Expression Pedals polarity schematics

Expression Pedal polarity schematics
There are countless expression pedals in the market and if you take the time to check the specifications that each manufacturer gives for their own model you will see that there a differencies.
One of the most important specifications you must check before buying (or building) an expression pedal is what many manufacturers call the "polarity". The term in our case is obviously not referring to a voltage but to the way the output of the expression pedal is wired to the internal potentiometer.
On the left we've marked the 3 ways an expression pedal is usually wired. You will often see those three "polarities" marked as TRS, RTS and TS.