Hello! Does anybody know the component in the red box in the figure below? I guess it a component to obtain the voltage across the capacitor C1 based on the content of Pages 8~9 in the attached file.

 

It looks like a symbol that is common in control systems where you compute the difference between a setpoint and the feedback to produce the error signal. IMHO it is measuring the voltage across the capacitor and calling it "displacement" which is the mechanical analog in a 2nd order differential equation of the standard RLC circuit.

 

It looks like a symbol that is common in control systems where you compute the difference between a setpoint and the feedback to produce the error signal. IMHO it is measuring the voltage across the capacitor and calling it "displacement" which is the mechanical analog in a 2nd order differential equation of the standard RLC circuit.

Do you know how to find it in the LTSpice? Thanks.

 

Do you know how to find it in the LTSpice? Thanks.

No - I don't. Try asking the author of the Ltspice schematic.
EDIT: Here is the one from the LTspice Control LIbrary available from @Bordodynov or Github. It would be a trivial task to modify the symbol and point to the existing implementation of the function.

httP://Bordodynov.ltwiki.org

 

No - I don't. Try asking the author of the Ltspice schematic.
EDIT: Here is the one from the LTspice Control LIbrary available from @Bordodynov or Github. It would be a trivial task to modify the symbol and point to the existing implementation of the function.

httP://Bordodynov.ltwiki.org

Thanks. I think the component you recommend has the same function. I have tried it.

 

No - I don't. Try asking the author of the Ltspice schematic.
EDIT: Here is the one from the LTspice Control LIbrary available from @Bordodynov or Github. It would be a trivial task to modify the symbol and point to the existing implementation of the function.

httP://Bordodynov.ltwiki.org

Sorry, I got another problem. Do you know how to obtain the voltage and current using the function?

 

Sorry, I got another problem. Do you know how to obtain the voltage and current using the function?
View attachment 241542

I have solved this problem by using behaviuor sources. Thanks.