The present invention relates to an overvoltage protection circuit (1) for protecting the electronics of a motor, in particular of an EC motor, against overvoltage pulses, with two protective devices (FS1, FS2) arranged in series connection between two connections (10, 20), wherein a resistor (R1) or (R2) is connected in parallel to each of the protective devices (FS1, FS2) and at least one capacitive element (C1) is provided in parallel connection to the first protective device (FS1), wherein the overvoltage protection circuit (1) has, between the connections (10, 20), at least a first (lower) and a second (higher) breakdown voltage point at a voltage U.sub.Z1 or U.sub.Z2 dependent on the voltage change over time k=(dU/dt) of a voltage U.sub.GA at the connections (10, 20).

The present invention relates to an overvoltage protection circuit (1) for protecting the electronics of a motor, in particular of an EC motor, against overvoltage pulses, with two protective devices (FS1, FS2) arranged in series connection between two connections (10, 20), wherein a resistor (R1) or (R2) is connected in parallel to each of the protective devices (FS1, FS2) and at least one capacitive element (C1) is provided in parallel connection to the first protective device (FS1), wherein the overvoltage protection circuit (1) has, between the connections (10, 20), at least a first (lower) and a second (higher) breakdown voltage point at a voltage U.sub.Z1 or U.sub.Z2 dependent on the voltage change over time k=(dU/dt) of a voltage U.sub.GA at the connections (10, 20).

An ignition device for igniting an air-fuel mixture in a combustion chamber, in particular an internal combustion engine, having a spark plug, which has a first electrode and a second electrode, and a high voltage source for generating an electrical high voltage pulse at an output of the high voltage source and having a high frequency voltage source for generating an electrical high frequency alternating voltage at an output of the high frequency voltage source, wherein the output of the high voltage source is electrically connected to the first electrode of the spark plug via a first electrical conductor path such that the high voltage pulse is applied to the first electrode, wherein the second electrode is electrically connected to an electrical ground potential, wherein the spark plug has a third electrode, wherein the output of the high frequency voltage source is electrically connected to the third electrode via a second electrical conductor path, such that the high frequency alternating voltage is applied to the third electrode.

A multiple spark-gap arrester is disclosed. In an embodiment the arrester includes a series connection of a plurality of spark gaps between a first potential node and a reference-ground potential node and a trigger circuit having an input and an output, the input being coupled to a second potential node between two adjacent spark gaps of the plurality of spark gaps, and the output being coupled to at least one of the spark gaps between the second potential node and the reference-ground potential node, wherein the trigger circuit is configured, when at least one spark gap between the first potential node and the second potential node is ignited, to supply a trigger signal for the at least one of the spark gaps between the second potential node and the reference-ground potential node.

A multiple spark-gap arrester is disclosed. In an embodiment the arrester includes a series connection of a plurality of spark gaps between a first potential node and a reference-ground potential node and a trigger circuit having an input and an output, the input being coupled to a second potential node between two adjacent spark gaps of the plurality of spark gaps, and the output being coupled to at least one of the spark gaps between the second potential node and the reference-ground potential node, wherein the trigger circuit is configured, when at least one spark gap between the first potential node and the second potential node is ignited, to supply a trigger signal for the at least one of the spark gaps between the second potential node and the reference-ground potential node.

Circuits and methods to control a current in a coil are disclosed. The circuit and methods provide over-dwell protection and soft shut-down functionality to safely discharge the coil. The safe discharge of the coil is facilitated by a soft-start ramp signal that reduces the coil current gradually by controlling a switching device according. A profile of the soft-start ramp signal over time determines the gradual reduction. The profile of the soft-start ramp signal can be adjusted to set (i) an over-dwell period of the coil current, after which the coil current is shut down, and (ii) a soft shut-down period, over which the coil current is gradually reduced.

Circuits and methods to control a current in a coil are disclosed. The circuit and methods provide over-dwell protection and soft shut-down functionality to safely discharge the coil. The safe discharge of the coil is facilitated by a soft-start ramp signal that reduces the coil current gradually by controlling a switching device according. A profile of the soft-start ramp signal over time determines the gradual reduction. The profile of the soft-start ramp signal can be adjusted to set (i) an over-dwell period of the coil current, after which the coil current is shut down, and (ii) a soft shut-down period, over which the coil current is gradually reduced.

The invention relates to a lightning and overvoltage protection device for data networks, telephony services, electroacoustic installations or bus systems having at least two grid-side input terminals and at least two output terminals, to which the load that is to be protected can be connected, furthermore having a gas-discharge surge arrester that connects the input terminals and an inductance located between the respective input and output terminal. According to the invention, the inductances are configured as current-compensated inductors having a core and a primary winding and a secondary winding, wherein the load current flows through the windings in different directions so that the respective magnetic fields cancel out. In the event of transient overvoltages, the arising surge current is bypassed by means of a switching device that then closes at one of the two windings, for example the secondary winding, in such a way that, owing to the winding through which current flows, for example the primary winding, the core reaches saturation and the coupling between the windings is released, with the result that no voltage is established across the load and the voltage applied to the winding through which current flows ignites the gas-discharge surge arrester.

The present invention concerns a device for pulsed electric discharge in a liquid comprising a control module configured to control a voltage generator such that the voltage generator applies a predetermined heating voltage setpoint between electrodes during a heating period until a pulsed electric discharge is obtained between the electrodes, in order to measure the breakdown voltage during the pulsed electric discharge, in order to estimate the quantity of energy supplied to the liquid during the heating period, referred to as the quantity of heating energy, from the predetermined heating voltage setpoint and the measured breakdown voltage, and in order to determine a new heating voltage setpoint to apply between the electrodes of the at least one pair of electrodes at the next pulsed electric discharge based on the estimated quantity of heating energy and a predefined breakdown voltage setpoint.

The present invention concerns a device for pulsed electric discharge in a liquid comprising a control module configured to control a voltage generator such that the voltage generator applies a predetermined heating voltage setpoint between electrodes during a heating period until a pulsed electric discharge is obtained between the electrodes, in order to measure the breakdown voltage during the pulsed electric discharge, in order to estimate the quantity of energy supplied to the liquid during the heating period, referred to as the quantity of heating energy, from the predetermined heating voltage setpoint and the measured breakdown voltage, and in order to determine a new heating voltage setpoint to apply between the electrodes of the at least one pair of electrodes at the next pulsed electric discharge based on the estimated quantity of heating energy and a predefined breakdown voltage setpoint.