Ferrite Inductor Tolerance
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From: Ian Bell on 12 Jun 2010 05:22 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
From: amdx on 12 Jun 2010 07:11 "Ian Bell" <ruffrecords(a)yahoo.com> wrote in message news:huvjlf$5ve$2(a)localhost.localdomain... > 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 I don't know, but given the brand, size, form and material, the manufacturers site would probably have that info. I have Ferroxcube and Amidon catalogs if you are using those let me know. Mike
From: John Larkin on 12 Jun 2010 11:07 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
From: Ian Bell on 12 Jun 2010 17:06 On 12/06/10 12:11, amdx wrote: > "Ian Bell"<ruffrecords(a)yahoo.com> wrote in message > news:huvjlf$5ve$2(a)localhost.localdomain... >> 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 > > I don't know, but given the brand, size, form and material, the > manufacturers site > would probably have that info. I have Ferroxcube and Amidon catalogs if > you are using those let me know. > Mike > > The ones I am thinking of are the VTB series by Carnhill. Cheers Ian
From: Joerg on 12 Jun 2010 17:10
Ian Bell 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? > That depends on how much you are willing to pay and whether it is a higher power core. 5% to 20% are common tolerance values, sometimes with inductors from China I spec 30% when it has to be really low cost. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |