A phase shifter includes a signal input, a signal output, an ESD protection circuit, first and second signal paths between the signal input and the signal output. The ESD protection circuit includes first and second two port devices, each two port device being switchable between a high impedance state and a low impedance state. The first signal path includes the first two port device of the ESD protection circuit and a first delay line configured to provide a first phase shift to a signal transmitted from the signal input to the signal output via the first signal path. The second signal path includes the second two port device of the ESD protection circuit and a second delay line configured to provide a second phase shift, different from the first phase shift, to the signal transmitted from the signal input to the signal output via the second signal path.

A protection circuit for connecting and disconnecting to a DC power source, and a DC operated device including such a protection circuit. The protection circuit has input terminals for receiving power from a DC power source and output terminals for providing power to a DC operated device; a first stage with a voltage measurement circuit coupled between the input terminals; and a second stage following the first stage including a pre-charge control circuit. The protection circuit further includes a digital controller arranged for controlling activating and de-activating a local PSU for supplying power to electronics of the DC operated device. The digital controller is arranged for measuring a voltage of the voltage measurement circuit and de-activating the local PSU when detecting a voltage drop on the first input terminal that exceeds a predetermined threshold dip and/or threshold slope.

Provided is a method for monitoring DC electrical power. The method including determining a rate of change of the DC electrical power, determining whether the rate of change of the DC electrical power is greater than a predetermined threshold, when the rate of change of the DC electrical power is greater than the predetermined threshold, determining whether the rate of change of the DC electrical power is greater than the predetermined threshold for a predetermined period of time, and when the rate of change of the DC electrical power is greater than the predetermined threshold for the predetermined period of time, sending a signal indicating an interruption in the DC electrical power.

A method for detecting arc faults when charging electric battery systems or lead acid batteries, which are electrically connected in series to form a string which is supplied via a DC voltage converter. A first value corresponding to an electric voltage applied to the string and a second value corresponding to an electric current flowing through the string are generated. As a first condition, it is checked whether the first value changes by more than a first limit value within a first time window. As the second condition, it is checked whether the second value changes by more than a second limit value within a second time window. An arc is detected if the first condition and the second condition are met within a third time window. Provided also is a method for manufacturing electric battery systems, in particular lead acid batteries, as well as to a cut-off device.

There is disclosed a circuit breaker arrangement for interrupting a current flowing through a direct current (DC) transmission line including a semiconductor switching device and a pulse injection circuit configured to inductively inject into the transmission line a pulse current that opposes the current flowing through the transmission line to thereby reduce the current in the transmission line to cause the semiconductor switching device to turn-off to interrupt the path for the current flow through the transmission line.

A method and system are provided to control circuit breaker operations. In the method and system, near-field RF signal is monitored at or around electrical contacts of the circuit breaker using at least one near-field radio frequency (RF) sensor, and far-field RF signal away from the contacts of the circuit breaker are monitored using at least one far-field RF sensor. A rate of change of current over time is also monitored on the circuit using at least one sensor. An arc fault on the circuit is detected based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current. A tripping operation is implemented on the circuit breaker to disconnect the power supply from the circuit, in response to the detection of the arc fault.

An apparatus for switching and/or protection of a load connected to said apparatus, said apparatus (1) comprising: a power switch (5) through which the connected load receives an electrical current; a sensor component (4) connected in series with said power switch (5) and adapted to generate directly an electrical voltage drop corresponding to a current rise speed of the electrical current flowing via the sensor component (4) and via the power switch (5) to said load; and a driver circuit (6) adapted to detect an occurring overcurrent depending on a voltage drop generated by said sensor component (4) with or without a voltage drop along the power switch (5) and to switch off said power switch (5) upon detection of an overcurrent within a switch-off period to protect said power switch (5) and said load.

Unique systems, methods, techniques and apparatuses of fault location in DC power distribution systems are disclosed. One exemplary embodiment is a DC power distribution system including a plurality of zones each including a DC power distribution line and a protective device. Each protective device structured to sense one or more electrical characteristics of a line and to controllably open a circuit including the line. At least one intelligent electronic device is structured to determine a line inductance based upon electrical characteristics sensed by one or more of the protective devices and to evaluate a location of the line fault based upon the determined line inductance.

A device comprises a solid-state power switch and a control configured to operate the power switch if at least one of a plurality of fault conditions of the device is triggered. An interface is configured to output a signal having a value selectively indicative of the triggered at least one fault condition in response to the at least one fault condition being triggered.

Techniques are disclosed relating to electrical safety systems that may be useful, for example, in electromagnetic geophysical prospecting. Electromagnetic streamer systems often include a number of electrical loads in series that are powered by a constant-current power supply unit. Known techniques for detecting electrical faults have various drawbacks in such an arrangement. Embodiments of this disclosure may be used to mitigate some or all of such drawbacks.