A power contact fault clearing device includes a first pair of terminals adapted to be connected across a first set of switchable contacts, and a second pair of terminals adapted to be connected across a second set of switchable contacts. The second set of switchable contacts coupled to an arc suppressor. A current sensor is adapted to be connected between a power load and the second set of switchable contacts. The current sensor is configured to measure a power load current associated with the power load. A controller circuit is operatively coupled to the current sensor and the first and second pairs of terminals. The controller circuit is configured to detect a fault condition based at least on the power load current, and sequence deactivation of the first set of switchable contacts and the second set of switchable contacts based on the detected fault condition.

An electronic control device includes an input terminal connected to a second terminal of a switch via an electrically conductive lead, an input circuit connected to the input terminal via a signal line, and a microcontroller to detect whether the switch is in an electrically conducting state or an electrically non-conducting state based on an output signal from the input circuit, and to perform at least one process in accordance with a detected result. The input circuit includes a first resistor connected to a supply voltage or ground and to the signal line, and a transient current circuit connected to the supply voltage or ground and to the signal line, the transient current circuit including a second resistor that allows a transient current to flow through the switch when the switch transitions from the electrically non-conducting state to the electrically conducting state.

A power accumulation system includes a power accumulation device, a relay device provided in a pair of power lines disposed between the power accumulation device and a power conversion device that exchanges power with the power accumulation device, a capacitor provided between the pair of power lines between the relay device and the power conversion device and an electronic control device that controls the relay device. The electronic control device is configured to execute a predetermined foreign matter removal process when it is not possible to bring one of a first relay and a second relay from a power blocking state to a conductive state.

This disclosure describes techniques for increasing wetting current for an electromechanical switch. In one example application, an aircraft may include one or more valves used to control the temperature of aircraft interior. The valves may include one or more valve position switches to indicate certain valve positions, e.g. fully open, fully closed, fifty percent open, and so on. In some examples, the valve position switches may receive current at electromechanical contacts of the switch that is less than the wetting current. The techniques of this disclosure provide additional wetting current at the time the switch contacts close to improve reliability of the valve position switches. In some examples, an analog to digital converter circuit may be configured to provide the additional wetting current to the switch.

A system includes a dry contact with a first pair of switchable electrodes, a wet contact with a second pair of switchable electrodes, an arc suppressor, and a controller circuit operatively coupled to the arc suppressor and the first and second pairs of switchable electrodes. The controller circuit is configured to detect a failure of the wet contact and determine a stick duration associated with the first pair of switchable electrodes. The stick duration is based on a duration between an instance when a coil of the dry contact is deactivated and an instance of separation of the first pair of switchable electrodes during deactivation of the coil. The controller circuit generates, in-situ and in real-time, health assessment for the first pair of switchable electrodes based on a comparison of the determined stick duration with an average stick duration associated with a window of observation.

A system, a method, a device, and an apparatus include a control unit configured to determine contact resistance of one or more electrical contacts of one or more circuits, and remove, via a wetting current, residue on the one or more electrical contacts.

Device, circuit, system, and method for contact sequencing are discussed. An electrical circuit includes a first pair of terminals adapted to be connected across a first set of switchable contacts, and a second pair of terminals adapted to be connected across a second set of switchable contacts that are coupled to an arc suppression circuit. A controller circuit is coupled to the first and second pairs of terminals and is configured to sequence activation or deactivation of the first and second sets of contacts based on a contact control signal. A first power switching circuit is coupled to the first pair of terminals and the controller circuit. The first power switching circuit is configured to switch power from an external power source and to trigger the activation or the deactivation of the first set of switchable contacts based on a first logic state signal from the controller circuit.

A power contact health assessor system includes a pair of terminals adapted to be connected to a set of switchable contact electrodes of a power contact and a contact separation detector configured to determine a time of separation of the set of switchable contact electrodes during deactivation of the power contact. The system includes a controller circuit operatively coupled to the pair of terminals and the contact separation detector. The controller circuit is configured to determine within a first observation window, a plurality of contact stick durations and an average contact stick duration. One or more additional observation windows with corresponding average contact stick durations are configured. A health assessment for the set of switchable contact electrodes may be based on a subsequent contact stick duration for a contact cycle after the first observation window and the corresponding average contact stick durations for the one or more additional observation windows.

A power contact electrode plasma therapy circuit includes a pair of terminals adapted to be connected to a set of switchable contact electrodes of a power contact. A plasma ignition detector is configured to detect an electrical parameter over the switchable contact electrodes indicative of the formation of plasma between the switchable contact electrodes and output a plasma ignition signal based on the electrical parameter as detected. A plasma burn memory is configured to receive and store the plasma ignition signal. A controller circuit is configured to receive from the plasma burn memory the plasma ignition signal, start a time based on receipt of the plasma ignition signal, and upon the timer meeting a time requirement, output a plasma extinguish command. A plasma extinguishing circuit, configured to bypass the pair of terminals upon receiving the trigger signal to extinguish the plasma between the switchable contact electrodes.

A transmission device includes a pair of terminals connected to an electrical coupler via a pair of signal lines, a transmission unit connected to the pair of terminals via a pair of capacitor, and a DC power supply, a switch, and inductances, each connected in series between the pair of terminals without interposition of the pair of capacitors. A transmission device includes a pair of terminals connected to an electrical coupler via a pair of signal lines, a reception unit connected to the pair of terminals via a pair of capacitors, and a load resistor and inductances each connected in series between the pair of terminals without interposition of the pair of capacitors.