Winding resistance

The resistance of the windings wound around the core of a transformer or choke coil. Windings are mainly made of copper wire with low electrical resistance. When current flows through the windings, losses occur due to their resistance, which are referred to as copper loss. Copper loss is also called load loss and increases in proportion to the square of the current. Therefore, in order to reduce the losses of a transformer or choke coil, it is desirable for the winding resistance to be as small as possible.