On 1/29/2012 6:49 PM, Phil Allison wrote:> "John S" > Phil Allison wrote: >> "John S" >>> >>>> >>>> Okay. I have on hand a Triad CSE187-L. You can look up the specs, if you >>>> like, but here are the pertinent ones: >>>> >>>> .1 to 30 amps at 50 to 400 Hz >>>> Np/Ns = 1:500 (has one turn on the sense, so the secondary is 500 turns) >>>> Suggested burden resistor: 60 ohms >>>> Sense DCR: 21 ohms >>>> >>>> I measured the core center leg dimensions as .2" x .2" >>>> >>>> The secondary winding resistance and the burden resistor are in series. >>>> 30A/500 through 81 ohms gives a secondary voltage of 4.86V. >>>> >>>> My calculations say the flux density is just under 17 kiloGauss at 50 >>>> Hz. >>> >>> >>> ** That means the core is heavily saturated. >> >> Yeah, it's what I would consider high and into saturation for most >> materials. >> >>> The makers specs say the unit is not usable beyond 20 amps at 50Hz. >>> >>> http://datasheet.octopart.com/CSE187L-Triad-Magnetics-datasheet-79667.pdf >> >> >> No, they say it is 70% useable. > > ** Utter, smartarse bullshit. > > All you are any good for. > > > > ... PhilIt doesn't matter to me what you think I am good for. Does it matter to you that I feel the same about you?
Current transformer
Started by ●November 30, 2011
Reply by ●January 29, 20122012-01-29
Reply by ●January 29, 20122012-01-29
"Phil Allison" wrote in message news:9om703Ffn6U1@mid.individual.net...> The makers specs say the unit is not usable beyond 20 amps at 50Hz.> =http://datasheet.octopart.com/CSE187L-Triad-Magnetics-datasheet-79667.pdf= I have had a lot of experience using that part in our Programmable = Overload=20 Device, or POD, which we developed in 2003 and still use. It is true = that=20 the linearity falls off above 20 amps, but we have tested it and use it = at=20 currents up to 60 amps. The design is somewhat flawed because the = secondary=20 goes through a FW silicon rectifier bridge before the sense resistor and = filter capacitor, so that the PIC can read the DC level, but even so, we = have obtained *usable* output much higher than the rated 20-30 amps. To = do=20 so, we have implemented a look-up table that deals with the linearity=20 issues. For my most recent project I am using a Talema AC-1200 PCB mounted CT = which=20 is rated at 200 amps nominal and 500 amps maximum. This design reads the = voltage on the sense resistor directly, and I have tested it with 1 ohm = and=20 10 ohm loads, which are less than the recommended 100 ohms 4W. I found = good=20 linearity (better than 1%) over the range of 0.5 amps to 200 amps with a = 10=20 ohm load, and even better linearity from 1 amp to almost 1000 amps using = a 1=20 ohm load. The specifications can be found here:=20 http://www.talema.net/en/products/pdf/CT%20Catalog%20Jun-06.pdf I'm sure the Triad part will perform about as well, although the Talema = part=20 is a toroid which is probably better. I have implemented the option to select between two load resistors in = this=20 new design, so I can choose what is best for the range of current being=20 measured. We need to handle up to 500-800 amps for short pulses, and = also=20 have the ability to measure currents as low as 0.5 amps to about 1%=20 accuracy. This device seems to do the job, and it's only about $15. This = project will be the first to use an iron-core CT, so we may find some = issues=20 with waveform distortion. Our other devices (much higher currents, up to = 100,000 amps) use Rogowski coils, which have proven satisfactory for = more=20 than 30 years. And for calibration purposes, we use a shunt, which has = been=20 proven reliable and accurate (at 60 Hz). Paul=20
Reply by ●January 29, 20122012-01-29
"P E Schoen" "Phil Allison"> The makers specs say the unit is not usable beyond 20 amps at 50Hz.> http://datasheet.octopart.com/CSE187L-Triad-Magnetics-datasheet-79667.pdfI have had a lot of experience using that part in our Programmable Overload Device, or POD, which we developed in 2003 and still use. ** Shame we have never seen one of them round here..... It is true that the linearity falls off above 20 amps, but we have tested it and use it at currents up to 60 amps. The design is somewhat flawed because the secondary goes through a FW silicon rectifier bridge before the sense resistor and filter capacitor, so that the PIC can read the DC level, but even so, we have obtained *usable* output much higher than the rated 20-30 amps. To do so, we have implemented a look-up table that deals with the linearity issues. ** Fascinating - but totally irrelevant. When I wrote the word "usable" - it was in reference to using the part in the normal way as a current transformer with reasonably good accuracy. It was also directly connected to the previous text from another poster, where it was claimed the makes spec included 30amps at 50Hz when it did not. But you snipped that out of sight so you could post your self aggrandising, fucking drivel. Piss off. ... Phil
Reply by ●January 29, 20122012-01-29
On 1/29/2012 7:34 PM, Phil Allison wrote:> "P E Schoen" > "Phil Allison" > >> The makers specs say the unit is not usable beyond 20 amps at 50Hz. > >> http://datasheet.octopart.com/CSE187L-Triad-Magnetics-datasheet-79667.pdf > > I have had a lot of experience using that part in our Programmable Overload > Device, or POD, which we developed in 2003 and still use. > > > ** Shame we have never seen one of them round here..... > > > It is true that > the linearity falls off above 20 amps, but we have tested it and use it at > currents up to 60 amps. The design is somewhat flawed because the secondary > goes through a FW silicon rectifier bridge before the sense resistor and > filter capacitor, so that the PIC can read the DC level, but even so, we > have obtained *usable* output much higher than the rated 20-30 amps. To do > so, we have implemented a look-up table that deals with the linearity > issues. > > > ** Fascinating - but totally irrelevant. > > When I wrote the word "usable" - it was in reference to using the part in > the normal way as a current transformer with reasonably good accuracy. It > was also directly connected to the previous text from another poster, where > it was claimed the makes spec included 30amps at 50Hz when it did not. > > But you snipped that out of sight so you could post your self aggrandising, > fucking drivel. > > Piss off. > > > ... PhilAccording to chart on the data sheet you posted, the device is not useable at all. It never reaches 100% under any circumstances. Chew on that then piss off yourself.
Reply by ●January 29, 20122012-01-29
"John Smith Radio Ham KD5YI = CUNTHEAD "> According to chart on the data sheet you posted, the device is not useable > at all.** Go telk the makers that one - you stinking pile of festering septic shit.
Reply by ●January 29, 20122012-01-29
On 1/29/2012 7:46 PM, Phil Allison wrote:> "John Smith Radio Ham KD5YI = CUNTHEAD" > > >> According to chart on the data sheet you posted, the device is not useable >> at all. > > > ** Go telk the makers that one -Well, you brought it up. You should telk them.
Reply by ●January 29, 20122012-01-29
"John Smith Radio Ham KD5YI = CUNTHEAD">>> According to chart on the data sheet you posted, the device is not >>> useable >>> at all. >> >> >> ** Go telk the makers that one - >> >> you stinking pile of festering septic shit.>> > Well, you brought it up.** It's YOUR * FUCKWIT * claim - you stinking, radio ham CUNT HEAD !!!
Reply by ●January 29, 20122012-01-29
On 1/29/2012 7:57 PM, Phil Allison wrote:> "John Smith Radio Ham KD5YI = CUNTHEAD"Do you have any licenses at all? I'm sure I can find a way to demeanor you as well if you tell me what they are.> >>>> According to chart on the data sheet you posted, the device is not >>>> useable >>>> at all. >>> >>> >>> ** Go telk the makers that one - >>> >>> you stinking pile of festering septic shit. > >>> >> Well, you brought it up. > > > ** It's YOUR * FUCKWIT * claimNo, it isn't. Look back at what you posted. You claimed: "The makers specs say the unit is not usable beyond 20 amps at 50Hz." Since the description of the device did not even hint at that assertion in writing, it must be that you deduced it from the graph where it shows the response curve to fall from 90% to 70% from 20A to 30A. From this you gleaned that it was not useable. If that is your ridiculous claim, then nothing less than 100% is useable. If that's not what you meant then, "Say what you mean and stop being a smartarse." Cheers
Reply by ●January 29, 20122012-01-29
"John Smith Radio Ham KD5YI = CUNTHEAD">>> According to chart on the data sheet you posted, the device is not >>> useable >>> at all. >> >> >> ** Go telk the makers that one - >> >> you stinking pile of festering septic shit.>> > Well, you brought it up.** It's YOUR * FUCKWIT * claim - you stinking, radio ham CUNT HEAD !!!
Reply by ●January 29, 20122012-01-29
On 1/29/2012 8:50 PM, Phil Allison wrote:> "John Smith Radio Ham KD5YI = CUNTHEAD" > > >>>> According to chart on the data sheet you posted, the device is not >>>> useable >>>> at all. >>> >>> >>> ** Go telk the makers that one - >>>> >>> >> Well, you brought it up. > > > ** It's YOUR * claim -It is no more my claim than yours, Phil. But you cut the relevant parts. Maybe because you have no valid argument. It's difficult to understand how your demented mind works. Try to have a nice day.
