Electronic circuit and method for heating a filament of an x-ray tube

An electronic circuit for providing an AC heating voltage for heating a filament of an X-ray tube, the electronic circuit comprising:

• an inverter configured to
• obtain a DC heating voltage at an input side,
• convert the DC heating voltage into an AC heating voltage based on a manipulated variable, and
• make the AC heating voltage available at an output side;
• and
• a controller configured to
• measure the DC heating voltage and a DC heating current that results from the DC heating voltage,
• determine a controlled variable based on the DC heating voltage and the DC heating current, and
• change the manipulated variable based on the controlled variable to control the controlled variable in an internal control circuit to a setpoint value.