Inductor permeability/Al and saturation current

Core saturation can be easily measured via a shunt resistor and scope. But core saturation is not the whole game, core and winding losses (skin effect etc.) are the other. Core losses can be vastly different between the various materials. Can be measured, for example via temperature rise.

Then I would switch suppliers. Seriously.

What does the other core look like under that pile of wire? Is it yellow and white by any chance?

The blue one will saturate around 0.5 to 1A. Ferrite must be gapped in order to store any useful energy.

Tim

-- Deep Friar: a very philosophical monk. Website:

You don't get detailed information about cores from suppliers but from manufacturers. The EPCOS web-site will tell you everything you need to know about the EPCOS core if you've got it's EPCOS part number.

I'd be a bit cautious about a supplier who didn't know enough to refer a customer to the relevant manufacturer's web site, but stocking ferrite cores doesn't seem to be a business where the broad-line suppliers can make money, so you end up buying small quantities of odd ferrites from niche businesses.

I've just found a hole in my files - I bought a "low distortion" ferrite core Ferroxcube EP13-3E55-A100 from a small and specialised distributor in Germany last year, but I had to dig the number off a back-up DVD, and the e-mail file that gives the name of the place hasn't come off it's back-up (though it may be hidden behind some cached data).

permeability of around 4300 and Al value of around 9740nH. It has 13 turns to achieve 1.8mH. outer dia is 20mm and inner dia is 10mm.

with blue color core due to its small size, will it be able to operate at 5A without saturating?

permeability and Al values.

Since you have both in hand,you can easily test them for saturation. Use a current transformer, or a very low value resistor in series for current sensing. Use a step voltage drive; before saturation the current will look like a linear ramp; saturation is indicated by what looks line exponential current increase. The faster the transition, the closer the closer is to a square-loop material.

The one with pile of copper wire, has geryish black or carbon color core.

-Sridhar

Agreed,

An ungapped high perm core will will not tolerate DC well before saturation. At best the inductance will "swing" like crazy.