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Toroid ID question...
Greetings,
Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Thanks for all assistance. Jim Shrum - KC9FFX |
Look at the tables in the ARRL Handbook, in 2003 it was in Chapter 24, for
tables with the info you need to calculate the inductance on a given core with a certain number of windings. You need to solve for AL obviously since you want to find your core. Uwe in article , J Shrum at wrote on 4/21/04 18:55: Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Thanks for all assistance. Jim Shrum - KC9FFX |
Look at the tables in the ARRL Handbook, in 2003 it was in Chapter 24, for
tables with the info you need to calculate the inductance on a given core with a certain number of windings. You need to solve for AL obviously since you want to find your core. Uwe in article , J Shrum at wrote on 4/21/04 18:55: Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Thanks for all assistance. Jim Shrum - KC9FFX |
The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. The equation goes; Turns = 100SQR(uH/Al) where Al is the inductance in uH per 100 turns) and 15 = 100SQR(150/Al) and (0.15)^2 = 150/Al and 150/0.0225 = Al = 6666. You have ferrite not powdered iron. For Ferrite, it's just the conversion Turns = 1000SQR (mH/Al) where Al = mH/1000 turns 15 = 1000SQR(.15/Al) and 0.15/0.00225 =66 which looks like, (for T50 core) material 61 W4ZCB |
The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. The equation goes; Turns = 100SQR(uH/Al) where Al is the inductance in uH per 100 turns) and 15 = 100SQR(150/Al) and (0.15)^2 = 150/Al and 150/0.0225 = Al = 6666. You have ferrite not powdered iron. For Ferrite, it's just the conversion Turns = 1000SQR (mH/Al) where Al = mH/1000 turns 15 = 1000SQR(.15/Al) and 0.15/0.00225 =66 which looks like, (for T50 core) material 61 W4ZCB |
and 0.15/0.00225 =66 which looks like, (for T50 core) material 61 And the T37 core, at 2200, looks like 75 material, look out for it's bulk resistivity which is pretty low. W4ZCB |
and 0.15/0.00225 =66 which looks like, (for T50 core) material 61 And the T37 core, at 2200, looks like 75 material, look out for it's bulk resistivity which is pretty low. W4ZCB |
"J Shrum" wrote in message ... Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com .. I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH Al = 150uH * square(1/15) = 667 T-37 9turns 30awg = ~180uH Al = 180uH * square(1/9) = 2200 See if these Al values look realistic. Even if not, this is the value of inductance of one turn for the core which some manufacturers used as Al many years ago when I worked with the devices. The inductance ratio varies as the square of the turns ratio. John |
"J Shrum" wrote in message ... Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com .. I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH Al = 150uH * square(1/15) = 667 T-37 9turns 30awg = ~180uH Al = 180uH * square(1/9) = 2200 See if these Al values look realistic. Even if not, this is the value of inductance of one turn for the core which some manufacturers used as Al many years ago when I worked with the devices. The inductance ratio varies as the square of the turns ratio. John |
Greetings,
Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Start at http://www.amidoncorp.com/aai_productselection.htm Follow the "Iron Powder Cores" and "Ferrite cores" links. The formulas, and the specific inductance index A(L) values for various toroid formulas, are on those pages. It's important to note that the A(L) values are stated in different units for the two toroid types. For iron-powder cores, it's given as "microhenries for 100 turns", while for ferrite cores it's "millihenries for 1000 turns". -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Greetings,
Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Start at http://www.amidoncorp.com/aai_productselection.htm Follow the "Iron Powder Cores" and "Ferrite cores" links. The formulas, and the specific inductance index A(L) values for various toroid formulas, are on those pages. It's important to note that the A(L) values are stated in different units for the two toroid types. For iron-powder cores, it's given as "microhenries for 100 turns", while for ferrite cores it's "millihenries for 1000 turns". -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
On Wed, 21 Apr 2004 17:55:20 -0500, "J Shrum" wrote:
Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... If they are not color coded then I guess they aren't Amidon toroids, at least all the Amidon toroids I have seen were color coded, Amidon does have all the specifications for all their toroids posted on their website though: http://www.amidoncorp.com/aai_productselection.htm The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. If you are running Windows, you can use this program to do quick inductance calculations for many different toroids types: http://www.qsl.net/dl5swb/minirk_e.htm , and to get specs on different toroid types. A real time saver for calculating the inductance values and it also shows the Inductance Index for each toroid and the frequency bandwidth for that composition type, which might help you to get a better idea of the composition type of your toroids. I think it will still be hard to determine the composition types for certain, although the different composition types do have different Inductance Index values for the same size toroid. |
On Wed, 21 Apr 2004 17:55:20 -0500, "J Shrum" wrote:
Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... If they are not color coded then I guess they aren't Amidon toroids, at least all the Amidon toroids I have seen were color coded, Amidon does have all the specifications for all their toroids posted on their website though: http://www.amidoncorp.com/aai_productselection.htm The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. If you are running Windows, you can use this program to do quick inductance calculations for many different toroids types: http://www.qsl.net/dl5swb/minirk_e.htm , and to get specs on different toroid types. A real time saver for calculating the inductance values and it also shows the Inductance Index for each toroid and the frequency bandwidth for that composition type, which might help you to get a better idea of the composition type of your toroids. I think it will still be hard to determine the composition types for certain, although the different composition types do have different Inductance Index values for the same size toroid. |
There are lots of web resources. Here's one:
http://www.amidoncorp.com/ace_iptcforrf.htm And another: http://www.bytemark.com/ You can search for Amidon or Bytemark or Fair-Rite or Ferronics, and also just search for 'powdered iron toroid' or 'ferrite toroid' and find lots of things. Those links will take you more-or-less directly to Al values for a wide range of cores. Just remember that inductance goes as the square of the number of turns, so if Al is uH/100 turns, the inductance will be Al*(your_turns/100)^2. Cheers, Tom "J Shrum" wrote in message ... Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Thanks for all assistance. Jim Shrum - KC9FFX |
There are lots of web resources. Here's one:
http://www.amidoncorp.com/ace_iptcforrf.htm And another: http://www.bytemark.com/ You can search for Amidon or Bytemark or Fair-Rite or Ferronics, and also just search for 'powdered iron toroid' or 'ferrite toroid' and find lots of things. Those links will take you more-or-less directly to Al values for a wide range of cores. Just remember that inductance goes as the square of the number of turns, so if Al is uH/100 turns, the inductance will be Al*(your_turns/100)^2. Cheers, Tom "J Shrum" wrote in message ... Greetings, Recently I bought a grab bag of mixed toroids from www.allelectronics.com . I bought some T-37's and T-50's. The problem is... they're not color coded, and not identified by mix. So I have mystery toroids T-37-?? and T-50-??... The question is, is there a way to come up w/ a rough estimate of the mix value? I wound some test coils and come up w/ these figures: T-50 15turns 30awg = ~150uH T-37 9turns 30awg = ~180uH Perhaps there is a chart or something similar somewhere that I have overlooked that will give me an idea. Thanks for all assistance. Jim Shrum - KC9FFX |
Use program TOROID from website below.
Enter into the program the data you already have, core dimensions and inductance, and the remaining information such as core permeability, the number of turns for other inductances, will be computed. Program avoids guessing who is the manufacturer. Who needs to know if you have already grab-bagged the items. From inductance/number-of-turns data you can guess the type of material, ferrite or iron powder, if you are interested. Download program TOROID in a few seconds and run immediately. --- .................................................. .......... Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.btinternet.com/~g4fgq.regp .................................................. .......... |
Use program TOROID from website below.
Enter into the program the data you already have, core dimensions and inductance, and the remaining information such as core permeability, the number of turns for other inductances, will be computed. Program avoids guessing who is the manufacturer. Who needs to know if you have already grab-bagged the items. From inductance/number-of-turns data you can guess the type of material, ferrite or iron powder, if you are interested. Download program TOROID in a few seconds and run immediately. --- .................................................. .......... Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.btinternet.com/~g4fgq.regp .................................................. .......... |
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