Yes. There is a ring core calculator available over at
Oookay. I have 3 yellow ones here, 2 small, 1 a little bigger, and a
Thx. Maybe I'll try it with wine ...
Allot of information about toroids and magnetic is corporate secrets. You
A couple of things I forgot to mention:
Is colour significant on toroids salvaged from scrap motherboards?
ine.LNX.4.64.0911271355250.24677@darkstar.example.net...specifically those of Micrometals. Other manufacturers have other"Michael Black" <et472@ncf.ca> wrote in message
news
On Fri, 27 Nov 2009, ian field wrote:
"Shaun" <rowl@nomail.com> wrote in message
news:dMBPm.40875$We2.9253@newsfe09.iad...
"Bernhard Kuemel" <bernhard@bksys.at> wrote in message
news:615c2$4b0d87ca$557f80c7$12673@news.inode.at...
Rich Webb wrote:
On Wed, 25 Nov 2009 13:28:44 +0100, Bernhard Kuemel
bernhard@bksys.at
wrote:
Hi sec!
Does the color with which ring cores are painted indicate magnetic
properties?
Yes.
Oookay. I have 3 yellow ones here, 2 small, 1 a little bigger, and a
green one. What does that mean?
There is a ring core calculator available over at
http://www.dl5swb.de/index.html that you may fine useful.
Thx. Maybe I'll try it with wine ...
Bernhard
A couple of things I forgot to mention:
Measure the outside diameter of the toroid in inches. (eg. for one
that is 0.255 inches is a T-25 core)
the size of the core determines in properties( microhenries per 100
turns)
as does the material that makes it up.
Those colors that you mentioned are common types.
The information that you get off the net will be the material type and
some properties and operating frequency.
I hope this helps
Shaun
Is colour significant on toroids salvaged from scrap motherboards?
They're often pale blue or yellow - I think I've seen red ones too.
There's no standardization for the color coding of toroids.
Decades ago, there was a certain consistency in hobby circles, because
virtually all toroids that got to hobbyists were from the same source,
and interestingly, that common source was not a manufacturer but a small
business that had set out to be the middleman, since the manufacturers
weren't wanting to sell in small quantities.
Then, toroids became a lot more common. Originally they'd only be seen
in non-consumer radio equipment, but eventually they became common
there (albeit just a few toroids per unit), likely dwarfing the numbers
used for non-consumer radio equipment.
Once that started happening, there was all kinds of opportunity to find
toroids at the surplus store, or in consumer electronics that begged to
be reused. But, without any information about who made the core, the
color coding meant nothing.
If it's in equipment, at least the context will provide some information
(and most of the time, it will be low frequency use, mostly power
supplies). A blank toroid at the surplus store doesn't offer such
information.
One generally has to wind a coil on the toroid, do some measurements
and then calculations with the results. The more detail you need,
the more effort has to be put in the testing. And then likely
you could have gotten an identifiable toroid direct from some company
that wouldn't have cost that much.
Michael
Michael,
There must be some consistency because if I look at Amidon, a popular
distributor, they carry products from 35 different manufacturers, and they
use a standard color coding.
Shaun
The colour coding of iron dust cores marketed by Amidon are
I know Amidon is not a manufacturer, they are the distributor of 35On Fri, 27 Nov 2009 17:50:21 -0600, "Shaun" <rowl@nomail.com> wrote:
"Michael Black" <et472@ncf.ca> wrote in message
news
On Fri, 27 Nov 2009, ian field wrote:
"Shaun" <rowl@nomail.com> wrote in message
news:dMBPm.40875$We2.9253@newsfe09.iad...
"Bernhard Kuemel" <bernhard@bksys.at> wrote in message
news:615c2$4b0d87ca$557f80c7$12673@news.inode.at...
Rich Webb wrote:
On Wed, 25 Nov 2009 13:28:44 +0100, Bernhard Kuemel
bernhard@bksys.at
wrote:
Hi sec!
Does the color with which ring cores are painted indicate magnetic
properties?
Yes.
Oookay. I have 3 yellow ones here, 2 small, 1 a little bigger, and a
green one. What does that mean?
There is a ring core calculator available over at
http://www.dl5swb.de/index.html that you may fine useful.
Thx. Maybe I'll try it with wine ...
Bernhard
A couple of things I forgot to mention:
Measure the outside diameter of the toroid in inches. (eg. for
one
that is 0.255 inches is a T-25 core)
the size of the core determines in properties( microhenries per 100
turns)
as does the material that makes it up.
Those colors that you mentioned are common types.
The information that you get off the net will be the material type and
some properties and operating frequency.
I hope this helps
Shaun
Is colour significant on toroids salvaged from scrap motherboards?
They're often pale blue or yellow - I think I've seen red ones too.
There's no standardization for the color coding of toroids.
Decades ago, there was a certain consistency in hobby circles, because
virtually all toroids that got to hobbyists were from the same source,
and interestingly, that common source was not a manufacturer but a small
business that had set out to be the middleman, since the manufacturers
weren't wanting to sell in small quantities.
Then, toroids became a lot more common. Originally they'd only be seen
in non-consumer radio equipment, but eventually they became common
there (albeit just a few toroids per unit), likely dwarfing the numbers
used for non-consumer radio equipment.
Once that started happening, there was all kinds of opportunity to find
toroids at the surplus store, or in consumer electronics that begged to
be reused. But, without any information about who made the core, the
color coding meant nothing.
If it's in equipment, at least the context will provide some information
(and most of the time, it will be low frequency use, mostly power
supplies). A blank toroid at the surplus store doesn't offer such
information.
One generally has to wind a coil on the toroid, do some measurements
and then calculations with the results. The more detail you need,
the more effort has to be put in the testing. And then likely
you could have gotten an identifiable toroid direct from some company
that wouldn't have cost that much.
Michael
Michael,
There must be some consistency because if I look at Amidon, a popular
distributor, they carry products from 35 different manufacturers, and
they
use a standard color coding.
Shaun
The colour coding of iron dust cores marketed by Amidon are
specifically those of Micrometals. Other manufacturers have other
coding methods - the most common being labeling of the part, with core
colour denoting the type of material (iron dust, 'high-flux',
permalloy, molybdenum permalloy, sendust iron-silicon-aluminum,
iron-silicon, or whatever) not the graded permeability of the
composite mixture.
Coating of ferrites is an option - the colour coding here generally
denoting both the coating material type and coating thickness (with
characteristic voltage withstand and physical characteristics)
specified by the mfr.
Amidon is not a manufacturer of cores.
RKL
Interesting to me because Micrometals' name came up in searches for RF
Micrometals supply app notes for it's products.
Thanks, the Micrometals guides look useful. I asked for a book recommendation
"Ferromagnetic-Core Design and Application Handbook", it's not clear
ine.LNX.4.64.0911291731290.27575@darkstar.example.net: Thankyou. Is out of reach though, the Bernard Babani book on coil design cost