http://www.bit-tech.net/article/32/ I want to make that circuit, but I cant get 2k pots in the style I want, the closest is 1k. What values would R1 and R2 be if I were to use 1k pots. Thanks all.
R2 stays the same, it's the led current-limit resistor. Two choices re the pot; 1. Use a 1k resistor in series with it, same 240R R1, which reduces the output range to 6.5v minimum (same max), my preferred solution as here or a 1k2 in series and 280R for R1 to give 6v minimum. 2. Forget the series resistor and change the 240R resistor R1 to 120R (ideally should be 135R but they don't make them) to keep minimum output down to 1.25v (but your fans will stop long before that )
