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Pspice : need help to implement an expression on a resistor value

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glias

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Hello,
I just would want to implement a simple expression on a resistor value to modulate the value of the resistor with a pulse generator (for example). I managed to do it with LTspice

Example_VCR.png


So I tried in the same way with Pspice but it doesn't work at all, it returns me an error :
* source TEST
R_R1 N16852 N15627 49.95+0.1*V(CDE)
---------------------------------------$
ERROR(ORPSIM-16145): unknown parameter

Could you please help me ?

Thanks a lot
 

The means to achieve arbitrary functional dependancies like this are the behavioral voltage and current sources BV and BI in LTSpice. Notice that a resistor can be modelled by a voltage source controlled by the current through itself.
 

Hello FvM,
I don't need Behavioral voltage to do it in LTspice because, by replacing the value of the resistor with a direct expression like mentioned in my first post works perfectly. But it's seem to be impossible to do the same with PSpice (Orcad product), and I have to it with Pspice. Any idea ?
 

Hi glias,

I never have done something like this - however, I know that expressions in PSpice normally are written between these kind of brackets {}.
Perhaps you like to try it?

LvW
 

Hello LvW,
Thanks for your reply, well, it's a good idea, I'm going to check if it works properly.
 

You need to use behavior source for this. As advised by FvM try voltage controlled current source for this.
 

Hi, I'm not familiar with LTspice, but I noticed that CDE net name is in capital letters near source, ant in equation they are not. Can't this be misunderstanding during calculation?

-- tantudaisu --
 

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