Control device and plasma energy protective apparatus for an ion thruster

A control device for a frequency generator, the control device comprising:

• a detection unit;
• and
• a computing unit;
• wherein the detection unit is configured to detect a voltage characteristic and current characteristic of a frequency generator and to execute a transmission thereof to the computing unit;
• wherein the computing unit is configured to determine a temporal offset (Δt1, Δt2) between one edge of the current characteristic and an associated edge of the voltage characteristic;
• wherein the computing unit is configured to generate and vary a switching signal for an output of the voltage characteristic, in order to reduce the temporal offset between one edge of the current characteristic and an associated edge of the voltage characteristic;
• wherein the detection unit is configured to detect a time point of a zero-crossing in the voltage characteristic and a time point of a zero-crossing in the current characteristic;
• and
• wherein the detection unit is configured, further to the detection of a zero-crossing in the voltage characteristic and/or of a zero-crossing in the current characteristic, to suspend any further detection of a zero-crossing in the voltage characteristic and/or of a zero-crossing in the current characteristic for a lock-out time, and only to permit a further detection of a zero-crossing in the voltage characteristic and/or of a zero-crossing in the current characteristic upon the expiry of the lock-out time.