Control method for an induction apparatus, and induction apparatus

A control method for an induction apparatus having at least one induction coil, at least one capacitor connected in parallel with the induction coil, the induction coil and the capacitor forming a parallel resonant circuit, and at least one switch connected in series with the parallel resonant circuit, between the parallel resonant circuit and a reference voltage, the method comprising:

• generating a digital test signal dependent on the voltage present in an intermediate node disposed between the switch and the parallel resonant circuit, the test signal comprising a first digital logic level when the voltage in the intermediate node is greater than a predetermined reference value and a second digital logic level when the voltage is smaller than the predetermined reference value,
• closing the switch for a first closure time,
• opening the switch at the end of the first closure time,
• evaluating the test signal for a waiting time when the switch is open to determine the presence or absence of a vessel on the induction coil, and
• determining the presence of a vessel on the induction coil if during the waiting time the test signal maintains its digital logic level or determining the absence of a vessel on the induction coil if during the waiting time the test signal does not maintain its digital logic level.