The Temperature Coefficient of Inductance

The author tries to explain the discrepancy between theory and experiment with regard to the temperature coefficient of inductance of coils. Experiments show that the temperature coefficient of inductance is not equal to the coefficient of linear expansion of the material of the coil, but exceeds it many timies. Such a considerable discrepancy cannot be explained by means of the factors pointed out by certain authors. There must still exist an unknown factor which is responsible for it, probably eddy currents in the mass of the winding as distinguished from skin effect. The author´s experiments confirm this. Other experiments show the influence of various factors in the construction of a coil on its temperature coefficient of inductance.