Very low power dynamo (alternator actually).
With JF and JT at each other, it looks like the Thanksgiving Diner sleep is over. Let the flame wars begin !!! ;-) |
Very low power dynamo (alternator actually).
On Tue, 29 Nov 2011 19:41:20 -0700, hamilton
wrote: With JF and JT at each other, it looks like the Thanksgiving Diner sleep is over. Let the flame wars begin !!! ;-) Your reading comprehension is lacking. We were both talking of how to handle Ian Field. You fail to note that I don't see an _original_ Ian Field post... I've had him killfiled for years. I was just adding on to JF's commentary. Likewise with that dork-of-all-dorks, John Larkin ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
"hamilton" wrote in message ... With JF and JT at each other, it looks like the Thanksgiving Diner sleep is over. Let the flame wars begin !!! As you can see from his reply to you, the cowardly lowlife JT has me KFd but takes any and every opportunity to hurl insults at me through other people. He is a troll and should be treated as such. |
Very low power dynamo (alternator actually).
"John Fields" wrote in message ... On Tue, 29 Nov 2011 22:43:33 -0000, "Ian Field" wrote: "John Fields" wrote in message . .. On Tue, 29 Nov 2011 15:43:20 -0000, "Ian Field" wrote: "Artemus" wrote in message ... "John Larkin" wrote in message ... On Sun, 27 Nov 2011 19:50:15 -0000, "Ian Field" wrote: "Jim Thompson" wrote in message ... On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, but not for the reason Larkin claims... no surprise ;-) ...Jim Thompson That's all we need - the schoolyard bully just turned up! And, as usual, he offers no actual information. John Jim makes you think. He might make you think (I shudder to think what about!!!), --- You should shudder, since you seem to have so little technical acumen and he isn't afraid to point you out as the village idiot. --- but when he's not posting his inane political rants, the thing I see him doing most is hurling insults at people he doesn't agree with - he was straight on the attack (totally unprovoked) at JL and didn't take long to follow up by calling me a village idiot. --- Why should it, when it certainly doesn't take long to state the obvious? --- He fits the profile of a troll perfectly - every time I post a question he turns it into a flame war and prevents me getting any answers. --- Please... You're just not important enough to be flamed for honest questions you ask and, as far as I can tell, you aren't. What you _do_ get flamed for is being an arrogant little prig. --- You soon get to know who people are - birds of a feather stick together. --- It's: "Birds of a feather flock together." Birds which stick together don't need to be "of a feather", they just need to land in an oil slick. -- JF Just keep on trolling - it suits me you showing your true colours. --- Then it should please you to know that because of the true colors of my lure, on which you bit, I don't have to troll anymore, on your case, since I've got you well and truly hooked. All that's left now is to exhaust you as I reel you in and decide what to do with you when you're thrashing around, gasping for breath, on my deck. I'll probably let you live, and throw you back into the melee with the lesson you learned which saved your life. -- JF Well you've successfully sabotaged my question - I'm sure you must be a very proud little troll. |
Very low power dynamo (alternator actually).
On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin
wrote: On Tue, 29 Nov 2011 15:45:26 -0000, "Ian Field" wrote: "John Larkin" wrote in message . .. On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John Just ignore the troll JT - every time I ask a question, him and JF troll up a flame war so I don't get any answers. JF doesn't understand enough to furnish help, --- Geez, I guess you either missed the "6 bit binary attenuator thread", the "Pots, loads, and nonlinearities" thread, the "Series, parallel, and series-parallel loads" thread, the "My God it works!" thread, the "Tracking ADC" thread, and the "Another question for those in the know" thread, or are just trying to spread rumors, misinformation and lies, as is your wont. --- and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help it's usually in the form of a fully annotated schematic and the resultant relevant waveforms from a simulation, so you, with your: "Figure out the values for yourself." schematics and your: "I know how his works and you don't" attitude are hardly in a position to be criticizing anyone about giving help. -- JF |
Very low power dynamo (alternator actually).
On Wed, 30 Nov 2011 15:44:47 -0000, "Ian Field"
wrote: "hamilton" wrote in message ... With JF and JT at each other, it looks like the Thanksgiving Diner sleep is over. Let the flame wars begin !!! As you can see from his reply to you, the cowardly lowlife JT has me KFd but takes any and every opportunity to hurl insults at me through other people. --- Does his filtering you because he doesn't want to wade through your **** on a daily basis make him a cowardly lowlife? Certainly not; it makes him sensible because there's really very little substance in any of your drivel. Does his sniping at you occasionally through others' posts make him a cowardly lowlife? Certainly not, since you can snipe back at through others' posts like you just did via Hamilton. Or maybe that makes you a cowardly lowlife too? --- He is a troll and should be treated as such. --- And just what kind of treatment did you have in mind, Nancy? -- JF |
Very low power dynamo (alternator actually).
On Wed, 30 Nov 2011 15:46:41 -0000, "Ian Field"
wrote: "John Fields" wrote in message .. . On Tue, 29 Nov 2011 22:43:33 -0000, "Ian Field" wrote: Just keep on trolling - it suits me you showing your true colours. --- Then it should please you to know that because of the true colors of my lure, on which you bit, I don't have to troll anymore, on your case, since I've got you well and truly hooked. All that's left now is to exhaust you as I reel you in and decide what to do with you when you're thrashing around, gasping for breath, on my deck. I'll probably let you live, and throw you back into the melee with the lesson you learned which saved your life. -- JF Well you've successfully sabotaged my question - I'm sure you must be a very proud little troll. --- ISTM that you've asked your question and that it's been answered many times, so I haven't sabotaged anything. On the contrary, ever since you got the right answer from Larkin, all you've been doing is arguing about that you don't think this'll work, and you don't think that'll work either, or it's too inconvenient, or too much work to try, and blah, blah, blah, blah, blah. Getting the picture? You're your own worst enemy, you spoiled brat. -- JF |
Very low power dynamo (alternator actually).
On Tue, 29 Nov 2011 15:31:58 -0000, "Ian Field"
wrote: "John Fields" wrote in message .. . On Mon, 28 Nov 2011 14:38:05 -0000, "Ian Field" wrote: "John Fields" wrote in message ... On Mon, 28 Nov 2011 13:29:16 -0000, "Ian Field" wrote: "John Fields" wrote in message om... On Sun, 27 Nov 2011 18:47:01 -0000, "Ian Field" wrote: FYI: I'm already getting more than 3W by using a voltage doubling bridge rectifier, --- How are you managing to double the voltage using a bridge rectifier? -- JF You don't know!!! --- Don't be ridiculous; I'm just interested in how _you're_ managing to do it. -- JF Same way as all those PC PSUs (and loads of other things) that have 2 electrolytics in the rectifier/reservoir and a 110/230V jumper link. --- So you're wasting two diodes and a switch? -- JF I don't think you've quite recovered from being dropped on your head (several times!). --- You'll be in 6th grade next year, huh? --- There was a very strong temptation not to dignify your idiotic comment with a response, however since you appear to be an absolute novice I will try as hard as I can to educate you. It started off as a plain bridge rectifier, but I used a "trick of the trade" --- The Delon circuit. --- of adding voltage doubler capacitors - although the SLA battery will prevent it actually doubling, in trying to do so it will force the alternator to push more current. --- Think so? Why not measure it and find out for sure? -- JF |
Very low power dynamo (alternator actually).
On Sun, 27 Nov 2011 14:56:00 -0000, "Ian Field"
wrote: Tinkering with the old Sturmey archer bicycle dynamo, I was wondering whether it would charge a 1.2Ah SLA any better if the loading was modified. The generator is rated 6V/3W, but off load at a decent rate of knots it can produce over a couple of hundred volts. What I was wondering was whether its possible to get more energy into the battery by letting the generator output voltage stretch its legs so to speak and convert the excessive voltage down with a buck converter. Can anyone advise on the practicality of this please? Thanks. Bwahahahahaha! So this was the original post? Bwahahahahaha! ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
"Jim Thompson" wrote in message ... On Tue, 29 Nov 2011 16:50:02 -0600, John Fields wrote: On Mon, 28 Nov 2011 16:51:45 -0800, John Larkin wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John --- And, indeed, it would be, would not Mother Nature conspire against it with the spoiler, resistance. When Larkin sets out to put his foot in it he just can't resist squishing his foot around to make sure it sticks. Suggestion to Larkin: Set up loose connection at battery post... connects but you can pull connector off easily. With engine running at 3000RPM (you'll need a helper, maybe Ian Field :-), right hand on car frame, left hand at battery post, take firm hold of connector and pull quickly off of battery. Unless you happen to have an alternator with built-in zeners to limit voltage, you will be dead... or at least multiple broken bones... it's a pulse. You do know what a "pulse" is? Then come back and talk to me about "infinite" ;-) Young bucks... DON'T try this... this instruction for Larkin-disposal purposes only! (Before zeners were added to alternators I had to design to a 400V kick, and have the regulator survive. How did I do it?) ...Jim Thompson My 95' GM alternator uses Avalanche diodes in it. It would not survive that test. Nor will it survive with a loose battery connection. Somewhere in the manual it says not to use for welding. Cheers |
Very low power dynamo (alternator actually).
"Martin Riddle" wrote in message ... "Jim Thompson" wrote in message ... On Tue, 29 Nov 2011 16:50:02 -0600, John Fields wrote: On Mon, 28 Nov 2011 16:51:45 -0800, John Larkin wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John --- And, indeed, it would be, would not Mother Nature conspire against it with the spoiler, resistance. When Larkin sets out to put his foot in it he just can't resist squishing his foot around to make sure it sticks. Suggestion to Larkin: Set up loose connection at battery post... connects but you can pull connector off easily. With engine running at 3000RPM (you'll need a helper, maybe Ian Field :-), right hand on car frame, left hand at battery post, take firm hold of connector and pull quickly off of battery. Unless you happen to have an alternator with built-in zeners to limit voltage, you will be dead... or at least multiple broken bones... it's a pulse. You do know what a "pulse" is? Then come back and talk to me about "infinite" ;-) Young bucks... DON'T try this... this instruction for Larkin-disposal purposes only! (Before zeners were added to alternators I had to design to a 400V kick, and have the regulator survive. How did I do it?) ...Jim Thompson My 95' GM alternator uses Avalanche diodes in it. It would not survive that test. Nor will it survive with a loose battery connection. Somewhere in the manual it says not to use for welding. Cheers An interesting point about motorcycle alternators is that many are permanent magnet type with 3-ph windings, regulation is accomplished by adding 3 SCRs in parallel with the 3 bottom diodes in the rectifier and using them to short the alternator when the battery V gets too high. The single ph alternators on smaller/older bikes are less brutal - only having one thyristor which leaves one arm of the bridge rectifier rectifying. If you rev it with no load it can give a nasty shock, I've no idea whether they have OV protection and I've never had one fail because of running off load (probably because I'm careful to avoid doing that). |
Very low power dynamo (alternator actually).
"Fred Abse" wrote in message d... On Tue, 29 Nov 2011 22:54:39 +0000, Ian Field wrote: You're a troll - that's all the evidence needed. A troll with eighteen patents How many MC1488/MC1489 have you used in your lifetime? The political rants he posts here alone speak for themselves. Then his remarks to/or about people foolish enough to ask a question here are becoming increasingly offensive. He might have been a great hero before he lost his marbles - now he just acts like a troll. |
Very low power dynamo (alternator actually).
On Thu, 01 Dec 2011 11:24:26 -0800, Fred Abse
wrote: On Tue, 29 Nov 2011 22:54:39 +0000, Ian Field wrote: You're a troll - that's all the evidence needed. A troll with eighteen patents How many MC1488/MC1489 have you used in your lifetime? Yep. My all-time biggest seller, though my venerable MC1530/31 OpAmp is _still_ being manufactured by Lansdale. But there's also the USB stuff I did for Intel... the numbers there have to be _really_high_! ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
On 12/1/2011 12:43 PM, Jim Thompson wrote:
On Thu, 01 Dec 2011 11:24:26 -0800, Fred Abse wrote: On Tue, 29 Nov 2011 22:54:39 +0000, Ian Field wrote: You're a troll - that's all the evidence needed. A troll with eighteen patents How many MC1488/MC1489 have you used in your lifetime? Yep. My all-time biggest seller, though my venerable MC1530/31 OpAmp is _still_ being manufactured by Lansdale. But there's also the USB stuff I did for Intel... the numbers there have to be _really_high_! ...Jim Thompson Are you still getting royalties ?? |
Very low power dynamo (alternator actually).
Fred Abse wrote: On Tue, 29 Nov 2011 22:54:39 +0000, Ian Field wrote: You're a troll - that's all the evidence needed. A troll with eighteen patents How many MC1488/MC1489 have you used in your lifetime? I should have over 100 of each in my inventory. This area gets a lot of lightning, and I used lots of them. -- You can't have a sense of humor, if you have no sense. |
Very low power dynamo (alternator actually).
On Thu, 01 Dec 2011 14:52:11 -0700, hamilton
wrote: On 12/1/2011 12:43 PM, Jim Thompson wrote: On Thu, 01 Dec 2011 11:24:26 -0800, Fred Abse wrote: On Tue, 29 Nov 2011 22:54:39 +0000, Ian Field wrote: You're a troll - that's all the evidence needed. A troll with eighteen patents How many MC1488/MC1489 have you used in your lifetime? Yep. My all-time biggest seller, though my venerable MC1530/31 OpAmp is _still_ being manufactured by Lansdale. But there's also the USB stuff I did for Intel... the numbers there have to be _really_high_! ...Jim Thompson Are you still getting royalties ?? No. "It was work for hire." But I was paid well ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
On Wed, 30 Nov 2011 11:31:35 -0600, John Fields
wrote: On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin wrote: On Tue, 29 Nov 2011 15:45:26 -0000, "Ian Field" wrote: "John Larkin" wrote in message ... On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John Just ignore the troll JT - every time I ask a question, him and JF troll up a flame war so I don't get any answers. JF doesn't understand enough to furnish help, --- Geez, I guess you either missed the "6 bit binary attenuator thread", which you got wrong the "Pots, loads, and nonlinearities" thread, which was done better in the Radiotron Handbook, about 50 years ago the "Series, parallel, and series-parallel loads" thread, the "My God it works!" thread, the "Tracking ADC" thread, and the "Another question for those in the know" thread, or are just trying to spread rumors, misinformation and lies, as is your wont. yawn. --- and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help He rarely does. He has just declared that alternators are current sources (which they obviously aren't) but won't say why. it's usually in the form of a fully annotated schematic No, it's usually a boast, an off-topic redneck political rant, a claim that he knows something but won't say, or a search for help for some tacky honeydoo project. John |
Very low power dynamo (alternator actually).
On Thu, 1 Dec 2011 14:33:24 -0000, "Ian Field"
wrote: "Martin Riddle" wrote in message ... "Jim Thompson" wrote in message ... On Tue, 29 Nov 2011 16:50:02 -0600, John Fields wrote: On Mon, 28 Nov 2011 16:51:45 -0800, John Larkin wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John --- And, indeed, it would be, would not Mother Nature conspire against it with the spoiler, resistance. When Larkin sets out to put his foot in it he just can't resist squishing his foot around to make sure it sticks. Suggestion to Larkin: Set up loose connection at battery post... connects but you can pull connector off easily. With engine running at 3000RPM (you'll need a helper, maybe Ian Field :-), right hand on car frame, left hand at battery post, take firm hold of connector and pull quickly off of battery. Unless you happen to have an alternator with built-in zeners to limit voltage, you will be dead... or at least multiple broken bones... it's a pulse. You do know what a "pulse" is? Then come back and talk to me about "infinite" ;-) Young bucks... DON'T try this... this instruction for Larkin-disposal purposes only! (Before zeners were added to alternators I had to design to a 400V kick, and have the regulator survive. How did I do it?) ...Jim Thompson My 95' GM alternator uses Avalanche diodes in it. It would not survive that test. Nor will it survive with a loose battery connection. Somewhere in the manual it says not to use for welding. Cheers An interesting point about motorcycle alternators is that many are permanent magnet type with 3-ph windings, regulation is accomplished by adding 3 SCRs in parallel with the 3 bottom diodes in the rectifier and using them to short the alternator when the battery V gets too high. A lot of aircraft alternator regulators do that, short the winding to regulate. Probably to avoid huge terminal voltages that you'd get by using some sort of series regulator. John |
Very low power dynamo (alternator actually).
On Tue, 29 Nov 2011 16:06:51 -0700, Jim Thompson
wrote: On Tue, 29 Nov 2011 16:50:02 -0600, John Fields wrote: On Mon, 28 Nov 2011 16:51:45 -0800, John Larkin wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John --- And, indeed, it would be, would not Mother Nature conspire against it with the spoiler, resistance. When Larkin sets out to put his foot in it he just can't resist squishing his foot around to make sure it sticks. Suggestion to Larkin: Set up loose connection at battery post... connects but you can pull connector off easily. With engine running at 3000RPM (you'll need a helper, maybe Ian Field :-), right hand on car frame, left hand at battery post, take firm hold of connector and pull quickly off of battery. Unless you happen to have an alternator with built-in zeners to limit voltage, you will be dead... or at least multiple broken bones... it's a pulse. You do know what a "pulse" is? Then come back and talk to me about "infinite" ;-) Pulse? There will be an initial ringing spike, then high voltage AC for as long as the field holds up... forever for a PM alternator like the one discussed here. "Pulse" is a cartoon of what the waveform will be. But it's not a current source. Young bucks... DON'T try this... this instruction for Larkin-disposal purposes only! (Before zeners were added to alternators I had to design to a 400V kick, and have the regulator survive. How did I do it?) ...Jim Thompson As I said, it's an AC voltage in series with an inductance. The current into a low-impedance load is relatively constant as speed varies above some threshold. But that doesn't make it a current source; at any speed and excitation, it has a finite impedance and a finite open-circuit voltage. John |
Very low power dynamo (alternator actually).
On Thu, 01 Dec 2011 16:24:02 -0800, John Larkin
wrote: On Wed, 30 Nov 2011 11:31:35 -0600, John Fields wrote: On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin wrote: On Tue, 29 Nov 2011 15:45:26 -0000, "Ian Field" wrote: "John Larkin" wrote in message m... On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John Just ignore the troll JT - every time I ask a question, him and JF troll up a flame war so I don't get any answers. JF doesn't understand enough to furnish help, --- Geez, I guess you either missed the "6 bit binary attenuator thread", which you got wrong --- Only the parts where the formula in the book led me astray, and which I found, fixed, and documented when you pointed out that there were errors. You certainly had no hand in it since all you ever do is accuse, malign, and declare yourself king of the heap. --- the "Pots, loads, and nonlinearities" thread, which was done better in the Radiotron Handbook, about 50 years ago --- LTspice examples were given in the 1961 handbook??? --- the "Series, parallel, and series-parallel loads" thread, the "My God it works!" thread, the "Tracking ADC" thread, and the "Another question for those in the know" thread, or are just trying to spread rumors, misinformation and lies, as is your wont. yawn. --- Typical. Feigning boredom when the ability to respond, and save face, is lacking. --- and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help He rarely does. He has just declared that alternators are current sources (which they obviously aren't) but won't say why. --- If they obviously aren't, then why don't you counter with why they aren't? BTW, if you swing a magnet past a wire, what's induced in the wire? --- it's usually in the form of a fully annotated schematic No, it's usually a boast, an off-topic redneck political rant, a claim that he knows something but won't say, or a search for help for some tacky honeydoo project. --- None of those are examples of _help_ that he furnishes, so they're really extraneous, irrelevant to the discussion and, indeed, are paralleled by some of _your_ "contributions." -- JF |
Very low power dynamo (alternator actually).
On Fri, 02 Dec 2011 06:23:36 -0600 John Fields
wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? |
Very low power dynamo (alternator actually).
On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote:
On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
"John Larkin" wrote in message ... On Wed, 30 Nov 2011 11:31:35 -0600, John Fields wrote: On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin wrote: On Tue, 29 Nov 2011 15:45:26 -0000, "Ian Field" wrote: "John Larkin" wrote in message m... On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John Just ignore the troll JT - every time I ask a question, him and JF troll up a flame war so I don't get any answers. JF doesn't understand enough to furnish help, --- Geez, I guess you either missed the "6 bit binary attenuator thread", which you got wrong the "Pots, loads, and nonlinearities" thread, which was done better in the Radiotron Handbook, about 50 years ago the "Series, parallel, and series-parallel loads" thread, the "My God it works!" thread, the "Tracking ADC" thread, and the "Another question for those in the know" thread, or are just trying to spread rumors, misinformation and lies, as is your wont. yawn. --- and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help He rarely does. He has just declared that alternators are current sources (which they obviously aren't) but won't say why. it's usually in the form of a fully annotated schematic No, it's usually a boast, an off-topic redneck political rant, a claim that he knows something but won't say, or a search for help for some tacky honeydoo project. John I've KFd the 2 trolls (JF & JT) - I can't stop them attacking whenever I post a question, but at least I don't have to read it. |
Very low power dynamo (alternator actually).
"John Larkin" wrote in message ... On Thu, 1 Dec 2011 14:33:24 -0000, "Ian Field" wrote: "Martin Riddle" wrote in message ... "Jim Thompson" wrote in message ... On Tue, 29 Nov 2011 16:50:02 -0600, John Fields wrote: On Mon, 28 Nov 2011 16:51:45 -0800, John Larkin wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John --- And, indeed, it would be, would not Mother Nature conspire against it with the spoiler, resistance. When Larkin sets out to put his foot in it he just can't resist squishing his foot around to make sure it sticks. Suggestion to Larkin: Set up loose connection at battery post... connects but you can pull connector off easily. With engine running at 3000RPM (you'll need a helper, maybe Ian Field :-), right hand on car frame, left hand at battery post, take firm hold of connector and pull quickly off of battery. Unless you happen to have an alternator with built-in zeners to limit voltage, you will be dead... or at least multiple broken bones... it's a pulse. You do know what a "pulse" is? Then come back and talk to me about "infinite" ;-) Young bucks... DON'T try this... this instruction for Larkin-disposal purposes only! (Before zeners were added to alternators I had to design to a 400V kick, and have the regulator survive. How did I do it?) ...Jim Thompson My 95' GM alternator uses Avalanche diodes in it. It would not survive that test. Nor will it survive with a loose battery connection. Somewhere in the manual it says not to use for welding. Cheers An interesting point about motorcycle alternators is that many are permanent magnet type with 3-ph windings, regulation is accomplished by adding 3 SCRs in parallel with the 3 bottom diodes in the rectifier and using them to short the alternator when the battery V gets too high. A lot of aircraft alternator regulators do that, short the winding to regulate. Probably to avoid huge terminal voltages that you'd get by using some sort of series regulator. I can't understand why more manufacturers haven't made quicker progress toward field controlled alternators, it doesn't have to be about reliability issues with slip rings and brushes, some of the later motorcycle alternators have a kind of co-axial pole cage coupling to the interleaved pole fingers mounted on the end of the crankshaft - the field winding is static as well as the stator. Wouldn't be surprised if car alternators went that way long ago. |
Very low power dynamo (alternator actually).
On Fri, 02 Dec 2011 06:23:36 -0600, John Fields
wrote: On Thu, 01 Dec 2011 16:24:02 -0800, John Larkin wrote: On Wed, 30 Nov 2011 11:31:35 -0600, John Fields wrote: On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin wrote: [snip] and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help He rarely does. He has just declared that alternators are current sources (which they obviously aren't) but won't say why. Seems I referred Larkin to patents, which Larkin obviously either hasn't read or can't understand... I suspect the latter. --- If they obviously aren't, then why don't you counter with why they aren't? Larkin has no clue. BTW, if you swing a magnet past a wire, what's induced in the wire? Larkin thinks it's a voltage :-) --- it's usually in the form of a fully annotated schematic You bet, and tested... I avoid posting things that _can't_possibly_work_, but Larkin posts _only_ those things. No, it's usually a boast, an off-topic redneck political rant, Yes, I do fret over the situation that Obama has acerbated. claim that he knows something but won't say, Often only to taunt Larkin, but sometimes because it's a patent application in progress. I do have 18 patents, How many does Larkin have? I bet that if he has any, they're pansy claims :-) or a search for help for some tacky honeydoo project. "Tacky"? My honey-do projects have more sophistication than Larkin's company products. Though he does admit he uses chips I've designed :-) --- None of those are examples of _help_ that he furnishes, so they're really extraneous, irrelevant to the discussion and, indeed, are paralleled by some of _your_ "contributions." Thanks, JF! ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
"John Larkin" wrote in message ... On Tue, 29 Nov 2011 16:06:51 -0700, Jim Thompson wrote: On Tue, 29 Nov 2011 16:50:02 -0600, John Fields wrote: On Mon, 28 Nov 2011 16:51:45 -0800, John Larkin wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John --- And, indeed, it would be, would not Mother Nature conspire against it with the spoiler, resistance. When Larkin sets out to put his foot in it he just can't resist squishing his foot around to make sure it sticks. Suggestion to Larkin: Set up loose connection at battery post... connects but you can pull connector off easily. With engine running at 3000RPM (you'll need a helper, maybe Ian Field :-), right hand on car frame, left hand at battery post, take firm hold of connector and pull quickly off of battery. Unless you happen to have an alternator with built-in zeners to limit voltage, you will be dead... or at least multiple broken bones... it's a pulse. You do know what a "pulse" is? Then come back and talk to me about "infinite" ;-) Pulse? There will be an initial ringing spike, then high voltage AC for as long as the field holds up... forever for a PM alternator like the one discussed here. "Pulse" is a cartoon of what the waveform will be. But it's not a current source. Young bucks... DON'T try this... this instruction for Larkin-disposal purposes only! (Before zeners were added to alternators I had to design to a 400V kick, and have the regulator survive. How did I do it?) ...Jim Thompson As I said, it's an AC voltage in series with an inductance. The current into a low-impedance load is relatively constant as speed varies above some threshold. But that doesn't make it a current source; at any speed and excitation, it has a finite impedance and a finite open-circuit voltage. I remember as a kid I borrowed a neighbour's (electrician) multimeter intending to measure the current output of a Sturmey Archer hub dynamo (6V/0.3A) and bent the pointer on the 10A range. Regarding motorcycle alternators (PM type) I'm reasonably familiar with the Honda one's - output rises steadily until it levels out at 5000rpm - pretty sure thats down to inductance. |
Very low power dynamo (alternator actually).
On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote:
On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? --- Let's say its ends are connected to each other. -- JF |
Very low power dynamo (alternator actually).
On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson
wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. It's sure not a current source. John |
Very low power dynamo (alternator actually).
On Fri, 2 Dec 2011 14:59:35 -0000, "Ian Field"
wrote: "John Larkin" wrote in message .. . On Wed, 30 Nov 2011 11:31:35 -0600, John Fields wrote: On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin wrote: On Tue, 29 Nov 2011 15:45:26 -0000, "Ian Field" wrote: "John Larkin" wrote in message om... On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John Just ignore the troll JT - every time I ask a question, him and JF troll up a flame war so I don't get any answers. JF doesn't understand enough to furnish help, --- Geez, I guess you either missed the "6 bit binary attenuator thread", which you got wrong the "Pots, loads, and nonlinearities" thread, which was done better in the Radiotron Handbook, about 50 years ago the "Series, parallel, and series-parallel loads" thread, the "My God it works!" thread, the "Tracking ADC" thread, and the "Another question for those in the know" thread, or are just trying to spread rumors, misinformation and lies, as is your wont. yawn. --- and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help He rarely does. He has just declared that alternators are current sources (which they obviously aren't) but won't say why. it's usually in the form of a fully annotated schematic No, it's usually a boast, an off-topic redneck political rant, a claim that he knows something but won't say, or a search for help for some tacky honeydoo project. John I've KFd the 2 trolls (JF & JT) - I can't stop them attacking whenever I post a question, but at least I don't have to read it. Don't worry about missing useful comments they have made about alternators, because there are none. John |
Very low power dynamo (alternator actually).
"John Larkin" wrote in message ... On Fri, 2 Dec 2011 14:59:35 -0000, "Ian Field" wrote: "John Larkin" wrote in message . .. On Wed, 30 Nov 2011 11:31:35 -0600, John Fields wrote: On Tue, 29 Nov 2011 08:44:40 -0800, John Larkin wrote: On Tue, 29 Nov 2011 15:45:26 -0000, "Ian Field" wrote: "John Larkin" wrote in message news:l3b8d75ti0st7uq9q3qcau8a8ogm6jdiku@4ax. com... On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: On Sun, 27 Nov 2011 10:50:39 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 10:28:17 -0800, John Larkin wrote: Alternators like this are often designed with a lot of internal series inductance. As speed increases, open-circuit terminal voltage increases, but the series inductance impedance increases too, tending to make them constant-current sources, ideal for driving light bulbs at sorta constant brightness at various speeds. What I was going to say. I think there is an ancient patent somewhere about just that. Well! Alternators _are_ current sources, Ah, so their terminal voltage must be infinite. John Just ignore the troll JT - every time I ask a question, him and JF troll up a flame war so I don't get any answers. JF doesn't understand enough to furnish help, --- Geez, I guess you either missed the "6 bit binary attenuator thread", which you got wrong the "Pots, loads, and nonlinearities" thread, which was done better in the Radiotron Handbook, about 50 years ago the "Series, parallel, and series-parallel loads" thread, the "My God it works!" thread, the "Tracking ADC" thread, and the "Another question for those in the know" thread, or are just trying to spread rumors, misinformation and lies, as is your wont. yawn. --- and JT might occasionally, within his narrow range of expertise, but all he wants to do is strut about past glories and inflate his ego, and doesn't actually want to be helpful. Both are sad old fools. --- When Jim furnishes help He rarely does. He has just declared that alternators are current sources (which they obviously aren't) but won't say why. it's usually in the form of a fully annotated schematic No, it's usually a boast, an off-topic redneck political rant, a claim that he knows something but won't say, or a search for help for some tacky honeydoo project. John I've KFd the 2 trolls (JF & JT) - I can't stop them attacking whenever I post a question, but at least I don't have to read it. Don't worry about missing useful comments they have made about alternators, because there are none. John JF hurls insults while claiming to have answered my question, JT just hurls insults - he might have once been one of the great pillars of the electronics industry, but now he's just a bad tempered and bitter old fart. I've absolutely no fear of missing anything worth reading from those two. |
Very low power dynamo (alternator actually).
On Fri, 02 Dec 2011 11:45:49 -0800, John Larkin
wrote: On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. --- If one were to connect a voltmeter across the otherwise open ends of a conductor, and that conductor was excited by a varying magnetic field, the voltmeter would indeed register a varying voltage. The underlying cause, however, would be the concentration and dilution of charge at the ends of the wire. That concentration and dilution would be caused by the movement of electrons in the wire, that movement being defined as current. -- JF |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 04:24:47 -0600, John Fields
wrote: On Fri, 02 Dec 2011 11:45:49 -0800, John Larkin wrote: On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. --- If one were to connect a voltmeter across the otherwise open ends of a conductor, and that conductor was excited by a varying magnetic field, the voltmeter would indeed register a varying voltage. After I posted I realized I'd put my foot in it because, in a way, that's how semiconductors work... particularly MOS. The underlying cause, however, would be the concentration and dilution of charge at the ends of the wire. Indeed. That concentration and dilution would be caused by the movement of electrons in the wire, that movement being defined as current. Yep. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 04:24:47 -0600, John Fields
wrote: On Fri, 02 Dec 2011 11:45:49 -0800, John Larkin wrote: On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. --- If one were to connect a voltmeter across the otherwise open ends of a conductor, and that conductor was excited by a varying magnetic field, the voltmeter would indeed register a varying voltage. The underlying cause, however, would be the concentration and dilution of charge at the ends of the wire. That concentration and dilution would be caused by the movement of electrons in the wire, that movement being defined as current. Blather. John |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 07:28:08 -0800, Fred Abse
wrote: On Fri, 02 Dec 2011 08:06:50 -0700, Jim Thompson wrote: BTW, if you swing a magnet past a wire, what's induced in the wire? Larkin thinks it's a voltage :-) I would have said an electromotive force. Something that will cause a current to flow, if it's got somewhere to go. Yes, I stand corrected. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 07:28:05 -0800, Fred Abse
wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: Well! Alternators _are_ current sources, but not for the reason Larkin claims... no surprise ;-) Are you referring to current limiting due to opposing flux cancellation? No. An alternator is a transformer, just that the primary is rotating. What do transformers transform? What is the mechanism? ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 08:23:23 -0700, Jim Thompson
wrote: On Sat, 03 Dec 2011 04:24:47 -0600, John Fields wrote: On Fri, 02 Dec 2011 11:45:49 -0800, John Larkin wrote: On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. --- If one were to connect a voltmeter across the otherwise open ends of a conductor, and that conductor was excited by a varying magnetic field, the voltmeter would indeed register a varying voltage. The only way to connect the voltmeter is to use leads. Then you have a loop. If you keep the leads very close to the wire, as you reduce the loop area, the voltage goes to zero. After I posted I realized I'd put my foot in it because, in a way, that's how semiconductors work... particularly MOS. Mosfets are magnetic devices? The underlying cause, however, would be the concentration and dilution of charge at the ends of the wire. Indeed. That concentration and dilution would be caused by the movement of electrons in the wire, that movement being defined as current. Yep. ...Jim Thompson OK: make a 1 meter radius wire ring with a small gap. Push through it a perpendicular, uniform magnetic field that ramps up at 1 T/second. What's the voltage across the gap? More importantly, what's the current in the wire? JF? JT? John |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 08:34:54 -0700, Jim Thompson
wrote: On Sat, 03 Dec 2011 07:28:05 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: Well! Alternators _are_ current sources, but not for the reason Larkin claims... no surprise ;-) Are you referring to current limiting due to opposing flux cancellation? No. An alternator is a transformer, just that the primary is rotating. What do transformers transform? What is the mechanism? ...Jim Thompson It's a transformer with a lot of leakage inductance. John |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 09:28:17 -0800, John Larkin
wrote: On Sat, 03 Dec 2011 08:23:23 -0700, Jim Thompson wrote: On Sat, 03 Dec 2011 04:24:47 -0600, John Fields wrote: On Fri, 02 Dec 2011 11:45:49 -0800, John Larkin wrote: On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. --- If one were to connect a voltmeter across the otherwise open ends of a conductor, and that conductor was excited by a varying magnetic field, the voltmeter would indeed register a varying voltage. The only way to connect the voltmeter is to use leads. Then you have a loop. If you keep the leads very close to the wire, as you reduce the loop area, the voltage goes to zero. After I posted I realized I'd put my foot in it because, in a way, that's how semiconductors work... particularly MOS. Mosfets are magnetic devices? The underlying cause, however, would be the concentration and dilution of charge at the ends of the wire. Indeed. That concentration and dilution would be caused by the movement of electrons in the wire, that movement being defined as current. Yep. ...Jim Thompson OK: make a 1 meter radius wire ring with a small gap. Push through it a perpendicular, uniform magnetic field that ramps up at 1 T/second. What's the voltage across the gap? More importantly, what's the current in the wire? JF? JT? --- JL. Since it's _you_ who's been taken to task, it behooves you to defend yourself. You're very big at telling people what to do, but tiny at doing your own legwork so, instead of pretending to authority, if you've got a point to make and you want to make it physically, why not just shut the **** up, do the work, and report back with findings which incontrovertibly quash your detractors? That is, since you proposed the experiment, why don't _you_ make a 1 meter radius wire ring with a small gap, push through it a perpendicular, uniform magnetic field that ramps up at 1 T/second, and report back with what happened? If you ever get to it, instead of just mouthing opinion I'd be interested in learning how the voltage across the gap changed, and especially interested in learning how you managed to measure the current in the unconnected wire. -- JF |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 09:30:29 -0800, John Larkin
wrote: On Sat, 03 Dec 2011 08:34:54 -0700, Jim Thompson wrote: On Sat, 03 Dec 2011 07:28:05 -0800, Fred Abse wrote: On Sun, 27 Nov 2011 12:06:24 -0700, Jim Thompson wrote: Well! Alternators _are_ current sources, but not for the reason Larkin claims... no surprise ;-) Are you referring to current limiting due to opposing flux cancellation? No. An alternator is a transformer, just that the primary is rotating. What do transformers transform? What is the mechanism? ...Jim Thompson It's a transformer with a lot of leakage inductance. John --- By your own admission it's still a transformer. JT 1 JL 0 -- JF |
Very low power dynamo (alternator actually).
On Sat, 03 Dec 2011 18:56:59 -0600, John Fields
wrote: On Sat, 03 Dec 2011 09:28:17 -0800, John Larkin wrote: On Sat, 03 Dec 2011 08:23:23 -0700, Jim Thompson wrote: On Sat, 03 Dec 2011 04:24:47 -0600, John Fields wrote: On Fri, 02 Dec 2011 11:45:49 -0800, John Larkin wrote: On Fri, 02 Dec 2011 07:51:45 -0700, Jim Thompson wrote: On Fri, 02 Dec 2011 09:11:00 -0500, JW wrote: On Fri, 02 Dec 2011 06:23:36 -0600 John Fields wrote in Message id: : BTW, if you swing a magnet past a wire, what's induced in the wire? Is the wire connected to anything? Bwahahahahaha! Larkin would opine that there's a voltage end-to-end. ;-) ...Jim Thompson It's an alternator. A voltage is induced, and the wire/coil has some impedance. --- If one were to connect a voltmeter across the otherwise open ends of a conductor, and that conductor was excited by a varying magnetic field, the voltmeter would indeed register a varying voltage. The only way to connect the voltmeter is to use leads. Then you have a loop. If you keep the leads very close to the wire, as you reduce the loop area, the voltage goes to zero. After I posted I realized I'd put my foot in it because, in a way, that's how semiconductors work... particularly MOS. Mosfets are magnetic devices? The underlying cause, however, would be the concentration and dilution of charge at the ends of the wire. Indeed. That concentration and dilution would be caused by the movement of electrons in the wire, that movement being defined as current. Yep. ...Jim Thompson OK: make a 1 meter radius wire ring with a small gap. Push through it a perpendicular, uniform magnetic field that ramps up at 1 T/second. What's the voltage across the gap? More importantly, what's the current in the wire? JF? JT? --- JL. Since it's _you_ who's been taken to task, it behooves you to defend yourself. You're very big at telling people what to do, but tiny at doing your own legwork so, instead of pretending to authority, if you've got a point to make and you want to make it physically, why not just shut the **** up, do the work, and report back with findings which incontrovertibly quash your detractors? That is, since you proposed the experiment, why don't _you_ make a 1 meter radius wire ring with a small gap, push through it a perpendicular, uniform magnetic field that ramps up at 1 T/second, and report back with what happened? It's impressive how much you and JT don't say about electronics, and the amazingly wide range of subjects in which you have no interest. If you ever get to it, instead of just mouthing opinion I'd be interested in learning how the voltage across the gap changed, and especially interested in learning how you managed to measure the current in the unconnected wire. You, not I, said that there would be current in such a wire. Can you explain how much? "Concentration and dilution" doesn't cut it. JT said there would be no voltage, but now seems to have changed his mind. Either you two never studied electromagnetics, or forgot what you were taught. But that doesn't stop you from blustering and pretending that you understand the basics. John |
All times are GMT +1. The time now is 05:51 AM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter