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 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.

An electronic device (10) includes: a power supply (11); a first switch (12) that is connected at least to one pole of the power supply (11) and interrupts power supplied from the power supply (11) to a load (13); a second switch (14) that is positioned on a load (13) side with reference to the first switch (12) and interrupts power supplied from the power supply (11) to the load (13); a first power line (L11) that is connected to one end portion of an electric contact of the second switch (14), the one end portion being located on a first-switch (12) side; a second power line (L12) that is connected to another end portion of the electric contact of the second switch (14); a third power line (L13) that is connected to another pole of the power supply (11); and an electric element (resistor 15) that is connected between the first and second power lines (L11, L12) in parallel to the electric contact or connected between the first and third power lines (L11, L13), such that the electric contact of the second switch (14) is not charged when the first and second switches (12, 14) interrupt power.

An electronic device (10) includes: a power supply (11); a first switch (12) that is connected at least to one pole of the power supply (11) and interrupts power supplied from the power supply (11) to a load (13); a second switch (14) that is positioned on a load (13) side with reference to the first switch (12) and interrupts power supplied from the power supply (11) to the load (13); a first power line (L11) that is connected to one end portion of an electric contact of the second switch (14), the one end portion being located on a first-switch (12) side; a second power line (L12) that is connected to another end portion of the electric contact of the second switch (14); a third power line (L13) that is connected to another pole of the power supply (11); and an electric element (resistor 15) that is connected between the first and second power lines (L11, L12) in parallel to the electric contact or connected between the first and third power lines (L11, L13), such that the electric contact of the second switch (14) is not charged when the first and second switches (12, 14) interrupt power.

A switch includes: a housing having a box shape; a plunger movable in a first direction intersecting an opening surface; and a movable piece arranged inside the housing and is elastically deformable in a second direction intersecting the first direction. The plunger has a touching portion which is arranged so as to face the movable piece in the second direction inside the housing and to be able to elastically deform the movable piece in the second direction by touching the movable piece, and further, a lubricant retaining portion that can retain a lubricant is provided in at least one of the touching portion of the plunger and a touched portion of the movable piece.

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 circuit for controlling an input current, the circuit includes a first input port configured to receive the input current. A current detector detects an input current value of the input current and generates a control signal indicative of the input current value. A first output port outputs an output current to a load. A second output port receives the output current from the load. A control circuit provides a low-impedance path in parallel with the load in response to the control signal indicating the input current value is below a threshold value.

Provided is a lubricant for a gas insulated switchgear, with which properties of a base oil such as heat resistance, evaporation loss, fluidity under a low temperature, and chemical stability (oxidation resistance and HF resistance) are balanced at a level higher than the conventional level, and long service life and high reliability of the gas insulated switchgear are achieved. A lubricant for a gas insulated switchgear according to the present invention, contains: a base oil containing a polyalphaolefin having a kinematic viscosity at 40° C. of 50 mm.sup.2/s or more; and a thickener containing bisamides.

A contact wetting circuit 100 is disclosed for supplying wetting current to sense the state of dry contacts of a switch SW1 setting for an electronic device 10. The contact wetting circuit includes an RC circuit 110 having a resistor R1 and a capacitor C1, and a controller 120 connected to a power supply 130 of the device. The controller supplies a first voltage to the RC circuit to produce a charging current having an average current and/or a peak current below the wetting current parameter of the dry contacts. The charging current is used to charge the capacitor C1 during the first time period. The controller stops the supply of the first voltage to the RC circuit after sufficient charging to allow the charged capacitor C1 to supply a second voltage, across the switch SW1, to produce a wetting current. Thereafter, the controller polls and senses the state of the switch SW1, and performs certain operations accordingly.

A circuit includes an evaluation node through which current flows from a voltage source node to a sensed switch when the sensed switch is closed. First and second control switches are disposed between the voltage source node and the evaluation node to switch between first and second current paths for the current. The current passes through the first control switch when flowing along the first current path. The second control switch is coupled to a control terminal of the first control switch to deactivate the first control switch and allow the current to flow through the second current path. Multiple passive circuit elements are configured to establish first and second current levels for the current. The passive circuit elements are disposed between the voltage source node and the evaluation node in a circuit arrangement in which no current path to ground is present when the sensed switch is open.