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| Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#281
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On Wed, 15 Jun 2005 18:31:26 -0500, John Fields wrote:
So, you miserable, troublemaking piece of ****, you've decided to take on John Larkin? Big mistake. There's no way you can even begin to think about getting close to his track record, let alone even get into the stadium, so why don't you just quit before you embarrass yourself by not even being able to leave the starting blocks? Was the topic "Olympic-Grade Trollfeeding?" John Fields, you won that one by a landslide some time ago. -- Flap! The Pig Bladder from Uranus, still waiting for that hot babe to ask what my favorite planet is. ;-j |
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"Kitchen Man" wrote in message ... On Mon, 13 Jun 2005 11:49:58 GMT, "daestrom" wrote: "Floyd L. Davidson" wrote in message ... "operator jay" wrote: It is not changing polarity. I would hesitate to call it alternating current. On the "dc sine wave" issue, I wouldn't even get into that debate. To me the terms involved are open to too many interpretations. As evidenced in this thread, I suppose. Where *do* you get this requirement for changing polarity? We don't call it "Alternating Polarity", we call it "Alternating Current". If the current is being altered, it's AC. You keep talking about AP, and it isn't the same. 'Alternating' is not the same as 'altering'. "Alternating current" is an electrical current where the magnitude and *direction* [emphasis added] varies cyclically. http://en.wikipedia.org/wiki/Alternating_current One may 'alter' the magnitude of a DC current without it becoming 'alternating current' The problem with that definition is that it is unnecessarily limiting. You can find other sources where the definition reads "magnitude *or* direction," the latter which I believe to be more correct. If the signal is steady state, then the current that changes magnitude but never direction is simply an AC signal with a DC component greater in positive amplitude than the negative peak of the AC component. -- Al Brennan "If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe." Nicola Tesla In any case, what you have to do in analysis is to treat each frequency separately, including the 0 frequency term. What's the big deal.?? -- Don Kelly remove the urine to answer |
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"Don Kelly" wrote in message news:0x6se.2355$El.2246@pd7tw1no... In any case, what you have to do in analysis is to treat each frequency separately, including the 0 frequency term. What's the big deal.?? Anybody who doesn't like it, feel free to bang out the de's. j |
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"Floyd L. Davidson" wrote in message ...
"Larry Brasfield" wrote: "Tom MacIntyre" wrote in message ... On Wed, 15 Jun 2005 18:01:25 -0500, John Fields wrote: On Tue, 14 Jun 2005 11:21:21 -0800, (Floyd L. Davidson) wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Not true, unless 0.01+ oC counts as "0C" or "boil" has some novel meaning other than a liquid to vapor phase transition occuring within the liquid due to applied heat. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. [Stuff on latent heat zapped.] I am simply going by memory of my old Physics classes, and I have no idea what pressure would be required to allow water to boil at 0 C. I think other substances have boiled at lower temperatures than that at STP though. If you peruse the phase space of water at http://www.lsbu.ac.uk/water/phase.html you will see that there is no liquid/vapor boundary at 0 oC. At a range of pressure well below standard atmospheric, it could happen near 0.01 oC. John's challenge is a bit of a trick and appears to show he knows how to read that graph and accompanying table. Are you saying that it could happen at 0.01C but not at 0.00C, because you see something in that chart which says water is liquid at 0.01C and not at 0.00C? I said "near 0.01 oC", not "at". At temperatures above the triple point (at 0.01 oC), a liquid/vapor phase change exists. Below that, there is no such phase change, so there is no possibility of boiling, which requires a liquid. Precisely at the triple point, I'm not sure it is meaningful to speak of boiling because the triple point exists under equilibrium conditions and boiling is not an equilibrium. (Boiling is a catastrophic process.) I don't see that in the chart at all. The chart does not have sufficient resolution. It doesn't discuss that in the text either. The table of triple points shows, in its first row, that triple point often referred to as "the triple point". (That is the one now used to define 0.01 oC on the Centrigrade temperature scale.) This triple point, between the liquid, Ih (hexagonal ice-one) and vapor phases, represents the lowest pressure at which an Ih/liquid phase transition exists, as can be seen from the graph. It is clear from the graph that the vapor phase boundary slope is continuous as it passes thru that triple point, and has positive slope. So, clearly, where it passes thru 0 oC has to be below that triple point. Did you mean something else? Nope. -- --Larry Brasfield email: Above views may belong only to me. |
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"Rich The Newsgroup Wacko" wrote in message
news  On Thu, 16 Jun 2005 01:54:45 +0000, ehsjr wrote: Rich The Philosophizer wrote: [in response to someone else whom ehsjr has failed to attribute] Er..the gospels are the biggest pile of erroneous nonsense one can come up with. Its all about those imaginary beings, that can do anything, be everywhere at once, knows everything etc... Hey! Let's not knock the imaginary! Where would electronics be today without sqrt(-1)? ;-) Up the paddle without a creek? ;-} That's another interesting question - is there really a "hole" in the donut, or are you buying a hole, with donut around it? The hole was there first, you know. ;-p -- Cheers! Rich Not in my donut - there was no hole till the donut was made - I was there and I saw it enter the mixture. Ken |
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#288
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John Fields wrote...
Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. -- Thanks, - Win |
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On Wed, 15 Jun 2005 23:11:02 -0500, "operator jay"
wrote: "Don Kelly" wrote in message news:0x6se.2355$El.2246@pd7tw1no... In any case, what you have to do in analysis is to treat each frequency separately, including the 0 frequency term. What's the big deal.?? Anybody who doesn't like it, feel free to bang out the de's. Like I said before, Don, the big deal is people with nothing better to do than start internet arguments, all the while ignoring all the bits of knowledge that spill out during the course of same. Case in point. -- Al Brennan "If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe." Nicola Tesla |
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On Thu, 16 Jun 2005 08:40:01 +1200, "Ken Taylor"
wrote: "Kevin Aylward" wrote in message .uk... John Fields wrote: On Wed, 15 Jun 2005 14:48:44 GMT, Pig Bladder wrote: On Wed, 15 Jun 2005 05:44:34 -0700, Kitchen Man wrote: On Wed, 15 Jun 2005 03:36:15 -0500, John Fields wrote: It is my belief that the widespread disagreement is due to participants that just like to argue a lot. --- No, they don't. ;^) Look, this isn't an argument, it's just contradiction! No, it's not! ;^j --- Yes, it is!^) No it isnt. An argument is a connected series of statements intended to establish a proposition... Sorry, your time's up....... That was never five minutes!? -- Al Brennan "If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe." Nicola Tesla |
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#291
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On Wed, 15 Jun 2005 23:11:46 -0400, Spehro Pefhany wrote:
On Thu, 16 Jun 2005 02:55:51 GMT, the renowned Pig Bladder wrote: On Wed, 15 Jun 2005 19:52:15 -0400, Spehro Pefhany wrote: On Wed, 15 Jun 2005 18:01:25 -0500, the renowned John Fields wrote: On Tue, 14 Jun 2005 11:21:21 -0800, (Floyd L. Davidson) wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. --- Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. Good one, John! Lame. Approx. 10^3 Pa. http://www.lsbu.ac.uk/water/phase.html ;^j Do you happen to know what the triple-point of water is? No, but there's an awesome graph - did I mention something that I called "the Annoying Point" - in either another branch here or another thread that had also degenerated to a virtually amusing point. ;-) Oh, as a matter of fact, I'm almost sure that it's in another response to this very John F. x Floyd L.D. ****fest. Anyways, if you go to the URL above, and just scroll down to below the first paragraph, which is a page in a teeny tiny monitor; there's a couple of awesome graphics. There are a whole bunch of points that could be construed as "The Triple Point", like, at 10^3 Pa - One kilopascal? at 273ish K, where water can freeze and boil simultaneously. And if you look up in the "increasing pressure" direction, you'll see a kind of "crowded" or "busy" area. There's an enlargement of that area - where the "Triple- Point" _could_ be construed to be that little blue area labeled "III". But that _couldn't_ be the triple point, because there's no steam! So, yeah, I have no idea what the triple-point of water is, other than that I'd heard where "the three states" all come together. So, OK - I'm guessing about 273ish K at about one kilopascal. ;-) (and the "lame" crack came about by your accolade of "Good one, J..." for merely expressing an invitation to do a web search that took me all of about four seconds. Sorry, I just didn't think that it was that great big a deal for a guy to say, "put your money where your mouth is." I since have, and nobody seems to have noticed that I've stumbled on a site that tells not only about the ten states of ice, but also, get this: ---q--- Enthalpy of Vaporization [61] 45.054 kJ mol-1 (0°C), 40.657 kJ mol-1 (100°C) Enthalpy of Fusion 6.0095 kJ mol-1 (0°C, 101.325 kPa) [60] 6.354 kJ mol-1 (81.6°C, 2150 MPa, ice VI) [535] Enthalpy of Sublimation 51.06 kJ mol-1 (0°C) ---/q--- from amongst parameters that I didn't even know there were, at http://www.lsbu.ac.uk/water/data.html .) Wait a minute! There's a picture of the triple-point! http://www.lsbu.ac.uk/water/data.html#d Kewl! "(273.16 K "exactly ...) The triple point is the temperature and pressure at which three phases (here liquid water, hexagonal ice, and water vapor) coexist at equilibrium, and will transform phase with suitable but tiny changes in temperature or pressure." So, now, I guess I do! :-D Thanks! Rich |
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Winfield Hill wrote:
John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". Confining comments to the topic makes newsgoups work better. He appears to be confusing sublimation and evaporation with boiling. I believe that the "boiling point" is when the partial pressure of the liquid at the applied pressure and temperature is equal to the applied pressure. "Boiling" may be entirely apporpriate. Bud-- |
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Don Bowey wrote:
On 6/15/05 7:23 AM, in article , "Bud" wrote: Don Lancaster has written many articles for electronics magazines. Also regular columns for several electronics magazines (probably still running). One of his books (CMOS cookbook) was a standard for many years. You might be able to learn something from him too. Bud-- John Larkin wrote: On Tue, 14 Jun 2005 00:41:47 -0700, Don Bowey wrote: He [Don Lancaster] has tutorials? You've got to be kidding. John The quoted posts were not as you have posted them. They did not include the "[Don Lancaster)." Shame on you, Bud. Don Reading back through the thread I can see how John attributed the "tutorials" to "the Phantom", but the "tutorials" quote (in "the Phantom" post) was lifted from a post by Don Lancaster. I used square brackets as they are commonly used. Bud-- |
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On Thu, 16 Jun 2005 14:58:11 -0500, Bud
wrote: Don Bowey wrote: On 6/15/05 7:23 AM, in article , "Bud" wrote: Don Lancaster has written many articles for electronics magazines. Also regular columns for several electronics magazines (probably still running). One of his books (CMOS cookbook) was a standard for many years. You might be able to learn something from him too. Bud-- John Larkin wrote: On Tue, 14 Jun 2005 00:41:47 -0700, Don Bowey wrote: He [Don Lancaster] has tutorials? You've got to be kidding. John The quoted posts were not as you have posted them. They did not include the "[Don Lancaster)." Shame on you, Bud. Don Reading back through the thread I can see how John attributed the "tutorials" to "the Phantom", but the "tutorials" quote (in "the Phantom" post) was lifted from a post by Don Lancaster. I used square brackets as they are commonly used. Bud-- OK, my final position: Whoever said that DC cannot exist, shouldn't authoring tutorials. and Whoever posts stuff typed by others, without the thingie first, is likely to confuse folks. John |
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On 6/16/05 12:58 PM, in article ,
"Bud" wrote: Don Bowey wrote: On 6/15/05 7:23 AM, in article , "Bud" wrote: Don Lancaster has written many articles for electronics magazines. Also regular columns for several electronics magazines (probably still running). One of his books (CMOS cookbook) was a standard for many years. You might be able to learn something from him too. Bud-- John Larkin wrote: On Tue, 14 Jun 2005 00:41:47 -0700, Don Bowey wrote: He [Don Lancaster] has tutorials? You've got to be kidding. John The quoted posts were not as you have posted them. They did not include the "[Don Lancaster)." Shame on you, Bud. Don Reading back through the thread I can see how John attributed the "tutorials" to "the Phantom", but the "tutorials" quote (in "the Phantom" post) was lifted from a post by Don Lancaster. I used square brackets as they are commonly used. I see what happened. In retrospect it is clear the "tutorial quote" came from one of Don Lancaster's posts. However, when the Phantom used it in his post, much of Don Lancaster's post was not attributed to him (Don): As with the Phantom's post, there were no attribution carrot(s) so it appeared to be part of the Phantom's post. Subsequent posts were targeting what incorrectly appeared to be Phantom's tutorials. All that aside, always in for a penny in for a pound, I now conclude that my remark was aimed at Don Lancaster's comment on DC. Take your best shots. Don (B) |
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On Thu, 16 Jun 2005 19:04:03 GMT, Rich Grise
wrote: (and the "lame" crack came about by your accolade of "Good one, J..." for merely expressing an invitation to do a web search that took me all of about four seconds. Sorry, I just didn't think that it was that great big a deal for a guy to say, "put your money where your mouth is." I since have, and nobody seems to have noticed that I've stumbled on a site that tells not only about the ten states of ice, but also, get this: ---q--- Enthalpy of Vaporization [61] 45.054 kJ mol-1 (0°C), 40.657 kJ mol-1 (100°C) Enthalpy of Fusion 6.0095 kJ mol-1 (0°C, 101.325 kPa) [60] 6.354 kJ mol-1 (81.6°C, 2150 MPa, ice VI) [535] Enthalpy of Sublimation 51.06 kJ mol-1 (0°C) ---/q--- from amongst parameters that I didn't even know there were, at http://www.lsbu.ac.uk/water/data.html .) Wait a minute! There's a picture of the triple-point! http://www.lsbu.ac.uk/water/data.html#d Kewl! "(273.16 K "exactly ...) The triple point is the temperature and pressure at which three phases (here liquid water, hexagonal ice, and water vapor) coexist at equilibrium, and will transform phase with suitable but tiny changes in temperature or pressure." So, now, I guess I do! :-D --- But only because Spehro laid that "triple point" clue on you. Had he not, you'd still be thrashing around wondering what the hell was going on, so instead of playing netcop and faulting him for daring to post "accolades" to which you object, (that is, not posting in accordance with your wishes) I think a nice "Thank you, Spehro!" is in order. -- John Fields Professional Circuit Designer |
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Winfield Hill -edu wrote:
John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either. But all of your squirming and name calling clearly does identify each of you! I don't need to call any of you names, because *you* are providing everyone who reads these articles with all they need to know, whether someone actually puts a label on it or not. If course when *you* provide so many handy labels, you'll have to expect readers to use exactly those when they think of you. -- Floyd L. Davidson http://web.newsguy.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
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On Thu, 16 Jun 2005 17:01:35 -0500, John Fields wrote:
On Thu, 16 Jun 2005 19:04:03 GMT, Rich Grise So, now, I guess I do! :-D --- But only because Spehro laid that "triple point" clue on you. Had he not, you'd still be thrashing around wondering what the hell was going on, so instead of playing netcop and faulting him for daring to post "accolades" to which you object, (that is, not posting in accordance with your wishes) I think a nice "Thank you, Spehro!" is in order. I didn't do any thrashing - I went right for the answer: ---------quote---------- Subject: DC Wave Questions From: Rich Grise Newsgroups: sci.electronics.basics,sci.electronics.design,sci. electronics.repair,alt.engineering.electrical Message-ID: Date: Thu, 16 Jun 2005 02:53:35 GMT On Wed, 15 Jun 2005 19:35:17 -0500, John Fields wrote: On Wed, 15 Jun 2005 23:37:49 GMT, Tom MacIntyre snip I am simply going by memory of my old Physics classes, and I have no idea what pressure would be required to allow water to boil at 0 C. I think other substances have boiled at lower temperatures than that at STP though. Yes. Liquefied gases, in particular, do that, and I'm anxiously awaiting Floyd Davidson's response which will nail down the pressure required to allow water to boil at 0°C. According to the graph at http://www.lsbu.ac.uk/water/phase.html , approx. 10^3 Pa, whatever the hell that means. Obviously, an atmosphere is up there near the "annoying point", ;-) , between 10^8 and 10^9 Pa. ---------/quote--------- But you might have missed it because it wasn't from "Pig Bladder". ;-) And, admittedly, at that point in time I hadn't realized that that's called the "triple point", but that _was_ the point I was referring to. Cheers! Rich |
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"Kitchen Man" wrote in message ... On Wed, 15 Jun 2005 23:11:02 -0500, "operator jay" wrote: "Don Kelly" wrote in message news:0x6se.2355$El.2246@pd7tw1no... In any case, what you have to do in analysis is to treat each frequency separately, including the 0 frequency term. What's the big deal.?? Anybody who doesn't like it, feel free to bang out the de's. Like I said before, Don, the big deal is people with nothing better to do than start internet arguments, all the while ignoring all the bits of knowledge that spill out during the course of same. Case in point. Either what I wrote did not come out how I intended, or you disagree that de's can be used to solve a circuit. You almost alluded to de's before so probably that's not it. So to Mr. Kelly, let me rephrase that to a more bland "Yes. Although I guess one could use time domain." Apologies. And to you, too, Al. I'm sorry. Sorry you got fired from the cafeteria at Motorola. After 30 years "in electronics" that's a pretty hard break for the "Kitchen Man". j |
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On Thu, 16 Jun 2005 14:08:59 -0800, Floyd L. Davidson wrote:
Winfield Hill -edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). Huh? The issue is not whether water can be a gas at 0C, rather can it *boil*. Since there is nowhere in the phase diagram that the water and gas phase touch each other at 0C, my guess is that it cannot boil at 0C, at *any* pressure. It's only a guess though. ;-) And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either. What? Evaporation only occurs between the liquid and gas phases. I suppose you're proposing that it somehow "tunnels" through the solid phase at 0C? Me thinks you need to go back to high school physics. But all of your squirming and name calling clearly does identify each of you! I don't need to call any of you names, because *you* are providing everyone who reads these articles with all they need to know, whether someone actually puts a label on it or not. Squirming? Try reading the phase diagram that has been put right in front of your nose. Water cannot "boil" at 0C. ...not possible. If course when *you* provide so many handy labels, you'll have to expect readers to use exactly those when they think of you. "Handy" labels like "gas", "liquid", "solid", "boil", "melt", and "sublimate"? I guess you have a point. We're being *so* judgemental. ....hurt your feelings? -- Keith |
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keith wrote:
On Thu, 16 Jun 2005 14:08:59 -0800, Floyd L. Davidson wrote: Winfield Hill -edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). Huh? The issue is not whether water can be a gas at 0C, rather can it *boil*. Since there is nowhere in the phase diagram that the water and gas phase touch each other at 0C, my guess is that it cannot boil at 0C, at *any* pressure. It's only a guess though. ;-) Did you even look at the charts? Did you read the many posts, all of which agreed that at 0.01C, water can be a solid, a liquid, or a gas. Since what was specified was "0C", *not* 0.00C, arguing that 0.01 is different than 0C is silly. As noted, 0C covers anything from -0.5 to +0.5C, because no decimal precison was specified. And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either. What? Evaporation only occurs between the liquid and gas phases. I suppose you're proposing that it somehow "tunnels" through the solid phase at 0C? Me thinks you need to go back to high school physics. Since at 0C it can be *any* of those... what's your point? you! I don't need to call any of you names, because *you* are providing everyone who reads these articles with all they need to know, whether someone actually puts a label on it or not. Squirming? Try reading the phase diagram that has been put right in front of your nose. Water cannot "boil" at 0C. ...not possible. If course when *you* provide so many handy labels, you'll have to expect readers to use exactly those when they think of you. "Handy" labels like "gas", "liquid", "solid", "boil", "melt", and "sublimate"? I guess you have a point. We're being *so* judgemental. ...hurt your feelings? Learn to read. People cannot understand the statement 'Water can "boil" at 0C too.' have a problem with the English language. I you are going to claim you speak English as a second language, I'll listen, otherwise not. All this pedantic nashing of teeth for people who can't even read common English syntax is amazing. -- Floyd L. Davidson http://web.newsguy.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
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On Thu, 16 Jun 2005 20:08:19 -0800, Floyd L. Davidson wrote:
keith wrote: On Thu, 16 Jun 2005 14:08:59 -0800, Floyd L. Davidson wrote: Winfield Hill -edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). Huh? The issue is not whether water can be a gas at 0C, rather can it *boil*. Since there is nowhere in the phase diagram that the water and gas phase touch each other at 0C, my guess is that it cannot boil at 0C, at *any* pressure. It's only a guess though. ;-) Did you even look at the charts? Did you read the many posts, all of which agreed that at 0.01C, water can be a solid, a liquid, or a gas. Since what was specified was "0C", *not* 0.00C, arguing that 0.01 is different than 0C is silly. As noted, 0C covers anything from -0.5 to +0.5C, because no decimal precison was specified. And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either. What? Evaporation only occurs between the liquid and gas phases. I suppose you're proposing that it somehow "tunnels" through the solid phase at 0C? Me thinks you need to go back to high school physics. Since at 0C it can be *any* of those... what's your point? you! I don't need to call any of you names, because *you* are providing everyone who reads these articles with all they need to know, whether someone actually puts a label on it or not. Squirming? Try reading the phase diagram that has been put right in front of your nose. Water cannot "boil" at 0C. ...not possible. If course when *you* provide so many handy labels, you'll have to expect readers to use exactly those when they think of you. "Handy" labels like "gas", "liquid", "solid", "boil", "melt", and "sublimate"? I guess you have a point. We're being *so* judgemental. ...hurt your feelings? Learn to read. People cannot understand the statement 'Water can "boil" at 0C too.' have a problem with the English language. I you are going to claim you speak English as a second language, I'll listen, otherwise not. I have no problem reading. OTOH, you have a problem with high school physics. At no pressure, at 0C, is water both a liquid and a gas, therefor water *CANNOT BOIL* at 0C. It must become a solid when transitioning between a liquid and gas at 0C. All this pedantic nashing of teeth for people who can't even read common English syntax is amazing. Correct physics is pedantic? Nice try, but perhaps you want to look at the phase diagram again. -- Keith |
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John Fields wrote:
On Thu, 16 Jun 2005 20:08:19 -0800, (Floyd L. Davidson) wrote: Learn to read. People cannot understand the statement 'Water can "boil" at 0C too.' have a problem with the English language. I you are going to claim you speak English as a second language, I'll listen, otherwise not. All this pedantic nashing of teeth for people who can't even read common English syntax is amazing. --- LOL, learn to _write_, you idiotic ****! Not writing what *you* want to read is hardly an error on *my* part. -- Floyd L. Davidson http://web.newsguy.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
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John Fields wrote:
On Thu, 16 Jun 2005 14:08:59 -0800, (Floyd L. Davidson) wrote: Winfield Hill -edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). --- Whether it's "correct" or not is moot. What you were challenged to do was to provide the _pressure_ required to make water boil at 0°C. You The pressure is commonly known, was not the point, and your question was out of place and trivially ignored. Which is to say, who cares if you asked a dumb question? And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either. --- "Existing as a vapor" doesn't constitute boiling, dumbass. --- Learn to read. Your life won't be so filled with angst and bitterness. -- Floyd L. Davidson http://web.newsguy.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
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"keith" wrote in message news On Thu, 16 Jun 2005 14:08:59 -0800, Floyd L. Davidson wrote: Winfield Hill -edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). Huh? The issue is not whether water can be a gas at 0C, rather can it *boil*. Since there is nowhere in the phase diagram that the water and gas phase touch each other at 0C, my guess is that it cannot boil at 0C, at *any* pressure. It's only a guess though. ;-) What a lot of you are missing though is that the diagrams you are looking at are equilibrium states. Take a large quantitiy of liquid water at 0.05 C and let it stand. Now, have it in a chamber at something like 1 kPa. Next, *rapidly* reduce the pressure on the surface (maybe suddenly open it to a large vacumn chamber). You can then get evaporation to cool the liquid and at the same time get some of the water to violently change phase to a gas (i.e. 'boil'). You will also get a far amount of ice formation as the latent heat of vaporization is supplied by fusing some of the water into ice. Of course, this is only a transitory phenomenon, but it is 'boiling' daestrom |
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On Fri, 17 Jun 2005 09:01:25 -0800, (Floyd L.
Davidson) wrote: John Fields wrote: On Thu, 16 Jun 2005 14:08:59 -0800, (Floyd L. Davidson) wrote: Winfield Hill -edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. *Look* at the statement: Water can "boil" at 0C too. It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to +.5 C!). --- Whether it's "correct" or not is moot. What you were challenged to do was to provide the _pressure_ required to make water boil at 0°C. You The pressure is commonly known, was not the point, and your question was out of place and trivially ignored. Which is to say, who cares if you asked a dumb question? --- No one, but _everyone_ seems to be getting on _your_ case about _your_ dumb answers. --- And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either. --- "Existing as a vapor" doesn't constitute boiling, dumbass. --- Learn to read. Your life won't be so filled with angst and bitterness. --- _I_ know how to read, as evidenced by the number of times I've caught you in errors or pointed out your stupidly conceived and poorly executed attempts at evasionary tactics, ya dumb ****! And, BTW, where's all this flaming I was supposed to beware of? So far all I've heard from you is juvenile crap which isn't doing anything except making _you_ look stupid. -- John Fields Professional Circuit Designer |
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On 16 Jun 2005 04:16:54 -0700 Winfield Hill
-edu wrote: John Fields wrote... Floyd L. Davidson wrote: John Fields wrote: Floyd L. Davidson wrote: The idea that water boils at 100C and freezes at 0C, without some mention of pressure, has little meaning. Water can "boil" at 0C too. Since, by your own admission, the boiling and freezing point temperatures of water are pressure dependent, I invite you to state what pressure would be required to be exerted on a volume of liquid water in order to cause it to boil at 0°C. The answer of course is: not much. Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?". He appears to be confusing sublimation and evaporation with boiling. No, it sounds to me like he knows his phase diagrams. Water can indeed be made to both boil and freeze (simultaneously) near 0C if the pressure is appropriately low. I don't recall the exact pressure, but it's a medium vacuum (1 Torr, 50 Microns,... ???) That combination of temperature and pressure is called the triple point of water because all 3 phases of water exist in equilibrium there. It is a fundamental property of water that can be used to calibrate thermometers. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- |
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On Fri, 17 Jun 2005 08:53:32 -0800, (Floyd L.
Davidson) wrote: John Fields wrote: On Thu, 16 Jun 2005 20:08:19 -0800, (Floyd L. Davidson) wrote: Learn to read. People cannot understand the statement 'Water can "boil" at 0C too.' have a problem with the English language. I you are going to claim you speak English as a second language, I'll listen, otherwise not. All this pedantic nashing of teeth for people who can't even read common English syntax is amazing. --- LOL, learn to _write_, you idiotic ****! Not writing what *you* want to read is hardly an error on *my* part. --- Boy, are you an ignorant piece of ****! I'm not talking about what _I_ want to read, I'm talking about _your_ abysmal command of the language, as exemplified by that little outburst of yours to which I was responding. Read it again, and if it still sounds OK to you then you've got a bigger problem than just being thick. OK, I'll give you a break... The first sentence needs a "who" after "People" in order to make sense, although it's pretty humorous that you inadvertently chastised some folks' problem with being able to understand an improperly crafted sentence, while at the same time being the dumbass who crafted it, LOL! And "nashing" of teeth??? Tsk, tsk, tsk... BTW, asshole, how about let's see some of those flames you've been threatening about unleashing. -- John Fields Professional Circuit Designer |
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John Fields wrote:
On Fri, 17 Jun 2005 10:45:27 -0800, (Floyd L. Davidson) wrote: John Fields wrote: I'm not talking about what _I_ want to read, ... In fact, that's all you *ever* talk about. And "nashing" of teeth??? Tsk, tsk, tsk... Perfect example! --- Learn to use the language and its subtleties properly if you want to be considered learned or, at the very least, competent in American English. The omission of the 'g' at the beginning of 'nashing' is inexcusable and marks you as a churl. Spelling flames, John, just *do* become you perfectly! -- Floyd L. Davidson http://web.newsguy.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
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On 6/17/05 3:59 PM, in article ,
"John Fields" wrote: On Fri, 17 Jun 2005 10:45:27 -0800, (Floyd L. Davidson) wrote: John Fields wrote: I'm not talking about what _I_ want to read, ... In fact, that's all you *ever* talk about. And "nashing" of teeth??? Tsk, tsk, tsk... Perfect example! --- Learn to use the language and its subtleties properly if you want to be considered learned or, at the very least, competent in American English. The omission of the 'g' at the beginning of 'nashing' is inexcusable and marks you as a churl. This type of discussion is pointless and harmful. I've known brilliant people, some at Bell Labs, who had difficulty spelling. Some Engineers and Scientists had excellent command of the language (both English and English!), but weren't as "swift" as the ones with language usage or spelling problems. It's the luck of the draw either way. It's quite difficult sometimes, but lets all try to be a bit nicer. Awaiting flames..... Don |
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On Thu, 16 Jun 2005 21:58:48 -0500, "operator jay"
wrote: Either what I wrote did not come out how I intended, or you disagree that de's can be used to solve a circuit. You almost alluded to de's before so probably that's not it. So to Mr. Kelly, let me rephrase that to a more bland "Yes. Although I guess one could use time domain." Apologies. Didn't get what you meant by "de's." It is now somewhat apparent that you mean "differential equations." So ok then, apologies all around. And to you, too, Al. I'm sorry. Sorry you got fired from the cafeteria at Motorola. After 30 years "in electronics" that's a pretty hard break for the "Kitchen Man". Actually, I've never worked for Motorola. I didn't even know they had a cafeteria. They have some nice cafeterias at Microsoft, but I've never worked for them, either. You must have me confused with some other guy who's good in the kitchen *and* the garage. It happens. -- Al Brennan "If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe." Nicola Tesla |
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The fundamental problem with the term "DC sine wave" is that it
suggests a way of viewing the situation which is incompatible with finding answers to the posed questions. To answer the question, the offset AC waveform has to be considered as the sum or a DC voltage and an AC component, with their effects on the R, L, and C analyzed seperately. The L and the C don't care about your DC offset, so you must still think of the signal as AC in order to understand their behavior. They don't care that the overall signal doesn't reverse polarity, they only care that derivative of voltage with respect to time is non-zero. |
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On Fri, 17 Jun 2005 15:55:50 -0800, (Floyd L.
Davidson) wrote: John Fields wrote: On Fri, 17 Jun 2005 10:45:27 -0800, (Floyd L. Davidson) wrote: John Fields wrote: I'm not talking about what _I_ want to read, ... In fact, that's all you *ever* talk about. And "nashing" of teeth??? Tsk, tsk, tsk... Perfect example! --- Learn to use the language and its subtleties properly if you want to be considered learned or, at the very least, competent in American English. The omission of the 'g' at the beginning of 'nashing' is inexcusable and marks you as a churl. Spelling flames, John, just *do* become you perfectly! --- Flame or not, the fact remains that you posit yourself as an arbiter of the proper use of the language and yet clumsily (and helplessly, it seems) make errors which belie your claim. I like to point them out because they're just another example of your hypocrisy and I wouldn't want you to think that your bull**** went undetected. -- John Fields Professional Circuit Designer |
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On Sat, 18 Jun 2005 10:53:48 GMT, TokaMundo
wrote: On Sat, 18 Jun 2005 04:56:59 -0500, John Fields Gave us: Flame or not, the fact remains that you posit yourself as an arbiter of the proper use of the language and yet clumsily (and helplessly, it seems) make errors which belie your claim. I like to point them out because they're just another example of your hypocrisy and I wouldn't want you to think that your bull**** went undetected. John Fields Professional Circuit Designer I'd say very much so LESS than professional. --- I'm sure this will come as a great shock to you, but your commentary is unimportant. -- John Fields Professional Circuit Designer |
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ehsjr wrote:
wrote: The L and the C don't care about your DC offset, so you must still think of the signal as AC in order to understand their behavior. They don't care that the overall signal doesn't reverse polarity, they only care that derivative of voltage with respect to time is non-zero. Er - there are cases where the L will be saturated by the DC component. Ed What you are suggesting is a good issue to keep in mind for the real world (and one I had overlooked). However, what you have actually said is not true. An inductance - a specific element we both referred to as L - will not saturate. Rather it will behave in accordance with the simple mathematical model of inductance. The real-world magnetic device chosen to play the role of an inductor can saturate, and it's something we might need to think about. However the propensity towards saturation would need to be specified by additional parameters beyond a simple constant value of L. While we're at it, we should put in parasitic resistance, temperature dependence, possible effects of external fields, and probably some other things that I'm not thinking about. If asked to solve a problem with an inductance, you treat it as such. If asked to solve a problem with an inductor, you have to consider the broader properties of that device, of which inductance is only one, and not necesssarily a constant one. |
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