Auto Transformer Working Principle The auto transformer working principle and construction is similar to that of conventional two winding transformers. However, it differs in the way in which the primary and the secondary are inter-related. In a two-winding transformer, primary and secondary are only magnetically linked by a common core but are completely insulated from

There are many types of transformers. These can be classified on a different basis. The following are the main types of transformers. Types of Transformers based on Voltage Level 1. Step-Down Transformer: The transformers having K > 1 i.e. N2 > N1 are known as the step-up transformer. Here, we get high output voltage as compared

The equivalent circuit of transformer is shown in the figure. No load Components The no-load primary current Io has two components, namely Im and Iw. Where Im = magnetizing component = Io sin φo and Iw = core-loss component = Io cos φo. Iw supplies for the no-load losses and is assumed to flow through

Output voltage of a transformer decreases as we put load on it and the voltage will fluctuate with the fluctuation in the load. These unwanted fluctuations in the output voltage cause many problems. This happens due to voltage drop in its winding. When we measure the output voltage of a transformer, without loading it, we

The efficiency of transformer is defined as the ratio of output power to input power. It is denoted by ἠ.  As the output power is always less than the input power due to losses in the transformer, practically the transformer efficiency is always between 0 and 1 i.e. 0% and 100% but it can never

The set up for short circuit test of transformer is shown in the figure. An auto transformer is used in the circuit to adjust the input voltage precisely to the rated voltage. The ammeter, voltmeter and watt meter are connected in the circuit to measure the current, voltage and power respectively. In this test generally, the high

The open circuit test of transformer is conducted to determine no-load loss or core loss and no-load I0 which is helpful in finding X0 and R0. One winding of the transformer whichever is convenient but usually high voltage winding is left open and the other is connected to its supply of normal voltage and frequency. The primary

The power loss in transformer can be divided into two types namely the copper and the iron loss. The iron losses can be further classified into two types namely the hysteresis losses and the eddy current losses. Copper Power Losses in Transformer The total losses that take place in the winding resistance of a transformer

The primary and the secondary winding of an actual transformer have some resistance which is represented by R1 and R2 respectively (shown external to the windings in the figure). The resistances of the two windings can be transferred to any one side. It is done in order to make the calculations easy. The resistance is transferred