can i replace a linear 100k potentiometer with multi turn potentiometer 100k to get more resolution. The linear potentiometer 100k which i mentioned is used in pwm which i brought from ebay for controlling speed of a 12v 9a 500rpm dc motor but when i am using 100k linear pot i am not able to get proper resolution in speeds of dc motor eg:at 1,2,3,4....hz.so i wanted to replace linear pot with multi turn pot is it possible or not.Do i need to mention anything else
Allow me to be a dissenting voice. Maybe not. Multi-turn pots are not inherently higher resolution than single turn pots of the same element length (and type), many merely contain a mechanism that may make it easier to set the wiper to a given position. The mechanism may have effects such as backlash that are annoying.
Generally if you find yourself using only a small range of a pot, perhaps near one end, a better choice is to replace the unused part of the pot element with fixed resistors.
For example, if you had a 100K pot voltage divider with 5V applied and only used the first 1V of it you could add a series 80K resistor and shunt the element with 25K.
Some pots such as the 10-turn panel-mount Helipot wirewound style actually have a very long (helical) element and do give you greatly improved resolution, however it may still be worth considering limiting the range where appropriate.