Dehn Se + Co Kg

Dehn Se

Dehn + Söhne Gmbh + Co Kg

Franz Schork

Thomas Böhm

Ralph Brocke

Ottmar Beierl

Josef Birkl

Bernhard Eichler

Dominik Donauer

Michael Stehle

Johannes Spies

An asymmetric surge protection device for a DC circuit () has a negative side () which can be connected to a current output () of the DC circuit (), a positive side () which can be connected to a current input () of the DC circuit (), and an asymmetric neutral section (). The asymmetric neutral section () has a positive protection level (V) for a positive voltage (V) between the positive side () and the negative side (), and a negative protection level (V) for a negative voltage (V) between the positive side () and the negative side (), the positive protection level (V) being different from the negative protection level (V). Furthermore, a DC circuit arrangement () and a DC network () are shown.

Asymmetric overvoltage protection apparatus, DC circuit arrangement and DC network

The invention relates to a circuit arrangement for combined protection of a load from temporary and transient overvoltages with emergency operation of the load in the presence of a temporary overvoltage and with integrated follow current limitation, wherein a first surge arrester, in particular a spark gap or a varistor, is provided between network-side input terminals and a second surge arrester, in particular a varistor, is provided between load-side output terminals for follow current limitation. According to the invention, at least one controlled semiconductor switch is provided in each case in the series branch between the input terminal and the output terminal and in the output-side parallel branch, wherein a mechanical switch and a series capacitance are connected in parallel with the semiconductor switch in the series branch. Furthermore, the semiconductor switch in the parallel branch is part of a series circuit comprising a parallel circuit comprising a second surge arrester and a parallel capacitance. A series inductance is provided in the series branch between the input terminal and the parallel circuit comprising the series capacitance, the controlled semiconductor switch and the mechanical switch. A microcontroller for controlling the semiconductor switches is also present, wherein the microcontroller is connected to a current detector in the series branch.

Circuit arrangement for combined protection of a load from temporary and transient overvoltages

Circuit assembly for protecting a unit to be operated from a supply network against surges, comprising an input having a first and a second input connection, which are connected to the supply network, an output to which the unit to be protected can be connected, and a protective circuit which is placed between the first and the second input connections in order to limit the voltage applied thereto, said protective circuit comprising a power semiconductor device. The power semiconductor device includes at least one Zener element between the collector and the gate, or a digital-to-analog converter is placed between the collector and the gate of the power semiconductor device. The protective level of this type of protective circuit can be easily adjusted by setting the clamping voltage for the power semiconductor device.

Circuit assembly for protecting a unit to be operated from a supply network against surges

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.

Lightning and overvoltage protection device for data networks, telephony services, electroacoustic installations or bus systems

The invention relates to an electronic circuit-breaker for a load (RL) that can be connected to a low-voltage dc-voltage network, the circuit-breaker consisting of assemblies provided between input terminals and the load and said assemblies comprising a voltage monitoring unit (TVS, R), a current monitoring unit (Shunt, OPV), semiconductor switch units (MOSFET) and controllers (uC) associated therewith. According to the invention, a series circuit consisting of a TVS diode (TVS) and a resistor (R) is connected to the input terminals, the resistor having a connection to a first connector () of a microcontroller (uC) and the resultant voltage drop at the resistor providing the microcontroller with an overvoltage identification signal if a breakdown voltage is reached at the TVS diode as a result of an overvoltage. A second connector () of the microcontroller has a connection to a first semiconductor switch unit (MOSFET), the first semiconductor switch unit being in series, as an elongate switch, with the load (RL), and the microcontroller disabling the switch in the event of an overvoltage detection signal. A shunt acting as a current monitoring unit is in series with the load, the voltage drop at the shunt being analysed by the microcontroller via a third connector () and if an overcurrent which exceeds a threshold value is identified, the load is switched off by means of the first semiconductor switch unit. In addition, a MOS-gated thyristor (MGT) is connected between the input terminals, the control input of said thyristor having a connection to a fourth connector () of the microcontroller, such that the MOS-gated thyristor can be activated in the event of an overvoltage identification signal.

Electronic circuit-breaker for a load that can be connected to a low voltage DC-voltage network

The invention relates to a method for sensing lightning-current parameters at installations comprising a plurality of capturing devices and lightning-current diversion paths, in particular for exposed and/or tall buildings, including wind turbines, by using a plurality of sensors on the lightning-current diversion paths to identify a lightning-current event, and comprising subsequent evaluation of the lightning-current event and the effect of the lightning-current event on the particular installation. According to the invention, a lightning-current detection sensor is formed on each of the capturing devices or each lightning-current diversion path, which lightning-current detection sensor provides a yes/no statement concerning a lightning-current event with respect to the particular capturing device or the particular lightning-current diversion path. Furthermore, at least one lightning-current measurement sensor is provided at a central point of the merging of the lightning-current diversion paths toward the ground, which at least one lightning-current measurement sensor detects both surge currents having a duration of less than 5 ms and long-term currents having a duration of more than 5 ms, wherein furthermore the magnitude of the charge of the particular long-term current that has occurred is determined and is used to determine possible effects on the installation.

Method for sensing lightning-current parameters at installations having one or more capturing devices and lightning-current diversion paths

The invention relates to a circuit assembly for protecting a unit to be operated from a supply network against overvoltage, comprising an input having a first and a second input connection, which are connected to the supply network, an output having a first and a second output connection, to which the unit to be protected can be connected, and a protection circuit, which is provided between the first and the second input connections in order to limit the voltage present at the first and the second input connections. According to the invention, the protection circuit has a power semiconductor, in particular an IGBT, wherein a series circuit consisting of a diac, i.e., a bidirectional electrode, and a Zener element is connected between the collector and the gate of the power semiconductor, wherein the sum of the Zener voltage and the diac voltage results in a clamping voltage for the power semiconductor, which lies above the voltage of the supply network and defines the protection level.

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Nuremberg, Germany

Franz Schork