A power strip having two or more powers strips daisy chained together where each of the two or more power strips include a sequence control module operable to sequentially activate and/or deactivate the outlets, thereby powering up or powering down each outlet separately across the two or more power strips. A pre-determined time delay, that can be set by a user, occurs between the activation and/or deactivation of the outlets. The sequence control module of each power strip is operatively coupled to the sequence control module of the subsequent next power strip so that one power strip can be used to trigger activation of the next power strip.

A wireless checking system of a switch and operation unit that are provided in a vehicle includes: a switch disposed at a predetermined location in the vehicle; an operation unit wirelessly connected with the switch and disposed at a predetermined location in the vehicle to be operated by the switch; and a diagnosis equipment wirelessly connected with each of the switch and the operation unit and configured to wirelessly operate the switch and the operation unit, detect an operation state of the switch and the operation unit, and diagnose a wireless connection state of the switch and the operation unit.

A method for diagnosing an operating state, i.e., wear, of a contactor which includes a processing unit directing voltage control means; an, actuating coil; means for measuring an electric characteristic of the actuating coil; and a diode in parallel with the coil and the measuring means; the method including creating, for a specific contactor design, a plurality of variation curves of an electric characteristic of the coils of such contactors, over a drop-out period, by testing said contactors by sending a drop-out order fixing a drop-out voltage across the coil; after the drop-out order, repeatedly measuring the electric characteristic of the coil during a drop-out period; later sending a diagnostic drop-out order fixing the same drop-out voltage across the terminals of an actuating coil of a subject contactor being diagnosed; then measuring the same electric characteristic of the subject coil during a drop-out period; identifying a measured value of that characteristic of the subject coil, then comparing that measured value with the variation curves of the plurality of contactors of the same design, thereby diagnosing a state of wear of the subject contactor.

A battery safety device for a vehicle and a method of detecting failure thereof is installed between a high-voltage battery mounted on the vehicle and a power line. The device includes a first main relay connected to a positive terminal of the battery in series, and a second main relay connected to a negative terminal of the battery in series. A capacitor is connected in parallel to the first main relay and connected to the positive terminal of the battery.

Disclosed are a medium and high voltage grid-connected power generation system, a medium and high voltage grid-connected system, and a control circuitry thereof. The voltage of the medium and high voltage power grid is collected through the control circuitry. A power grid amplitude and a power grid phase synchronization signal are obtained, and then sent to an inverter unit through a communication line.

Disclosed are a medium and high voltage grid-connected power generation system, a medium and high voltage grid-connected system, and a control circuitry thereof. The voltage of the medium and high voltage power grid is collected through the control circuitry. A power grid amplitude and a power grid phase synchronization signal are obtained, and then sent to an inverter unit through a communication line.

Circuitry for controlling relay activation timing is described. The circuitry includes voltage zero cross detection circuitry configured to produce a zero cross detection signal indicating a zero cross time of an alternating current (AC) signal. The circuitry also includes current measuring circuitry coupled to voltage zero cross detection circuitry. The current measuring circuitry is configured to produce a current flow detection signal indicating a current flow start time of the AC signal. The circuitry further includes relay circuitry coupled to the current measuring circuitry. The circuitry additionally includes a processor coupled to the voltage zero cross detection circuitry, to the current measuring circuitry, and to the relay circuitry. The processor is configured to determine a relay time error based on the zero cross time and the current flow start time. The processor is also configured to control relay activation signal timing to reduce the relay time error.

A power circuit abnormality detection method for a power circuit detects whether an abnormality in a power source relay exists. The power circuit includes a pre-charge circuit opening and closing a connection between a direct current power source and a smoothing condenser by bypassing the power source relay to pre-charge the smoothing condenser, and a discharge circuit connected in parallel to the smoothing condenser to discharge electric charges stored in the smoothing condenser via a discharge resistance when a discharge switch is closed. The power circuit abnormality detection method includes a step of detecting whether the open contact abnormality in the power source relay exists based on whether a charge voltage of the smoothing condenser is reduced when a predetermined period of time has elapsed since both the discharge circuit and the power source relay are closed after the pre-charge circuit is opened.

A power circuit abnormality detection method for a power circuit detects whether an abnormality in a power source relay exists. The power circuit includes a pre-charge circuit opening and closing a connection between a direct current power source and a smoothing condenser by bypassing the power source relay to pre-charge the smoothing condenser, and a discharge circuit connected in parallel to the smoothing condenser to discharge electric charges stored in the smoothing condenser via a discharge resistance when a discharge switch is closed. The power circuit abnormality detection method includes a step of detecting whether the open contact abnormality in the power source relay exists based on whether a charge voltage of the smoothing condenser is reduced when a predetermined period of time has elapsed since both the discharge circuit and the power source relay are closed after the pre-charge circuit is opened.

An electronic circuit arrangement for use in an explosive area may include an electrical signal line, which connects an electrical input connector to an electrical output connector, and an electrical earth line, which can be or is electrically connected to the electrical signal line by at least one electrical earthing line. An inductive component and a semiconductor switch may be arranged in the at least one earthing line. The semiconductor switch may be switched between a closed state, in which the signal line is electrically connected via the at least one earthing line to the earth line, and an open state, in which this electrical connection is interrupted.