Abstract: An electromagnetic actuation system includes an electrical coil, a magnetic core, an armature, a controllable bi-directional drive circuit for selectively driving current through the coil in either of two directions, and a control module providing an actuator command to the drive circuit. Current is driven though the electrical coil in a first direction when an actuation is desired. When the actuation is not desired current is driven through the electrical coil including in a second direction sufficient to reduce residual flux within the actuator below a level passively attained within the actuator at zero coil current.

Abstract: An electromagnetic relay is provided. The electromagnetic relay includes a first port and a second port, a first coil and a second coil, a movable armature coupled between the first port and the second port constructed to connect and disconnect the first port and the second port, a switch circuit, and a coil control circuit. The switch circuit is constructed to connect the first coil to an external power source to induce the first coil to create a first magnetic field having a first direction and disconnect the first coil from the external power source to cause the first magnetic field to collapse. The coil control circuit is constructed to induce the second coil to create a second magnetic field having a second direction responsive to the switch circuit being in the second state, the second direction being opposite the first direction.

Abstract: The present disclosure provides a control device for solid state lighting fixtures. The control device is programmable and is configured to adjust the intensity of light emitted by solid state lighting fixtures. The control device includes a housing assembly and a programmable controller.

Abstract: A safety switching apparatus for switching on or off a technical installation has a failsafe control/evaluation unit with an input for receiving an input signal. The failsafe control/evaluation unit is designed to process the input signal in order to produce an output signal for switching on or off the technical installation at a defined output signal time. The failsafe control/evaluation unit has a first output for transmitting the output signal to an electromechanical switch. The electromechanical switch has an operating contact for switching a load circuit of the technical installation and has a positively guided auxiliary contact in an auxiliary contact current path. The auxiliary contact can be used to carry a current for checking the switching position of the operating contact. A switching element is arranged in the auxiliary contact current path.

Abstract: Electrical power supply device for wireless sensor unit provided with a circuit for managing very low consumption electrical energy configured to limit the given level of electrical power between a lower limit and an upper limit, with the circuit being implemented with a JFET or MOSFET depletion transistor.

Abstract: A method and apparatuses for handling delayed zero crossing in fault current through a circuit breaker are disclosed. An interface arrangement is configured to couple an alternating current, AC, power system with a direct current, DC, power system, or vice versa. The interface arrangement includes at least one converter for conversion of AC power to DC power, or vice versa, which includes a DC side for coupling of the converter to the DC power system and an AC side for coupling of the converter to the AC power system. A circuit breaker is arranged in a current path between the AC side of the at least one converter and the AC power system. There may be a risk of delayed zero crossing in fault current occurring in case a fault occurs in a predefined portion of the interface arrangement.

Abstract: An electromagnetic actuation system includes an actuator having an electrical coil, a magnetic core, and an armature. The system further includes a controllable bi-directional drive circuit for selectively driving current through the electrical coil in either of two directions. The control module provides an actuator command to the drive circuit effective to drive current through the electrical coil in a first direction to actuate the armature and in a second direction subsequent to armature actuation to oppose residual flux within the actuator. The control module includes a residual flux feedback control module configured to adapt the actuator command to converge residual flux within the actuator to a preferred flux level.

Abstract: An electromagnetic actuation system includes an actuator having an electrical coil, a magnetic core, and an armature. The system further includes a controllable bi-directional drive circuit for selectively driving current through the electrical coil in either of two directions. The control module provides an actuator command to the drive circuit effective to drive current through the electrical coil in a first direction to actuate the armature and in a second direction subsequent to armature actuation to oppose residual flux within the actuator. The control module includes a feed forward control module configured to adapt the actuator command to converge residual flux within the actuator to a preferred flux level.

Abstract: An assembly including an insulated gate bipolar transistor (IGBT) is provided. The IGBT is coupled with a gate driver for receiving a gating signal to drive the IGBT and providing a feedback signal of the IGBT which indicates a change of a collector-emitter voltage of the IGBT. The assembly further includes a failure mode detection unit for determining whether the IGBT is faulted based on a timing sequence of the gating signal and feedback signal. The failure mode detection unit is capable of differentiating fault types including a gate driver fault, a failed turn-on fault, a short-circuit fault, a turn-on over-voltage fault and a turn-off over-voltage fault. Accordingly, an IGBT failure mode detection method is also provided.

Abstract: Provided is an optional unit configured to be connected, in series, to a power supply apparatus for supplying drive electricity, the optional unit including: a receiving unit which receives the electricity supplied from the power supply apparatus or an optional unit in a higher connection level; a supply unit which supplies the electricity to a receiving unit of an optional unit in a lower connection level; and an operation unit which operates based on the electricity received by the receiving unit. In accordance with a voltage of the supplied electricity, based on which the operation unit of the optional unit in the higher level operates, exceeding a predetermined threshold value, the operation unit of the optional unit in the lower level below the optional unit in the higher level starts to receive the supplied electricity.

Abstract: A method, apparatus, media and signals for generating a computer representation of a three-dimensional swept envelope of a vehicle having a wheeled chassis operable to support a vehicle body for movement along a terrain is disclosed. The method involves receiving terrain data representing a 3D terrain, receiving data defining parameters of the vehicle, and receiving data defining a path for movement of the vehicle from an initial position on the terrain to a displaced position on the terrain. The method also involves disposing a computer representation of the vehicle on the 3D representation of the terrain at successive locations along the path using the parameters. Disposing involves determining points of engagement between wheels of the wheeled chassis and the 3D representation of the terrain to dispose the chassis with respect to the terrain, and determining a corresponding 3D location of the vehicle body with respect to the terrain.

Abstract: There is a method of fault clearance for a voltage source converter that interconnects a DC network and an AC network. The voltage source converter is connected to the DC network via one or more DC circuit interruption devices. The method comprises the steps of: (a) detecting a fault in the DC network; (b) carrying out a primary protection sequence, wherein the step of carrying out the primary protection sequence involves carrying out a first sub-sequence that includes the steps of: i. opening the or each DC circuit interruption device, ii. setting a DC power order of the voltage source converter to zero, iii. controlling the voltage source converter to exchange re-circuit breaker active power with the AC network.

Abstract: A relay (1) includes a motor (20) and a primary electrical switch assembly (132). Primary electrical switching attachment points (113) are switched by a moveable switching link (101) which is moved in and out of the switch on an switched off position axially by the motor (20) in response to electrical signals delivered to the coil (26) via the flexible leads (32, 33). The switching link (101) includes a mercury reservoir (119). A piezoelectric disk bender (105) displaces mercury to close the gaps between the attachment points (113).

Abstract: A method is disclosed for controlling a valve having a spring with a spring force, an actuator with an actuator force opposing the spring force, and a pin that is actuated by the actuator, a seal element that can be coupled with the pin, and a seal seat, the valve being closed when the seal element sits against the seal seat. The method includes determining an expected natural opening time when the seal element is lifted off the seal seat based on a pressure difference in front and behind the valve, impressing a specified current on the actuator at a point in time within a specified interval prior to the natural opening time, the seal element sitting against the seal seat at the point in time such that the pin contacts the seal element and the actuator force matches the spring force, which is reduced by a specified value.

Abstract: A hand held hub sterilization and data acquisition device includes a housing having an opening for receiving a medical device, a sterilization chamber formed in the housing, a source of UV radiation disposed within the sterilization chamber for uniform emission of UV-C radiation into the sterilization chamber, and a safety interlock mechanism. The safety interlock mechanism comprises a Hall sensor and a rare earth magnet, and wherein the Hall sensor senses the magnetic field of the magnet when the access door is closed and sends a signal to the user interface indicating a ready state for excitation of the radiation source.

Abstract: The present disclosure describes techniques and apparatuses for a customizable lighting controller. In some aspects a lighting controller is described that includes a display device to display selectable lighting functions, switches that each correspond to one of the selectable lighting functions, and a lighting controller manager to receive an input of a selectable lighting function at one of the switches of the lighting controller. The lighting controller manager can then initiate a display of the selected lighting level on the display device of the lighting controller. The lighting controller manager can also control a dimming module to set the selected lighting level.

Abstract: An electronic bridge system includes a first interface to couple to an electrical or electro-mechanical installation to receive system information from the installation, and a second interface to couple to a second component of the installation, wherein the second component is to be bypassed or interrupted by the bridge system. Further, the system includes a bridge circuit coupled to the second interface and having a control port, and a safety circuit coupled to the first interface and having an output coupled to the control port. The bridge circuit is configured to cause bypassing or interrupting the second component upon activation, and the safety circuit is configured to output one of an enable signal and a disable signal as a function of the system information, wherein the enable signal activates the bridge circuit.

Abstract: A relay driving device includes first and second power supply modules, a switching circuit, and a control module. The first power supply module outputs a first voltage that has a magnitude sufficient to activate the relay. The second power supply module outputs a second voltage that has a magnitude sufficient to maintain an activated state of the relay. The control module is configured to control the switching circuit to connect the relay to the first power supply module so as to provide the first voltage to the relay for activating the relay, and to subsequently connect the relay to the second power supply module so as to provide the second voltage to the relay for maintaining the activated state of the relay.

Abstract: An electrical power system including a first power entry unit, at least one receptacle, and a second power entry unit. The at least one receptacle is electrically connected to the first power entry unit. The second power entry unit is electrically connectable to the at least one receptacle. The first power entry unit and the second power entry unit include at least one detection device. Either the first power entry unit or the second power entry unit is a selected power entry unit and the remaining one is another power entry unit. The detection device is configured to preclude an electrical power connection of both the selected power entry unit and the other power entry unit to the at least one receptacle.

Abstract: A lighting dimmer for surface mount or in-wall mount comprising: a lighting dimmer main body, the main body comprising: a lighting control board positioned in the main body for controlling one or more light emitting diode based light sources; a surface mount attachment connected to the main body for facilitating surface mount connection of the lighting dimmer; a controller connected to the lighting control board and configured to input a command to the lighting control board, and; a surface portion configured to receive an insert for in-wall mounting of the lighting dimmer.

Abstract: A contactor unit includes an input lead connectable to a first lead of an energy output device, an output lead connectable to a first lead of a voltage bus, a contactor that connects and disconnects the input lead from the output lead, a driver configured to operate the contactor, a serial data link connectable to a system controller that is external to the contactor unit, and an integrated circuit (IC) positioned within the contactor unit and configured to output a control command to the driver to open the contactor based on at least one of a current in either the input lead or the output lead and a voltage differential across the contactor, and output a contactor control status via the serial data link.

Abstract: The present invention relates to a height adjustable piece of furniture comprising at least one extendable column, an electric motor adapted for driving the extendable column, at least one switch for operation control of the electric motor, and a power control unit adapted to control the power distribution to the height adjustable piece of furniture, and wherein the power control unit is connected to a power source. The connection between the power source and the height adjustable piece of furniture is provided via the switch, and the switch is in an activated state adapted to connect the power source to the height adjustable piece of furniture, and in a deactivated state adapted to disconnect the power source from the height adjustable piece of furniture. The present invention further relates to a power control unit for control of power distribution to a height adjustable piece of furniture.

Abstract: An example system for determining the actuation duration of a relay can include a relay, a current-sensing device, and a controller. The relay can have an actuation coil, and armature, and a first and second contact. The current-sensing device can measure a current through the actuation coil. The controller can actuate the relay. The controller can also receive from the current-sensing device a plurality of measurement values for the current through the actuation coil. The controller can determine an actuation duration based on a local minimum value for the plurality of measurement values. The actuation duration can correspond to a duration of a movement of an armature of the relay from the first contact of the relay to the second contact of the relay. An actuation delay of the relay can be calculated based on the zero-crossing time of an input voltage value and the actuation duration.

Abstract: The invention provides an electricity distribution system, which can keep a voltage to ground low, and can commonly detect abnormity, such as an electrical leak etc. produced in AC and DC feed lines. An AC-DC converter 21 is installed between the AC feed line (branch electrical circuit Lb) of a single phase three wire system for supplying the power to AC devices 41, and the DC feed line (main electrical circuit Ld) of a three wire system for supplying the power to DC devices. The DC feed line comprises a neutral wire N commonly connected to a neutral wire N of the AC feed line within the AC-DC converter 21, a positive voltage wire L+ having a positive electrical potential to an electrical potential of its neutral wire N, and a negative voltage wire L? having a negative electrical potential to the electrical potential of its neutral wire N. A voltage of +150 [V] is applied to the positive voltage wire L+, and a voltage of ?150 [V] is applied to the negative voltage wire L?.

Abstract: Method and apparatus for a mechanical latching of at least one pole of a relay selected from SPST, SPDT, DPDT, reversing DPDT, multi pole MPST and MPDT including the integration of one of a single and plurality of hybrid SPDT or DPDT switches with one of SPDT and DPDT mechanically latching relay using conductive structured contactors to connect the poles of the relay and the switch including PCB assembly, for operating electrical loads via the switch manual key and remotely by powering the relay coil by a power pulse, including a CPU program for providing any of the manual keys of each SPDT or DPDT connected in a traveler lines to the integrated switch-relay to switch on-off group of loads and all the loads of home automation network or grid via optical cable, RF, IR in line of sight and bus line.

Abstract: A configurable, connectorized method and apparatus for driving a solenoid coil reduces energy consumption and heating of the solenoid coil, allows detection of the solenoid state, and simplifies connections to the solenoid.

Abstract: A battery module may include a housing, a plurality of battery cells disposed in the housing, a battery terminal extending from the battery module for coupling the battery module with electrical components in the vehicle, and a contactor. A voltage supplied to a relay coil in the contactor may generate a magnetic field to actuate a contactor switch. The battery module may also include a printed circuit board (PCB) disposed in the housing. The PCB may include a relay control circuit configured to control a current flowing across the relay coil, and the relay control circuit may operate in a pull-in mode to transition the contactor switch into a closed position and in a hold mode to maintain the contactor switch in the closed position.

Abstract: A switching device comprising control means for controlling the switching operations of the device, the control means receiving the sensing signals generated by a sensor means; the control means are arranged so that, during execution of a switching operation, the control means send a first control signal to a power supply means to start with the supply of excitation current from a first instant onwards; determine, on the base of the information provided by the sensing signals, a second instant, at which the power supply means have to stop with the supply of excitation current, the second instant occurring before the movable plunger has reached the stop position during the movement from the start position towards the stop position; send a second control signal to the power supply means to stop with supply of excitation current from the second instant and until a movable plunger reaches the stop position.

Abstract: A normal relay emulator is described. The normal relay emulator may include a trigger circuit configured to detect a condition on a first power rail, the first power rail having a first voltage supply level. A boost converter electrically coupled to the first power rail and configured to boost the first voltage supply level to a second, higher, voltage supply level is provided. A bi-stable relay having a first terminal and a second terminal and an actuator electrically coupled to the boost converter and communicatively coupled to the trigger circuit is also provided. The actuator may be configured to energize the bi-stable relay using the second voltage supply level such that electrical contact between the first terminal and the second terminal changes between a first state and a second state based on the trigger circuit detecting the condition.

Abstract: An electrical relay (2) includes an electromagnetic drive system for providing bi-directional drive. The electrical relay (2) includes a first a coil (212) and a second coil (213). A current is supplied to the coils (212) and (213) in opposite directions. The two coils (212) and (213) can be used to accelerate the armature in either direction in relation to the two contacts. This can be used to drive the armature to either one of the contacts and to accelerate and decelerate the armature during a single transit. In the latter regard, the armature can be accelerated and decelerated to shorten the transit time, reduce bounce, reduce wear on the contacts, and allow for different contact material options.

Abstract: The electrical contactor (100) according to the invention comprises at least one first switch (104) that includes a first moving contact (112) and several second switches (106) that include a second moving contact (116). The contactor further comprises at least one control device for controlling the movement of the or each first (112), second (116) moving contact, respectively. The control device is capable of controlling the movement of the or each first moving contact (112) into the open position before that of each second moving contact (116) into the open position, and when the or each first moving contact (112) is in the closed position, the second switches (106) are connected in parallel, whereas when the or each first moving contact (112) is in the open position, the second switches (106) are connected in series.

Abstract: The restraining strap has a rectangular cross section with a broad side against cylindrical sections holding a release member. The moment of inertia for a rectangular cross section strap is represented by the formula I=BH3/12. The lower moment of inertia reduces the load on the fusible link. With no limit to the number of wraps around the cylindrical sections, higher preloads can be accommodated by increasing the number of wraps of the restraining strap without affecting the moment of inertia or the amount of force borne by the fusible link. The actuator has a catch extending between the restrainer and actuator. The catch ends engage the restrainer and actuator and, upon release from the actuator, the catch rotates to allow the restrainer to unwind from about the cylindrical sections.

Abstract: A driver circuit and a diagnostic method are provided. The driver circuit includes a first voltage driver, a second voltage driver, and a microprocessor. The microprocessor generates a first pulse width modulated signal to induce the first voltage driver to output a second pulse width modulated signal to energize a contactor coil. The microprocessor sets a first diagnostic flag equal to a first value if a first filtered voltage value is greater than a first threshold value. The microprocessor sets a second diagnostic flag equal to a second value if a second filtered voltage value is greater than a second threshold value. The microprocessor stops generating the first pulse width modulated signal to de-energize the contactor coil if the first and second diagnostic flags are set equal to the first and second values, respectively.

Abstract: The power supply control device in accordance with the present invention includes: a power reception terminal for receiving power; a power supply terminal for supplying power; a relay configured to make and break an electrical connection between the power reception terminal and the power supply terminal; a control circuit configured to control the relay; a power supply circuit configured to supply power to the control circuit by use of power received via the power reception terminal; and a printed wiring board. The control circuit and the power supply circuit are mounted on the printed wiring board.

Abstract: There is provided a power supply circuit, in which cost reduction is realized by reducing the number of electric wires. An inverter 3 and a motor 4 are supplied with power by a high-voltage battery 21. Relays 22a to 22c are provided between the high-voltage battery 21 and the inverter 3. Both ends of each of relay coils C provided to the relays 22a to 22c are connected to an ECU 5, and the ECU 5 controls a current flowing through the relay coils C and thereby controls the turning on and off of the relays 22a to 22c. A service plug 6 is detachably provided between batteries making up the high-voltage battery 21, and when the service plug 6 is detached, the supply of power from the high-voltage battery 21 to the inverter 3 and the motor 4 is blocked and when the service plug 6 is attached, the supply of power from the high-voltage battery 21 to the inverter 3 and the motor 4 is enabled.

Abstract: A method and apparatus using electromagnetic switching in a two-step connection process is provided to minimize surge currents and torque oscillations in three-phase motors during starts.

Abstract: A load control device for controlling an amount of power delivered from an alternating current (AC) power source to an electrical load includes a relay operable to be coupled in series electrical connection between the AC power source and the electrical load. The relay has one or more relay contacts. The load control device includes a zero-cross detector operable to detect zero crosses of the alternating current and to generate zero cross signals, and a controller operatively coupled to a control input of the relay and the zero-cross detector for rendering the controllably conductive device conductive and non-conductive. The controller determines a relay actuation adjustment such that the contact reliably completes bouncing just prior to a zero cross and may initiate an actuation of the relay based on the actuation adjustment and the zero cross signal.

Abstract: A method for controlling a normally closed relay includes: providing power to at least one of a first electromagnet and a second electromagnet via a power input port, then cause a first actuation member and a second actuation member to separate from each other, and the relay is then in an open state; and stopping providing power to the at lease one first electromagnet and the second electromagnet which being powered by the power input port such that the first actuation member and the second actuation member makes contact with each other, and the relay is then in a closed state.

Abstract: This invention provides an electromechanical transfer switch having a transfer time sufficiently fast, less than 20 milliseconds, as to allow computer based equipment to ride through a power interruption without shutdown. The transfer switch utilizes relatively slow acting, high amperage, electromechanical power relays that have been modified by replacing the relay armature spring with a higher tension substitute and applying overdrive voltage to the relays.

Abstract: An exemplary coil actuator for an associated switching device which can be actuated during its operation from an open position to a closed position to allow a current to flow therethrough and from the closed position to the open position to interrupt such flowing from flowing therethrough. The coil actuator includes a coil electromagnet arranged to move between a rest position and an actuating position, wherein movement from the rest position to the actuating position is suitable to cause the actuation of the switching device; and an electronic component arranged to count an operation time which is indicative of the duration of the actuation of the switching device.

Abstract: A driver circuit and a diagnostic method are provided. The circuit includes a first voltage driver having a first output line electrically coupled to a main contactor coil of a main contactor. The circuit further includes a microprocessor that measures a first voltage on a first voltage feedback line if the main contactor coil is not energized. The microprocessor measures a second voltage on a second voltage feedback line if the main contactor coil is not energized. The microprocessor sets a status flag equal to a fault condition value if the first voltage is greater than a threshold voltage value. Also, the microprocessor sets the status flag equal to the fault condition value if the second voltage is greater than the threshold voltage value.

Abstract: Disclosed herein is an electro-magnetic contactor and an electro-magnetic contactor monitoring system. The present disclosure may sense and display the status of input power that supplies electric energy to a power input end of the electro-magnetic contactor in real time, and when a failure occurs to generate a low voltage or over voltage, it may be sensed in real time to notify it to a user or the like, thereby allowing the user to monitor the status from a remote location. According to the present disclosure, it may be possible to prevent a load from being damaged by a fire due to a phenomenon of chattering in the electro-magnetic contactor, and eradicating a phenomenon that a coil of the contactor is damaged by a fire due to the over voltage, and minimizing losses that can be caused in a factory management system.

Abstract: The invention relates to a relay controller for controlling an excitation current of a relay, wherein the relay controller is designed, upon the energization of the relay by means of a switch, to control the excitation current through the excitation winding of the relay in such a way that through the excitation winding there flows firstly a pull-in current and, after a pull-in time has elapsed, through the excitation winding there flows a holding current that is lower than the pull-in current, and wherein the relay controller is designed, upon the switching-off of the relay by means of the switch, to feed a commutation current that flows through the excitation winding to the commutation device through the first terminal and through the second terminal of the relay controller.

Abstract: A system for controlling a relay to reduce acoustic noise of connections and disconnections being made within the relay. An impact of closing and opening contacts in a relay may cause the acoustic noise. For instance, when a relay coil causes the contacts to come together for a connection, an acoustic noise may occur. When the relay coil causes the contacts to separate for breaking a connection, another acoustic noise may occur. Reduction of acoustic noise may be realized by controlling movement of the contacts. The present system may control current to the relay coil to slow the movement of contacts while closing and opening to reduce the acoustic noise.

Abstract: Exemplary embodiments of the present invention relate to a charging and discharging apparatus of a DC link capacitor in an electric power steering relay, in which the DC link capacitor turning-on the electric, power steering relay includes at least two switching elements charged or discharged by a collector current so as not to relay on an internal temperature, facilitates a circuit design, and meets an electronic control system which applies time constants in a lump using software, and a method thereof.

Abstract: An adjustment device for a hydrostatic expeller unit includes an electrically actuable adjustment unit and a replaceable ballast unit. The ballast unit has at least one measuring transducer which converts a manipulated variable for the adjustment device into an electrical control signal for the adjustment unit and transmits it to the electrically actuable adjustment unit.

Abstract: A switchgear operating apparatus provided with an electronic switching device (7) connected to a negative electrode side of a DC power supply and a plurality of operating coils (4) which are simultaneously energized and controlled by the electronic switching device (7) for performing on/off operations of a three-phase switchgear includes diodes (6a, 6b, 6c) connected between the individual operating coils (4) and the electronic switching device (7), and a voltage detector (9) for detecting potential differences applied to the individual diodes (6a, 6b, 6c) and the electronic switching device (7).

Abstract: An electric storage apparatus includes an output terminal configured to be electrically connected to a system including an engine, an electric storage device, a monitoring apparatus including a detector and a controller, and a relay disposed between the output terminal and the electric storage device. The detector is configured to detect a variation value corresponding to an amount of charge of the electric storage device. The controller is configured to determine whether the variation value is equal to or lower than an opening threshold, and execute an opening process to switch the relay from a closed state to an open state if the variation value is equal to or lower than the opening threshold. The opening threshold is larger than an engine activation low-threshold by a predetermined value. The engine activation low-threshold is a lowest level of the amount of charge at which the engine is able to be started.

Abstract: A method and system for diagnostic coverage of safety components monitors the state of a safety chain and each of the safety devices in the chain. A fault condition is detected if one of the safety devices indicates that the safety chain should be open but the safety chain indicates that it is closed. In order to prevent an inadvertent reset of the fault condition by opening the safety chain via a second safety device, the fault condition is latched until the monitoring system verifies that the faulty safety device has been corrected.

Abstract: The present invention is provided with a fixed contact; a movable contact which selectively contacts with or separates from the fixed contact; and a drive means which has at least an electromagnetic coil and drives the movable contact so that the movable contact comes into contact with the fixed contact. The drive means generates a first driving force for bringing the movable contact into contact with the fixed contact, and a second driving force larger than the first driving force for maintaining the contact state between the movable contact and the fixed contact.