A load zone of a DC system includes a connection interface for supplying the load zone with electrical energy, an electronic switch arranged between the connection interface and a DC bus, and at least two electrical devices connected in parallel to the DC bus. A voltage sensor measures a voltage across a fuse arranged between the DC bus and a respective electrical device. An evaluation unit identifies a defective device of the at least two electrical devices based on a polarity of the voltage measured by the voltage sensor across the fuse. A DC system with such a load zone and an energy source connected to the connection interface of the load zone, as well as a method for operating such load zone or DC system are also disclosed. A device is identified as being defective when the voltage measured across the fuse exceeds a specified limit value.

The invention relates to a lightning protection spark gap assembly. The lightning protection spark gap assembly comprises: a lightning protection spark gap (1); a safety fuse device (8) which can be triggered by a bridge initiator (7) and which is connected between a first or second voltage line (S1, S2) and a corresponding main connection (1, 1b) of the lighting protection spark gap (1); and an indicator device (4′) for detecting a secondary current flow connecting to a pulse current flow or a corresponding portion of the secondary current flow, and for triggering the safety fuse device (8) by activating the bridge initiator (7) when the detected secondary current flow or the corresponding portion of the secondary current flow fulfills a first predefined criterion, wherein the lightning protection spark gap (1) has a first and a second divergent electrode (21a, 21b) and an arcing chamber (25), and wherein the indicator device (4′) is electrically connected to the first or second divergent electrode (21a, 21b) and/or the arcing chamber (25) in such a way that it detects the secondary current flow or the corresponding portion of the secondary current flow in the area (L) in which the secondary current arc flows.

Circuits and methods for reading fusible links that allows use of low-voltage logic circuitry utilizing devices that may have a high-voltage stand-off capability. Embodiments provide predictable operation that is less susceptible to PVT variations, allow the use of arrays of fuses that may be scaled to relatively large memory sizes, uses little integrated circuit area, and do not require extra pins for operation. Embodiments utilize a latch circuit and voltage dividers to generate a reference voltage V.sub.REF and a fuse voltage V.sub.FUSE, and then compares and latches the greater of those voltages. The circuitry does not require any more supply voltage than is needed to turn ON input pass transistors to the latch at a slightly higher voltage (V.sub.TH) than V.sub.REF. Since V.sub.REF may be about 0.1V, that turn-ON voltage may be as low as about 0.1V+V.sub.TH, and thus would be less than a V.sub.DD_MIN of about 1V.

Circuits and methods for reading fusible links that allows use of low-voltage logic circuitry utilizing devices that may have a high-voltage stand-off capability. Embodiments provide predictable operation that is less susceptible to PVT variations, allow the use of arrays of fuses that may be scaled to relatively large memory sizes, uses little integrated circuit area, and do not require extra pins for operation. Embodiments utilize a latch circuit and voltage dividers to generate a reference voltage V.sub.REF and a fuse voltage V.sub.FUSE, and then compares and latches the greater of those voltages. The circuitry does not require any more supply voltage than is needed to turn ON input pass transistors to the latch at a slightly higher voltage (V.sub.TH) than V.sub.REF. Since V.sub.REF may be about 0.1V, that turn-ON voltage may be as low as about 0.1V+V.sub.TH, and thus would be less than a V.sub.DD_MIN of about 1V.

A method of detecting welded contacts in a relay. The method includes performing, at a first point in time, the applying of a drive to the activation coil to conduct a coil current through the activation coil, the coil current increasing to a first current level, the first current level being less than a pull-in current of the relay; responsive to the coil current reaching the first current level, turning off the drive to the activation coil to discharge the coil current at a first clamping voltage; and measuring a first discharge time corresponding to a first inductance from the turning off of the drive to the activation coil to the coil current reaching a second current level, the second current level being less than the first current level. These operations are repeated at a second point in time to obtain a second inductance. Comparison of the first inductance and second inductance determines whether a difference between the first and second inductances exceeds a comparison criterion.

A method of detecting welded contacts in a relay. The method includes performing, at a first point in time, the applying of a drive to the activation coil to conduct a coil current through the activation coil, the coil current increasing to a first current level, the first current level being less than a pull-in current of the relay; responsive to the coil current reaching the first current level, turning off the drive to the activation coil to discharge the coil current at a first clamping voltage; and measuring a first discharge time corresponding to a first inductance from the turning off of the drive to the activation coil to the coil current reaching a second current level, the second current level being less than the first current level. These operations are repeated at a second point in time to obtain a second inductance. Comparison of the first inductance and second inductance determines whether a difference between the first and second inductances exceeds a comparison criterion.

A fluid-affected fuse includes a structural housing, a pair of electric terminals, one or more fuse elements, and a fluid arranged in an internal volume of the structure. The structure provides rigidity to the fuse. The terminals are coupled to the structural housing and are configured to be coupled to an electric power circuit of a battery circuit. The one or more fuse elements are electrically connected in series to the pair of electric terminals and are arranged in the internal volume. The fluid is configured to affect a temperature of the fuse element. A fluid-filled fuse is filled with fluid, optionally sealed, and operated with the increased heat capacity of the fluid to affect temperature of the fuse. A fluid-cooled fuse is filled with the fluid, undergoing a stream of the fluid thus allowing control of fuse temperature. A control system controls the fluid stream and fuse operation.

Systems and methods for estimating a thermal-mechanical fatigue in an electrical conductor in a thermal-mechanical fatigue assessment system include an electrical conductor having a cold resistance and a non-linear resistance when connected to an electrical power system, and a controller receiving temperatures of the conductor as inputs, wherein the controller is operable to estimate a service life of the conductor based on at least the input temperatures of the conductor and the cold resistance of the conductor.

Systems and methods for estimating a thermal-mechanical fatigue in an electrical conductor in a thermal-mechanical fatigue assessment system include an electrical conductor having a cold resistance and a non-linear resistance when connected to an electrical power system, and a controller receiving temperatures of the conductor as inputs, wherein the controller is operable to estimate a service life of the conductor based on at least the input temperatures of the conductor and the cold resistance of the conductor.

Systems, apparatuses, and methods are described for thermal fuse circuit breakers. The thermal fuses described herein may be disposed in a connector, so that, should an overheating condition occur, for example, due to an arc discharge across or inside of the connector, the heat of the arc discharge melts a portion of the fuse, thereby preventing a potentially catastrophic event, such as fire, or damage to a component which may be more expensive than the thermal fuse itself.