MOTOR armature        current   : Motor field strength??
                      The motor armeture a current  = ((Vin - Vb)/Za) where Vin 
                      is the applied
                      (terminal) voltage, Vb is the back EMF produced by the 
                      windings moving in
                      the field from the field coils. Vb is proportional to The 
                      field strength
                      and the speed of the motor. If the field current is 
                      reduced the current will
                      increase (Due to lower Vb) increasing the speed until 
                      equalibrium is restored.

                      Original Subject: Re: skin effect question
                          With ro    = radius of the round wire (meters)
                               del   = skin depth (meters)
                                     = 1/(pi*f*mu*sigma)^.5
                               f     = frequency
                               mu    = material permeability (henrys/meter)
                                       (4*pi*10^-7 for good conductors)
                               sigma = material conductivity (mhos/meter)
                                       (5.8*10^7 for copper, for example)
                               Ro    = 1/(pi*sigma*ro^2)   (DC resistance)
                          O  ro/del < 2  (low frequencies)
                                 R/Ro = 1 + (1/48)*(ro/del)^4
                             (approx. 6 0.000000e+00rror at ro/del = 2)
                          O  ro/del > 2  (high frequencies)
                                 R/Ro = ro/(2*del)
                      equation for current  as:
                           | Iz/Io | = e^[-(ro-r)/del]
                      where r is  distance measured from  center of wire
                      (So it looks to me that at 2*del from  conductor edge,
                      current has decreased to e^(-2) of its value at edge.)D3

Generator from motor  2 HP engine will not generate enough to supply 2500 watts.
                      probably need 5 HP engine. assumes  have efficient motor
                      2 HP  power a hair dryer or TV. 
======================MOTORS======================

                      Motors
                      
                      V           N*delta_Phi/delta_time
                                  w*N*Phi*sin(wt)
                      Torque      K*I *sin(wt)