An abnormal operation of a movable contact is correctly detected. The abnormal operation of the movable contact (9) to the fixed contact (10) is detected based on at least one of a separation transient response signal of a coil current passed through the excitation coil (6) during the supply of a separation pulse signal and an attraction transient response signal of the coil current during the supply of an attraction pulse signal.

Power interface control device of a vehicle propulsion battery potential ports to carry out differential potential measurements, a current sensor to measure a current supplied by the propulsion battery and a closed container made of insulating material to which said ports and said sensor are associated, wherein said container comprises connection means to allow a mechanical coupling between the container and said electrical conductor.

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.

An electrical switch includes a fixed contact member and a plurality of movable contact fingers that pivot into and out of engagement with the fixed contact member. The electrical switch also includes a fixed magnetic member and a plurality of U-shaped magnetic members housing the plurality of movable contact fingers. Upon occurrence of a fault condition, each of the plurality of U-shaped magnetic members is magnetically pulled towards the fixed magnetic member, without contacting the fixed magnetic member, such that each of the plurality of movable contact fingers is held in engagement with the fixed contact member.

A control method for an HV contactor and a control unit for the implementation thereof in a battery storage device, preferably a battery storage device of an electric vehicle, wherein in the battery storage device, modules are interconnected via electromechanical components in the form of contactors, fuses, and busbars and are connected to a battery management system for controlling charging and discharging, wherein at least one respective contactor is provided for potential-free isolation at external electrical terminals. The control unit uses HV contactors installed bidirectionally in a positive and negative path of the high-voltage battery storage device to trigger an opening actuation of an HV contactor in order to interrupt a current flow only in a preferred direction of the respective contactor.

In the present invention, the connection between an external power supply and a unit for detecting welding of a relay is disestablished at least when a short circuit is detected, thereby preventing the short circuit from being falsely detected in the event that the short circuit and the welding of the relay can both be detected. A device for detecting welding of a relay detects welding of a relay provided to a path via which a cell is charged by an external power supply. Welding of a power-supply-side relay or a ground-side relay is detected on the basis of a current flowing disproportionately more toward the external power supply than the power-supply-side relay or ground-side relay when a control unit has deactivated the power-supply-side relay or ground-side relay during an interrupting in charging. A disconnecting switch establishes or disestablishes the connection between the external power supply and a weld-detection switch.

In the present invention, the connection between an external power supply and a unit for detecting welding of a relay is disestablished at least when a short circuit is detected, thereby preventing the short circuit from being falsely detected in the event that the short circuit and the welding of the relay can both be detected. A device for detecting welding of a relay detects welding of a relay provided to a path via which a cell is charged by an external power supply. Welding of a power-supply-side relay or a ground-side relay is detected on the basis of a current flowing disproportionately more toward the external power supply than the power-supply-side relay or ground-side relay when a control unit has deactivated the power-supply-side relay or ground-side relay during an interrupting in charging. A disconnecting switch establishes or disestablishes the connection between the external power supply and a weld-detection switch.

In the present invention, the connection between an external power supply and a unit for detecting welding of a relay is disestablished at least when a short circuit is detected, thereby preventing the short circuit from being falsely detected in the event that the short circuit and the welding of the relay can both be detected. A device for detecting welding of a relay detects welding of a relay provided to a path via which a cell is charged by an external power supply. Welding of a power-supply-side relay or a ground-side relay is detected on the basis of a current flowing disproportionately more toward the external power supply than the power-supply-side relay or ground-side relay when a control unit has deactivated the power-supply-side relay or ground-side relay during an interrupting in charging. A disconnecting switch establishes or disestablishes the connection between the external power supply and a weld-detection switch.

The reliability of testing a normally closed contact in a relay unit may involve the following. While the load is de-energized, sending a test signal to a normally closed contact (b1, b2) and detecting the state of the returning test signal sent. Resending a test signal when a detection result does not satisfy a predetermined criteria, and re-detecting the state of the returning test signal resent. The state of the returning test signal resent may be assessed as normal when the re-detection result satisfies the predetermined criteria.

In the present invention, the connection between an external power supply and a unit for detecting welding of a relay is disestablished at least when a short circuit is detected, thereby preventing the short circuit from being falsely detected in the event that the short circuit and the welding of the relay can both be detected. A device for detecting welding of a relay detects welding of a relay provided to a path via which a cell is charged by an external power supply. Welding of a power-supply-side relay or a ground-side relay is detected on the basis of a current flowing disproportionately more toward the external power supply than the power-supply-side relay or ground-side relay when a control unit has deactivated the power-supply-side relay or ground-side relay during an interrupting in charging. A disconnecting switch establishes or disestablishes the connection between the external power supply and a weld-detection switch.