The title pretty much says it all. I am looking to generate a "fake" RPM signal for a switch that I modded to fit a 120mm fan. Basically, I have removed the 40m 8000RPM fan which was noisy, cut a hole in the top of the case and affixed a 120mm fan. My main issue is that the IOS now thinks there is a fan failure because the 120mm spins no where near 8000rpm (but moves much more air). I read somewhere that this can be done with a 555 timer but I am unsure what the circuit would look like (and how to emulate specifically ~8000 RPM). If someone could explain this for me I would be VERY grateful. My goal is to stop the IOS from generating fail failures (there does not appear to be a way to disable this) and to return the "System" light on the front of the switch back to green (it is orange now). Thanks!