You have written:
“The primary difference that is evident here is that a normal transformer provides you with only one voltage, for example, say 240 V. But a center tapped transformer will provide you with two voltages each of 240/ 2 i.e. 120 V, so that we can drive two independent circuits.”
Nasir – This is incorrect. You seem to get this right earlier in your comments. There are in fact 3 different circuits from the centre-tapped transformer. This is typical of North American distribution systems, where there are two 120V circuits, and one 240V circuit (two live conductors, one neutral conductor). The 240V circuit is made up of the summation of the two 120V circuits. Yes, the 120V circuits are opposite in polarity, but if you were to measure between the two live conductors (Vtotal) you would have 240V (and in phase with Va). This is easily shown using basic circuit theory. Some poor soul is going to read your comments and end up electrocuting themselves. To the public community – this goes to show that the only way to receive a proper education in Electrical Engineering is to attend a real university. Nasir – it is my only hope that you think twice before posting ‘theory’… your diagram doesn’t even show the polarity of the voltages to begin with. How about you try showing this with phase angles and prove your comments through equations? Prove that Vtotal is the summation of Va with Vb using example voltages. What would happen if the neutral conductor is broken? I know all the answers to this because I am actually an Electrical Engineer specialising in power system protection. I’m sick of wannabes that give us real Engineer’s a bad name. It is a respectable profession and we take pride in our work, because mistakes can result in death.