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    Identify green toroid cores in common-mode chokes?

    Hello,

    I've seen green toroid cores for common-mode chokes in few power supplies from different manufacturers. Can somebody please write the manufacturer?

    Regards

    •   Alt30th June 2011, 10:25

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    Re: Identify green toroid cores in common-mode chokes?

    Has anybody here seen real power supply?



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    Re: Identify green toroid cores in common-mode chokes?

    Measured relative permeability (mu) is about 2700.



    •   Alt13th September 2011, 09:59

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    Re: Identify green toroid cores in common-mode chokes?

    I don't have any specifics for you, but while you're waiting
    I recommend you try chasing through vendor web sites for
    switching power supplies, for app notes and reference
    designs on EMI/EMC. These may have BOMs or part detail
    for the input filter components and maybe that's the start
    of the trail.


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    Re: Identify green toroid cores in common-mode chokes?

    Thank you, it's a good advice, however the trouble is that AN authors usually don't bother much about this, they buy some off-the-shelf choke and state the part number and the manufacturer. I'll keep trying.



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    Re: Identify green toroid cores in common-mode chokes?

    Hi,
    I have seen some other colors too like Yellow but there is no specific link between the color type of material. If you can extend your efforts a bit just measure a known material's permeability and then compare with this one for the same inductance. As I could conclude is that this paint is just to give an extra shortening feature to the wire used for winding.
    Could not fine any particular datasheet about the color identified cores.



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    Re: Identify green toroid cores in common-mode chokes?

    I know at least micrometals use colors to identify the core material, with no other markings, but I don't believe they make any cores that are completely green. If the permeability is that high it must be a ferrite or tape wound core. I'd try looking at Arnold magnetics to see if they make anything like it in that color.

    But honestly if it's meant as a common more choke, then its exact properties probably aren't terribly important. You know the permeability and size, so that's a lot right there. Just find something similar. The only other thing you might want to look at is what frequency it works up to (if you have a network analyzer).



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