On Sun, Jan 19, 2020 at 09:07 PM, Leo Bodnar wrote:
This originates I think from the idea that around a maximum or minimum a function is quadratic plus higher order terms.
If you short together both ends of a linear pot then the resistance to the wiper is maximum midway and decreases quadratically (in this case exact, without higher order terms) when moving away from midway. In our instrument consider a wiper as a wiper of a 10 k pot, blocked midway in one direction.
I must confess that I only recognized the trick after further investigation.