> How would I calculate the saturation current of a inductor? I know the
> formula probably needs to account for wire diameter, turns, turn
> spacing and core permeability. Also, is there a formula for inductance
> vs current so I could chart the inductance knee?
>
> The reason I'm asking is because I'm working with a shorted RLC model,
> but the model I'm using doesn't take into account the inductor
> saturating.

Alas it can be considered a  simple problem with complex practice or a
complex problem :-).

Starting point:
Amp turns in coil provide core flux.
Looking at your above list, you can initially largely ignore wire
diameter and turns spacing. If you are working with a given
manufacturer's core profile and material then you can look up it's
amp-turn rating and expect to get a reasonably good idea. Reality in
the form of DC and AC currents, frequency effects in a given core
material, hysteresis etc will complicate things.
Reputable core makers will provide nomograms and formulae and/or
online calculators to make this all easy.

Knowing more about what you are doing would make question answering
easier. Application, circuit, frequency, power level, DC component,
core material, amp turns, ... .

Have a look at http://www.micrometals.com/
Very good people to deal with, good products. wide range of materials,
good prices.
I'm just a very occasional satisfied customer.
Whether they have what you want depends on what you are doing.

In practice you can get a very good idea re saturation by looking at
current ramp when an eg square wave is applied to a core and power
level ramped up. Below saturation current will ramp relatively
linearly for constant applied voltage. As saturation is approached
current ramp will trend upwards from straight line and depending on
core etc can increase rapidly towards vertical above a certain level.
In a typical inverter circuit just looking at the current ramp will
give you an excellent idea if a core is being pushed beyond its
reasonable limits.

Note that temperature and losses can affect a core's long term
performance, depending on material. Micrometals goi into this in
detail in their literature.



            Russell
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