Stepper motors can come in various wire
formats, from 4 wire to 8 or more wires.
Use a multimeter to determine which
lead is which, then connect a couple of bridge rectifiers
As the mini windmill uses a small two
blade design the RPM will be quite high ( very high!
). Therefore I would use high speed rectifiers and a
smoothing capacitor to reduce electrical noise in the
Once you have the wind mill up and going,
measure the output voltage. If you intend to run voltage
sensitive devices from the windmill output, I would
recommend a 5 watt zener across the output
To use the Mini Mill as a battery charger
I used the following circuit. You may need to adjust
the resistance or R1 to achieve a good charging current
based on. Charging current should be 1/10th of rated
battery current for 10 hours to achieve best battery
Change the double AA battery
holder for a quad C battery holder to give you 6 volts worth
of Nicad batteries. Design a circuit to using a light dependant
resistor to turn on a mini relay and mount that on the windmill
along with a 6 volt lamp ( as used in a torch ). During the
day the windmill charges the nicad batteries, and at night
the lamp turns on to light up the area.