Hi,

I would like to create a variable resistor as shown in the attached pictures.

How can I create this function?

I saw the following tutorial, but I don't know hot to replicate my function (where some parameters change during the time).

Is it possible in LTspice?

Thank you.

 

hi F02,
Do you have an asc file you could post showing the problem.?
E

 

hi F02,
Do you have an asc file you could post showing the problem.?
E

Dear Ericgibbs,

Please find attached the asc file. The supply V3 is a pulse (it is not important).
I would like to have a resitor R1 varaible as shown in the previous equation, but I don't know how to da that.
Please, can you help me?

 

hi f02,
Do you mean something like this simple demo program.?

NOTE: the behavioural voltage sources.
E

 

hi f02,
Do you mean something like this simple demo program.?

NOTE: the behavioural voltage sources.
E

The problem is more complicated because the resistance value depend on the current I which in turn depend on the time, as in the attached equation. Is it clear?

 

The problem is more complicated because the resistance value depend on the current I which in turn depend on the time, as in the attached equation. Is it clear?

Hi
Where is the “time” variable in your equation?
eT

 

Hi
Where is the “time” variable in your equation?
eT

You are right eetech00. The variable is independet from time, but is dependent from the value of the current I.
Some parameters (alpha1, K1,alpha2, K2, alpha3, K3) are dependet from the value of current I.
How can I change them when I reach those values?

Thank you.

 

hi f02,
Do you mean something like this simple demo program.?

NOTE: the behavioural voltage sources.
E

Hi MrAL

Your on the right track.
You can plug the equation into the resistor value by using R=equation.
I haven’t looked at the .asc file but I think the TS needs to “step” variables “a” and “K”.

eT

 

Hi MrAL

Your on the right track.
You can plug the equation into the resistor value by using R=equation.
I haven’t looked at the .asc file but I think the TS needs to “step” variables “a” and “K”.

eT

I think that the problem is that the "step" function is based on time. How can I create a "step" function based on the value of curret?
Thank you.