Curve Fitting

[ptc-2714371]

Hi,

I am working on fitting the diode equation to real data. I need to solve for three variables, Is, N, and Rs. I have looked at the help files but it is not completely obvious to me how to set up mathcad to fit the curve. How do I set up mathcad to find the value for Is, N, and Rs that best fit the real data?

Thanks in advance, Bill

[ptc-2714371]

I thought I would add the equation:

The equation used to describe the DC forward characteristics is:

VD=Id*Rs+Vt*ln(Id/Is+1)

With:

Vt=N*k*t/q, k*t/q is around 26mV for 25degC

Rs: Diode series resistance
Is: Saturation current
N: Emission coefficient

Bill

[ptc-1368288]

Attach in version 2001i or lower.

jmG

[ptc-2714371]

Saved in version 12

[ptc-1368288]

On 8/4/2009 12:47:15 PM, mrbill wrote:
>Saved in version 12
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>Attach in version 2001i or lower. [jmG]<<br> >Saved in version 12 < [Bill]
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That kind of stuff was very popular, recently ... with many work sheets *.MCD 11

jmG

[TomGutman]

Fitting is generally done using a model and minerr.

You might find the thread at http://collab.mathsoft.com/read?125801,16 useful.
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� � � � Tom Gutman