fan speed controler

Discussion in 'The Projects Forum' started by electronis whiz, Mar 30, 2011.

  1. electronis whiz

    Thread Starter Well-Known Member

    Jul 29, 2010
    i have pulled a board from a pc power supply that controled fan speed. i tryed runing off a 9v batery ant the thermister had no afect when heated with a solder iron. it has anl211 tip117 i beleve to be a darlington transistor and an ST lm324N, 699nj0209 st says it is a quad op amp however there i do not understand the pinout. this link will take you to the page with the chip info
    it apears that outputs 1&2 have ben joined in paralell and feed the base of the darlington. there are 3 conections that conected to the otherboard that go to the chip i usume for ligic power but not sure. 1 of themm apears to go to pin 4 +vccand -vcc apers conected to ground. what is the voltage for this chip? 5V i usume. the other 2 outputs go throug resitors and ceramic caps and back to the chip. another conection goes to pins 3&5 for non inverting input i have no idea of the porpose of this pin. any ideas on how to get this working or to simplify it will be apreceated. i can make up a schmatic if needed just let me know.