Ferrite Inductor Tolerance
in [Design]
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From: Proteus IIV on 14 Jun 2010 05:05 On Jun 13, 5:50 pm, Archimedes' Lever <OneBigLe...(a)InfiniteSeries.Org> wrote: > On Sun, 13 Jun 2010 14:43:31 -0700, Joerg <inva...(a)invalid.invalid> > wrote: > > > > > > >k...(a)att.bizzzzzzzzzzzz wrote: > >> On Sun, 13 Jun 2010 14:08:03 -0700, Joerg <inva...(a)invalid.invalid> wrote: > > >>> Archimedes' Lever wrote: > >>>> On Sun, 13 Jun 2010 13:24:21 -0700, Joerg <inva...(a)invalid.invalid> > >>>> wrote: > > >>>>> Oh, and how do you suppose you get an "original design" into production > >>>>> without an ECO? > > >>>> You must also be an acronymical retard as well. > > >>>> There is a difference between a design release and a change order of an > >>>> existing design. > > >>> So you guys release new designs without due ECO process? I sure hope you > >>> don't design anything that can harm people. > > >> AlwaysWrong doesn't design anything, so no he doesn't release ECOs. Everyone > >> else here who does, uses an ECO process, certainly. > > >Yup. > > >Maybe they have a different release process for new stuff even though it > >typically _changes_ a product from previous to next generation. Having > >two different release processes doesn't strike me as particularly smart, > >but who knows :-) > > ECO is NOT for a "release", and not all releases are next gen designs > of previous work, idiot. > > Two proofs that you are chasing your own tail. JUST LIKE YOUR DISRESPECTFUL RESPONSE PROVES THAT YOU ARE DIGGING INTO AND SNIFFING YOUR OWN ANUS STILL YOU CLAIM TO BE A CREATIVE AND THOUGHTFUL ENGINEER I AM PROTEUS
From: Ian Bell on 14 Jun 2010 06:58 On 14/06/10 01:51, Joerg wrote: > Ian Bell wrote: >> On 13/06/10 21:26, Joerg wrote: >>> Ian Bell wrote: >>>> On 13/06/10 16:02, Joerg wrote: >>>>> Ian Bell wrote: >>>>>> On 12/06/10 23:00, Joerg wrote: >>>>>>> Ian Bell wrote: >>>>>>>> On 12/06/10 16:07, John Larkin wrote: >>>>>>>>> On Sat, 12 Jun 2010 10:22:59 +0100, Ian Bell<ruffrecords(a)yahoo.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> When winding modest inductors of a few hundred milliHenries on a >>>>>>>>>> ferrite >>>>>>>>>> core, given Al and a number of turns, what is the typical >>>>>>>>>> tolerance on >>>>>>>>>> the actual value of inductance when these are made in quantity? >>>>>>>>>> >>>>>>>>>> Cheers >>>>>>>>>> >>>>>>>>>> Ian >>>>>>>>> >>>>>>>>> An ungapped ferrite core could be all over the place. 25% wouldn't >>>>>>>>> surprise me. They will vary with temperature, too. You can buy >>>>>>>>> gapped >>>>>>>>> pot cores in tolerances around 2-5%, I think. Or use a pot core >>>>>>>>> with a >>>>>>>>> slug adjuster if you need 1% or better. See the datasheets. >>>>>>>>> >>>>>>>>> Powder-type cores can be bought with better tolerances. >>>>>>>>> >>>>>>>>> The people who wind inductors commercially get the exact number of >>>>>>>>> turns every time. >>>>>>>>> >>>>>>>>> John >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> It seems to me there are quite a few factors that could affect the >>>>>>>> actual inductance achieved and perhaps the least of them is the >>>>>>>> accuracy >>>>>>>> in counting the number of turns. I would expect there to be some >>>>>>>> tolerance in the Al value of the ferrite, that its exact dimensions >>>>>>>> would have an effect along with how neatly or otherwise the turns >>>>>>>> are >>>>>>>> wound. I have absolutely no idea if these are the major factors >>>>>>>> nor of >>>>>>>> the likely size of the actual major factors affecting the actual >>>>>>>> inductance. I am just trying to get a feel for the likely >>>>>>>> tolerance of >>>>>>>> ready made inductors. >>>>>>>> >>>>>>>> The reason I ask is am am designing some passive audio filters and I >>>>>>>> know exactly what tolerance of resistance and capacitance I can >>>>>>>> obtain >>>>>>>> but not a clue about inductance. It is no good me using 1% >>>>>>>> capacitors >>>>>>>> and resistors if inductors normally fail to achieve 5%. >>>>>>>> >>>>>>> >>>>>>> You can get 5% catalog inductors from Delevan, Miller, TDK and >>>>>>> several >>>>>>> others. If it needs to be more precise then you'd be off to boutique >>>>>>> lines, meaning $$$. >>>>>>> >>>>>>> Example: >>>>>>> >>>>>>> http://www.delevan.com/seriesPDFs/1782.pdf >>>>>>> >>>>>> >>>>>> Those devices seem to be in the sub milliHenry range, the one I >>>>>> need are >>>>>> in the humfreds of milliHenries. >>>>>> >>>>> >>>>> Then you'll likely have to live with 5%, for example: >>>>> >>>>> http://www.yuden.co.jp/us/product/pdf/elhl_e.pdf >>>>> >>>>> There are other ideas but you'd have to let us know about the nature of >>>>> the product. Things such as yearly qty, why it must be passive, how >>>>> many >>>>> inductors per unit, whether end-test trimming is ok, et cetera. >>>>> Otehrwise it'll all be speculation. >>>>> >>>> >>>> Thanks for the input but I think you have misunderstood me. I already >>>> have a source of suitable inductors. What I am interested in is the >>>> factors that govern the tolerance of a production inductor (as it comes >>>> off the line and before any selection process) and what the resultant >>>> overall tolerance is likely to be for inductors around 1H. I am not >>>> asking for help designing a product or in selecting parts. >>>> >>> >>> Having designed several custom inductors and transformers, the largest >>> tolerance contribution came from the core material. Not the dimensions, >>> those are very precise, but from the materials properties. >>> >> >> Thanks Joerg, that is exactly the sort of thing I was looking for. I >> have heard the Al can vary by 20% for some core types. has this been >> your experience too? >> > > Yes, 20% is quite common, often 30%. It depends on where you get the > core material from. It can be quite constant for hundreds of cores and > then all of a sudden there is a jump to another value. IOW, you cannot > rely on measurements and extrapolate. At least not for longer or larger > production runs. > Very interesting Joerg. I have also heard some winders over wind then remove turns until the correct inductance is achieved. Cheers ian
From: Ian Bell on 14 Jun 2010 07:08 On 14/06/10 03:39, John Larkin wrote: > On Mon, 14 Jun 2010 00:12:58 +0100, Ian Bell<ruffrecords(a)yahoo.com> > wrote: > >> On 13/06/10 19:10, John Larkin wrote: >>> On Sun, 13 Jun 2010 18:40:25 +0100, Ian Bell<ruffrecords(a)yahoo.com> >>> wrote: >>> >>>> On 13/06/10 16:02, Joerg wrote: >>>>> Ian Bell wrote: >>>>>> On 12/06/10 23:00, Joerg wrote: >>>>>>> Ian Bell wrote: >>>>>>>> On 12/06/10 16:07, John Larkin wrote: >>>>>>>>> On Sat, 12 Jun 2010 10:22:59 +0100, Ian Bell<ruffrecords(a)yahoo.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> When winding modest inductors of a few hundred milliHenries on a >>>>>>>>>> ferrite >>>>>>>>>> core, given Al and a number of turns, what is the typical tolerance on >>>>>>>>>> the actual value of inductance when these are made in quantity? >>>>>>>>>> >>>>>>>>>> Cheers >>>>>>>>>> >>>>>>>>>> Ian >>>>>>>>> >>>>>>>>> An ungapped ferrite core could be all over the place. 25% wouldn't >>>>>>>>> surprise me. They will vary with temperature, too. You can buy gapped >>>>>>>>> pot cores in tolerances around 2-5%, I think. Or use a pot core with a >>>>>>>>> slug adjuster if you need 1% or better. See the datasheets. >>>>>>>>> >>>>>>>>> Powder-type cores can be bought with better tolerances. >>>>>>>>> >>>>>>>>> The people who wind inductors commercially get the exact number of >>>>>>>>> turns every time. >>>>>>>>> >>>>>>>>> John >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> It seems to me there are quite a few factors that could affect the >>>>>>>> actual inductance achieved and perhaps the least of them is the accuracy >>>>>>>> in counting the number of turns. I would expect there to be some >>>>>>>> tolerance in the Al value of the ferrite, that its exact dimensions >>>>>>>> would have an effect along with how neatly or otherwise the turns are >>>>>>>> wound. I have absolutely no idea if these are the major factors nor of >>>>>>>> the likely size of the actual major factors affecting the actual >>>>>>>> inductance. I am just trying to get a feel for the likely tolerance of >>>>>>>> ready made inductors. >>>>>>>> >>>>>>>> The reason I ask is am am designing some passive audio filters and I >>>>>>>> know exactly what tolerance of resistance and capacitance I can obtain >>>>>>>> but not a clue about inductance. It is no good me using 1% capacitors >>>>>>>> and resistors if inductors normally fail to achieve 5%. >>>>>>>> >>>>>>> >>>>>>> You can get 5% catalog inductors from Delevan, Miller, TDK and several >>>>>>> others. If it needs to be more precise then you'd be off to boutique >>>>>>> lines, meaning $$$. >>>>>>> >>>>>>> Example: >>>>>>> >>>>>>> http://www.delevan.com/seriesPDFs/1782.pdf >>>>>>> >>>>>> >>>>>> Those devices seem to be in the sub milliHenry range, the one I need are >>>>>> in the humfreds of milliHenries. >>>>>> >>>>> >>>>> Then you'll likely have to live with 5%, for example: >>>>> >>>>> http://www.yuden.co.jp/us/product/pdf/elhl_e.pdf >>>>> >>>>> There are other ideas but you'd have to let us know about the nature of >>>>> the product. Things such as yearly qty, why it must be passive, how many >>>>> inductors per unit, whether end-test trimming is ok, et cetera. >>>>> Otehrwise it'll all be speculation. >>>>> >>>> >>>> Thanks for the input but I think you have misunderstood me. I already >>>> have a source of suitable inductors. >>> >>> Then why don't you ask them? >>> >> >> I have asked them. What I am asking here is what is typical/normal and >> what are the contributing factors. > > What do they suggest as normal tolerances? What can they do for more > money? > > John > > They replied "They are 10%..... but measured inductance usually varies with level and frequency." This make is half the price of similar inductors made by Sowter. Neither specifies inductance tolerance on their respective web sites. I think I'll ask Brian Sowter what tolerance his are. I would hope they are rather better than 10% for twice the price. Cheers Ian
From: Archimedes' Lever on 14 Jun 2010 07:51 On Mon, 14 Jun 2010 03:10:01 -0400, "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote: > >"krw(a)att.bizzzzzzzzzzzz" wrote: >> >> On Sun, 13 Jun 2010 14:50:22 -0700, Archimedes' Lever >> <OneBigLever(a)InfiniteSeries.Org> wrote: >> >> >On Sun, 13 Jun 2010 14:43:31 -0700, Joerg <invalid(a)invalid.invalid> >> >wrote: >> > >> >>krw(a)att.bizzzzzzzzzzzz wrote: >> >>> On Sun, 13 Jun 2010 14:08:03 -0700, Joerg <invalid(a)invalid.invalid> wrote: >> >>> >> >>>> Archimedes' Lever wrote: >> >>>>> On Sun, 13 Jun 2010 13:24:21 -0700, Joerg <invalid(a)invalid.invalid> >> >>>>> wrote: >> >>>>> >> >>>>>> Oh, and how do you suppose you get an "original design" into production >> >>>>>> without an ECO? >> >>>>> >> >>>>> You must also be an acronymical retard as well. >> >>>>> >> >>>>> There is a difference between a design release and a change order of an >> >>>>> existing design. >> >>>>> >> >>>> So you guys release new designs without due ECO process? I sure hope you >> >>>> don't design anything that can harm people. >> >>> >> >>> AlwaysWrong doesn't design anything, so no he doesn't release ECOs. Everyone >> >>> else here who does, uses an ECO process, certainly. >> >> >> >> >> >>Yup. >> >> >> >>Maybe they have a different release process for new stuff even though it >> >>typically _changes_ a product from previous to next generation. Having >> >>two different release processes doesn't strike me as particularly smart, >> >>but who knows :-) >> > >> > ECO is NOT for a "release", and not all releases are next gen designs >> >of previous work, idiot. >> >> AlwaysWrong is , *SURPRISE*, wrong again. It is an engineering change to the >> database so an Engineering Change Order is necessary. It's really that >> simple, AlwaysWrong. You should know simple, by mirror. >> >> > Two proofs that you are chasing your own tail. >> >> DimBulb just can't avoid the hind-end references. > > > If his parents had read that last ECO, dimmie would have been born >human. :( Said the utter retard that claims to be such a patriot, yet makes stupid remarks like this about people. You are not a patriot, dumbfuck, you are the antithesis of patriotism.
From: Joerg on 14 Jun 2010 10:50
Ian Bell wrote: > On 14/06/10 01:51, Joerg wrote: >> Ian Bell wrote: >>> On 13/06/10 21:26, Joerg wrote: >>>> Ian Bell wrote: >>>>> On 13/06/10 16:02, Joerg wrote: >>>>>> Ian Bell wrote: >>>>>>> On 12/06/10 23:00, Joerg wrote: >>>>>>>> Ian Bell wrote: >>>>>>>>> On 12/06/10 16:07, John Larkin wrote: >>>>>>>>>> On Sat, 12 Jun 2010 10:22:59 +0100, Ian >>>>>>>>>> Bell<ruffrecords(a)yahoo.com> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> When winding modest inductors of a few hundred milliHenries on a >>>>>>>>>>> ferrite >>>>>>>>>>> core, given Al and a number of turns, what is the typical >>>>>>>>>>> tolerance on >>>>>>>>>>> the actual value of inductance when these are made in quantity? >>>>>>>>>>> >>>>>>>>>>> Cheers >>>>>>>>>>> >>>>>>>>>>> Ian >>>>>>>>>> >>>>>>>>>> An ungapped ferrite core could be all over the place. 25% >>>>>>>>>> wouldn't >>>>>>>>>> surprise me. They will vary with temperature, too. You can buy >>>>>>>>>> gapped >>>>>>>>>> pot cores in tolerances around 2-5%, I think. Or use a pot core >>>>>>>>>> with a >>>>>>>>>> slug adjuster if you need 1% or better. See the datasheets. >>>>>>>>>> >>>>>>>>>> Powder-type cores can be bought with better tolerances. >>>>>>>>>> >>>>>>>>>> The people who wind inductors commercially get the exact >>>>>>>>>> number of >>>>>>>>>> turns every time. >>>>>>>>>> >>>>>>>>>> John >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> It seems to me there are quite a few factors that could affect the >>>>>>>>> actual inductance achieved and perhaps the least of them is the >>>>>>>>> accuracy >>>>>>>>> in counting the number of turns. I would expect there to be some >>>>>>>>> tolerance in the Al value of the ferrite, that its exact >>>>>>>>> dimensions >>>>>>>>> would have an effect along with how neatly or otherwise the turns >>>>>>>>> are >>>>>>>>> wound. I have absolutely no idea if these are the major factors >>>>>>>>> nor of >>>>>>>>> the likely size of the actual major factors affecting the actual >>>>>>>>> inductance. I am just trying to get a feel for the likely >>>>>>>>> tolerance of >>>>>>>>> ready made inductors. >>>>>>>>> >>>>>>>>> The reason I ask is am am designing some passive audio filters >>>>>>>>> and I >>>>>>>>> know exactly what tolerance of resistance and capacitance I can >>>>>>>>> obtain >>>>>>>>> but not a clue about inductance. It is no good me using 1% >>>>>>>>> capacitors >>>>>>>>> and resistors if inductors normally fail to achieve 5%. >>>>>>>>> >>>>>>>> >>>>>>>> You can get 5% catalog inductors from Delevan, Miller, TDK and >>>>>>>> several >>>>>>>> others. If it needs to be more precise then you'd be off to >>>>>>>> boutique >>>>>>>> lines, meaning $$$. >>>>>>>> >>>>>>>> Example: >>>>>>>> >>>>>>>> http://www.delevan.com/seriesPDFs/1782.pdf >>>>>>>> >>>>>>> >>>>>>> Those devices seem to be in the sub milliHenry range, the one I >>>>>>> need are >>>>>>> in the humfreds of milliHenries. >>>>>>> >>>>>> >>>>>> Then you'll likely have to live with 5%, for example: >>>>>> >>>>>> http://www.yuden.co.jp/us/product/pdf/elhl_e.pdf >>>>>> >>>>>> There are other ideas but you'd have to let us know about the >>>>>> nature of >>>>>> the product. Things such as yearly qty, why it must be passive, how >>>>>> many >>>>>> inductors per unit, whether end-test trimming is ok, et cetera. >>>>>> Otehrwise it'll all be speculation. >>>>>> >>>>> >>>>> Thanks for the input but I think you have misunderstood me. I already >>>>> have a source of suitable inductors. What I am interested in is the >>>>> factors that govern the tolerance of a production inductor (as it >>>>> comes >>>>> off the line and before any selection process) and what the resultant >>>>> overall tolerance is likely to be for inductors around 1H. I am not >>>>> asking for help designing a product or in selecting parts. >>>>> >>>> >>>> Having designed several custom inductors and transformers, the largest >>>> tolerance contribution came from the core material. Not the dimensions, >>>> those are very precise, but from the materials properties. >>>> >>> >>> Thanks Joerg, that is exactly the sort of thing I was looking for. I >>> have heard the Al can vary by 20% for some core types. has this been >>> your experience too? >>> >> >> Yes, 20% is quite common, often 30%. It depends on where you get the >> core material from. It can be quite constant for hundreds of cores and >> then all of a sudden there is a jump to another value. IOW, you cannot >> rely on measurements and extrapolate. At least not for longer or larger >> production runs. >> > > Very interesting Joerg. I have also heard some winders over wind then > remove turns until the correct inductance is achieved. > Yes, I did that as well. Just had gotten my first PC in the 80's and a friend had a crude piece of software that acted like a spreadsheet, under DOS and all text-based. This allowed to enter a formula, measure, enter the number of wound turns and it would tell me how many to remove to get to the target inductance. Took a long time to calculate (until I forked over a serious chunk of cash for a Cyrix math coprocessor), today it would probably be under a millisecond :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |