A current sense system may include a relay, a load conductor, and an integrator sub-circuit. Current may be provided to an electrical load via the load conductor and a latch of the relay. The current carried via the load conductor may induce a sense voltage in a coil of the relay. Based on the sense voltage induced in the relay coil, the integrator sub-circuit may determine a load sense voltage that indicates a level of the current carried via the load conductor. In some implementations, a current indication module may provide an indicator signal based on the load sense voltage. In addition, the indicator signal may be provided to additional components or devices, such as a relay controller configured to activate the latch. In some implementations, the relay controller may be configured to open the latch based on the current level described by the indicator signal.

A load control device (e.g., a switching device) for controlling power delivered from an AC power source to an electrical device (e.g., a lighting load) may be configured to detect that a relay is stuck closed and attempt to fix the relay. The relay of the load control device may be adapted to be coupled between the source and the electrical device to control the power delivered to the electrical device so as to generate a switched-hot voltage. The load control device may comprise a detect circuit configured to generate a detect signal indicating a magnitude of the switched-hot voltage, and a control circuit configured to monitor the detect signal. The control circuit may be configured to determine that the relay is stuck closed in response to the detect signal, and to control the relay in order to attempt to fix the relay by repeatedly closing and opening the relay.

Various embodiments of the teachings herein include a sensor facility for determining a switching state of an electromechanical switching element. The sensor facility may include: connection elements for electrically contacting respective connection contacts of the switching element; a coupling capacitor having two capacitor connections, wherein the first is coupled to a first connection element; a voltage generator providing a temporally variable electrical voltage, coupled to the second capacitor connection; a first overvoltage protection circuit coupled to a second connection element and blocking an electrical voltage greater than a maximum value of the temporally variable electrical voltage of the voltage generator; and a detector circuit coupled to the first overvoltage protection circuit and detecting electrical voltage to determine the switching state of the electromechanical switching element by evaluating the detected electrical voltage.

The present disclosure relates to a power grid separating apparatus using a latch relay and a method thereof. An exemplary embodiment of the present disclosure provides a power net separating apparatus including: a switch configured to have a first end connected to a first power source and a second end connected to a second power source; a latch relay coil configured to control on and off of the switch; a first signal terminal connected to the first power source; a second signal terminal to which a connection signal for opening the switch is applied; a third signal terminal configured to serve as a power terminal of the latch relay coil; a fourth signal terminal to which a blocking signal for closing the switch is applied; and a fifth signal terminal connected to the second power source.

Systems and methods for contact erosion mitigation are provided. To perform contact erosion mitigation, an order of opening/closing poles and/or contact relays of particular poles is altered, resulting in a sharing of potential arcing conditions amongst the poles/contact relays of these poles.

A switching device includes: a header, a first magnet and a second magnet, a first magnetic sensing element and a second magnetic sensing element, a first inductor and a second inductor, a printed circuit board including an upper face on which are mounted upfront the first magnetic sensing element and the second magnetic sensing element and a lower face on which are mounted upfront the first inductor and the second inductor, a first microcontroller unit and a second microcontroller unit, wherein the first microcontroller unit and the second microcontroller unit are configured to send a stimulus signal respectively to the second conductor and to the first conductor, wherein the first microcontroller unit is configured to read a response produced by the first magnetic sensing element, the response corresponding to a magnetic field produced by the first inductor having received the stimulus signal sent by the second microcontroller unit, wherein the second microcontroller unit is configured to read a response produced by the second magnetic sensing element, the response corresponding to a magnetic field produced by the second inductor having received the stimulus signal sent by the first microcontroller unit, wherein the first microcontroller unit and the second microcontroller unit are configured to determine a state of the switching device based on the read responses.

An input circuit for reading in an analog input signal of a sensor comprises: first and second input ports connectable to the sensor; a first current-measuring signal converter connected to the first input port and comprising a current-measuring apparatus to determine a first output signal from the analog input signal; a current-limiting apparatus inside the first current-measuring signal converter for limiting a maximum current flowing through the first current-measuring signal converter; and a second current-measuring signal converter connected to the second input port and comprising a current-measuring apparatus to determine a second output signal from the analog input signal, wherein the first and second current-measuring signal converters are connected in series; and a testing apparatus for comparing the first and second output signals to detect faults of the first and second current-measuring signal converters in response to deviations between the first and second output signals exceeding a limit value.

A circuit for a circuit interrupter is provided. The circuit may in include a first SCR configured to receive a first trigger signal at a gate of the first SCR, a second SCR configured to receive a second trigger signal at a gate of the second SCR, and a third SCR configured to receive a third trigger signal at a gate of the third SCR. A cathode of the first SCR may be connected to an anode of the third SCR. A cathode of the second SCR and a cathode of the third SCR may be connected to a ground. Methods of operating a circuit interrupter and a circuit are also provided.

Electromechanical relay constructions comprise an external housing, a pair of switchable electrical contacts disposed within the housing, an element for activating the pair of electrical contacts, and a temperature sensing element disposed within the housing adjacent the electrical contracts. The temperature sensing element provides a signal for determining the temperature within the relay housing. The relay may comprise two or more temperature sensing elements disposed within the housing a desired distance from one another. The temperature sensing element may be attached to a member or substrate disposed within the housing, may be attached to an existing internal structure of the housing, or may be attached to one of the contacts. The temperature sensing element may be selected from the group consisting of resistance temperature detectors, negative temperature coefficient thermistors, thermopile sensors, thermocouples, and combinations thereof.

A battery unit includes a positive relay switch, a negative relay switch, a first resistor disposed in a third wiring portion extending between a positive external terminal and a negative external terminal, a second resistor serially connected to a portion on more negative side than the first resistor, a third resistor disposed in a second wiring portion and connected in parallel with the negative relay switch, a potential difference detection section capable of detecting a first potential difference which is a potential difference between the portion of the third wiring portion on more negative side than the first resistor and a negative terminal and a failure determination section for determining a failure of the positive relay switch and the negative relay switch respectively, based on the first potential difference.