In order to control fans, which are arranged for example in power supplies for cooling the components arranged there, a method and a circuit arrangement are proposed which, on the basis of control pulses which are derived from the input current of the fan, effect the control in such a way that the control pulses are re-shaped into monostable pulses and are fed, via an asymmetrical resistance circuit for charging and discharging, to a storage component whose charge state is a measure for the control of the fan.