Control device for a frequency generator, the control device having: a recording unit; and a computing unit; wherein the recording unit is designed to record a voltage profile and a current profile of the one frequency generator and to transmit these to the computing unit; wherein the computing unit is designed to determine a temporal offset (Δt 1, Δt 2) between an edge of the current profile and an associated edge of the voltage profile; wherein the computing unit is designed to generate and change a switching signal for outputting the voltage profile in order to reduce the temporal offset between an edge of the current profile and an associated edge of the voltage profile; wherein the recording unit is designed to detect a time of a zero crossing of the voltage profile and a time of a zero crossing of the current profile; characterized in that, after detecting a zero crossing of the voltage profile and/or a zero crossing of the current profile, the recording unit is designed to suspend further detection of a zero crossing of the voltage profile and/or of a zero crossing of the current profile for a blocking time, and to allow further detection of a zero crossing of the voltage profile and/or of a zero crossing of the current profile only after the blocking time has elapsed; the recording unit is designed to allow further detection of a zero crossing of the voltage profile and/or a zero crossing of the current profile after the blocking time has elapsed for the duration of a recording time; and the recording time directly follows the blocking time and has a duration that corresponds to double the difference between the present period duration of the voltage profile and/or the current profile and the proportion of the blocking time in this present period duration. a recording unit; and a computing unit; wherein the recording unit is designed to record a voltage profile and a current profile of the one frequency generator and to transmit these to the computing unit; wherein the computing unit is designed to determine a temporal offset (Δt 1, Δt 2) between an edge of the current profile and an associated edge of the voltage profile; wherein the computing unit is designed to generate and change a switching signal for outputting the voltage profile in order to reduce the temporal offset between an edge of the current profile and an associated edge of the voltage profile; wherein the recording unit is designed to detect a time of a zero crossing of the voltage profile and a time of a zero crossing of the current profile; characterized in that, after detecting a zero crossing of the voltage profile and/or a zero crossing of the current profile, the recording unit is designed to suspend further detection of a zero crossing of the voltage profile and/or of a zero crossing of the current profile for a blocking time, and to allow further detection of a zero crossing of the voltage profile and/or of a zero crossing of the current profile only after the blocking time has elapsed; the recording unit is designed to allow further detection of a zero crossing of the voltage profile and/or a zero crossing of the current profile after the blocking time has elapsed for the duration of a recording time; and the recording time directly follows the blocking time and has a duration that corresponds to double the difference between the present period duration of the voltage profile and/or the current profile and the proportion of the blocking time in this present period duration.