SHELL COIL

 Shell coil is a type of transformer that consist of  a coil enclosed in a shell

the primary and the secondary winding are wound over the central limbs of a three-limb core 

The HV and LV are slip into a number of sections and the section are inter-leaved 

PRINCIPLE OF OPERATION

When an alternating voltage V1 is applied to the primary and alternating flux is set up in the coil. This alternating flux links both the winding and induce e.m.f  E1 and E2 in them, according to faradays law of electromagnetic induction. the e.m.f E1 is termed as primary e.m.f and e.m.f E2 is stand as secondary e.m.f

          

             E1=-N1d0/dt

           E2=-N2d0/dt

            E1/E2=N2/N1

NOTE; The magnitude of E2 and E1 depend on number of turn on the secondary and primary respectively if 

N2>N1=E2>E1 (step - up transformer)

N2<N1=E2<E1(step-down transformer)

            E1=-N1dE1