Abstract: A circuit arrangement is described with the aid of which a control signal can be generated in dependence upon the occurrence of an extreme value of a sinusoidal oscillation. The circuit arrangement (10) includes a storage member (22) which is adapted to be charged via a diode (20) to one of the extreme values of the sinusoidal oscillation. A discharge path (26) for the storage member (22) is present, the time constant of which is so dimensioned that within the period duration of the sinusoidal oscillation an appreciable discharge of the storage member (22) takes place. A switch element (24) controllable by the charge voltage of the storage member (22) furnishes the control signal at its output (14) for the period of time during which the charge voltage at the storage member (22) is smaller than the extreme value of the sinusoidal oscillation. The circuit arrangement can be used in maintaining the oscillations of a resonance circuit stimulated to oscillate by means of a momentary HF carrier wave pulse.