Calculations

Transformer Calculations

(1)

Voltage in Secondary = Turns in Secondary
Voltage in Primary           Turns in Primary

or

Vs = Ns
Vp   Np

 

(2)

If we apply the law of conservation of energy to the transformer we have:

Energy in Primary = Energy in Secondary

VpIpt = VsIst

Time is the same in the primary and the secondary coils.

 

e.g. Step Down Calculation

Vp = 200V
Np = 600
Vs = 10V
Ns = ?

Vs = Ns
Vp   Np

Ns = Vs x Np
             Vp

= (10 x 600)/20

=30 Turns

Vp=200V
Ip = 4A
Vs = 10V
Is = ?

VpIpt = VsIst

Is = VpIp
           Vs

= (200X4)/10

= 80A