Lt Spice Inductor saturation

ronv

Well-Known Member

Most Helpful Member

• Oct 16, 2014

• #1

I've Googled around and found some stuff to make LTSpice show the effect of saturation in an inductor, but I haven't been able to make it work.

Just replace the value 10u with the formula below.
(Watch the 12.5 = 1/0.08, x is the coil current)
flux=10u*12.5*tanh(x*0.08)

Click to expand...

I think my problem may be with x. I don't get any errors, but it reacts just like a resistor. Can someone help?

 

MikeMl

Well-Known Member

Most Helpful Member

• Oct 16, 2014

• #2

Ron, I don't have your answer, but I would ask this question on the Yahoo LtSpice group...

 

ronv

Well-Known Member

Most Helpful Member

• Oct 16, 2014

• #3

Thanks Mike, but that statement above was Helmit's. I think I just haven't figured out the equation.

 

MikeMl

Well-Known Member

Most Helpful Member

• Oct 17, 2014

• #4

I haven't been there for months. Is Helmut still active?

 

ericgibbs

Well-Known Member

Most Helpful Member

• Oct 17, 2014

• #5

Yes Mike, he is adding models daily to Yahoo.
E

 

ericgibbs

Well-Known Member

Most Helpful Member

• Oct 17, 2014

• #6

hi Ron,
Do you have an asc file to post, might give a shot.
Eric

 

alec_t

Well-Known Member

Most Helpful Member

• Oct 17, 2014

• #7

Like this?
The LTspice 'Help' ..... helps

 

Attachments

• Inductor.asc

  501 bytes · Views: 530

ronv

Well-Known Member

Most Helpful Member

• Oct 17, 2014

• #8

God, I am so dense. I kept trying to put something in X.
Thanks.

 

Attachments

• StepUp555.asc

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M

MrAl

Well-Known Member

Most Helpful Member

• Oct 21, 2014

• #9

Hi,

The tanh() function models the BH curve, with H as the x axis and B as the y axis.
Since H is proportional to the current I, x would be the current through the inductor or at least proportional to current.
If you do a 2d plot of tanh(x) from say -5 to +5 you can see an entire anisotropic BH curve.

This kind of BH curve is called an "anisotropic" BH curve. Unlike a pure inductance that has a perfectly linear curve (straight line) it models saturation, but it does not model hysteresis. It does allow for faster calculations though.