Energy transfer system and reception unit for the wireless transcutaneous transfer of energy

A receiver unit configured to interact for wireless energy transfer with a transmitter unit separate from the receiver unit and to supply energy to a cardiac support system, the transmitter unit comprising a primary coil supplied with a supply voltage, the receiver unit comprising:

• a secondary coil configured to interact with the primary coil of the transmitter unit;
• a DC link capacitor connected to the secondary coil by a rectifier;
• a voltage measuring device configured to determine a value of a DC link voltage applied to the DC link capacitor when the supply voltage is supplied to the primary coil;
• and
• a control unit configured to perform, based on the determined value of the DC link voltage or a variable derived therefrom, at least one function comprising:
• outputting a first acoustic signal when the determined value of the DC link voltage or the variable derived therefrom is below a first threshold value;
• outputting a second acoustic signal when the determined value of the DC link voltage of the variable derived therefrom is above the first threshold value and below a second threshold value, wherein the second acoustic signal differs from the first acoustic signal in at least one of a repetition frequency, tonal range, or volume;
• and
• discontinuing the second acoustic signal and outputting a switch signal to close a first switch to connect an energy storage unit to the rectifier the determined value of the DC link voltage or the variable derived therefrom is above the second threshold value, wherein the second threshold value is higher than the first threshold value.