Active protection device for low voltage circuits in items of low voltage equipment

Method for supplying circuit units with an overvoltage (101) present on a high voltage circuit (100), in which connected items of low voltage equipment (116) are protected from damage due to the applied overvoltage (101), with the steps:

• a) provision of a high voltage circuit (100) for the application of an overvoltage (101), which supplies the circuit units;
• b) provision of at least one item of low voltage equipment (116) with at least one low voltage circuit (115) for carrying out low voltage circuit functions and with at least one protection voltage source (114) for the provision of at least one protection voltage (113);
• c) connection of a protection device (111) for the protection of the item of low voltage equipment (116) from damage due to the overvoltage (101) present on the high voltage circuit (100) in such a way that the protection device (111) is connected in series between the high voltage circuit (101) [sic] and the item of low voltage equipment (116);
• and
• d) clamping, by means of the protection device (111), of a low voltage (102), which is applied to a low voltage node (110), which is arranged between the protection device (111) and the item of low voltage equipment (116), and which is made available to the item of low voltage equipment (116), to a voltage value, which does not exceed a definable voltage value of the protection voltage (113), in such a way that the item of low voltage equipment (116) is protected from damage due to overvoltages.