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#1
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Transformer Core Loss Test
Since I firmly advised ( :-0 ) Mr Stewart yesterday that testing for HF core loss can only be done with a single winding in place - I decided to try out my own suggestion. I had a standard 160 VA toroidal core (with plastic covers ) left over from an old project - so I would 40 turns of 1mm copper wire onto it, spread evenly around. I used a SS amplifier to drive the winding with a 2 ohm WW resistor in series to allow current sensing - a dual beam scope monitored the drive voltage and current waveforms. The input level was held at 5 volt rms and the traces overlapped on the scope screen to allow the relative phase angle to be measured at each frequency. Hz phi PF mA mW 50 36 0.8 100 400 100 35 0.82 85 348 300 35 0.82 58 239 1k 29 0.88 42 185 3k 25 0.91 34 155 10k 22 0.93 27 126 30k 23 0.92 21 97 100k 24 0.92 17 78 Points to note: 1. The phase angle is always lagging and fairly constant. 2. Both current and power fall with rising frequency all the way to 00kHz - and beyond. 3. The is no secondary winding to bugger things up. 4. The core was just showing signs of saturation at 50 Hz and 5 volts. 5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. ............ Phil |
#2
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Phil Allison wrote:
Since I firmly advised ( :-0 ) Mr Stewart yesterday that testing for HF core loss can only be done with a single winding in place - I decided to try out my own suggestion. I had a standard 160 VA toroidal core (with plastic covers ) left over from an old project - so I would 40 turns of 1mm copper wire onto it, spread evenly around. I used a SS amplifier to drive the winding with a 2 ohm WW resistor in series to allow current sensing - a dual beam scope monitored the drive voltage and current waveforms. The input level was held at 5 volt rms and the traces overlapped on the scope screen to allow the relative phase angle to be measured at each frequency. Hz phi PF mA mW 50 36 0.8 100 400 100 35 0.82 85 348 300 35 0.82 58 239 1k 29 0.88 42 185 3k 25 0.91 34 155 10k 22 0.93 27 126 30k 23 0.92 21 97 100k 24 0.92 17 78 Points to note: 1. The phase angle is always lagging and fairly constant. 2. Both current and power fall with rising frequency all the way to 00kHz - and beyond. 3. The is no secondary winding to bugger things up. 4. The core was just showing signs of saturation at 50 Hz and 5 volts. 5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. ........... Phil I am almost afraid to respond. But here goes. Useful information but I wonder about your current sensing resistor at 100KHz. It has inductance, a critical property in this kind of mesurement. That could yender data at the higher frequencies useless. I will dive into the nearest culvert in order to receive your response. JLS |
#3
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"John Stewart" I am almost afraid to respond. But here goes. Useful information ... ** Blows your putrid pseudo technical ****e right out of the water. but I wonder about your current sensing resistor at 100KHz. ** More asinine nit picking - the hall mark of a complete fool. It has inductance, a critical property in this kind of mesurement. That could yender data at the higher frequencies useless. ** You are totally wrong - YET AGAIN !!! The 2 ohm WW resistor used stays within 1% of value to well over 100 kHz - this is a very easy thing to test and I have done so. Self inductance is a serious issue with LOW value current shunts - ie of a few milliohms. EG For a 1 inch long copper wire of 1 sq.mm section ( = 0.45 mohms) - inductive reactance equals resistance at only 3kHz. I will dive into the nearest culvert in order to receive your response. ** One massive "Daisy Cutter" is headed your way - ****head. ................ Phil |
#4
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John Stewart wrote: Phil Allison wrote: Since I firmly advised ( :-0 ) Mr Stewart yesterday that testing for HF core loss can only be done with a single winding in place - I decided to try out my own suggestion. I had a standard 160 VA toroidal core (with plastic covers ) left over from an old project - so I would 40 turns of 1mm copper wire onto it, spread evenly around. I used a SS amplifier to drive the winding with a 2 ohm WW resistor in series to allow current sensing - a dual beam scope monitored the drive voltage and current waveforms. The input level was held at 5 volt rms and the traces overlapped on the scope screen to allow the relative phase angle to be measured at each frequency. Hz phi PF mA mW 50 36 0.8 100 400 100 35 0.82 85 348 300 35 0.82 58 239 1k 29 0.88 42 185 3k 25 0.91 34 155 10k 22 0.93 27 126 30k 23 0.92 21 97 100k 24 0.92 17 78 Points to note: 1. The phase angle is always lagging and fairly constant. 2. Both current and power fall with rising frequency all the way to 00kHz - and beyond. 3. The is no secondary winding to bugger things up. 4. The core was just showing signs of saturation at 50 Hz and 5 volts. 5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. ........... Phil I am almost afraid to respond. But here goes. Useful information but I wonder about your current sensing resistor at 100KHz. It has inductance, a critical property in this kind of mesurement. That could yender data at the higher frequencies useless. I will dive into the nearest culvert in order to receive your response. JLS Not good enough John, PA wrath is denser than air, and will smoke you out like mustard gas. But hey, I'd reckon phil used one of the many common resistors that measure negligible R difference at least up to 100 kHz. I have measured the core behaviour similarly to PA's method, but used about 200 turns on a bobbin into which some E&I lams can be assembled. From what PA has posted, the inductance could be added to his figures by first calculating the test winding impedance, 5v / I, and then dividing by ( 6.28 x F ) Hz phi PF mA mW Lwinding ZL, ohms 50 36 0.8 100 400 159mH 50 100 35 0.82 85 348 93 mH 59 300 35 0.82 58 239 45 mH 86 1k 29 0.88 42 185 19mH 119 3k 25 0.91 34 155 8mH 147 10k 22 0.93 27 126 3mH 185 30k 23 0.92 21 97 2.3mH 238 100k 24 0.92 17 78 0.47mH 294 I wonder what the distortion % was in the current he measured. Probably it was low compared to using some old E&I steel from the 1950s. If the winding phil used was for a primary on an OPT, and we wanted to go no lower than 50 Hz, which could be the -3 dB point for an amp with current output, then the load value could be say 50 ohms, and the combined Z L+R is 35 ohms at 50 Hz It would gradually rise as F is raised, but the maximum rise is only ever going to be from 35 ohms to just under 50 ohms at 100 kHz. Pentode amps display this slight slope in the response when L&R are in parallel on the load, also triode amps, but not as pronounced because the low Ra is in parallel with RL which is higher than Ra. Notice how phil's figures show the worst losses to be where F is lowest. Notice also how the inductance isn't 159mH at all F. It falls as F rises. This is because the U of the iron falls with rising F. There would be a frequency where removing the core would make very little difference to the inductance measured, in other words, the U has become very low. The toroidal iron U could be 40,000 max. By comparison, fencing wire coiled up to make a toroid would have a U of about 20 only. Not shown is the range of impedances for the test L taken at just one F at 0.5, 1, 2, 1v and 2.5v. Had phil done the measure with lower voltages, he may have found that for 2.5v at 50 Hz, the current may have been 33 mA and ZL = 75 ohms. The iron U rises from what it is at near saturation to a peak, then falls again as V is reduced below the peak. From Phil's test he could work out the Bmax for the iron, because he'd know what Afe was and he knows F and V. He is using 8 turns per volt for his tests. If he used 2,000 turns, he could apply 50 times the 5v or 250v across the 2,000 turn winding, and the core would have the same B as he tested with at 5v into 40 turns, and thus be at the onset of saturation as he claims. Lp would be proportional to the turn increase squared, so he'd have 397 Henrys in the winding of 2,000 turns. This would be 125 kOhms at 50 Hz, and current would be a tiny 2 mA I assume the power factor would be the same and losses would be 250v x 0.002A x 0.8 = 0.4w = 400 mW. The iron U is probably quite high for the toroidal core, but he can find out what the U is from his measurement, by applying the inductance formula. The point I am making is that a lot can be found from a test like phil's, and then more if you draw the arched graph of the ZL with varying winding voltages. I like to set my power trannies up where the primary impedance of the winding is at its maximum. It usually corresponds to a Bmax between 0.7 and 0.9 Tesla, depending on steel variety. So with Phil's core, and 40 turns, we could say that for saturation at 1/3 of 50 Hz, 17 Hz, we could apply only 1/3 of the voltage, 1.7 v. Or we have to use 3 times the turns to allow 5 v at 17 Hz. Here are two equations for iron wound coils:- 22.6 x V x 10,000 Fs = ---------------------- B x Np x Afe Where Fs = frequency of saturation, 22.6 is a constant for all equations, 10,000 is a constant for all equations, V = voltage in rms across the primary, Np = primary turns, B = maximum magnetic field strength in Tesla in the core, Afe = cross sectional area of the central core leg, in square mm. For an iron cored inductor, with no net DC flow in only one direction, as in an SE amp, or with balanced DC, as in the case of a PP amp, 1.26 x N squared x Afe x U L = -------------------------------- 1,000,000,000 x ML Where L = primary inductance in Henrys, 1.26 is a constant, N = primary turns, Afe is the cross sectional area of the core in square mm, U is the mu of the iron at voltage levels below saturation, 1,000,000,000 is a constant for all equations, ML is the magnetic path length around the core in mm. BTW, for a gapped core, the ML becomes effectively greater due to the gap, so L is lower, but I don't have an equation for the gapped core handy. Patrick Turner. |
#5
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On Fri, 25 Feb 2005 01:09:57 +1100, Patrick Turner
wrote: John Stewart wrote: Phil Allison wrote: (more bile, as usual) I will dive into the nearest culvert in order to receive your response. JLS Not good enough John, PA wrath is denser than air, and will smoke you out like mustard gas. Isn't Phil denser than Osmium? :-) -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#6
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"Patrick Turner" = anencephalic, geriatric turd. Phil Allison From what PA has posted, the inductance could be added to his figures by first calculating the test winding impedance, 5v / I, and then dividing by ( 6.28 x F ) ** What a load of ABSOLUTE CRAP !!!! The Turneroid **FOOL** assumes the load presented by the primary is a pure inductance, which with a phase angle of 24 to 35 degrees is clearly is NOT !!!!!! The Lwinding figures below are all totally WRONG !!!!!! ------------------------------------------------------------------------ Hz phi PF mA mW Lwinding ZL, ohms 50 36 0.8 100 400 159mH 50 100 35 0.82 85 348 93 mH 59 300 35 0.82 58 239 45 mH 86 1k 29 0.88 42 185 19mH 119 3k 25 0.91 34 155 8mH 147 10k 22 0.93 27 126 3mH 185 30k 23 0.92 21 97 2.3mH 238 100k 24 0.92 17 78 0.47mH 294 ---------------------------------------------------------------------- I wonder what the distortion % was in the current he measured. ** Only the 50 Hz test showed any visible distortion on the scope - about 10%, 3H Notice also how the inductance isn't 159mH at all F. It falls as F rises. ** The Turneroids figures are all CRAP !!!!! ............... Phil |
#7
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come on Phil, just say what you mean, you don't have to rose-tint
anything for us. |
#8
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On Thu, 24 Feb 2005 17:28:48 +0000, Stewart Pinkerton wrote:
Isn't Phil denser than Osmium? :-) No, he's denser than depleted uranium. I'd pass this on to some real transformer engineers, but they already have plenty of work to do and plenty of BS to get a laugh out of, without Phil's help. -- Ned Carlson Triode Electronics Chicago,IL USA www.triodeelectronics.com |
#9
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Stewart Pinkerton wrote: On Fri, 25 Feb 2005 01:09:57 +1100, Patrick Turner wrote: John Stewart wrote: Phil Allison wrote: (more bile, as usual) I will dive into the nearest culvert in order to receive your response. JLS Not good enough John, PA wrath is denser than air, and will smoke you out like mustard gas. Isn't Phil denser than Osmium? :-) When philium goes off you get phillium clawro-alliate, a pentupsical clawrine hypo fixilated radical compound, which has a short term irritant chemical structure, which when inhaled becomes oxidised and it causes a precipitate to be deposited rewards, after which the nausea ceases and the brain compensates emotionally. I have never met an Osmium. Its become a fashionable name in Oz now, and people call their first born son Osmium, ( "Ozzo" is the usual shortened name..) Girls don't count, and are called anything. Some can't count, which is another worry. Sometimes the really keen nationalists add a second name such as Straya, or Bonzo, as a refreshing change from Charles, or William. Very few girls get called Camilla. Patrick Turner. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#10
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"Ned Carlson" ** Ned C is just another arrogant, know ****ing nothing, red necked, ****** hating, Jew baiting, Septic Tank **** that the world would be far better off without. No wonder so many folk LOATHE the USA. No wonder 9-11 happened. Worse is yet to come. The pigs a will never wake up. .............. Phil |
#11
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"Phil Allison" wrote
4. The core was just showing signs of saturation at 50 Hz and 5 volts. What signs? cheers, Ian |
#12
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Phil Allison wrote: "Patrick Turner" = anencephalic, geriatric turd. Phil Allison From what PA has posted, the inductance could be added to his figures by first calculating the test winding impedance, 5v / I, and then dividing by ( 6.28 x F ) ** What a load of ABSOLUTE CRAP !!!! The Turneroid **FOOL** assumes the load presented by the primary is a pure inductance, which with a phase angle of 24 to 35 degrees is clearly is NOT !!!!!! The Lwinding figures below are all totally WRONG !!!!!! ------------------------------------------------------------------------ Hz phi PF mA mW Lwinding ZL, ohms 50 36 0.8 100 400 159mH 50 100 35 0.82 85 348 93 mH 59 300 35 0.82 58 239 45 mH 86 1k 29 0.88 42 185 19mH 119 3k 25 0.91 34 155 8mH 147 10k 22 0.93 27 126 3mH 185 30k 23 0.92 21 97 2.3mH 238 100k 24 0.92 17 78 0.47mH 294 ---------------------------------------------------------------------- I wonder what the distortion % was in the current he measured. ** Only the 50 Hz test showed any visible distortion on the scope - about 10%, 3H With GOSS, you may have noticed how the distortion radidly increases above a threshold of low distortion, ie, the core saturation is abrupt. With some old types of steels the distortion current is 10% even at very levels, and just gets worse as V increases, even with a very low voltage source impedance. Notice also how the inductance isn't 159mH at all F. It falls as F rises. ** The Turneroids figures are all CRAP !!!!! .............. Phil Well of course I could have guessed you'd say they were CRAP. You don't say why. So SFA ppl will believe you. The unloaded test winding around a core you used to gain the table of figures looks like an inductance to me. You have the current in the winding, the voltage across the winding, and your test winding has such low resistance it can be neglected, so what you were applying voltage to quacks like inductance, has inductive feathers, so I reckon its an inductance duck. If you were measuring an R in series with a C where R = ZC, and you had 10v input, then expect to measure 7 v across the C. There is also 7v across the R. Ppl could be forgiven for saying 14v exists somewhere, but it don't; there is a 45 degree phase shift though. The current must be equal in R and C, and thus the value of C can be found, etc. But in this inductor case, we just have V from what I assume to be a low impedance source; there is no significant R component. So let's here from you what the correct way is to calculate the inductance from what you tested and measured. Could you be so kind as to provide us with one correct sample line from your figures? The current you measure has between 24 and 35 degrees of phase shift, so something must be causing that. What is it? Patrick Turner. |
#13
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Ian Iveson wrote: "Phil Allison" wrote 4. The core was just showing signs of saturation at 50 Hz and 5 volts. What signs? I don't mean to butt in, but it is a public forum, so get used to it please. The onset of saturation *current* becomes obvious to anyone gradually cranking up some voltage across an inductor, especially one wound with GOSS and without a gap and with a toroidal core spiral. The current distortion is low until a threshold is reached and then the iron cannot magnetize any more near the peaks in the cycle, and without the further magnetization of the core by the applied voltage change, there is no further magnetic field generated to oppose the flow of the current, and no more linear inductor action. Inductors oppose the flow of current resulting from a voltage applied. So although Phil would have kept his 5v supply constant from a low Z source, the current would show a rapid distortion increase at above say 4.5v, 10% at 5v, and beyond 5v the distortion increases exponentially, as current begins to flow unopposed through the DC resistance of the winding wire for an increasing part of the cycle as V is increased. Phil might like to say that I am all CRAP, but he'd have to point out why... But above is what I have observed..... Patrick Turner. cheers, Ian |
#14
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"Patrick Turner" = one foul, evil, anencephalic, geriatric turd. Phil Allison From what PA has posted, the inductance could be added to his figures by first calculating the test winding impedance, 5v / I, and then dividing by ( 6.28 x F ) ** What a load of ABSOLUTE CRAP !!!! The Turneroid **FOOL** assumes the load presented by the primary is a pure inductance, which with a phase angle of 24 to 35 degrees is clearly is NOT !!!!!! You don't say why. ** I just ** did ** say why !!!!!! The phase angle is not 90 degrees so it cannot be a pure inductance !! --------------------------------------------------------------------- The current you measure has between 24 and 35 degrees of phase shift, so something must be causing that. What is it? ** Sure as hell is not pure inductance. Pure inductors dissipate ZERO power - you putrid ****ing arsehole !!!! Notice the PF is 0.8 to 0.9 ??????? Have the slightest idea what that means ??? --------------------------------------------------------------- The vile Turneroid bricklayer is utterly ****ED !!!!!!!! Cancer is far too good for this POS. But it will have to do. ............... Phil |
#15
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"Patrick Turner" wrote
"Phil Allison" wrote 4. The core was just showing signs of saturation at 50 Hz and 5 volts. What signs? I don't mean to butt in, but it is a public forum, so get used to it please. As if I'm not. The onset of saturation *current* becomes obvious... ...blah, blah, blah, etc... ...But above is what I have observed..... How can you know what signs he saw? Is there a chapter on Phil in RDH4? Is there a section on what he saw? I know what saturation is, and what it looks like. Just wondered if Phil does. Now you've given him a clue. Luckily not a very good one. cheers, Ian |
#16
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"Ian Iveson" I know what saturation is, and what it looks like. Just wondered if Phil does. ** Do you have brain tumor - Ian ?? I just wondered. Might explain a lot. ............. Phil |
#17
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Phil Allison wrote: "Patrick Turner" = one foul, evil, anencephalic, geriatric turd. Phil Allison From what PA has posted, the inductance could be added to his figures by first calculating the test winding impedance, 5v / I, and then dividing by ( 6.28 x F ) ** What a load of ABSOLUTE CRAP !!!! The Turneroid **FOOL** assumes the load presented by the primary is a pure inductance, which with a phase angle of 24 to 35 degrees is clearly is NOT !!!!!! You don't say why. ** I just ** did ** say why !!!!!! The phase angle is not 90 degrees so it cannot be a pure inductance !! So what you are saying is that there is an R element between the two "L" terminals we apply a voltage across. Be more concise if you wouldn't mind. And BTW, if I am ignorant, it doesn't make me evil. So unless you don't mind being thought of as short fused git, kindly be polite at all times. --------------------------------------------------------------------- The current you measure has between 24 and 35 degrees of phase shift, so something must be causing that. What is it? ** Sure as hell is not pure inductance. Pure inductors dissipate ZERO power - you putrid ****ing arsehole !!!! But there is a current flow within and a voltage across, so we can make some impedance measurements, no? Notice the PF is 0.8 to 0.9 ??????? Have the slightest idea what that means ??? You tell us this time in your own concise words, be calm, and take your time. You tell us where energy is being dissipated. I reckon I know, but I think I'll keep it secret because the insult noise is rather high. Unless you try to teach with a civil tongue, who will ever listen? --------------------------------------------------------------- The vile Turneroid bricklayer is utterly ****ED !!!!!!!! Cancer is far too good for this POS. But it will have to do. .............. Phil Just as well I don't care or react anymore to your absurd character analysis or life path wishes for those with whom you choose to parly with. If you wish to talk with us, and wish that we get cancer ASAP, then doesn't it seem rather inconsistent? Patrick Turner. |
#18
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Patrick wrote:
And BTW, if I am ignorant, it doesn't make me evil. So unless you don't mind being thought of as short fused git, kindly be polite at all times. That's like asking Australians to outlaw beer. Why do you reply to this potty-mouthed misanthrope? He needs to sit alone in the corner until he can behave!!! |
#19
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Ian Iveson wrote: "Patrick Turner" wrote "Phil Allison" wrote 4. The core was just showing signs of saturation at 50 Hz and 5 volts. What signs? I don't mean to butt in, but it is a public forum, so get used to it please. As if I'm not. The onset of saturation *current* becomes obvious... ...blah, blah, blah, etc... ...But above is what I have observed..... How can you know what signs he saw? Is there a chapter on Phil in RDH4? Is there a section on what he saw? There most certainly isn't a chapter in RDH4 with ballistic philistic concerns addressed. There is a lot of good reading though..... From what Phil did in his tests with a core and some wire, I can see what he must have, because I have done a similar test myself, but without determining the power factor. I know what saturation is, and what it looks like. Just wondered if Phil does. Now you've given him a clue. Luckily not a very good one. He may call us both idiots now. I just want him to come clean with the facts as he seees them in a plain and dispassionate manner without death wishes, and the discussion can move forward, and the whole group would be better informed. And without making measurents about power factor in unloaded primaries one would be making mistakes about the properties of the iron one was examining. There is a corelation between unloaded input primary magnetizing current x input voltage and core heating. What is it? I'd just like Phil to tell us in his own words, allowing for the fact that others here don't have a clue what "power factor" and "phase angle" mean. Phil seems crazy when he engages us to parly on anything and everything, but like professor with a mental problem he lashes us with a cane for our ignorance. If he had a soul, our ignorance would be his responsibility to adjust, and without blood on the lecture room floor thankyou. "Those damn fools at RAT, why don't they get cancer soon and die!" That's what I hear his brain saying.... Counter productive, really, if we did all die he'd have nobody at all to talk to. Maybe we'll take our time to die. Worse for him, many of us are slow learners. Maybe he could apply for the position advertised for a teacher in the school without students. In "Yes Minister", there was a hospital without patients...... It was a great place for all the bad tempered doctors. Patrick Turner. cheers, Ian |
#20
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"Patrick Turner" If you wish to talk with us, and wish that we get cancer ASAP, then doesn't it seem rather inconsistent? ** I wish the most excruciating, lingering death possible for you - Pat Turner. You and all like you are a vile POX on the face of the earth. I have no wish to talk with you - not ever - but there is simply no way to avoid vile, criminal, autistic ****s like you on usenet. Even your neighbours in Canberra think you are a piece of **** they are cursed to live next to. The words "Autistic Public Menace " should be tattooed on your forehead. Go straight to hell. .............. Phil |
#21
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Jon Yaeger wrote: Patrick wrote: And BTW, if I am ignorant, it doesn't make me evil. So unless you don't mind being thought of as short fused git, kindly be polite at all times. That's like asking Australians to outlaw beer. Why do you reply to this potty-mouthed misanthrope? He needs to sit alone in the corner until he can behave!!! He has something interesting to say about cores that nobody else can say. He just can't quite just say it..... I'd like to tie him up in the corner, but in fact in a real classroom situation I'd have to escort him out of the room for his own survival because the other guys would beat him up on the spot. Don't you worry too much about our Phil. The rest of the world has an enormously larger number of cranky buggers out there. One is called Osama, and he makes Phil seem saintly. Patrick Turner. |
#22
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"Patrick Turner" There is a corelation between unloaded input primary magnetizing current x input voltage and core heating. What is it? ** Copper loss minus total watts. I'd just like Phil to tell us in his own words, allowing for the fact that others here don't have a clue what "power factor" and "phase angle" mean. ** Then they can go look it up - just as you obviously need to. But as a result of your gross mental defect incapable of ever comprehending. Got a pain in the bowels today - Pat ?? I certainly hope it gets worse. .............. Phil |
#23
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Phil Allison wrote: "Patrick Turner" If you wish to talk with us, and wish that we get cancer ASAP, then doesn't it seem rather inconsistent? ** I wish the most excruciating, lingering death possible for you - Pat Turner. You and all like you are a vile POX on the face of the earth. I have no wish to talk with you - not ever - but there is simply no way to avoid vile, criminal, autistic ****s like you on usenet. Even your neighbours in Canberra think you are a piece of **** they are cursed to live next to. The words "Autistic Public Menace " should be tattooed on your forehead. Go straight to hell. ............. Phil We know all that. We are unimpressed in any way with the oft heard litany of finely honed above insults. No need to repeat them, ok. Please be so kind to explain about core losses, your brain won't fall out of your head if you try. Patrick Turner. |
#24
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"Patrick Turner" = hell is too good for this vile pig Phil Allison wrote: If you wish to talk with us, and wish that we get cancer ASAP, then doesn't it seem rather inconsistent? ** I wish the most excruciating, lingering death possible for you - Pat Turner. You and all like you are a vile POX on the face of the earth. I have no wish to talk with you - not ever - but there is simply no way to avoid vile, criminal, autistic ****s like you on usenet. Even your neighbours in Canberra think you are a piece of **** they are cursed to live next to. The words "Autistic Public Menace " should be tattooed on your forehead. Go straight to hell. ............ Phil Please be so kind to explain about core losses, ** I already have, in detail - then the Turneroid **** spread his excreta around. Since I firmly advised ( :-0 ) Mr Stewart yesterday that testing for HF core loss can only be done with a single winding in place - I decided to try out my own suggestion. I had a standard 160 VA toroidal core (with plastic covers ) left over from an old project - so I would 40 turns of 1mm copper wire onto it, spread evenly around. I used a SS amplifier to drive the winding with a 2 ohm WW resistor in series to allow current sensing - a dual beam scope monitored the drive voltage and current waveforms. The input level was held at 5 volt rms and the traces overlapped on the scope screen to allow the relative phase angle to be measured at each frequency. Hz phi PF mA mW 50 36 0.8 100 400 100 35 0.82 85 348 300 35 0.82 58 239 1k 29 0.88 42 185 3k 25 0.91 34 155 10k 22 0.93 27 126 30k 23 0.92 21 97 100k 24 0.92 17 78 Points to note: 1. The phase angle is always lagging and fairly constant. 2. Both current and power fall with rising frequency all the way to 100kHz - and beyond. 3. The is no secondary winding to bugger things up. 4. The core was just showing signs of saturation at 50 Hz and 5 volts. 5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. ............ Phil |
#25
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Phil Allison wrote: "Patrick Turner" There is a corelation between unloaded input primary magnetizing current x input voltage and core heating. What is it? ** Copper loss minus total watts. What has copper loss got to do with core losses? I thought we were testing a core with a winding of negligible copper losses to try to be able to comprehend the core behaviour, and thus build better transformers, or be better able to reject a poor design, or to better measure core losses. Starting a new thread with a new title on every post won't work with me Phil. We still want answers to the real questions. I'd just like Phil to tell us in his own words, allowing for the fact that others here don't have a clue what "power factor" and "phase angle" mean. ** Then they can go look it up - just as you obviously need to. Oh but they won't, they need to hear detailed argument from you rather than empty insults. Well, they might, if you primed them with something sensible.... We like to be able to see that **you** really know your stuff. If you spent as long explaining as you do insulting, your life would be a lot more rewarding. We all know we don't know everything, we forgive each other's shortcomings as we progress, but what we really do know we share fairly easily, without making our friends eat a **** sandwich everytime we give out some piece of information. I have the deepest amount of patience. So what is the corelation between input magnetizing current in an unloaded tranny winding and core heating, and the power factor and the phase angle? From a measurement of the phase of the current in relation to the phase of the voltage input, how does one calculate the core heating?, ie, the core losses. I am sure you could explain it in less words than the ones below used to say idiotic things about bowels. Patrick Turner. But as a result of your gross mental defect incapable of ever comprehending. Got a pain in the bowels today - Pat ?? I certainly hope it gets worse. ............. Phil |
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Phil Allison wrote: "Patrick Turner" = hell is too good for this vile pig Phil Allison wrote: If you wish to talk with us, and wish that we get cancer ASAP, then doesn't it seem rather inconsistent? ** I wish the most excruciating, lingering death possible for you - Pat Turner. You and all like you are a vile POX on the face of the earth. I have no wish to talk with you - not ever - but there is simply no way to avoid vile, criminal, autistic ****s like you on usenet. Even your neighbours in Canberra think you are a piece of **** they are cursed to live next to. The words "Autistic Public Menace " should be tattooed on your forehead. Go straight to hell. ............ Phil Please be so kind to explain about core losses, ** I already have, in detail - then the Turneroid **** spread his excreta around. No, I simply wanted you to further explain why a core heats up, how much of the input voltage x input current gets converted to heat in the core and why. If you are going to play teacher here, you should be prepared to answer questions, all and any of them, to make it absolutely clear. Be prepared to talk around the concept. The basics of phase shift take most ordianry folks a lot of getting used to. Since I firmly advised ( :-0 ) Mr Stewart yesterday that testing for HF core loss can only be done with a single winding in place - I decided to try out my own suggestion. I had a standard 160 VA toroidal core (with plastic covers ) left over from an old project - so I would 40 turns of 1mm copper wire onto it, spread evenly around. I used a SS amplifier to drive the winding with a 2 ohm WW resistor in series to allow current sensing - a dual beam scope monitored the drive voltage and current waveforms. The input level was held at 5 volt rms and the traces overlapped on the scope screen to allow the relative phase angle to be measured at each frequency. Hz phi PF mA mW 50 36 0.8 100 400 In considering this experiment, then do you have 400 mW of power converted to heat in the core? If the L was a perfect L, we'd still have Vin and I. But no power is converted to heat in a perfect L. What is the relation between phase angle difference between current and power factor? Put that cane down, I have a crash helmet on, I won't feel a thing. Patrick Turner. 100 35 0.82 85 348 300 35 0.82 58 239 1k 29 0.88 42 185 3k 25 0.91 34 155 10k 22 0.93 27 126 30k 23 0.92 21 97 100k 24 0.92 17 78 Points to note: 1. The phase angle is always lagging and fairly constant. 2. Both current and power fall with rising frequency all the way to 100kHz - and beyond. 3. The is no secondary winding to bugger things up. 4. The core was just showing signs of saturation at 50 Hz and 5 volts. 5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. ........... Phil |
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"Patrick Turner" Phil Allison wrote: There is a corelation between unloaded input primary magnetizing current x input voltage and core heating. What is it? ** Copper loss minus total watts. What has copper loss got to do with core losses? ** Core loss = total loss - copper loss. Starting a new thread with a new title on every post won't work with me Phil. ** Nothing but a silver bullet would work on an evil, zombie **** like the Turneroid. I'd just like Phil to tell us in his own words, allowing for the fact that others here don't have a clue what "power factor" and "phase angle" mean. ** Then they can go look it up - just as you obviously need to. So what is the corelation between input magnetizing current in an unloaded tranny winding and core heating, and the power factor and the phase angle? ** Yet again: I had a standard 160 VA toroidal core (with plastic covers ) left over from an old project - so I would 40 turns of 1mm copper wire onto it, spread evenly around. I used a SS amplifier to drive the winding with a 2 ohm WW resistor in series to allow current sensing - a dual beam scope monitored the drive voltage and current waveforms. The input level was held at 5 volt rms and the traces overlapped on the scope screen to allow the relative phase angle to be measured at each frequency. Hz phi PF mA mW 50 36 0.8 100 400 100 35 0.82 85 348 300 35 0.82 58 239 1k 29 0.88 42 185 3k 25 0.91 34 155 10k 22 0.93 27 126 30k 23 0.92 21 97 100k 24 0.92 17 78 Points to note: 1. The phase angle is always lagging and fairly constant. 2. Both current and power fall with rising frequency all the way to 100kHz - and beyond. 3. The is no secondary winding to bugger things up. 4. The core was just showing signs of saturation at 50 Hz and 5 volts. 5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. From a measurement of the phase of the current in relation to the phase of the voltage input, how does one calculate the core heating?, ie, the core losses. ** Core loss = total watts loss - copper loss. Total watts = V x I x PF ( all waves being sine waves) Copper loss = I squared R Very basic stuff - you vile, pig ignorant autistic ****. Got a NASTY pain in the bowels today - Pat ?? I certainly hope it gets much worse. And is inoperable. ............. Phil |
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"Patrick Turner" = hell is too good for this vile pig
The basics of phase shift take most ordianry folks a lot of getting used to. ** Tough. In considering this experiment, then do you have 400 mW of power converted to heat in the core? ** Yep. If the L was a perfect L, we'd still have Vin and I. But no power is converted to heat in a perfect L. ** Yep. What is the relation between phase angle difference between current and power factor? ** PF = cos phi. Very basic stuff - even for a ****ing anencephalic, autistic, geriatric, **** bricklayer. How is that gut pain going?? ............. Phil |
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5. The resistance of the winding was 0.16 ohms - making copper loss a negligible at 1.6 mW at 50 Hz. From a measurement of the phase of the current in relation to the phase of the voltage input, how does one calculate the core heating?, ie, the core losses. ** Core loss = total watts loss - copper loss. Total watts = V x I x PF ( all waves being sine waves) Copper loss = I squared R Very basic stuff Yes, and we know all that. I am wondering what the figures you tabled for your tests with 40 turns around a toroid really mean. The copper losses are negligible. Core loss = total loss - copper losses. In your experiment, Core loss = total loss, because copper loss is negligible. One has Vin, and In, and the phase of the current in relation to the phase of the voltage, and a power factor, and power factor x V x I = mWatts of power. What is the core loss? How does phase angle and power factor relate, and what is an equvalent model of the loss mechanism? Copper we know about. Patrick Turner. |
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Phil Allison wrote: "Patrick Turner" = hell is too good for this vile pig The basics of phase shift take most ordianry folks a lot of getting used to. ** Tough. In considering this experiment, then do you have 400 mW of power converted to heat in the core? ** Yep. If the L was a perfect L, we'd still have Vin and I. But no power is converted to heat in a perfect L. ** Yep. What is the relation between phase angle difference between current and power factor? ** PF = cos phi. Very basic stuff - even for a ****ing anencephalic, autistic, geriatric, **** bricklayer. How is that gut pain going?? ............ Phil So why take so long to tell us? It must be painful to tell anyone anything you know, eh. You resist it just like a demon possessed person resists telling the truth. But all your theatrical demonic behaviour means nothing to me, I am immune. Patrick Turner. |
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"Phil Allison" wrote
** Do you have brain tumor - Ian ?? I just wondered. Might explain a lot. But what were the signs of saturation? You said you observed them, but you haven't said what they are. Why bother doing a test if you are not going to support your assertions with the details of your observations? What were the signs of saturation, specifically? cheers, Ian |
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"Phil Allison" wrote
4. The core was just showing signs of saturation at 50 Hz and 5 volts. What signs? cheers, Ian |
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"Patrick Turner" = hell is too good for this vile pig
Phil Allison What is the relation between phase angle difference between current and power factor? ** PF = cos phi. So why take so long to tell us? ** 1. You never asked. 2. The same formula was posted here on 24th by John Stewart. 3. It is childishly basic info that the simplest search will find. 4. So the definition of PF is not given in RDH4 - so the Turneroid anencephalic does not know it ? .............. Phil |
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"Ian Iveson" "Phil Allison" But what were the signs of saturation? You said you observed them, but you haven't said what they are. ** As the voltage increases above a certain threshold the current waveform becomes distorted in a characteristic way. There is firstly increasing 3H - then peaks of both polarities develop in the waveform. After this the rms value of the current rises almost exponentially with increasing applied voltage. Why bother doing a test if you are not going to support your assertions with the details of your observations? ** Because it is common knowledge and covered in all the texts. Plus YOU are only asking to annoy. YOU are just a ****ING TROLLING PITA **** . Clear enough now ?? Go drop dead. ............. Phil |
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"Patrick Turner" What is the core loss? ** Just as stated in the mW column. How does phase angle and power factor relate, ** Yet again: PF = cos phi. and what is an equvalent model of the loss mechanism? ** It approximates to an L and R in parallel - with both values being a function of frequency. .............. Phil |
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"Patrick Turner" wrote in message ... Mega-snip I'd just like Phil to tell us in his own words, allowing for the fact that others here don't have a clue what "power factor" and "phase angle" mean. Don't flatter yourself, Patrick. The following quote by you from another thread proves that YOU don't have a clue either.. Measurements of power trannies for losses and magnetizing currents using a measure of current and voltage can be confusing. Not if you understand power factor and phase angle. I measured a Pt 1 Leak PT last night, and the Im at 245v across the P at 50Hz and no load was 100 mA, so you'd think there was 24 watts of magnetization core losses. I wouldn't think that. Only people who "don't have a clue" would think that! The REALLY shameful part is that the whole thing is explained in RDH4, pages 143-144. Guess you didn't memorize those pages, huh? I left this suspect tranny on for 4 hrs on this warm evening, and it only warmed slightly, and it seems impossible that core losses amounted to 24 watts. That's because they DON'T amount to 24 watts. You then preach a whole bunch of "touchy-feely" baloney about 3rd harmonics. I used to think you knew something about this stuff. I don't think that anymore. |
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So to add to the forgoing on core issues, and while ignoring the personal BS used to decorate knowledge, we can say more about testing of transformer cores for losses. For a reference, Power Factor with inductive elements is dealt with on page 144 of RDH4. If we have a voltage across a perfect inductance, the phase difference between the voltage and current flow is 90 degrees. Power factor = cos 90d = 0, therefore the power factor is 0, and no power is liberated anywhere except the R component of generator or source of the voltage, since the inductive load returns stored energy to the source; the only power power liberated in the L is I squared x R where R is the dcr of the L, and that is zero in a perfect L. The core acts like an R in the circuit of a transformer primary. If the input to the tranny winding generated no phase difference between V and I, the cos of zero degrees = 1 so the power factor = 1 so all the input V x I power is liberated in the R component, and in fact the load must be an R. So where there is a phase difference of 30d, then cos 30 = 1.7321/2.0 = 0.866 so there is a considerable proportion of the applied input V x input I being dissipated into the hidden R that is the core. After testing a Luxman OPT and 2 other power trannies with a dual trace CRO for phase angle at 50 Hz, and at low levels, all measured in the vicinity of 30 degrees of phase shift, so a high % of the V x I was causing the core to heat up. I have usually designed power trannies on the basis that total copper and core losses = less than 10% at the full rated load or less, and that the idle input V x I = 5% of the input VA. Copper losses are also 5% of input VA. And I have assumed all the input V x I when unloaded was power that contributed to heating the core, but it was a safe wrong assumption to make. In actual fact only about 80% of the V x I is power converted to heat at 50 Hz. The use of GOSS with a mu of 17,000 means the V x I figure when unloaded is tiny compared to Lycore 150, the cheapo non oriented Si Fe, which has a max u of maybe 3,000. Then the V x I is high, and 0.8 x this high VI heats the core a lot. To avoid heating a core this the core has to be large to get the inductive element higher, or more turns have to be used. The down side is that the copper losses increase. But if you want a cool running power tranny for a class A amp which draws the constant high power for class A, and you want only use low grade iron, it will be a much larger tranny than something designed by accountants, and which runs so hot it can be barely touched. On page 239 of RDH4, a typical transformer is used to illustrate the design process. The copper losses are worked out on the basis of I squared x R for all the windings. That's easy, and no reactive elements are needed to be considered. But for the core losses RDH4 decides on a core size and then says that there are so many pounds of 'silcor 2' and that iron losses are the pounds x core loss per pound. The sample design gives 46 VA as the iput power, 4.2 watts of copper losses and 2.2 watts of core losses. This is a tyipcal design of the era, and from what is said and the graph for T rise, we can work out the T rise. It is usual today to make core losses using E&I higher than copper losses, so that the iron heats up more than the copper, which is more expensive than iron. Winders also try to use cheap iron. Expensive GOSS used in the same design as for a hot tranny with low grade iron will run a lot cooler, but it may not be very quiet, so the tpv has to be raised and hence copper losses increase, so I use a lot more iron than most other ppl to get negligible iron losses and also low copper losses, and a T rise after 4 hours of maybe 10C. The majority of OPTs have a high R component, ie, the unloaded input looks like a resistance, since the phase angle is low. Whilst examining a Luxman 30 watt OPT at 50 Hz from the variac the ph angle between V&I was about 30 degrees, so the power factor is still high. The power factor doesn't matter because the VI input voltage current at audio F going into OPTs is low all AF, although its the highest as F is at its lowest. The power lost as heat in the cores of most OPTs can therefore be neglected. The R element in a transformer winding when unloaded is the core. Its a very non linear R. But less so in an OPT. So modelling of the input of a transformer will have some R alright, but also limiting diodes and a network which produces the same distortions seen in the current wave forms, and this I have not seen modeled anywhere with explanations showing the model is right. Patrick Turner. |
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BFoelsch wrote: "Patrick Turner" wrote in message ... Mega-snip I'd just like Phil to tell us in his own words, allowing for the fact that others here don't have a clue what "power factor" and "phase angle" mean. Don't flatter yourself, Patrick. The following quote by you from another thread proves that YOU don't have a clue either.. Measurements of power trannies for losses and magnetizing currents using a measure of current and voltage can be confusing. Not if you understand power factor and phase angle. Many people don't. I measured a Pt 1 Leak PT last night, and the Im at 245v across the P at 50Hz and no load was 100 mA, so you'd think there was 24 watts of magnetization core losses. I wouldn't think that. Only people who "don't have a clue" would think that! It does not matter if ppl do think this and use it as a guide for design. Then if you always keep the unloaded V x I of a new tranny below 5% of the input VA max for the tranny, the core should run cool. The REALLY shameful part is that the whole thing is explained in RDH4, pages 143-144. Guess you didn't memorize those pages, huh? I left this suspect tranny on for 4 hrs on this warm evening, and it only warmed slightly, and it seems impossible that core losses amounted to 24 watts. That's because they DON'T amount to 24 watts. You then preach a whole bunch of "touchy-feely" baloney about 3rd harmonics. I used to think you knew something about this stuff. I don't think that anymore. Feel welcome to crow about your superior knowledge and self importance. The actual heating power of the leak PT core was obviously less than the measured rms V x I. My ignorance hasn't affected the design of my own trannies since I had assumed the PF was 1. It has forced me to make the inductance of the primaries high, and if possible operating away from the serious distortion currents I see in everyone else's transformers, but not mine. But a PF of 0.8 is very common, so the Leak PT may have had a heating power of maybe 16 watts, I am not sure, and it don't matter, the tranny is happily back in the amp. The owner had told me something was wrong with the PT. There isn't. But there was a dud KT66 he'd not spotted. See my other post where I have quoted RDH4 extensively. Patrick Turner. |
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Phil Allison wrote:
"Ned Carlson" ** Ned C is just another arrogant, know ****ing nothing, red necked, ****** hating, Jew baiting, Septic Tank **** that the world would be far better off without. No wonder so many folk LOATHE the USA. No wonder 9-11 happened. Worse is yet to come. The pigs a will never wake up. Just because the water in your toilet flows in the opposite direction is no reason to get upset. Also its much easier to understand you without that dick in your mouth. I feel better knowing Phil is here. Hes the one constant in this ever changing world. At any time of the day I know that Phil is here spewing curse words to people that aren't listening. George Carlin would applaud you for being able to use all the the seven dirty words in a single post. I honestly don't see the point of your posts. They pretty much all sound the same. It can't be that amusing to call the same dozen people stupid ****wit ****s every day. Adam |
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