so I have three options for controlling a 4-wire fan’s blue wire (pwm) and they all kinda seem dumb. I work in Applications Engineering at an electrical converter company, our products don’t come with any cooling solutions, just temperature (Celcius integer) over I2C (but this project is open loop, no feedback from temperature to fan speed) (1) an analog pwm controller box with no part number, seems like a 555 timer and a comparator and a potentiometer and some fixed passives that a coworker assembled ages ago. (2) just turn down the DC input voltage on the power rail since I’ll be using a lab bench power supply not a computer PSU (3) use the lab bench function generator, which does the same thing as (1) but it has a known part number and more stable frequency and known duty cycle (4) use an arduino, which doesn’t work because it’s an extra unknown which we don’t trust as being assembled correctly compared to the rest of the formalized test bench, also our computers are not set up to develop and flash firmware.

project manager said to keep it simple try to get it done sooner rather than better but each option sounds like it doesn’t fit my desires.