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Creating a Mutual Inductor in LTSpice and Eagle?

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essedra

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Hi folks. I'm a novice LTSpice & Eagle user. I need to create a mutual inductor using LTSpice and Eagle. The circuit I intend to design is here:

Tina.jpg

which I designed using TINA 7 by TI.

I tried to design the same circuit in Eagle and LTSpice but I couldn't create a mutual inductor:

Eagle.jpg

(Eagle)

LTSpice.jpg

(LTSpice)

Can someone guide me how to create this mutual inductor in LTSpice & Eagle?
The mutual inductor's values are as follows:
L2= 10mH
L1= 2.5mH
N1=5
N2=10
k=0.8

Many thanks in advance!
 
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FvM

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Mutual inductance is defined by placing a K statement in the schematic, see the LTSpice help file for details.

I don't know what you mean with creating coupled inductors in Eagle, the schematic editor has no knowledge of component properties. As far as you are using Eagle as front end for a Simulator, consult the simulator manual.

Your circuit is useless as shown.
 

essedra

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I didn't say coupled inductor, I said mutual inductor. The problem is I don't know how to create this "K" statement in LTSpice. I've watched some Youtube videos on LTSpice simulation but they weren't helpful neither. This is a LED driver circuit and it actually works. I might have designed it with mistakes because I'm new into these kind of programs. I can send you the circuit that I sketched on the paper.

---------- Post added at 10:40 ---------- Previous post was at 10:36 ----------

The mutual inductor symbolizes a ferrite toroidal core.
 

keith1200rs

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A coupled inductor is one where there is mutual inductance between two inductors.

I don't use LTspice but you add Spice directives from the menu - "Add | Spice Directive" or hit the letter S. Then add the mutual coupling you want e.g.

k1 l1 l2 0.8

With a PCB layout package you need to create a component with the correct footprint and a symbol which looks like what you want it to look like. The PCB layout package knows nothing about what it really is. Have a look in one of the Eagle inductor libraries for examples of how it is done e.g. inductors-neosid.lbr or inductors.lbr

Keith.

---------- Post added at 08:51 ---------- Previous post was at 08:50 ----------

By the way, you are missing junctions on your Eagle schematic where wires join - they will not show as connected when you go to lay out the PCB. Run an error check from the schematic and it will tell you of any problems like that.

Keith.
 

FvM

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I didn't say coupled inductor, I said mutual inductor.
Yes I know. I prefer the correct term, because mutual inductance is actually a property of coupled inductors.
The problem is I don't know how to create this "K" statement in LTSpice. I've watched some Youtube videos on LTSpice simulation but they weren't helpful neither.
I don't know how instructive these Youtube videos are. I suggested the LTSpice help which contains exact instructions how to use the K statement. The K syntax is a common SPICE feature, so you'll find more information in general SPICE literature, although I think the LTSpice help is quite helpful.
I don't use LTspice but you add Spice directives from the menu - "Add | Spice Directive" or hit the letter S. Then add the mutual coupling you want e.g.

k1 l1 l2 0.8
Exactly.
 

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