I working on mini project to create a magnetic drink stirrer out of an old PC Case Fan.
(For those that don't know, a magnetic stirrer is basically a spinning magnet under your glass and a magnetic bar in the glass that spins with it and mixes the drink.)
The Fan I'm using is a old 12V DC PC Fan, one of the two wire types, I tried connecting it to a 5V connection and it span but was too slow to mix the drink properly and so I'm now using a 12V power supply but that spins too quickly for the magnets.
I tried connecting a 100K B Potentiometer as a variable resistor to the circuit to adjust the speed but all that does is has the fan off for 95% of the pots range and then full speed for the last bit. Is there any way I can adjust the circuit easily to control the fan speed?
I don't want to replace the fan with a 3 or 4 wire type and I ideally want to keep using the 12V supply, I'm looking for a solution that will allow me to do this with only one or two component additions or changes such as a different or additional potentiometer etc. I'm pretty new to electronics so don't know if I'm doing something stupid here.