On Saturday, September 26, 2020 at 6:48:34 PM UTC+10, piglet wrote:> On 26/09/2020 09:12, Piotr Wyderski wrote: > > Piglet wrote: > > > >> Very roughly indeed, an octave out - I make 1pF 100uH resonant at 16MHz > > > > I would say an octave is good enough for a SWAG. Even a decade would > > pass in most of the cases. > > > > Best regards, Piotr > You are right when some information is missing but in this case all the > data was available to calculate better.I agree with piglet. I'm not in the least pleased with myself. -- Bill Sloman, Sydney
Type 43 material for common-mode choke
Started by ●September 24, 2020
Reply by ●September 26, 20202020-09-26
Reply by ●September 26, 20202020-09-26
On 9/24/2020 8:36 PM, bitrex wrote:> The article here says type 43 NiZn ferrite's resistive impedance exceeds > it's reactance at about 2MHz > > <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> > > > but I think that's a misprint, looks more like 15MHz: > > <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> > > The data-sheet is here: > > <https://www.fair-rite.com/43-material-data-sheet/> > > I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH > common-mode choke for about 3 MHz, the calculator says about 30 turns > should give me that but I'm unclear if this is an appropriate materialIt was my understanding the that the point where u' and u" cross on a permeability curve is where the material Q = 1.> https://www.fair-rite.com/43-material-data-sheet/ On this curve that > is at about 7MHz.How do I reconcile that with the curve on this page.> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.Mikek -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
Reply by ●September 26, 20202020-09-26
On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:>On 9/24/2020 8:36 PM, bitrex wrote: >> The article here says type 43 NiZn ferrite's resistive impedance exceeds >> it's reactance at about 2MHz >> >> <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> >> >> >> but I think that's a misprint, looks more like 15MHz: >> >> <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> >> >> The data-sheet is here: >> >> <https://www.fair-rite.com/43-material-data-sheet/> >> >> I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >> common-mode choke for about 3 MHz, the calculator says about 30 turns >> should give me that but I'm unclear if this is an appropriate material > >It was my understanding the that the point where u' and u" cross on a >permeability curve is where the material Q = 1. > >> https://www.fair-rite.com/43-material-data-sheet/ On this curve that >> is at about 7MHz. >How do I reconcile that with the curve on this page. > >> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix. >MikekThere is no such thing as material 'Q'. When you assume subjective properties in magnetics, you make a fool of you and me. RL
Reply by ●September 26, 20202020-09-26
On 9/26/2020 10:33 AM, legg wrote:> On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote: > >> On 9/24/2020 8:36 PM, bitrex wrote: >>> The article here says type 43 NiZn ferrite's resistive impedance exceeds >>> it's reactance at about 2MHz >>> >>> <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> >>> >>> >>> but I think that's a misprint, looks more like 15MHz: >>> >>> <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> >>> >>> The data-sheet is here: >>> >>> <https://www.fair-rite.com/43-material-data-sheet/> >>> >>> I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >>> common-mode choke for about 3 MHz, the calculator says about 30 turns >>> should give me that but I'm unclear if this is an appropriate material >> >> It was my understanding the that the point where u' and u" cross on a >> permeability curve is where the material Q = 1. >> >>> https://www.fair-rite.com/43-material-data-sheet/ On this curve that >>> is at about 7MHz. >> How do I reconcile that with the curve on this page. >> >>> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix. >> Mikek > > There is no such thing as material 'Q'. > > When you assume subjective properties in > magnetics, you make a fool of you and me. > > RL >I think the crossing point is where the resistance is equal to the reactance. No? If so, then the Q at that point is 1. No?
Reply by ●September 26, 20202020-09-26
On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org> wrote:>On 9/26/2020 10:33 AM, legg wrote: >> On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote: >> >>> On 9/24/2020 8:36 PM, bitrex wrote: >>>> The article here says type 43 NiZn ferrite's resistive impedance exceeds >>>> it's reactance at about 2MHz >>>> >>>> <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> >>>> >>>> >>>> but I think that's a misprint, looks more like 15MHz: >>>> >>>> <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> >>>> >>>> The data-sheet is here: >>>> >>>> <https://www.fair-rite.com/43-material-data-sheet/> >>>> >>>> I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >>>> common-mode choke for about 3 MHz, the calculator says about 30 turns >>>> should give me that but I'm unclear if this is an appropriate material >>> >>> It was my understanding the that the point where u' and u" cross on a >>> permeability curve is where the material Q = 1. >>> >>>> https://www.fair-rite.com/43-material-data-sheet/ On this curve that >>>> is at about 7MHz. >>> How do I reconcile that with the curve on this page. >>> >>>> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix. >>> Mikek >> >> There is no such thing as material 'Q'. >> >> When you assume subjective properties in >> magnetics, you make a fool of you and me. >> >> RL >> > >I think the crossing point is where the resistance is equal to the >reactance. No? > >If so, then the Q at that point is 1. No?The material itself doesn't have reactance. It does have a bulk resistivity, but that isn't directly related to core loss effects, though lossy materials can often be identified by their low bulk resistance. "It was my understanding the that the point where u' and u" cross on apermeability curve is where the material Q = 1." - Refers to a graph constructed using measurements performed on a predifined core shape and turns count, as comparative reference information for the core material in question. The graphical contents would change with a different core shape or winding configuration - shifting this specific 'Q' point, without altering the material composition of the core. Another common graph is for the single-turn bead, which attempts to reduce winding effects on measurement of the loss characteristic. Each bead size and shape will still have its own curves, without alteration in the core material type. Anyone can stipulate that a Q factor exists for the relation between any two measurable quantities. providing that its definition is presented within the scope of the work. In a non-resonant circuit, the term has little meaning, as losses in the core are (non-linearly) dependent on the amplitude of the peak flux excursion, and many other inter-related physical factors of the core and winding. RL
Reply by ●September 26, 20202020-09-26
On Sat, 26 Sep 2020 16:13:07 -0400, legg <legg@nospam.magma.ca> wrote:>On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org> >wrote: > >>On 9/26/2020 10:33 AM, legg wrote: >>> On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote: >>> >>>> On 9/24/2020 8:36 PM, bitrex wrote: >>>>> The article here says type 43 NiZn ferrite's resistive impedance exceeds >>>>> it's reactance at about 2MHz >>>>> >>>>> <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> >>>>> >>>>> >>>>> but I think that's a misprint, looks more like 15MHz: >>>>> >>>>> <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> >>>>> >>>>> The data-sheet is here: >>>>> >>>>> <https://www.fair-rite.com/43-material-data-sheet/> >>>>> >>>>> I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >>>>> common-mode choke for about 3 MHz, the calculator says about 30 turns >>>>> should give me that but I'm unclear if this is an appropriate material >>>> >>>> It was my understanding the that the point where u' and u" cross on a >>>> permeability curve is where the material Q = 1. >>>> >>>>> https://www.fair-rite.com/43-material-data-sheet/ On this curve that >>>>> is at about 7MHz. >>>> How do I reconcile that with the curve on this page. >>>> >>>>> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix. >>>> Mikek >>> >>> There is no such thing as material 'Q'. >>> >>> When you assume subjective properties in >>> magnetics, you make a fool of you and me. >>> >>> RL >>> >> >>I think the crossing point is where the resistance is equal to the >>reactance. No? >> >>If so, then the Q at that point is 1. No? > >The material itself doesn't have reactance. It does >have a bulk resistivity, but that isn't directly >related to core loss effects, though lossy materials >can often be identified by their low bulk resistance. > >"It was my understanding the that the point where u' and u" >cross on apermeability curve is where the material Q = 1." > >- Refers to a graph constructed using measurements performed >on a predifined core shape and turns count, as comparative >reference information for the core material in question. >The graphical contents would change with a different core >shape or winding configuration - shifting this specific 'Q' >point, without altering the material composition of the core. > >Another common graph is for the single-turn bead, which >attempts to reduce winding effects on measurement of the >loss characteristic. Each bead size and shape will still >have its own curves, without alteration in the core >material type. > >Anyone can stipulate that a Q factor exists for the relation >between any two measurable quantities. providing that its >definition is presented within the scope of the work. > >In a non-resonant circuit, the term has little meaning, >as losses in the core are (non-linearly) dependent on the >amplitude of the peak flux excursion, and many other >inter-related physical factors of the core and winding.A lot of instruments to measure inductors and capacitors report Q, by which they mean the ratio of reactance divided by resistance at the chosen test frequency, well away from resonance. Joe Gwinn
Reply by ●September 26, 20202020-09-26
On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <user@example.net> wrote:>The article here says type 43 NiZn ferrite's resistive impedance exceeds >it's reactance at about 2MHz > ><https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> > >but I think that's a misprint, looks more like 15MHz: > ><https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> > >The data-sheet is here: > ><https://www.fair-rite.com/43-material-data-sheet/> > >I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >common-mode choke for about 3 MHz, the calculator says about 30 turns >should give me that but I'm unclear if this is an appropriate materialI've tested some commercial AC-line CM chokes. I was surprised by how little normal-mode DC current it takes to saturate the ones I tried. They seem to assume that all AC loads are exactly DC balanced. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●September 26, 20202020-09-26
On Sat, 26 Sep 2020 16:54:54 -0400, Joe Gwinn <joegwinn@comcast.net> wrote:>On Sat, 26 Sep 2020 16:13:07 -0400, legg <legg@nospam.magma.ca> wrote: > >>On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org> >>wrote: >> >>>On 9/26/2020 10:33 AM, legg wrote: >>>> On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote: >>>> >>>>> On 9/24/2020 8:36 PM, bitrex wrote: >>>>>> The article here says type 43 NiZn ferrite's resistive impedance exceeds >>>>>> it's reactance at about 2MHz >>>>>> >>>>>> <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> >>>>>> >>>>>> >>>>>> but I think that's a misprint, looks more like 15MHz: >>>>>> >>>>>> <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> >>>>>> >>>>>> The data-sheet is here: >>>>>> >>>>>> <https://www.fair-rite.com/43-material-data-sheet/> >>>>>> >>>>>> I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >>>>>> common-mode choke for about 3 MHz, the calculator says about 30 turns >>>>>> should give me that but I'm unclear if this is an appropriate material >>>>> >>>>> It was my understanding the that the point where u' and u" cross on a >>>>> permeability curve is where the material Q = 1. >>>>> >>>>>> https://www.fair-rite.com/43-material-data-sheet/ On this curve that >>>>>> is at about 7MHz. >>>>> How do I reconcile that with the curve on this page. >>>>> >>>>>> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix. >>>>> Mikek >>>> >>>> There is no such thing as material 'Q'. >>>> >>>> When you assume subjective properties in >>>> magnetics, you make a fool of you and me. >>>> >>>> RL >>>> >>> >>>I think the crossing point is where the resistance is equal to the >>>reactance. No? >>> >>>If so, then the Q at that point is 1. No? >> >>The material itself doesn't have reactance. It does >>have a bulk resistivity, but that isn't directly >>related to core loss effects, though lossy materials >>can often be identified by their low bulk resistance. >> >>"It was my understanding the that the point where u' and u" >>cross on apermeability curve is where the material Q = 1." >> >>- Refers to a graph constructed using measurements performed >>on a predifined core shape and turns count, as comparative >>reference information for the core material in question. >>The graphical contents would change with a different core >>shape or winding configuration - shifting this specific 'Q' >>point, without altering the material composition of the core. >> >>Another common graph is for the single-turn bead, which >>attempts to reduce winding effects on measurement of the >>loss characteristic. Each bead size and shape will still >>have its own curves, without alteration in the core >>material type. >> >>Anyone can stipulate that a Q factor exists for the relation >>between any two measurable quantities. providing that its >>definition is presented within the scope of the work. >> >>In a non-resonant circuit, the term has little meaning, >>as losses in the core are (non-linearly) dependent on the >>amplitude of the peak flux excursion, and many other >>inter-related physical factors of the core and winding. > >A lot of instruments to measure inductors and capacitors report Q, by >which they mean the ratio of reactance divided by resistance at the >chosen test frequency, well away from resonance. > >Joe GwinnAs long as they tell you what they're talking about, then they can call it anything they want. Q is not a characteristic of the core material. RL
Reply by ●September 26, 20202020-09-26
On 9/26/2020 5:16 PM, legg wrote:> On Sat, 26 Sep 2020 16:54:54 -0400, Joe Gwinn <joegwinn@comcast.net> > wrote: > >> On Sat, 26 Sep 2020 16:13:07 -0400, legg <legg@nospam.magma.ca> wrote: >> >>> On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org> >>> wrote: >>> >>>> On 9/26/2020 10:33 AM, legg wrote: >>>>> On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote: >>>>> >>>>>> On 9/24/2020 8:36 PM, bitrex wrote: >>>>>>> The article here says type 43 NiZn ferrite's resistive impedance exceeds >>>>>>> it's reactance at about 2MHz >>>>>>> >>>>>>> <https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.> >>>>>>> >>>>>>> >>>>>>> but I think that's a misprint, looks more like 15MHz: >>>>>>> >>>>>>> <https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg> >>>>>>> >>>>>>> The data-sheet is here: >>>>>>> >>>>>>> <https://www.fair-rite.com/43-material-data-sheet/> >>>>>>> >>>>>>> I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH >>>>>>> common-mode choke for about 3 MHz, the calculator says about 30 turns >>>>>>> should give me that but I'm unclear if this is an appropriate material >>>>>> >>>>>> It was my understanding the that the point where u' and u" cross on a >>>>>> permeability curve is where the material Q = 1. >>>>>> >>>>>>> https://www.fair-rite.com/43-material-data-sheet/ On this curve that >>>>>>> is at about 7MHz. >>>>>> How do I reconcile that with the curve on this page. >>>>>> >>>>>>> https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix. >>>>>> Mikek >>>>> >>>>> There is no such thing as material 'Q'. >>>>> >>>>> When you assume subjective properties in >>>>> magnetics, you make a fool of you and me. >>>>> >>>>> RL >>>>> >>>> >>>> I think the crossing point is where the resistance is equal to the >>>> reactance. No? >>>> >>>> If so, then the Q at that point is 1. No? >>> >>> The material itself doesn't have reactance. It does >>> have a bulk resistivity, but that isn't directly >>> related to core loss effects, though lossy materials >>> can often be identified by their low bulk resistance. >>> >>> "It was my understanding the that the point where u' and u" >>> cross on apermeability curve is where the material Q = 1." >>> >>> - Refers to a graph constructed using measurements performed >>> on a predifined core shape and turns count, as comparative >>> reference information for the core material in question. >>> The graphical contents would change with a different core >>> shape or winding configuration - shifting this specific 'Q' >>> point, without altering the material composition of the core. >>> >>> Another common graph is for the single-turn bead, which >>> attempts to reduce winding effects on measurement of the >>> loss characteristic. Each bead size and shape will still >>> have its own curves, without alteration in the core >>> material type. >>> >>> Anyone can stipulate that a Q factor exists for the relation >>> between any two measurable quantities. providing that its >>> definition is presented within the scope of the work. >>> >>> In a non-resonant circuit, the term has little meaning, >>> as losses in the core are (non-linearly) dependent on the >>> amplitude of the peak flux excursion, and many other >>> inter-related physical factors of the core and winding. >> >> A lot of instruments to measure inductors and capacitors report Q, by >> which they mean the ratio of reactance divided by resistance at the >> chosen test frequency, well away from resonance. >> >> Joe Gwinn > > As long as they tell you what they're talking about, then > they can call it anything they want. > > Q is not a characteristic of the core material. > > RL >Perhaps not. But as soon as you put a wire through the hole it has Q at some point. What good is the core if it not used?
Reply by ●September 26, 20202020-09-26
legg <legg@nospam.magma.ca> wrote:> On Sat, 26 Sep 2020 16:54:54 -0400, Joe Gwinn <joegwinn@comcast.net> > wrote:>>A lot of instruments to measure inductors and capacitors report Q, by >>which they mean the ratio of reactance divided by resistance at the >>chosen test frequency, well away from resonance.>>Joe Gwinn> As long as they tell you what they're talking about, then > they can call it anything they want.> Q is not a characteristic of the core material.> RLMany LCR meters report Q as a ratio of reactance divided by resistance. For example, the Agilent / Keysight U1733C 100Hz/120Hz/1kHz/10kHz/100kHz Handheld LCR Meter: https://literature.cdn.keysight.com/litweb/pdf/U1731-90076.pdf
