Crowbar circuit, in particular for a voltage transformer, in explosion-protected applications

A crowbar circuit, for use in a voltage converter, comprising:

• a triggering device configured to trigger or cause a short circuit across input terminals depending on a control voltage;
• a comparator configured to trigger the triggering device for triggering the short circuit depending on a comparator voltage at a comparator input of the comparator and depending on a predetermined reference voltage threshold value,
• a Zener diode with a predetermined breakdown voltage in series with a first resistor, which are connected between one of the input terminals and the comparator input, such that when an applied input voltage exceeds the predetermined breakdown voltage, the comparator voltage exceeds or falls under the predetermined reference voltage threshold value, thus triggering or causing the short circuit;
• a series connection of a second resistor, an third resistor, the first resistor and a fourth resistor, wherein a load current at an output of the crowbar circuit flows through the second and fourth resistors and the comparator input is electrically connected to a node between the first and eighth third resistors, and the series connection is connected between the input terminals, such that when a predetermined threshold current is exceeded, the comparator voltage exceeds or falls under the predetermined reference voltage threshold value, thus triggering the short circuit.