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inductor saturation current
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dmills:
As always with any component you read the datasheet and remember always that the headlines have marketing department drool all over them.

Regards, Dan.
Simon:

--- Quote from: T3sl4co1l on June 01, 2019, 10:00:13 pm ---Bahaha, it's the same core and winding (wire, turns) and they're only varying the gap.

The best inductor in that series is the value where Irms = Isat, which stores the most energy at thermal ratings.  Give or take if you need more or less saturation for a given application.

What are you actually filtering?  Do you really need that much inductance?

Tim

--- End quote ---

I'm looking at PWMing a brushed motor so wanted something to take the edges aff the transitions. i was going to do a pi filter.
T3sl4co1l:
Oh, that still, just use a few uH.  Not even that.  Put a few dozens nF either side of it and you're fine.

How much PWM was that going to be?  Just on and off?  Or at a modest frequency to get some buck action?

Tim
coppercone2:
Rated Current ..........Inductance drops 20 % at Isat1
Inductance drops 30 % at Isat2

Waht they should do, is have a separate data sheet or a separate table on the data sheet because it just looks bad.

it's probably made that way so they can use the same tooling to  make a bunch of inductors and possibly get more value from the machine setup. Add-on.


So the part is rated for high surges which just basically ignore it, but will function as a inductor at lower currents.
Siwastaja:

--- Quote from: Simon on June 01, 2019, 10:15:17 pm ---I'm looking at PWMing a brushed motor so wanted something to take the edges aff the transitions. i was going to do a pi filter.

--- End quote ---

You are doing it wrong. A motor controller doesn't need an inductor - the motor is the inductor, and a massive one.

There are special cases such as air-core micromotors which have so little inductance that you add external L to allow not-over-the-top PWM frequency while maintaining low ripple current, but I bet this is not the case.

Your motor likely is a 10 or 100 times larger inductor (often measured in millihenries), so adding a 33uH in series is meaningless for ripple current. If your concern is EMI from brush noise and/or PWM edge rates, it's way too big.

If you are looking for EMI suppression (from brush noise), you do it with small ceramic capacitors (two in series, from line to line, center tap to the motor case), and if this is not enough, by adding a common mode choke, after which you can add another capacitor. Note that this is really high frequency noise, so it's dealt with small magnetics and small capacitors, it doesn't need to store a lot of energy, the motor inductance does that for you.
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