1. Dec 7, 2009

### xclr82xtc

guys im trying to do calculations for coils that i want to use...i dont know how to do faradays law..this is the information i have....

2inch coils, 80 turns (4layers, 20turns each layer) average diameter is .75 inches. distance from magnet is .25inches.

speed is 80turns in 1.123seconds (1 coil in 1.123 seconds) or .05615 per 4 turns

magnet information (using 2 magnets...one on each side of coil)

DCX8

# Dimensions: 3/4" dia. x 1 1/2" thick
# Tolerances: ±0.002" x ±0.002"
# Plating/Coating: Ni-Cu-Ni (Nickel)
# Magnetization Direction: Axial (Poles on Flat Ends)
# Weight: 2.87 oz. (81.5 g)
# Pull Force, Case 1: 37.70 lbs
# Pull Force, Case 2: 37.70 lbs
# Surface Field: 6403 Gauss
# Max Operating Temp: 176ºF (80ºC)
# Brmax: 13,200 Gauss
# BHmax: 42 MGOe

this is not a homework problem...im an amateur windmillist

this is what i have...im trying to find output at 1rpm of a 34inch turbine with 21 coils (7 coils each phase) if someone will tell me how to plug in the equations i could do the math, but this is beyond me...if you need more info i will get it. please help.

2. Dec 7, 2009

### uart

It's hard to say without more details (do you have an iron circuit for example?) but at that speed don't expect too much.

Here's a very rough calculation.

Coil area approx 0.75" x 0.75" (0.00036 m^2)
flux density approx +/- 0.32T (guestimate)
V would be approx 4.44*0.00036* 0.32 * 80 = 36mV per coil

BTW. The const 4.44 is 2 pi / sqrt(2). It's only really appropriate for sinusoidal fux density but the above calc is only a rough guide anyway.