[DIY] PWM Fan Controller


Jan 27, 2003
I'm currently making my own PWM fan controller using some off the shelf parts and some modification help from my dad who is an electrical engineer. I'll document this year so others can try it.

Problem: No PWM output on old X58 motherboard to use for fan control of 4x NF-A14 iPPC 2000 fans on my 2x 280mm HWLabs Xflow radiators and potentially other case fans. I want to have a knob to control fan speed without software or opening the case.

PWM signal: Adjustable Pulse Width Modulator Module SG3525A - $5.95
PWM power: 8 Way PWM Splitter-Sata $10 ($12.49 prime on amazon)

I need to swap the onboard PWM duty cycle potentiometer for a larger one with extension cable for a knob to control.
I need to connect the signal output to the PWM input on the Swiftech PWM splitter

More to come on this, I'm unsure if the RPM control knob will be mounted in an expansion slot or potentially 5.25 bay LCD display with two in-line water sensors with LCD, rad1 IN and rad 2 out, to measure temperature delta
So...is that 100Hz to 400KHz on that thing? Or 100KHz to 400KHz? 'Cause the PWM signal to the fans is supposed to be around 20KHz or so.
Yea according to the data sheet it's 100hz-400khz, my dad and I are going to work on it in a few weeks. I've been a bit swamped with work and life, it would like to resume the project after my 7/23 project deadline :)

Data sheet: http://www.mpja.com/download/SG3525A-Datasheet.pdf