I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
On 2/28/25 04:50, john larkin wrote:
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
I can't see the Digikey link. They want me to switch off
my adblocker, which is just no.
If this is a solenoid, turning it 180 degrees is not going
to make any difference! It will still be the same winding
direction!
Jeroen Belleman
On 2025-02-28 04:50, john larkin wrote:
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
It works fine, but the total inductance will be somewhat higher than just 2x.
The external field is way less, I use that trick in a sensitive environment (ADC's etc).
If you mount them parallel to the PCB, try alternating 90 degree positioning from pair to pair to minimize coupling.
On 2/27/25 7:50 PM, john larkin wrote:
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
Typically that is the case.
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.
Best is to shoot off an Email to Murata. They are usually quite
responsive to technical inquiries. That one email could save your
production folks a lot of future grunt work.
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.
But those also talk a lot :-)
On Fri, 28 Feb 2025 10:01:44 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
On 2/28/25 04:50, john larkin wrote:
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
I can't see the Digikey link. They want me to switch off
my adblocker, which is just no.
Try this:
https://www.dropbox.com/scl/fi/5mcmrincxepmhkve64rse/kmp_1900r-2.pdf?rlkey=a1p10nn8lgecslf1k6cmlp5jb&dl=0
My module has just about 1" of allowable component height, so this
uses the volume well. And this shape will have good cooling in the air
flow.
If this is a solenoid, turning it 180 degrees is not going
to make any difference! It will still be the same winding
direction!
Jeroen Belleman
If I swap the pins, namely reverse the current direction, won't the
mag field direction reverse?
On Thu, 27 Feb 2025 21:24:23 -0800, Joerg <news@analogconsultants.com>
wrote:
On 2/27/25 7:50 PM, john larkin wrote:
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.
But those also talk a lot :-)
One could make a 10s of kilovolt isolated power supply with a pair of "shielded" inductors separated by a sheet of plastic.
On 2/28/25 04:50, john larkin wrote:
I need to put 16 of these on a very dense PC board.
https://www.digikey.com/en/products/detail/murata-power-solutions-inc/19R476C/5798223
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.)
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.
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.
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.
I can't see the Digikey link. They want me to switch off
my adblocker, which is just no.
If this is a solenoid, turning it 180 degrees is not going
to make any difference! It will still be the same winding
direction!
Jeroen Belleman
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