SMT power inductor DC field

Above the Earth's field I trust. :^)

Something that looked like a pot core might be better. Some of the "shielded" inductors look to have the gap at the top which I'm guessing will leak more.

Hmm do they make toroids in surface mount? (none that I see on DK)

George H.

There are plenty of surfmount toroids. Pulse Engineering, Coilcraft, others. A fully wound toroid should have low external field.

LOL. Yes, zero'd before I turn the box on.

No, not that I've seen, but some (Wurth) are wound with the coil axis in the X-Y direction rather than Z.

--sp

Den tirsdag den 14. juli 2015 kl. 22.38.26 UTC+2 skrev Spehro Pefhany:

digikey has plenty

-Lasse

Picky, picky. I suspect you have to just test.

If you can arrange your supplies to double up all the inductors in pairs that are placed tight against each other, with the magnetic field vectors pointing in opposite directions, there will be a wingwazzle* in the magnetic field, but I'm pretty sure it'll drop off way quicker with distance than the field from one inductor.

• That's a highfalutin' physics term.

Nice, what ever search path I followed through DK didn't find them.

George H.

Fun, Phil H. put a pcb trace underneath to cancel the current around the toroid. (some long past thread.) You could do the same thing but stack toroids on top of each other, counter wound/ (or stimulated). (I have no desire to make such a product. :^)

George H.

I got the idea from Joerg, iirc.

Cheers

Phil Hobbs

I only found one toroid on DK capable of double-digit amps and I don't think it was SMT.

--sp

Den onsdag den 15. juli 2015 kl. 07.09.15 UTC+2 skrev Spehro Pefhany:

a search on; toroid, +10A, smd, in stock, gets ~50 results

-Lasse

As Lasse says I get ~ 30 (the link goes on for many lines... :^) How many double digit amps? lots near 10, a few over 20 (with smaller L's)

George H.