Does anyone know how I could model a variable resistor as a linear potentiometer in Simulink? The library I have does not currently contain this block

I am currently running MATLAB 2015b and using Simulink. I need to create a model and run a simulation for a linear potentiometer which uses a wiper arm. Unfortunately my current Simulink library does NOT contain a potentiometer so I am attempting to recreate this using a variable resistor. Do anyone know how I could go about doing this? I want this to use a digital voltmeter which has an input resistance of 10Mohm.

Answer 1

[Zhao Wang]

I understand that you want to recreate the function of a potentiometer using a variable resistor in your current Simulink library.

I assume you have Simscape installed since the "variable resistor" block is available to you. If you also have the Simscape Electronics library, the "potentiometer" block is in the directory 'passive devices'.

Or you can recreate the function of the "potentiometer" block using the "variable resistor" block by adding a "Gain" block. The input to the "potentiometer" block is the position of the wiper arm (assuming it's between 0 and 1). The input to the "variable resistor" block is the resistance value (assuming the maximum is R Ohm).

You only need to use a "Gain" block with a gain of 'R'. Then as you send a position input (between 0 and 1) to the recreated "potentiometer" block, the "variable resistor" block actually receives the desired resistance value.