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Solving an equation

ygormarca
4-Participant

Solving an equation

Hi there,

 

I have the equation below which Vout and Io are variables and I need to isolate Vout from the right side of the formula, but the function is too large to display.

   

I could manually isolate Vout, but I found a third order equation that again MathCad could not solve...

  

The problem is that I have two variables, Vout and Io and I have to plot a graph of Vout/Vin in function of Io.

8 REPLIES 8

Hi,

 

The equation is too hard to read from the graphic.  Enclose your worksheet please.

Regards

Terry

Sorry, I just uploaded a worksheet. 

 

Thank you

LucMeekes
23-Emerald III
(To:ygormarca)

What's the circuit and what are you calculating in the circuit?

(How did you get to this formula?)

Or did you just type this entire formula in from your head?

(I'll accept a picture of the schematic, worksheets preferrably saved as Mathcad 11 .mcd)

 

Luc

ygormarca
4-Participant
(To:LucMeekes)

Hi Luc,

 

Well, it`s a static gain of a converter.

I think the schematic would not help in this case because it is too complex to understand it quickly. The problem is the math behind this equation.

 

I uploaded a worksheet in mathcad 11 if you want to see.

 

Regards.

LucMeekes
23-Emerald III
(To:ygormarca)

Is this what you are after?

LM_20181205_Problem.png

(Still I think it would be better to start from the design)

Success!
Luc

ygormarca
4-Participant
(To:LucMeekes)

The problem there is that qdcm cannot depend on Vout, that`s why I tried to isolate Vout from the expression.

ygormarca
4-Participant
(To:LucMeekes)

What you`ve done is correct, but if qdcm doesn`t depend on Vout anymore, it`ll give just one curve and that`s what I need.

 

Regards.

LucMeekes
23-Emerald III
(To:ygormarca)

I don't see how qdcm could be independent of Vout, it's in there!

The only way I could imagine it drops out, if it drops out together with Vin.

Once again: how did you get the expression for qdcm...?

 

Luc

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