Re: inductor polarity

"Jeroen Belleman" <jeroen@nospam.please> wrote in message
news:vprtop$3jbo5$1@dont-email.me...

On 2/28/25 04:50, john larkin wrote:

I need to put 16 of these on a very dense PC board.
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https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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Each of the eight channels needs two of these. If I can put each pair
of inductors close together and with the same current but opposed
field direction, I'll get minimum mag field leakage to other channels
(and to other boards.)
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I see that one lead is longer than the other. I wonder if that implies
a consistent winding direction, so my manufacturing people could use
that as the "pin1" indicator.
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If that's not dependable, I'll have to set up a rig to determine mag
field polarity, and mark one side with a red dot or something.
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I'd rather use surface-mount shielded inductors, but these tall
unshielded drum cores have way more L and less R than a shielded part,
for a given PCB footprint.
>

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I can't see the Digikey link. They want me to switch off
my adblocker, which is just no.

You don't have to. I haven't seen any ads on Digikey. But I do sometimes see
this issue which can be fixed as follows.
Open Microsoft Edge.
Go to Digikey or paste the link.
Do the "Prove you're human" test by holding the mouse button down as needed.
Once the site opens, close Edge and forget about it again.
Open Firefox and paste the link. The site will open normally.

What's going on here is likely to be a system which stores the fact that the
human test was passed at your specific public IP address.
The reason for this is to stop the myriad of bots out there from scraping
the site content for their own purposes (AI training comes to mind).
As long as you're using the the same public IP address then you won't have
to do the human test again for a specific length of time but I don't know
how long (maybe a few days).

If you are on a system where your public IP address is likely to change
often then you will likely have to do this often.

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If this is a solenoid, turning it 180 degrees is not going
to make any difference! It will still be the same winding
direction!
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Jeroen Belleman
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