecil. Wouldn't such a statement be considered by most to be ad hominem, i.e. about the person, rather than about the subject being discussed? You accuse people of doing it to you all the time, but never seem to be able to fess up to it yourself. Once again, AC current changes direction every 1/2 cycle and the sign of the cos(phase) function determines which of two, and only two directions, it flows. Why do you keeps saying the sign of the _cosine_ of the phase determines instantaneous direction? That's no more true than saying the sign of the sine of the phase determines the instaneous direction. It could in fact be completely untrue. Current is NOT a vector. Current is a phasor with two and only two directions in a wire. According to definition, current is a rate. That should be obvious from it's units of coulombs per second. Alternating current can be expressed as a rotating vector, or phasor. Your phasor current "phase" is only an imaginary math function, a crutch to make the math easier. Are you talking to me? Helloooo. One amp at 90 degrees exists in your head, not in the real world.. Methinks that conversation must exist only in your head, Cecil. 73, and good health de Jim AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: That is what has been confusing you all along. No confusion here, Cecil. Wouldn't such a statement be considered by most to be ad hominem, i.e. about the person, rather than about the subject being discussed? You accuse people of doing it to you all the time, but never seem to be able to fess up to it yourself. It's not ad hominem if it's true, Jim. You have demonstrated a certain level of confusion about the direction of AC current travel (of which there are only two) in a wire. In a single source, single load configuration, instantaneous AC current is either flowing toward the load or toward the source. For a phasor current in a wire, phase is an imaginary concept which exists only in your mind's math model. It is simply an artifact of the math model which doesn't exist in reality. That's why I keep harping on the seduction by the math models. Ask yourself, exactly where does that one amp at 90 degrees exist and exactly how can you measure it? Why do you keeps saying the sign of the _cosine_ of the phase determines instantaneous direction? Because it's true, Jim. Given that the reference is the source at zero degrees, which indicates a forward direction for current flow, all other current phases are referenced to the source. i=I*cos(phase_angle) If the cosine of that phase angle is positive, by convention, the instantaneous AC current is flowing toward the load. If the cosine of that phase angle is negative, by convention, the instantaneous AC current is flowing toward the source. According to definition, current is a rate. That should be obvious from it's units of coulombs per second. Alternating current can be expressed as a rotating vector, or phasor. Yes, but it goes in only one of two directions at a time. That is what you are missing. There are only two directions possible in a wire. The direction of travel in that wire is the sign of cos(phase_angle) referenced to the source. i*cos(20) and i*cos(60) are traveling in *EXACTLY* the same direction. Until you comprehend that fact of physics, you will not understand the superposition of forward current and reflected current, which is the original point of confusion. When you take time to understand the basics, and comprehend the difference between a vector and a phasor, then we can return to the original argument. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote:
You have demonstrated a certain level of confusion about the direction of AC current travel (of which there are only two) in a wire. Any confusion in this thread must be on your end. It began when you claimed more current goes into one end of an inductor than comes out the other end. That notion is utterly without merit. You may continue to try to defend your notion if you like, but please don't do it by insulting the intelligence of your correspondents. According to definition, current is a rate. That should be obvious from it's units of coulombs per second. Yes, but it goes in only one of two directions at a time. There are no "buts"; no exceptions to the definition of current. That is what you are missing. Saying I am "missing" something does not make it true. Repeatedly explaining how alternating current alternates does nothing but illustrate what a low level of understanding you have for the point being made by your correspondent. Why not just ask what I mean? 73, Jim AC6XG |
Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: That is what has been confusing you all along. No confusion here, Cecil. Wouldn't such a statement be considered by most to be ad hominem, i.e. about the person, rather than about the subject being discussed? You accuse people of doing it to you all the time, but never seem to be able to fess up to it yourself. It's not ad hominem if it's true, Jim. You have demonstrated a certain level of confusion about the direction of AC current travel (of which there are only two) in a wire. In a single source, single load configuration, instantaneous AC current is either flowing toward the load or toward the source. For a phasor current in a wire, phase is an imaginary concept which exists only in your mind's math model. It is simply an artifact of the math model which doesn't exist in reality. That's why I keep harping on the seduction by the math models. Ask yourself, exactly where does that one amp at 90 degrees exist and exactly how can you measure it? Why do you keeps saying the sign of the _cosine_ of the phase determines instantaneous direction? Because it's true, Jim. Given that the reference is the source at zero degrees, which indicates a forward direction for current flow, all other current phases are referenced to the source. i=I*cos(phase_angle) If the cosine of that phase angle is positive, by convention, the instantaneous AC current is flowing toward the load. If the cosine of that phase angle is negative, by convention, the instantaneous AC current is flowing toward the source. According to definition, current is a rate. That should be obvious from it's units of coulombs per second. Alternating current can be expressed as a rotating vector, or phasor. Yes, but it goes in only one of two directions at a time. That is what you are missing. There are only two directions possible in a wire. The direction of travel in that wire is the sign of cos(phase_angle) referenced to the source. i*cos(20) and i*cos(60) are traveling in *EXACTLY* the same direction. Until you comprehend that fact of physics, you will not understand the superposition of forward current and reflected current, which is the original point of confusion. When you take time to understand the basics, and comprehend the difference between a vector and a phasor, then we can return to the original argument. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Jim Kelley wrote:
Any confusion in this thread must be on your end. No, you have demonstrated confusion over and over and are doing it again in the following quote: It began when you claimed more current goes into one end of an inductor than comes out the other end. That notion is utterly without merit. Can more current go into one end of a transmission line than comes out the other? Of course it can. Current varies up and down a transmission line with reflections. It can be one amp at zero degrees at one point and half an amp at 180 degrees at another point. Therefore, it is possible to have one amp of current at the bottom of a coil and half an amp at the top of a coil, just like it is possible in a transmission line. It is obviously possible for one amp of instantaneous current to be flowing into a transmission line while half an amp is flowing into the same transmission line in the opposite direction at the other end. It appears that you don't comprehend distributed networks at all and that's a pity. Hint#1: in a distributed network, current can be any magnitude flowing in any direction at different points. Exactly the same thing holds true for a coil installed in a distributed network. Hint#2: Current at a current loop may be one amp while 1/4WL away, the current is always zero. How you can say that is without merit is beyond comprehension. Yes, but it goes in only one of two directions at a time. There are no "buts"; no exceptions to the definition of current. Yes, and it's time that you learned that fact. There are two and only two possible directions of current in a wire. You seem to think there are an infinite number of directions in a wire like there are in free space for light waves. Current in a wire is ***NOT*** a vector. Current in a wire can have only two directions. Saying I am "missing" something does not make it true. Denying that you are missing something makes you omniscient only in your own mind, not in reality. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Jim Kelley proclaimed:
It began when you claimed more current goes into one end of an inductor than comes out the other end. That notion is utterly without merit. Aaaah, Flat Earth Society demonstrating their "knowledge". Look at www.K3BU.us at pictures of RF ammeters SHOWING reality. Not good enough? Keep harping, the eggs on your faces are getting bigger and bigger. Yuri |
Yuri Blanarovich wrote:
Jim Kelley proclaimed: It began when you claimed more current goes into one end of an inductor than comes out the other end. That notion is utterly without merit. Aaaah, Flat Earth Society demonstrating their "knowledge". Look at www.K3BU.us at pictures of RF ammeters SHOWING reality. Not good enough? Keep harping, the eggs on your faces are getting bigger and bigger. The Flat Earth Society just cannot accept the fact that there can be one amp of current at one end of the coil and zero amps at the other end, just like a piece of transmission line. Never mind that the coil is on top of a mobile antenna and the current at the very top has no place to go. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Yuri, the earth *is* almost flat, at least on one side. I have pictures
from major earth-satellites showing that reality. The pictures also prove that there must be strong winds on at least one of the satellites, cuz a US flag in some of the pictures is not hanging straight down. Maybe you and Cecil can explain to us why, with all the evidence in the pictures, the guy is wearing the funny suit, and isn't eating an egg-on-his-face omelet made with the locally-cultured chartreuse-colored cheese, in his skivvies, under some trees on a park bench. Or is there another picture? 73, Dave, N3HE "Yuri Blanarovich" wrote in message ... Jim Kelley proclaimed: It began when you claimed more current goes into one end of an inductor than comes out the other end. That notion is utterly without merit. Aaaah, Flat Earth Society demonstrating their "knowledge". Look at www.K3BU.us at pictures of RF ammeters SHOWING reality. Not good enough? Keep harping, the eggs on your faces are getting bigger and bigger. Yuri |
Cecil wrote,
The Flat Earth Society just cannot accept the fact that there can be one amp of current at one end of the coil and zero amps at the other end, just like a piece of transmission line. Never mind that the coil is on top of a mobile antenna and the current at the very top has no place to go. -- 73, Cecil http://www.qsl.net/w5dxp What's that you said about ad hominem attacks, Cecil? I'm still waiting for Yuri to make his far-out-outtasite-wow! mobile antenna based on the results he gets from measuring coils with fish tank thermometers. As for your ideas about current, they're just another example of someone being led astray by the reification of abstract words and don't really account for much. You often use the technique of telling other people what they believe, Cecil, in order, I suppose, to get them so embroiled in trying to explain what they do believe that the original argument is obscured. This is what you've done in the above posting. If you have to sink to misrepresenting other people's ideas in order to "win" your argument, you've actually admitted that you've lost. 73, Tom Donaly, KA6RUH |
Yuri Blanarovich wrote: Jim Kelley proclaimed: It began when you claimed more current goes into one end of an inductor than comes out the other end. That notion is utterly without merit. Aaaah, Flat Earth Society demonstrating their "knowledge". Look at www.K3BU.us at pictures of RF ammeters SHOWING reality. Not good enough? Keep harping, the eggs on your faces are getting bigger and bigger. Yuri Yuri, I think you're missing the point - just as Cecil is. You seem to have forgotten that I agree with the idea that there is a current gradient across these inductors - just as there is a current gradient along any quarter wavelength of transmission line with standing waves. That doesn't mean there's more current "going in one end" than is "coming out of the other end." It's a sophomoric notion. Do you wanna be a simpleton? You're almost there with this nonsense. Why do you want to screw up a valid idea by attaching a ridiculous one to it? 73, Jim AC6XG |
Yuri,
I think you're missing the point - just as Cecil is. You seem to have forgotten that I agree with the idea that there is a current gradient across these inductors - just as there is a current gradient along any quarter wavelength of transmission line with standing waves. That doesn't mean there's more current "going in one end" than is "coming out of the other end." It's a sophomoric notion. Do you wanna be a simpleton? You're almost there with this nonsense. Why do you want to screw up a valid idea by attaching a ridiculous one to it? 73, Jim AC6XG OK, so it is more current "coming out in one end", than is "coming in at the other end"? Is this what IS is? The argument was "virtually same" vs. "different" (gradient, more at one end than the other, etc.) Are we taking off on tangents to muddy the waters? I am almost done with cleaning the "lab", wx is warming up, I will soon get out, do more tests and finish the article. More articles I see in publications, more perpetuation of the wrong picture and idea that current is the same in loading coils. Even QEX and new Antenna Book keep on misleading. Yuri, K3BU/m |
Cecil, W5DXP wrote:
"The Flat Earth Society just cannot accept the fact that there can be one amp of current at one end of a coil and zero amps at the other end, just like a piece of transmission line." What causes one amp of current at one end of a coil and zero amps at the other end of the coil? It is reflection. When an incident wave meets a discontinuity which can`t take all the voltage or current contained in the incident wave, the surplus voltage or current is reflected back toward the source by the mismatched load. At a point we might call "P" somewhere along an antenna wire, the incident wave required a period of time, we might express in electrical degrees, to reach "P" from the generator. At the same point "P", the reflected wave takes longer to arrive as it traveled past "P" to reach the reflection point, then it traveled back to "P". Further, either the voltage or current associated with the reflected wave is delayed by an additional 180-degrees. If the load impedance is too low to accept all the voltage in the incident wave, the current is reversed without additional delay, but there is a reversal in the phase of the reflected voltage. This can be recalled by the fact that with a complete short, equal but opposite volts cancel making zero volts across a short. If the load impedance is too high to accept all the current in the incident wave, the voltage is reversed without additional delay but there is a reversal in phase of the reflected current. At a discontinuity there is a phase reversal of either reflected volts or amps, but not a reversal of phase in both. At the open-circuits at the ends of a simple dipole antenna, nearly all the incident current runs out of wire and has nowhere to go except toward the generator that it came from. To go to zero, the reflected current must equal the incident current but it is traveling in the reversed direction. The cancellation of current requires H-field energy to momentarily transfer to the E-field. This so-called Ferranti effect doubles the incident voltage at the open-circuit. The impedance of the near open circuit is the doubled voltage divided by the near zero amps. At 1/4-wave back from the extremely high-voltage, high-impedance points at the dipole tips, the picture is inverted. The volts are minimum and the amps are maximum. Every segment of wire in a simple dipole of overall length of 1/2-wave or less has higher voltage and higher impedance on its end nearer the the dipole tip than it does on its end nearer the center of the dipole. If any part of the simple dipole, 1/2-wave or shorter, is made of a coil instead of a straight piece of wire, the coil too has a higher impedance on the end nearer the dipole tip and a lower impedance on the coil end near the center of the dipole. The difference in current at opposite ends of an antenna loading coil is due to the interaction of incident and reflected waves just as in a straight wire. The above seems a clear as sailing west to reach the east, to me. Best regards, Richard Harrison, KB5WZI |
Yuri Blanarovich wrote: Yuri, I think you're missing the point - just as Cecil is. You seem to have forgotten that I agree with the idea that there is a current gradient across these inductors - just as there is a current gradient along any quarter wavelength of transmission line with standing waves. That doesn't mean there's more current "going in one end" than is "coming out of the other end." It's a sophomoric notion. Do you wanna be a simpleton? You're almost there with this nonsense. Why do you want to screw up a valid idea by attaching a ridiculous one to it? 73, Jim AC6XG OK, so it is more current "coming out in one end", than is "coming in at the other end"? Do you think that is how to best describe what is happening in antenna circuits, Yuri? You do understand what a standing wave pattern is, right? 73, Jim AC6XG |
Jim Kelley wrote:
That doesn't mean there's more current "going in one end" than is "coming out of the other end." It's a sophomoric notion. Nope, it's not, Jim. Current cannot stand still. The current at the bottom of the coil is referenced to the source current which in EZNEC, is usually one amp at zero degrees which, *by convention*, has the RMS value flowing into the antenna. The same convention is used for circuit components. EZNEC then tells us that the current at the bottom of the coil is 0.87a at -1.23 deg and the current at the top of the coil is 0.67a at -1.57 deg. All these currents are phasors. One amp at zero degrees is flowing into the antenna. 0.87a at -1.23 degrees is flowing into the bottom of the coil, by convention, because the cosine of the phase_angle is positive. 0.67a at -1.57 degrees is flowing out the top of the coil, by convention, because the cosine of the phase_angle is positive. All referenced to the source current (you know, that little current arrow that you draw on a diagram to indicate the RMS current flow). What is a sophomoric notion is your notion that current doesn't flow when it's associated with a coil. Does it just sorta vegetate around the ends of the coil or what? If you were asked to draw RMS current arrows on a diagram associated with a coil, would you say it can't be done? Why do you think the RMS conventions were invented? Incidentally, this concept of current into the coil and current out of the coil was introduced by Tom, W8JI who said in the original argument: "If you look at HOW an inductor works, the current flowing in one terminal ALWAYS equals the current flowing out the other terminal." Even if Tom was wrong about the equal currents, he clearly comprehends the AC current flow convention. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote: Jim Kelley wrote: That doesn't mean there's more current "going in one end" than is "coming out of the other end." It's a sophomoric notion. Nope, it's not, Jim. Current cannot stand still. You keep saying that as if it was relevant. The current at the bottom of the coil is referenced to the source current which in EZNEC, is usually one amp at zero degrees which, *by convention*, has the RMS value flowing into the antenna. Both in to and out of. Not one or the other. What is a sophomoric notion is your notion that current doesn't flow when it's associated with a coil. I have no such notion. It's another of the straw constructs you use to try to win an argument by any means possible. Incidentally, this concept of current into the coil and current out of the coil was introduced by Tom, W8JI who said in the original argument: "If you look at HOW an inductor works, the current flowing in one terminal ALWAYS equals the current flowing out the other terminal." Even if Tom was wrong about the equal currents, he clearly comprehends the AC current flow convention. Then I observe that neither you nor Tom completely understands standing waves. 73, Jim AC6XG |
Richard Harrison wrote:
If any part of the simple dipole, 1/2-wave or shorter, is made of a coil instead of a straight piece of wire, the coil too has a higher impedance on the end nearer the dipole tip and a lower impedance on the coil end near the center of the dipole. Yep, and for the same power level, a higher impedance usually means a lower current and vice versa. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote: Richard Harrison wrote: If any part of the simple dipole, 1/2-wave or shorter, is made of a coil instead of a straight piece of wire, the coil too has a higher impedance on the end nearer the dipole tip and a lower impedance on the coil end near the center of the dipole. Yep, and for the same power level, a higher impedance usually means a lower current and vice versa. But the impedance *at* such points does not affect the current *at* those points? 73, Jim AC6XG |
Jim Kelley wrote:
You do understand what a standing wave pattern is, right? At any instant of time at a standing wave current maximum point (loop, antinode), the charge carriers are either moving toward the load (ends of the dipole) or toward the source (feedpoint). By convention, if the charge carriers are moving away from the source, the current, dQ/dt, is positive. If the charge carriers are moving toward the source, by convention, the current dQ/dt is negative. Even standing wave current cannot stand still and there are only two directions available in a wire. If the current is not zero, it changes directions every 1/2 cycle. Standing wave current is the sum of the forward current and reflected current both of which are flowing. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
| All times are GMT +1. The time now is 08:48 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com