Hi friends in this video we are going to see construction of a transformer there are two basic parts first is magnetic coke and second windings or coils so let’s discuss magnetic or force so the transformer magnetic code is like this this is called as a limb this is also limb and this is called as a you know what is the job of this magnetic or coal provides path for magnetic flux so maximum flux will be passing through this cool hence there are two types of losses that will occur inside the core and those losses are hysteresis and eddy-current together these losses are called as a magnetic losses or iron losses now we need to construct or make a course such a way that these two losses are as low as possible how we can get that through design so let’s discuss how to minimize hysteresis loss so generally code is made up of high grade silicon still this is the best magnetic material how to choose the best magnetic material magnetic material with hi permeability this is what is provided by this high grade silicon steel it is a high permeability material earlier core is made up of iron but now due to advancement in material science we can get a high permeability magnetic material so that hysteresis loss is very low so why we need this core made up of a high permeability material in order to minimize hysteresis losses second loss is eddy-current so how to reduce etiquette loss we make core which is made up of thin laminations in order to minimize eddy current losses because any current is happening because of a with hybrid material so what we are doing Orion we are providing the thin laminations of 0.5 or 0.7 mm so that we can have a width very very less and now this thin laminations we can put one over the other to form a step and this laminations are insulated from each other by insulation called as varnish so how to form a code so this curve is actually made up of thin laminations of high magnetic material like this and this laminations are insulated from each other by varnish so this is how core is for let us go to next part that is winding or coins windings are won over limbs of core like this so these are the windings this is called as a primary winding because you are going to connect a supplier to this and here since load will be connected we call this as a secondary winding so what is the job of his winding winding scary primary and secondary current so electric current passes through windings so we need a material which will have less resistivity so we will use copper for carrying the current so windings are made up of copper and are warm on the legs of magnetic core so there will be many number of turns on this limb so obviously there is a risk of touching to subsequent turns but that we are going to avoid with the help of insulation so remember these windings are insulated from each other since there is a length area of cross section and some resistivity for this material hence there will be some resistance at the primary as your a secondary site so current is passing through this resistance give rise to I square R losses so windings are subjected to I square R losses which are also called as copper losses so based on the arrangement of CO and windings we have two types of transformer the first type is core type of transfer core type of transformer is like this this is cool and these are windings this is secondary winding and this is primary winding now what is so special about this here if you see corn is inside and then we have windings so I can say the winding encircles the core or you can say core is surrounded by winding let’s see another type of transformer that is shell type so this is core and we have windings like this so what happened here we are having two magnetic circuits this is a forced magnetic circuit and this is second magnetic circuit so here if you see what happened there is a core outside and windings are inside so I can say the core encircles the windings or in other words you can say windings are surrounded by go so if you see the structure properly there are some differences between this two first is obviously based on the construction second this is having only one magnetic circuit whereas this shell type is having two magnetic circuits suppose I want to replace the windings it is very easy over here just to take this part of a core outside and take the windings out and replace but replacing windings over here is not a easy job so based on the arrangement of core and windings we have seen two types of transformer normally very high voltage transformers are of shell type thank you