Abstract: A method for protecting an electrical low-voltage circuit includes ascertaining the level of the voltage of the low-voltage circuit in the form of instantaneous voltage values. A change in the current is ascertained over time such that instantaneous current change values are provided. The instantaneous current change values are compared to instantaneous current change threshold values in order to recognize a short circuit in the low-voltage circuit, and if the current change thresholds are exceeded, an electronic interruption unit switches from the low-resistance state to the high-resistance state in order to interrupt the low-voltage current circuit. The process has a trigger time from the short circuit event to the high-resistance state. The trigger time is largely independent of the phase angle. A circuit breaker device for protecting an electrical low-voltage circuit is also provided.

Abstract: A circuit breaker device for protecting a low-voltage electric circuit includes a mechanical break contact unit connected in series with an electronic interruption unit. The break contact unit is switchable by opening contacts to prevent current flow or by closing the contacts to allow current flow in the low-voltage circuit. The electronic interruption unit is switchable by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow or into a low-resistance state of the switching elements to allow current flow in the low-voltage circuit. The amplitude of the current in the low-voltage circuit is ascertained to provide instantaneous current values which are compared with at least one current threshold value, and if the threshold value is exceeded, prevention of current flowing in the low-voltage circuit is initiated. The at least one current threshold value is adjusted according to a temperature level of the circuit breaker device.

Abstract: A circuit breaker device for a low-voltage circuit has a mechanical isolating contact unit connected in series with an electronic disconnection unit. The mechanical isolating contact unit is switched by opening contacts to prevent current flow or closing the contacts for current flow in the low-voltage circuit. The electronic disconnection circuit is switched by semiconductor-based switching elements into a high-resistance state of the switching elements or into a low-resistance state of the switching elements for current flow in the low-voltage circuit. When the amount of an instantaneous current value of the low-voltage circuit exceeds at least one current threshold value, prevention of the current flow of the low-voltage circuit is initiated. The at least one current threshold value is adjusted according to the magnitude of the voltage of the circuit breaker device.

Abstract: A circuit breaker device protects an electrical low-voltage current circuit. The level of a current of the low-voltage current circuit is ascertained periodically such that current values are provided incrementally. The level of the voltage of the low-voltage current circuit is ascertained periodically such that voltage values are provided incrementally. The change in the current is ascertained from the periodically ascertained current values over time such that current change values are provided incrementally, and a differential voltage is ascertained from the periodically ascertained voltage values and an expected value of the voltage such that differential voltage values are provided incrementally. Each current change value is compared with a second threshold, and each differential voltage value is compared with a first threshold. If the first and second thresholds are exceeded, an interruption of the current circuit is initiated by switching elements being set to a high-ohmic state.

Abstract: A circuit breaker device has a mechanical break contact unit connected in series with an electronic interruption unit. The mechanical break contact unit is switched by breaking contacts to prevent current from flowing or by closing the contacts to allow current to flow in the low-voltage circuit. The electronic interruption unit is switched by semiconductor-based switching elements into a high-impedance state of the switching elements to prevent current from flowing or into a low-impedance state of the switching elements to allow current to flow in the low-voltage circuit. An amplitude of the current in the low-voltage circuit is ascertained such that analog momentary current values are provided which are compared with a current threshold value by an analog comparator, and if the threshold value is exceeded, prevention of current flowing in the low-voltage circuit is initiated, in particular by switching the electronic interruption unit into the high-impedance state.

Abstract: A circuit breaker device protects an electric low-voltage current circuit. A level of a voltage of a low-voltage current circuit is ascertained such that ascertained voltage values are provided. A differential voltage is ascertained from the ascertained voltage values and an expected value of the voltage such that differential voltage values are provided incrementally. Each differential voltage value is compared with a first threshold, and if at least two successive differential voltage values exceed the threshold, an interruption of the low-voltage current circuit is initiated by semiconductor-based switching elements, which are set to a high-ohmic state, in order to protect the low-voltage current circuit from a short-circuit.

Abstract: A circuit breaker for a low-voltage electric circuit includes a mechanical break contact unit which is connected in series with an electronic interrupting unit. The mechanical break contact unit is switched by breaking contacts to prevent current from flowing or by closing the contacts to allow current to flow in the low-voltage circuit. The electronic interrupting unit switches semiconductor-based switching elements into a high-impedance state to prevent current from flowing or into a low-impedance state to allow current to flow in the low-voltage circuit. The amplitude of the current in the low-voltage circuit is ascertained as instantaneous current values. If the instantaneous current value is exceeded relative to at least one current threshold value, prevention of current flowing in the low-voltage circuit is initiated. The at least one current threshold value is adapted in dependence on the amplitude of the current in the low-voltage circuit.

Abstract: A method for actuating a semiconductor power switch of an AC circuit is provided, which can be activated or deactivated by the semiconductor power switch. The method has the following steps: a) ascertaining the present current value and the present voltage value of the AC circuit; b) ascertaining whether the present current value exceeds a specifiable maximum value and if so, c1) generating an actuation signal for deactivating the current circuit, c2) generating an actuation signal for activating the current circuit within a period of time after generating the actuation signal for deactivating the current circuit, wherein the period of time is less than or equal to the period duration of the voltage, and c3) ascertaining whether the present current value exceeds a specifiable maximum value, which corresponds to the previous maximum value or is less than the previous maximum value, after activating the current circuit.