Hi howard 

thanks for your kind reply 

If the insulation boundary is not needed ? so how should I connect two coil terminals  ? 

I assigned two coil terminals with N=1 as shown in figures

and added two coils to a winding 

actually the program doesnot run to calculate currents, only run when the coil is outside the moving band 

back to maxwell help I found this, that hollow cylinders can not be used for band object ! and substraction can not be perfermoed within the band object ! Although that it runs normally when the coil is out side the ring 

Again, the coil is stationary and the band is rotating around Z-axis 

So what if I have stationary coil passing through rotating magnet disc and I want to calculate the EMF at its termianls ? what should I do in this case ?

please help