What things stay constant in a transformer


transformer,Transformers, converters, an electrotechnical component for the conversion of electrical alternating currents into those with a different amplitude of voltage and current at a constant frequency. The simplest implementation is the Single-phase transformer, which consists of two windings, which are applied to a common, simply connected (e.g. ring shape or rectangular torus) iron core (see Fig.). The windings are called according to the transformation direction Primary- and Secondary coil or, according to the level of their voltage, referred to as high-voltage and low-voltage winding. To reduce scattering losses, the coils must be as close together as possible. This can be achieved through the Cylinder winding with concentric arrangement and the Disc winding with primary and secondary coil layers layered one on top of the other. To avoid eddy current losses, the iron core is usually laminated, i.e. composed of thin sheet metal.

If both coils are sufficiently close to one another and connected by a closed magnetic circuit, the same magnetic flux passes through both coils Φ. As a result, the voltages in the coils behave roughly like the number of turns and the currents like the reciprocal values ​​of the number of turns. It also follows from this that the power on both coils (apart from internal losses which must be minimized) is the same. Under the Gear ratio of the transformer one always understands the ratio of the number of turns.

Transformer: a) transformer with separately wound coils, b) with coils wound next to each other (U1: Primary voltage, U2: Secondary voltage, N1: Number of primary turns, N2: Number of secondary turns).