New to the forums and arduino. Im doing a custom pc build and am looking to make a 5 Fan controller with arduino UNO at the heart. (Radiator Fans Water cooling)
Lets start with the fans (SANYO DENKI DC San Ace 140L 109L1448MB505 48V DC Fan 140mm Aluminium)
I've managed to get these fans as I liked the all aluminium aesthetics. Now the goal of my project is to control the speed of these fans using PWM as this is what this 4 pin fan is designed for.Ive purchased a seperate 48v 5amp power supply so i wont interfere with PC PSU. I have purchased a function generator and applied a TTL voltage of 3v and can definitely see the fan speed increase as I increase the duty cycle from the Function Generator. Now the issue is there is no technical spec sheet for this fan so I am doing a lot of trial and error. Now my gut tells me a 3v or even 5v pwm signal is not strong enough to truly control the 48v fan, have read in some forums a 30v TTL is required. Is there a way to calculate the required voltage (TTL) needed on the PWM wire to get best results? The function generator does affect the speed but only if I push the duty cycle above 60% anything lower and fan just stops. Having set the function generator at 25Khz seems to be fine. Pretty sure its using the intel standards for frequency at least.
Ive attached pictures to show a sample of what im working on, im no expert so please be as blunt as necessary to get project done. Please note the wiring into fans are just design elements im playing with with some vintage style cords so its not yet truly wired as 4 wire.
