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 battery module includes a housing, a plurality of battery cells disposed in the housing, and a printed circuit board (PCB) assembly disposed in the housing. The PCB assembly includes a PCB and a shunt disposed across a first surface of the PCB. A second surface of the shunt directly contacts the first surface of the PCB, and the shunt is electrically coupled between the battery cells and a terminal of the battery module.

Shade mitigation systems and devices to mitigate adverse effects of shade on a primary photovoltaic cell powering a load via an output terminal. The shade mitigation devices include a relay switch and a secondary photovoltaic cell. The relay switch selectively completes a circuit between the primary photovoltaic cell and the load when energized. The secondary photovoltaic cell is electrically coupled to the relay switch and is mounted in a position to monitor illumination on the primary photovoltaic cell. The secondary photovoltaic cell energizes the relay switch to selectively complete the circuit between the primary photovoltaic cell and the load when the secondary photovoltaic cell is illuminated by at least a threshold illumination. The secondary photovoltaic cell stops energizing the relay switch to selectively open the circuit between the primary photovoltaic cell and the load when the secondary photovoltaic cell is shaded sufficiently to illuminate it below the threshold illumination.

A power supply circuit, a relay device and a Power over Ethernet system related to the electronic technical field are provided. In the power supply circuit, each rectifier module has its positive output end connected to a positive supply pin, and a negative output end connected to a first end of a switch control module. The positive supply pin is connected to a positive terminal of a relay circuit in the relay device. The switch control module has a second end connected to a negative supply pin, and a control end connected to the positive supply pin. The negative supply pin is connected to a negative terminal of the relay circuit. The switch control module allows conduction between the first end and the second end when the rectifier module outputs a voltage greater than a preset threshold.

A method for diagnosing an operating state of a switching device including separable contacts, which are driven by an electromagnetic actuator including a coil connected to an electronic control device, and sensors, which are configured to measure an intensity of a coil current and a coil voltage. The method comprises: a) receiving an order to close via the electronic control device; b) controlling the electromagnetic actuator so that it closes; c) measuring and recording the coil voltage and coil current values; d) calculating and recording values of a magnetic flux through the coil, by integrating the recorded values of the coil current, the coil voltage and resistance and inductance values of the coil; and e) evaluating and recording positions of a core of the electromagnetic actuator according to a data table, which is previously recorded in the electronic control device and which defines a bijective relation between the position of the core, the magnetic flux and the coil current.

A method for diagnosing an operating state of a switching device including separable contacts, which are driven by an electromagnetic actuator including a coil connected to an electronic control device, and sensors that measure a coil voltage and an intensity of a coil current. The method includes: a) receiving an order to open the switching device via the electronic control device; b) controlling the electromagnetic actuator so that it opens; c) measuring and recording the coil voltage and coil current values d) calculating and recording values of a magnetic flux through the coil, by integrating the recorded values of the coil current, the coil voltage and resistance and inductance values of the coil; and e) evaluating and recording positions of a core of the electromagnetic actuator according to a data table, which defines a bijective relation between the position of the core, the magnetic flux and the coil current.

A method for estimating a property of an electrical switching device includes: measuring the electric current flowing through the coil; measuring the supply electrical voltage of a control circuit for the actuator; injecting an electric current pulse into the coil; identifying a first time corresponding to the time for which the current flowing through the coil reaches a predetermined threshold value when the current increases following the injection of the pulse; identifying a second time corresponding to the time for which the current flowing through the coil again reaches the predetermined threshold value when the current decreases after the spike; and estimating the resistance of the coil on the basis of the ratio of the sum of the values of the voltage that are measured between the second time and the first time, to the sum of the values of the current that are measured between the second time and the first time.

A system may include an armature configured to move between a first position that electrically couples the armature to a first contact and a second position that electrically couples the armature to a second contact. The system may also include a coil configured receive a current, such that the current conducting in the coil is configured to magnetize a core. The magnetized core may cause the armature to move from the first position to the second position. The system may also include a control system configured to detect a position of the armature based on an inductance of the coil.

A system may include an armature configured to move between a first position that electrically couples the armature to a first contact and a second position that electrically couples the armature to a second contact. The system may also include a coil configured receive a current, such that the current conducting in the coil is configured to magnetize a core. The magnetized core may cause the armature to move from the first position to the second position. The system may also include a control system configured to detect a position of the armature based on an inductance of the coil.

A method for operating a medium voltage circuit breaker or recloser comprising at least one electric pole, each including a movable contact and a fixed contact, being in a closed or an open position after switching operations of the medium voltage circuit breaker or recloser, and an electromagnetic actuator, includes: monitoring a travel curve of the movable contact, the travel curve being derived by an evaluation of a shape of an applied current and a shape of an applied voltage using a mathematical representation of the electromagnetic actuator.