Methods and systems for suppressing arc formation in branch breakers provide a load center that can monitor a branch breaker for indications of arc formation. The load center may include a main breaker that can immediately cut current to the upon receiving an indication of an arc forming in the branch breaker. The indication may be provided by a sensor circuit that sends a trigger signal to the main breaker when arc formation is detected within the branch breaker. The main breaker checks that the trigger signal indicates arc formation, then cuts current to suppress the arc. The main breaker then waits a short period for the branch breaker to clear before restoring current. The wait period is sufficiently short such that devices receiving power from the load center are not adversely affected. To improve cutoff and restoration response times, the main breaker employs a solid-state trip switch.

A power supply controller works to control electrical power supplied to a surroundings monitor including an in-vehicle camera and an image processor which monitors surroundings of a vehicle using an output from the in-vehicle camera. The power supply controller includes a voltage monitor which determines whether an operating voltage for the image processor lies in a normal voltage range and an abnormal voltage range. Until a given threshold changing condition is met after start of power supply to the surroundings monitor, the voltage monitor alters at least one of an upper limit threshold and a lower limit threshold of the normal voltage range to decrease a difference between the upper and lower limit thresholds to be lower than that after the given threshold changing condition is satisfied. This ensures the stability in supplying electrical power to the surroundings monitor without restricting an operation of the surroundings monitor more than required.

A power supply controller works to control electrical power supplied to a surroundings monitor including an in-vehicle camera and an image processor which monitors surroundings of a vehicle using an output from the in-vehicle camera. The power supply controller includes a voltage monitor which determines whether an operating voltage for the image processor lies in a normal voltage range and an abnormal voltage range. Until a given threshold changing condition is met after start of power supply to the surroundings monitor, the voltage monitor alters at least one of an upper limit threshold and a lower limit threshold of the normal voltage range to decrease a difference between the upper and lower limit thresholds to be lower than that after the given threshold changing condition is satisfied. This ensures the stability in supplying electrical power to the surroundings monitor without restricting an operation of the surroundings monitor more than required.

A DC circuit switching apparatus having a novel structure is disclosed that can reduce the number of electromagnetic contactors with a simple structure, and can realize a compact and low-cost apparatus. A DC circuit switching apparatus to be connected between a battery and a load that includes a power supply line that connects between the battery and the load, wherein the power supply line includes a positive electrode-side power supply line and a negative electrode-side power supply line, a main relay is connected to one of the positive electrode-side power supply line and the negative electrode-side power supply line, and an active fuse is connected to the other of the positive electrode-side power supply line and the negative electrode-side power supply line.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

A superconducting magnet comprising: a field coil comprising high temperature superconducting material and having a joint; a bypass resistance comprising a non-superconducting conductive material, wherein the bypass resistance is electrically connected to the field coil on both sides of the joint; wherein the joint is openable to break the field coil such that current flowing in the superconductor flows though the bypass resistance in order to dump energy from the field coil, and wherein the superconducting magnet is configured to open the joint in response to detection of a quench in the magnet.

An electronic control device includes: a microcomputer; a wake-up circuit; and a relay switch self-retaining a power relay, and the wake-up circuit operates the relay switch in response to a wake-up signal from an OTA electronic control device, and starts power supply to the microcomputer to cause starting-up. During shutdown processing for the microcomputer, the microcomputer outputs a stop command to the relay switch before outputting a stop command to the wake-up circuit, whereby an output terminal (INH terminal) of the wake-up circuit is diagnosed for fixation based on an output signal from the wake-up circuit.

A method, apparatus, and system for disconnecting loads from the electrical grid based on a power line frequency are disclosed. An electricity meter may monitor a power line frequency of a source power line connected to the electricity meter, and in response to determining that the power line frequency is lower than a disconnect threshold frequency, may open an internal switch and disconnect a load side output of the electricity meter from the source power line.

A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.