I have an Intel E29477-002 stock cooler laying around and I want to turn it into a 9v battery powered fan with a Low/Off/High SP3T switch. I tried to reduce the voltage to 5v on the low setting, but it made a high pitched humming noise while spinning at the low speed. On the high setting it spins at full speed without issue. How do I remake the circuit so the fan doesn't hum on the low setting?
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