 I am Priyanka Bidla from Electronics and Telecommunication Engineering and today we are going to solve the example based on delta 2 star conversion. This is the learning outcome of this video lecture. At the end of this session students will be able to analyze and simplify complicated circuits using delta 2 star conversion. These are the contents of this video lecture specifically we will be concentrate on what is delta network, what is star network, expression for delta 2 star conversion and at the end of the lecture we will see example based on delta 2 star conversion. Based upon we will see use of delta connection in electrical circuit. So what is the use of delta connection? So delta connection is generally used in distribution networks since insulation required is also less. It is used for shorter distances and in applications which require high starting torque. What is the importance of delta 2 star conversion? Here both actually star 2 delta and the delta 2 star conversion allows us to convert one type of circuit connection into the another type. In such a way that we can analyze the circuit easily. In some complicated circuits we cannot be analyze the Ohm's law, then KVL law or KCL law. So at that time using star 2 delta or delta 2 star conversion we can analyze the circuits. Let us move towards to the delta network. So here this is the figure of delta network, here the circuit elements are connected in such a way that they form a shape of triangle or delta. Here A, B and C are the nodes of the network and R, A, B, R, B, C and R, A, C are the connected in between these 3 nodes. Then this is star network, here you can see in this figure the circuit elements are connected in such a way that they form a star shape. So its name is star network. Now let us see delta 2 star conversion. So this is delta network, we want to convert in star network. Now we will see the procedure for the conversion. So here the first step is what you have to draw the star network into the delta network. So if you have to draw this star network into the delta network it looks like this. Before moving towards for the conversion of delta 2 star network pause this video for few seconds and you have to recall formulae for conversion of delta 2 star network. Yes you have to observe the figure and then you have to write down the equations for this. So first is R, A plus R, B. So R, A plus R, B are the elements of the star network. So R, A, B is parallel with the R, B, C plus R, C, A. So here these 2 connections are in parallel. So you have to apply the formula 1 upon R, A, B plus 1 upon R, B, C plus R, C, A. So after doing the cross multiplication we are getting R, A plus R, B is equal to R, A, B in bracket R, B, C plus R, C, A upon R, A, B plus R, B, C plus R, C, A. So this is equation 1. So similarly you have to write down the equation for R, B plus R, C. So R, B plus R, C is equal to R, B, C in bracket R, C, A plus R, A, B upon R, A, B plus R, B, C plus R, C, A. So this is equation number 2. Then write the equation for R, C plus R, A. So here this is the R, C plus R, A is equal to R, C, A in bracket R, A, B plus R, B, C upon R, A, B plus R, B, C plus R, C, A. This is equation 3. Now adding equation 1, 2 and 3 we will get this equation. So after simplification we will get R, A plus R, B plus R, C is equal to R, A, B into R, B, C plus R, B, C into R, C, A plus R, C, A into R, A, B upon R, A, B plus R, B, C plus R, C, A. That is total resistance. So this is equation 4 and this is equation 2. Now subtract equation 2 from equation 4 then we will get this equation, yes. Now you have to do the calculation and some terms are cancelled out. So after cancelling the terms we will get the final value of R, A. R, A is equal to R, C, A into R, A, B upon R, A, B plus R, B, C plus R, C, A. Then by subtracting equation 3 from equation 4 we will get the value of R, B. So R, B is equal to R, A, B into R, B, C upon R, A, B plus R, B, C plus R, C, A. Similarly by subtracting equation 1 from equation 4 we will get this equation that is R, C is equal to R, B, C into R, C, A upon R, A, B plus R, B, C plus R, C, A. Now if we want to find any arm of the star network from the delta network, so this is the standard equation. So with the help of that we will find out the any arm of the star network. So any arm of the star connection is equal to what product of two adjacent arms of delta upon sum of arms of delta. These are the standard equations we have calculated already. So these equations are used for solving the problem. Let us see the example of delta to star conversion. So here find the equivalent resistances of star network which are equivalent to that of delta network as shown in this following figure. So this is delta network and the value of the elements are given. So you have to convert into the star network and find the arm values of the star network. So this is the solution. Here these are the standard equations. So with the help of this we will get the values of the respective arm of the star network. So the actual values means the given values of the delta network you have to put into the equation and then we will get the values of the star network. So here we are getting the arm values of the star network that is rA is equal to 30 ohm then rB is equal to 18 ohm and rC is equal to 6 ohm. So in this way we have to convert delta to star network and with the help of that we have to find out the values of the arm values of the star network. And this is the last step of the delta to star conversion. So at the end of the example you have to draw the diagram, draw the network. What is delta network and after calculation you have to draw the star network. These are the references of this video lecture, thank you.