Meter is 0 to 50 or 0 to 100 scale, and can be mA. or uA. range. Bottom battery is really small DC motor. In simulator, vary battery voltage to see meter reading change.
To make three cup paddle wheel: cut two golf ball sized "whiffle" balls in half. Attach three halves to PVC hub with 6-32 machine screws. Center of hub goes over and attaches to DC motor shaft.
How to calibrate. On still wind day, have car driver go at steady speed while you hold DC motor with wind cups outside of car window to adjust 1 k ohm variable resistor for sensitive movement of meter when starting to turn wind cups. Now, record meter readings with car speedometer MPH readings over wide wind ranges, or else, make own scale over meter scale for direct reading of wind speeds.
