ELECTRICAL ENGINEER

Principal of transformer Transformer works on the principal of electromagnetic induction between two coupled circuit. According to this principal an emf is induction in a coil if it links a changing flux. In core type transformer, half of the L.V and H.V winding is on one limb and other half on the second limb. In small type transformer, the H.V and L.V winding are sandwiched. The diagram as shown Transformer The primary winding Pis connected to an alternative voltage source, therefore alternative current IE starts following through N1 turns. The alternative flux mmf N1IE set up alternative flux which is confide to the high permeability iron path as indicating in fig. The alternative flux induces voltage E1 in the primary P and E2 in the secondary S. If the load is connected across the secondary a load current start flowing.

Transformer construction There are two types of transformer Core type Shell type Both different from each other, and in which winding around the magnetic core. Magnetic core is a stack of thin silicon steel lamination about 0.35mm thick for 50hz transformer. To reduce eddy current losses, these laminations are insulated from each other by thick vernish. For core losses , all transformer have their magnetic core made from cold-rolled grain oriented sheet-steel(C.R.G.O). Core and Shell type  The vertical portion of the core are usually called LIMB or LEG, top and bottom are yoke. This means single-phase transformer, core type 2-legged core where as shell type 3-legged core.

Step up If the secondary winding has more turns then the primary winding, then the secondary voltage higher then primary voltage and the transformer is called step-up transformer. Step down Secondary winding has less turns then the primary winding, then secondary voltage lower then primary voltage and the transformer is called s tep-down transformer. Transformer

Transformer  Transfer electrical energy from one electrical circuit to another electrical circuit through the medium of magnetic field and without change in frequency. Transformer is an electromagnetic energy conversion device. Energy received by the primary is first and it is then converted to electrical energy in the secondary. The coupling magnetic field allows the transfer of energy in either direction, from high voltage to low voltage circuit or from low voltage to high volatge. Types of Transformer Step up. Step down. Transformer