I want to model a modulated transformer for a pump mechanism (slider crank mechanism in reciprocating pump). The MTF element accepts a modulation signal that is a nonlinear function of the crank angle. How do I make this in LTspice?
This requires an MTF element with the modulus being an expression that converts the rotational flywheel motion to the linear slider motion. ( I have got the relation)

 

Hi A7.
Welcome to AAC.
Please post your LTSpice asc file, so that we can compare results.
E

 

If I send the bond graph, will it serve the purpose?

 

hi A7,
Send it and we can look at it.

E

 

 

 

How do I make the LTspice model of a reciprocating pump? I have drawn the bond graph of it (ATTACHED). I want to know how to model the modulated transformer and the modulating resistor in LTspice along with the whole circuit and run it. Please help me..

 

@ericgibbs Can you help?

 

hi Ans,
I have looked over the problem a few times, it is a major exercise to convert that model into a LTSpice simulation, I really don't have the time free to do that, perhaps another member may step forward who has worked on this type of problem.
E

 

It looks like it would take a while to understand the "bond graph" notation well enough to translate it into LTspice. I'm retired and I have less than zero motivation to learn this notation. OTOH the Wikipedia article has a section on turning circuits into bond graphs, but nothing about going the other way. Certainly a "bond graph" simulator might be helpful to you, but there probably isn't one that is readily available.

https://en.wikipedia.org/wiki/Bond_graph

I'm sure the TS is familiar with the material in the above article, but maybe another member can absorb the material faster with a younger, more agile brain. It is quite beyond my ability to grok quickly at the moment.

https://en.wikipedia.org/wiki/Grok

 

I'm not familiar with Bond graphs either, but the following model of a reciprocating pump could perhaps be edited/refined to match the graph :

 

I'm not familiar with Bond graphs either, but the following model of a reciprocating pump could perhaps be edited/refined to match the graph :
View attachment 282891

What is the voltage source? (is it b source depicting nonlinear relationship in the slider crank mechanism)

 

What is the voltage source? (is it b source depicting nonlinear relationship in the slider crank mechanism)

The voltage source labeled "PumpPressure" is generating a sine wave with a "DC offset" of "0V", an amplitude of "+5V", and a frequency of 10 Hz. (aka cycles per second).