Concept
I decided me for a relay potentiometer because the position after power-on is defined (in contrast to a motor potentiometer) and I assumed programming of the driver is easier. To dimension I used the homepage of Jos van Eijndhoven with the following settings:
Hardware
I warmly recommend to use precision resistors (0.1%). In my case three resistor values were temporary not available at Reichelt, so I bought 1% resistors instead and tried to select them. As result I got one point of discontinuity:
I found no way to correct this (with other resistor values) but the error isn't dramatically so I left it. The whole KiCad-project (including Gerber-files) can be found here. Remark: it was made under Linux with KiCad-version 4.0.7 using this additional libaries. The bill of material (bom) as semicolon separated text file contains some comments about part dimensioning / quality.
License
Please keep in mind: all content on this page is licensed under the terms of the GPLv3.
falk.richter*at*yandex.com
Last update: December 20, 2019