This will never work, even though the frequency changes the duty cycle stays the same. Therefore the average voltage is the same no mater the speed of the drill.
Yes, this is analog pulse width modulation. Not RPM, but cool visualization nonetheless. This is using a kind of mechanical analog to a transistor to lower the voltage of the battery (by turning the circuit on and off really quickly). In theory, the voltage drop should be equal to the area of the cork that is not conductive. Slow RPM gives more fluctuation in the output voltage. More RPM gives a more stable output voltage. To measure RPM, you would need to a way to read the voltage pulses.
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This will never work, even though the frequency changes the duty cycle stays the same. Therefore the average voltage is the same no mater the speed of the drill.
i think it needs a capacitor between red and black
it's kinda like PWM
Yes, this is analog pulse width modulation. Not RPM, but cool visualization nonetheless. This is using a kind of mechanical analog to a transistor to lower the voltage of the battery (by turning the circuit on and off really quickly). In theory, the voltage drop should be equal to the area of the cork that is not conductive. Slow RPM gives more fluctuation in the output voltage. More RPM gives a more stable output voltage. To measure RPM, you would need to a way to read the voltage pulses.
Ugh