A method for operating a brushed direct current electric motor, comprising the method steps: a) receiving an input signal indicating a requested rotational speed of the brushed direct current electric motor or indicating a requested output motor voltage to drive the brushed direct current electric motor, b) determining an output duty cycle depending on the received input signal, c) determining an output frequency, d) generating a pulse width modulated output signal with the determined output duty cycle and the determined output frequency to drive the brushed direct current electric motor, e) driving the brushed direct current electric motor by the generated pulse width modulated output signal, characterized in that - in step c) the determined output frequency depends on the determined output duty cycle, - in step c) the determined output duty cycle is compared with at least one predefined output duty cycle threshold, - if the determined output duty cycle is less than or equal to the predefined output duty cycle threshold, a first operating frequency is determined as output frequency, or if the determined output duty cycle is higher than the predefined output duty cycle threshold, a second operating frequency is determined as output frequency, - wherein the first operating frequency is higher than the second operating frequency. the method steps: a) receiving an input signal indicating a requested rotational speed of the brushed direct current electric motor or indicating a requested output motor voltage to drive the brushed direct current electric motor, b) determining an output duty cycle depending on the received input signal, c) determining an output frequency, d) generating a pulse width modulated output signal with the determined output duty cycle and the determined output frequency to drive the brushed direct current electric motor, e) driving the brushed direct current electric motor by the generated pulse width modulated output signal, a) receiving an input signal indicating a requested rotational speed of the brushed direct current electric motor or indicating a requested output motor voltage to drive the brushed direct current electric motor, b) determining an output duty cycle depending on the received input signal, c) determining an output frequency, d) generating a pulse width modulated output signal with the determined output duty cycle and the determined output frequency to drive the brushed direct current electric motor, e) driving the brushed direct current electric motor by the generated pulse width modulated output signal, characterized in that - in step c) the determined output frequency depends on the determined output duty cycle, - in step c) the determined output duty cycle is compared with at least one predefined output duty cycle threshold, - if the determined output duty cycle is less than or equal to the predefined output duty cycle threshold, a first operating frequency is determined as output frequency, or if the determined output duty cycle is higher than the predefined output duty cycle threshold, a second operating frequency is determined as output frequency, - wherein the first operating frequency is higher than the second operating frequency. - in step c) the determined output frequency depends on the determined output duty cycle, - in step c) the determined output duty cycle is compared with at least one predefined output duty cycle threshold, - if the determined output duty cycle is less than or equal to the predefined output duty cycle threshold, a first operating frequency is determined as output frequency, or if the determined output duty cycle is higher than the predefined output duty cycle threshold, a second operating frequency is determined as output frequency, - wherein the first operating frequency is higher than the second operating frequency.