EF 152
Lee Allan
TJ Burrell
Catherine Click
Chris Earwood

Design
Generator
Plexiglass, copper wire, magnets, metal rod
Windmill
Balsa wood, cut by us with scroll saw

• Magnets rotate perpendicular to the coils of the copper wire
• Magnets rotation excited electrons to allow them to travel along coils
• Electrons travel to LED to complete a full circuit lighting up the LED

• Blades of the fan are not flat and perfectly straight to allow them to spin in the wind easily
• When the fan rotates the metal rod connected to it rotates
• Metal rod then allows magnets to rotate within copper wires to create circuit

Pmax = 0.5 * ρ * A * v 3
Pmax = maximum available power from wind = .49403 Watts
ρ = air density = 1.225 kg/m^3 v = wind speed = 1.7 m/s
A = area of rotor sweep = πr^2
R = radius = 9in = 0.2286 m
V = 2.24volts
I = 56.3mAmperes = 0.0563A
Pgen = power from generator=V * I = 0.126112 Watts
Efficiency = Pgen / Pmax = 0.126112W / (0.5 * 1.225kg/m^3
* π(0.2286m)^2 * (1.7 m/s)^3) = 0.25527 = 25.5%

• First problem was copper coils wrapped parallel to the way the magnets were spinning
• Magnets did not have enough strength to produce much of a charge in our original design
• Magnet orientation was inhibiting magnetic field formation
• Creating a windmill that will rotate enough to spin the magnets to produce the charge we needed

• Orientation of magnets affects the electric current through the coil
• Sometimes better to start over from scratch then try to fix another project
• Efficiency was increased by simplifying the design which reduced sources of friction