An autotransformer is a transformer which has part of its winding common to the primary and secondary circuits. Fig. 1(a) shows the circuit for a double-wound transformer and Fig. 1(b) that for an auto transformer. The latter shows that the secondary is actually part of the primary, the current in the secondary being (I2-I1). Since […]
The magnetic flux ϕ set up in the core of a transformer when an alternating voltage is applied to its primary winding is also alternating and is sinusoidal. Let ϕm be the maximum value of the flux and f be the frequency of the supply. The time for 1 cycle of the alternating flux is
EMF EQUATION OF A TRANSFORMER Read More »
Some small transformers for low-power applications are constructed with air between the two coils. Such transformers are inefficient because the percentage of the flux from the first coil that links the second coil is small. The voltage induced in the second coil is determined as follows. E=NdΦ/dt108 where N is the number of turns in
AIR CORE TRANSFORMER Read More »