A test system (10) for testing an electric device (30), in particular a high-voltage device, has a portable main device (100) with a housing (140), an electric connection assembly (120, 121) and a mechanical connection assembly (145) and has a portable additional device (200, 300) with a separate housing (240, 340), an electric connection assembly (220, 320) and a mechanical connection assembly (245). The main device (100) can be mechanically connected to the additional device (200, 300) in a releasable manner by coupling the mechanical connection assemblies (145, 245) to form a structural unit, wherein the main device (100) can be electrically connected to the additional device (200, 300) via the first electric connection assemblies (120, 121, 220, 320).

A fault diagnosis method includes detecting a state of a relay device, sending a fault diagnosis trigger signal to the relay device based on the stateto enable the relay device to enter a fault diagnosis mode, where the fault diagnosis trigger signal includes one or more of a variable supply voltage value, a transmit/receive control signal, and a diagnosis control signal, detecting a state of the relay device in the fault diagnosis mode, determining a fault code based on the state, and determining a fault based on the fault code.

In a case where a load current flows in an energized state where a power supply is connected to a load, it is assumed that a measured voltage fluctuates due to a voltage drop caused by contact resistance of a relay contact, and thus the relay state cannot be accurately diagnosed. A relay control device that controls a relay connected between a secondary battery and a load device calculates, in a failure diagnosis during energization with the relay being closed, a contact resistance value of the relay based on a voltage applied to the relay and a current flowing through the secondary battery, and determines a first threshold set as a variable value in accordance with a temperature change amount of the relay and compares the calculated contact resistance value with the first threshold to diagnose a failure of the relay.

A monitored switch gear device that includes a switch gear, a plurality of magnets, a magnetic field sensor and a processing circuitry. The switch gear includes an opening/closing mechanism adapted to selectively open and close an electrical circuit. The opening/closing mechanism includes a pivotally mounted shaft configured to rotate about a pivot axis as the opening/closing mechanism moves between an open and a closed state. The magnets of the plurality of magnets are spaced from each other and fixedly attached to the shaft. The magnetic field sensor senses a magnetic field generated by each magnet of the plurality of magnets as the shaft pivots. Each magnet of the plurality of magnets defines a different angular position of the shaft detected by the magnetic field sensor in which the magnetic field sensor senses a respective magnet of the plurality of magnets. The processing circuitry computes a first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the magnetic field generated by at least two magnets of the plurality of magnets as the shaft pivots in one direction.

A monitored switch gear device that includes a switch gear, a plurality of magnets, a magnetic field sensor and a processing circuitry. The switch gear includes an opening/closing mechanism adapted to selectively open and close an electrical circuit. The opening/closing mechanism includes a pivotally mounted shaft configured to rotate about a pivot axis as the opening/closing mechanism moves between an open and a closed state. The magnets of the plurality of magnets are spaced from each other and fixedly attached to the shaft. The magnetic field sensor senses a magnetic field generated by each magnet of the plurality of magnets as the shaft pivots. Each magnet of the plurality of magnets defines a different angular position of the shaft detected by the magnetic field sensor in which the magnetic field sensor senses a respective magnet of the plurality of magnets. The processing circuitry computes a first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the magnetic field generated by at least two magnets of the plurality of magnets as the shaft pivots in one direction.

A safety switch input diagnosis device includes a circuit formed from a series connection of an emergency stop switch and a line having a resistor. A connection state of the emergency stop switch and failure modes of the lines are diagnosed on the basis of a voltage value at one end of the circuit. Consequently, an operation of the switch and failure modes of a circuit relating to the switch can be diagnosed.

A power conversion device includes a power converter, a relay, and a welding detector. The welding detector includes a first resistor connected to a terminal of the relay on a first side, a capacitor and a second resistor, both of which are connected to a terminal of the relay on a second side, an application unit to apply an inspection signal to the relay via the capacitor and the second resistor, and a determiner connected between the capacitor and the second resistor, the determiner detecting a signal based on application of the inspection signal by the application unit to determine whether or not the relay is welded.

An optical fiber protection system includes an optical fiber, a light source, a protection circuit, a sensor, and a controller. The light source is configured to transmit a signal to the optical fiber. The protection circuit extends along a length direction of the optical fiber. The sensor is electrically connected to the protection circuit. The controller is electrically connected to the sensor and the light source.

An optical fiber protection system includes an optical fiber, a light source, a protection circuit, a sensor, and a controller. The light source is configured to transmit a signal to the optical fiber. The protection circuit extends along a length direction of the optical fiber. The sensor is electrically connected to the protection circuit. The controller is electrically connected to the sensor and the light source.

A system and method for monitoring a device includes a temperature sensor, a processing unit, and an output unit. The temperature sensor acquires a temperature measurement during a heat-up phase of a component and provides a temperature measurement to the processing unit, which selects a simulated transient temperature distribution of the simulated component of the simulated device from a plurality of simulated transient temperature distributions of the simulated component of the simulated device. The selection comprises a comparison of the at least one temperature measurement with the plurality of simulated transient temperature distributions at an equivalent time point in the simulated heat-up to a time point at which the temperature measurement was acquired. When a hot spot is developing an output unit outputs an indication of a fault associated with the component.