Abstract: A device for controlling the field current of a DC motor supplied from an AC network and which is operated beyond the normal speed of the DC motor in the higher speed range obtainable by weakening of the field of the DC motor, there being provided for the apportioning of the field current of the DC motor a phase angle control circuit which is operated depending on a control variable obtained from the respective measured speed of the DC motor by a function-forming device as a function of the speed, the function-forming device comprising a function memory which contains values of the control variable correlated to individual speed values stored in a matrix in tabulated form, the correlation of these values individually corresponding to the DC motor being established when the DC motor starts up for the first time, and where a constant dependence of the control variable on the speed is established either by a polygonal line obtained by linear interpolation from the value pairs stored in tabulated form or by a cur