OK, since I now have 3 fans apart and scattered across my desk I've come up with an idea. PWM and RPM Sensing.
Heres the idea.
This circuit I'm looking at is from the BLORBs fan but it should be similar in most fans. The 12V line enters the fan, its split between the HES(Hall Effect Switch) and 2 windings. Now If I cut the trace between the HES and windings I can run 12V to the HES. Now will I be able to solder on a new lead to the windings and send whatever voltage/pwm signal to the windings and still get an RPM signal.
Forgive me if this is totally crazy, I'm not a big electronics Guru.
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