Abstract: A non-intrinsically safely supplied measurement device (1) with a connecting device (3) having an “increased safety” type of protection for connecting the measurement device (1) to a feed connection (2) in order to supply the measurement device (1) with electricity, an electronic device (4) which contains electronic components of the measurement device (1), a display device (8), a sensor (7) made with “increased safety” or “intrinsic safety” type of protection, and an output circuit (9) that is without at least the “intrinsic safety” type of protection. The electronic device (4) has an “encapsulation” type of protection, the display device (8) has an “intrinsic safety” type of protection and the display device (8), the sensor (7) and the output circuit (9) are connected to the electronic device (4) via connections having an “increased safety” type of protection.

Abstract: The provided relay system includes a load having a first terminal and a second terminal, a relay coupled to a common ground and the first terminal of the load and a relay protection circuit eliminating an arc generated by the relay. The relay protection circuit has an energy storage element with a first terminal coupled to the first terminal of the load and a second terminal and electrically connected to the relay in parallel for storing and releasing an electrical power, and a high-impedance element coupled to the second terminal of the load to cause the energy storage element to have a relatively speedy charge and a relatively slow discharge.

Abstract: A ballast and method for operating a ballast includes a switch or other circuit for connecting and disconnecting a voltage multiplier to a rectifier circuit. A control circuit for controlling the switch senses an input voltage and connects the voltage multiplier to the rectifier circuit when an input voltage falls below a selected voltage level.

Abstract: The present invention has an object to provide a switching regulator power supply apparatus capable of realizing a plurality of light emitting amount outputs without increasing a total number of structural components thereof which may impede a reduction of costs and an area saving effect in various sorts of potable devices which require the plurality of light emitting amount outputs. A switching regulator power supply apparatus according to the present invention includes a switching type power converting circuit, a current detecting circuit for producing a feedback signal in response to a load current; and an SWR control circuit for driving the power converting circuit. In the switching regulator power supply apparatus, the SWR control circuit is provided with a control signal input terminal and a reference voltage circuit capable of outputting a plurality of reference voltages based upon a control signal inputted to the control signal input terminal.

Abstract: A switching mode power supply includes a power supply circuit, a feedback circuit, and a switching controller. The power supply circuit includes a main switch coupled to a primary coil of a transformer, and supplies power to a secondary coil of the transformer according to an operation of the main switch. The feedback circuit generates a feedback voltage corresponding to an output voltage provided to the secondary coil of the transformer. The switching controller controls the main switch to turn off according to a sense voltage corresponding to the current flowed by the main switch. In this instance, the switching controller quickly senses the output short phenomenon by using the duty ratio of the main switch and the feedback voltage and shuts down the main switch to protect the circuit.

Abstract: In an integrated circuit apparatus made up of three or more integrated circuits which are supplied with power from three or more power supply sources that can be subjected to individually-controllable shutoff and which are sequentially subjected to interruption of power supply, control of a power shutoff circuit inserted into a signal line between integrated circuits is facilitated without regard to the physical layout of integrated circuits. A power shutoff control signal is imparted to a power shutoff circuit which is inserted into a signal line for interconnecting integrated circuits and which controls an output from a power shutoff circuit to a fixed state during shutoff of power to a connection-target integrated circuit. Accordingly, the integrated circuits are selected in sequence of interruption of power supply.

Abstract: A fault current limiter is disclosed. The fault current limiter of the present invention includes a current limiting module and a superconducting bypass reactor. The current limiting module includes at least two pancake type bifilar winding modules, which are stacked and connected to each other in series. Each bifilar winding module has a bobbin, a first superconducting wire wound around the bobbin in a bifilar manner, and at least one pair of first metal blocks, which are installed and fixed to the bobbin and attached to the first superconducting wire. The superconducting bypass reactor is formed into a hollow shape so that the current limiting module can be disposed therein. A second superconducting wire is wound around the bypass reactor such that the superconducting bypass reactor is connected in parallel with the current limiting module.

Abstract: An electrical current limiting device has a superconductive switching element. Unlike prior art superconductive current limiters whose switching mechanism is based on a quenching of the switching element, the inventive superconductive switching element is designed in such a manner that it is in the Shubnikov phase when the required short-circuit cutoff current is reached in the event current is limited. This enables the switching element to be operated in an operating state in which the generation of heat is limited to such an extent that the coolant surrounding the superconductor is able to completely dissipate the heat whereby achieving a stationary state at TS. A quenching of the superconductor, which is associated with an exceeding of TC, can thus be actively prevented so that, after an event in which current is limited, the superconductor is not required to be removed from the mains and recooled.

Abstract: A method for reducing the occurrence of false ground fault detections in a central office terminal is provided. The method includes generating a no-fault signal when no ground current is detected, delaying generation of a fault signal when ground current is detected at least for the duration of an expected pulse in AC induced signal, and when the ground current persists for a sufficient period, generating a signal indicating a fault condition.

Abstract: A magnetic movement mechanism usable in a ground fault circuit interrupter, comprising: (i) a first permanent magnet, (ii) a second permanent magnet positioned apart from the first permanent magnet, (iii) a soft magnet positioned between the two permanent magnets, (iv) a balance frame positioned between the two ends of the soft magnet, (v) a first coil and (vi) a second coil, wherein the first coil and the second coil are arranged such that when a current passes through the first coil, a first magnetic force is generated to cause the soft magnet and the balance frame to move towards the first permanent magnet in a first direction, and when a current passes through the second coil, a second magnetic force is generated to cause the soft magnet and the balance frame to move towards the second permanent magnet in a second direction that is opposite to the first direction.

Abstract: Systems and methods for auto-resetting span power protection are provided. In one embodiment, a method for deactivating a protective device is provided. The method comprises determining when an overload condition occurs on a communication medium; when the overload condition occurs, deactivating at least one protective device by applying, for a first predetermined period of time, a short-circuit to an output of a power supply that provides a holding current to the at least one protective device; and after the first predetermined period of time has elapsed, removing the short-circuit on the output of the power supply.

Abstract: An interface circuit connected between the functional unit and the output/input bus in a multi-chip system is disclosed. One characteristic of the present invention is that the positive voltage protecting diode located between the independent power of the functional unit and the output/input bus in the functional circuit is not required. Therefore, the signal on the output/input bus will not be distorted due to the low resistance load caused by shutting down the independent power of the functional unit. Another characteristic of the present invention is that the negative voltage protecting diode located between the output/input bus and the grounding in the functional circuit is changed to a stable voltage Zener diode. Therefore, the high voltage static electricity is guided into the grounding via the Zener diode so that the goals of anti-static electricity and protecting the functional unit are achieved.

Abstract: The present invention relates to a method for protection of power transformers and other power system components, which are vulnerable to geomagnetically induced currents, which comprises feeding from an overhead line/s or cable conductor/s one or more DC-diverter consisting of primary diverter windings and compensation windings applied on a respective magnetic core leg, which diverter is connected to critical busses, and diverting “quasi” direct current flowing on the overhead lines or cable conductors as a result of the earth surface potential gradients caused by geomagnetically induced currents, as well as a DC diverter to carry out the method.

Abstract: An input protection circuit comprises a reverse flow preventing diode, a series circuit of a diode and a Zener diode, and a current path forming resistor or diode. The reverse flow preventing diode is connected between an input terminal and an internal circuit. The series circuit is connected between the input terminal and a ground. The current path forming resistor or diode is connected between a first common connection point of the reverse flow preventing diode and the internal circuit and a second common connection point of the series circuit, and sets a potential at the first common connection point to be less than a potential at the input terminal when the surge voltage is applied to the input terminal.

Abstract: A device for controlling at a fault condition. An apparatus is connected by a connection line to a grid point of a transmission net in an electric power network. A voltage raising apparatus includes a first branch connected to the grid point including a switching element and a second branch including a current resisting means. The voltage raising apparatus includes a computer for signal processing of a sensed fault condition on the network and for affecting the operation of the switching element such that on a fault condition at least part of the current is diverted through the voltage raising apparatus and for evaluation of further actions.

Abstract: A device (1) for protecting an electrical installation from overvoltages, having at least one protection component (2) and disconnection means (3) capable of changing from a closed configuration to an open configuration, as well as signalling means (5) capable of indicating the configuration of the disconnection means (3). The disconnection means (3) and the signalling means (5) respectively comprise a mobile disconnection element (4) and a mobile signalling element (12) arranged such that, when going from the closed configuration to the open configuration, the mobile disconnection element (4) moves in a rotational movement according to a first trajectory and cooperates with the mobile signalling element (12) to drive the mobile signalling element in rotation along a second trajectory different from the first trajectory.

Abstract: A device (1) for providing protection for an electrical installation against overvoltages including at least one protection component (2), the device having a first mounting (14) delimiting a first interstitial space (14?) with a dimension fixed by construction that at least partially houses a first conducting element (10) and a second conducting element (11) to make the electrical connection between the first conducting element and the second conducting element, the device also having a second mounting (15) delimiting a second interstitial space (15?) with a dimension fixed by construction that at least partially houses a third conducting element (12) and a fourth conducting element (13) so as to make the electrical connection between the third conducting element and the fourth conducting element.

Abstract: It is intended to provide a control circuit of power supply, a power supply and a control method thereof capable of achieving power saving in an integrated circuit and reducing a delay time of the integrated circuit. The control circuit 50 of a power supply 10 which outputs plural DC voltages VCC, VBGP, VBGN each having a different voltage value includes a voltage changing portion SW1 which detects an output current I1 relating to a first DC voltage VCC which is one of the plural DC voltages and sets at least one DC voltage except the first DC voltage VCC based on the detected output current I1, and the like.

Abstract: An insertion type fuse with breakage indication comprises a seat having a long receiving chamber for receiving a metal fuse; an rectangular bi-directional SMD form LED set being located on the buckle portions; the LED set being a coating device and being high temperature tolerant; the LED set being connected to a circuit; the LED including two LEDs and being serially connected with a voltage divided resistor; a fuse wire being connected between the LED set and a load; the LED set being buckled to the buckle portions; when the fuse wire breaks, light will emit out so as to show that the fuse wire breaks; thereby a break fuse can be fined rapidly. In assembly, the seat and the cover are integrally formed. The LED set is adhered to the metal fuse and then the metal fuse is assembled into the long receiving chamber.

Abstract: A tri-phase surge protector comprises a first zinc oxide ceramic body; a first electrode layer on a surface of the first zinc oxide ceramic body and having a first electrode, and the first electrode includes a first terminal; a second electrode layer on another surface of the first zinc oxide ceramic body; a second zinc oxide ceramic body on the second electrode layer; a third electrode layer on another surface of the second zinc oxide ceramic body and having a second electrode, and the second electrode includes a second terminal; a third zinc oxide ceramic body on the second electrode layer and at the second zinc oxide ceramic body; and a fourth electrode layer on another surface of the third zinc oxide ceramic body and having a third electrode, and the third electrode includes a third terminal. The invention also discloses a method for manufacturing a tri-phase surge protector.

Abstract: A surge varistor contains a varistor member and a disengagement member. The varistor member is parallel-connected to a load; while the disengagement member is series-connected to the load. The disengagement member is an elastic thin plate which contains a base portion and an elastically folded portion. The folded portion is soldered to a contact block extended from a terminal of the varistor member, thereby establishing a series connection between the varistor and disengagement members. When a surge to the load occurs, the varistor member enters shunts a large amount of current. If the temperature rises above a specific threshold, the soldering material binding the folded portion and the contact block is melted and the folded portion escapes from the contact block by its own elasticity, thereby breaking the electrical connection between the varistor and disengagement members.

Abstract: A device (1) for protecting an electrical installation from overvoltages, including a casing (2) that defines an interior recess (3), a varistor (4) placed in the recess (3), and having a first and a second pole (9, 10) and first and second opposite surfaces (5, 6) from which the first and second poles (9, 10) respectively emerge, and means (17) for holding the varistor (4) in position in the recess (3), wherein the holding means (17) extend between a first end (17A) toward which the holding means (17) are attached to the casing (2) and a second end (17B) toward which the holding means (17) are attached to the first surface (5), the holding means (17) extending, between the ends (17A, 17B), substantially outside of the space (18) located opposite each of the first and second surfaces (5, 6).

Abstract: A lightning protection or internal surge device designed to suppress surges on electrical transmission or distribution lines by expending some of the excess energy in the form of corona discharge in both wet and dry conditions. The device is a very thin (of diameter not exceeding 0.1 mm) conducting wire, fiber, filament, or a bundle of such filaments, or a yarn or woven or knitted fabric made of such fibers or wires which is wound around a live conductor or ground wire forming a coil. When the coil is exposed to the fields created by the voltage surges on the line or ground wire it enhances corona losses on the line thereby damping/suppressing the surges as well as prolonging the front time of the surge to reduce its steepness.

Abstract: The invention provides an electrostatic chuck capable of widening a temperature range when the temperature of a flat substrate is controlled and reducing a variation in thermal conductivity between the electrostatic chuck and the flat substrate over time. According to an aspect of the invention, an electrostatic chuck includes: a body that has an internal electrode for attracting a flat substrate by an electrostatic force provided therein; a plurality of protrusions that are formed on one surface of the body, serving as an electrostatic attraction surface; and one or more minute projections that are provided on each of top surfaces of some or all of the plurality of protrusions. In the electrostatic chuck, a region of the top surface of each of the minute projections on which the flat substrate is loaded is referred to as a mounting surface, and the total area of the mounting surfaces of the minute projections is equal to or larger than 0.

Abstract: Disclosed herein is a power device. The power device has a power source; timing circuitry powered by the power source for producing a current pulse output having a pulse width; a switch for triggering the current pulse output produced by the timing circuitry; an armature motor powered by the power source and in electrical communication with the timing circuitry for receiving the current pulse therefrom, the armature motor comprising: an electro-magnetic core; a first winding for carrying electric current to energize a magnetic field associated with the electro-magnetic core; a second winding for carrying current to reset the magnetic field associated with the electro-magnetic core, the first and second windings wound about the electro-magnetic core; and a swinging armature for providing movement in response to the energizing of the magnetic field about electro-magnetic core. The first winding and the second winding are bifilar wound together about the electro-magnetic core.

Abstract: An aircraft telescopic in-flight refueling mast comprising a metallic structural beam (31), electrically connected to the aircraft by flexible conductive means (33), having inside a fixed metallic tube (11) and a metallic telescopic tube (11) providing the fuel conduit, and, attached to said beam (31), flight control surfaces (41) and protection means against electric discharges, specially lightning strikes and electro-static discharges, including insulated means (39, 51) and low conductive means (15, 17) for reducing the lightning currents at a safe level and for draining the static charge created during the refueling, and conductive means (19, 21, 23, 33, 43) providing a safe lightning current path and good electrical bonding for electro-static discharge.

Abstract: An electrostatic chuck using the Johnson-Rahbek force, comprising: a dielectric material layer including a ceramics layer and a resin layer formed on the ceramics layer; and an electrode for generating an electrostatic adsorption power.

Abstract: The invention provides a means for estimating a self-bias voltage under arbitrary etching conditions via a simple procedure.

Abstract: The present invention provides a method and an apparatus for carrying at least one substrate for plasma processing. The method and apparatus comprising a carrier for transporting the substrate, that is located unbonded on the carrier, onto a substrate support within a plasma system for plasma processing. An electrostatic clamp, that is coupled to the substrate support, electrostatically secures the substrate to the substrate support through the carrier during plasma processing.

Abstract: A microelectrical device comprising two generally parallel electrodes (20,21) at least one of which is movable, and at least one of the electrodes comprising a layer of a semiconductor presenting space charge characteristics. The electrodes have a closed position an open position. A spring effect biases the movable electrode (21) towards the open position. When the movable electrode (21) is closed by a first voltage pulse (P1) a sufficiently high space charge density (10) is generated to hold the movable electrode (21) closed. When zero voltage is applied the movable electrode (21) is held closed by the built in space charge until the application of a second voltage pulse (P2) which decreases the space charge in the semiconductor (10) to allow the movable electrode(s) to be moved to the open position by the spring effect.

Abstract: A filter capacitor comprising a substrate of at least one layer of a low temperature co-fires ceramic (LTCC) tape supporting alternating active and ground electrode layers segregated by a dielectric layer is described. The substrate is preferably a laminate of three LTCC tapes pieces that are heated under pressure and at a relatively low temperature to become a laminate that maintains its shape and structure dimensions even after undergoing numerous sintering steps. Consequently, relatively thin active and ground electrode layers along with the intermediate dielectric layer can be laid down or deposited on the LTCC substrate by a screen-printing technique. A second laminate of LTCC tapes is positioned on top of the active/dielectric/ground layers to finish the capacitor. Consequently, a significant amount of space is saved in comparison to a comparably rated capacitor or, a capacitor of a higher rating can be provided in the same size as a conventional prior art capacitor.

Abstract: A method of creating a capacitor in an integrated circuit. According to a basic version of the invention the capacitor uses intensive fringing fields to create a capacitance. This is achieved by creating a capacitor with vertical overlapping conducting electrodes between two planes of the integrated circuit, instead of plates parallel to the planes. A capacitor according to the invention can additionally comprise horizontal, i.e. parallel plates. A capacitor according the method is also disclosed.

Abstract: A laminated ceramic capacitor includes a body having an inner layer portion and an outer layer portion and a plurality of terminal electrodes spaced apart from each other in a length direction of the body. The inner layer portion has a plurality of internal electrodes stacked in a height direction of the body. The internal electrodes have led-out portions led out to a side face of the body. The outer layer portion is disposed on one of opposite faces of the inner layer portion in the height direction. Each terminal electrode extends along the height direction to cover corresponding one of the led-out portions and is provided with an intermediate portion and an end portion. The intermediate portion has a larger electrode width than the led-out portion. The end portion has a smaller electrode width at an edge of the side face than the intermediate portion.

Abstract: A capacitor having a large current carrying capacity includes a hollow core formed by a non-conducting tubular section, and a capacitor winding wrapped around the tubular section. A thermal cutoff device is disposed within the hollow core. The thermal cutoff device is configured to sense a predetermined temperature level within the hollow core and disable the current carrying capacity of the capacitor. The thermal cutoff device is disposed at a geometric center of the capacitor winding, which is also the hot spot of the capacitor winding. The thermal cutoff device includes first and second conductors electrically connected to each other with a predetermined solder alloy. The first conductor includes a cross-sectional portion that is attached to the second conductor. The cross-sectional portion is subjected to a springing force in a lateral direction away from the second conductor.

Abstract: A system includes a plurality of equipment racks and a plurality of PDUs mounted in respective ones of the plurality of equipment racks and configured to distribute power via plural branch circuit outputs. The system further includes a UPS rack, a plurality of UPSs mounted in the UPS rack and a plurality of power cables directly coupling outputs of respective ones of the UPSs to inputs of respective ones of the PDUs. Each UPS may include a first output connector directly connected to a PDU via a power cable, and a second output connector coupled to a second connector of another UPS to provide output paralleling. For example, a connectorized bus assembly may be mounted in the UPS rack and may include a UPS output bus and a plurality of connectors, respective ones of the connectors coupling the UPS output bus to the outputs of respective ones of the UPSs.

Abstract: A track formed on a housing of an electronic device provides a space for a sliding element to slide. The housing includes a first stopper and a second stopper formed on a first side of the track for preventing the sliding element from deviating from the track.

Abstract: An intelligent power supply is described. The intelligent power supply includes a case, a circuit board, a fan, a detecting module, and an alarm module. The circuit board transforms an alternating current from a main supply to a direct current for an electronic equipment. The fan reduces the operating temperature of the intelligent power supply and can also reduce the operating temperature of the electronic equipment. The detecting module detects the operating status of the intelligent power supply and the alarm module sends out an alarm signal when the operating status is abnormal.

Abstract: A modular electronic equipment system includes a plurality of equipment racks. Each equipment rack includes a equipment rack frame configured to receive and support electronic equipment, a power input cable having a first end fixedly attached to the equipment rack frame and configured to be electrically coupled to electronic equipment supported by the equipment rack frame to provide power thereto and a first connector attached to a second end of the power input cable. The system further includes a power distribution rack. The power distribution rack includes a power distribution rack frame and a plurality of second connectors supported by the power distribution rack frame and configured to pluggably mate with the first connectors of the equipment racks.

Abstract: A portable electronic device comprises a base, a cover and a connecting element. The cover comprises a track and a rotating portion next to the track. The connecting element is pivoted to the base and movably connected to the track. When the connecting element moves in the rotating portion, the connecting element can be rotated.

Abstract: According to one embodiment an information processing apparatus includes a display unit, a discriminator discriminating, if a window of a screen of the display unit displaying moving picture information transmitted from a terminal is overlapped by the other window, whether or not there is a viewable area in the window displaying the moving picture information, and a transmitter transmitting to the terminal an instruction signal to order transmitting moving picture information corresponding to the other area of the window displaying the moving picture information except an area where the window displaying the moving picture information and the other window overlap, if it is discriminated by the discriminator that there is a viewable area in the window displaying the moving picture information.

Abstract: This invention relates generally to computer displays, and more specifically, to systems and methods for providing a movable laptop computer display. In one embodiment, the invention includes a system having a display, the display having a first hinge; a computer, the computer having a second hinge; a member, the member having a first and second end, the first end being coupled to the first hinge and the second end being coupled to the second hinge. In a further embodiment, the first hinge is configured to permit the display to tilt relative to the computer. In yet another embodiment, the second hinge is configured to permit the display to fold and swivel relative to the computer. In an additional embodiment, the display has a back portion and the first hinge is centrally coupled to the back portion.

Abstract: A housing arrangement for a mobile communication device comprises first and second housing sections connected together and movable relative to one another between open and closed positions. The first housing section includes a display that is substantially concealed by the second housing section in a closed configuration. The second housing section includes a window that reveals a portion of the display in the closed configuration. In the open configuration, a touch sensitive input is accessible through the window in the second housing section.

Abstract: An electronic apparatus includes a housing having a hole, an electronic component disposed adjacent to the hole, and a support fitting that supports the electronic component. The support member has a partition that supports the electronic component and defines a space around the hole in cooperation with an inner wall of the housing.

Abstract: A display apparatus including a display main body that displays an image thereon and a base member, the display apparatus further including a lifting unit which includes a guide frame to stand on the base member and a lifting member coupled with the guide frame to move with the display main body; a pivoting unit which is provided between the display main body and the lifting member and supports the display main body to pivot around a pivot axis in clockwise and counterclockwise directions; and a locking unit which includes a moving member to be lifted together with the display main body and to move with a pivoting operation of the display main body, and a locking projection provided on the guide frame to limit the moving member from moving downward when the display main body remains pivoted.

Abstract: A portable electronic device comprises a base, a cover and a linkage mechanism. The linkage mechanism comprises a first linkage assembly and a second linkage assembly. The first linkage assembly pivots to the cover. The second linkage assembly pivots to the first linkage assembly and the base, respectively. The second linkage assembly is movably installed on the base.

Abstract: A multiple split ring clamp for securing a printed circuit board on a cathode ray tube, in which the clamp first split ring has overlapping jaws and teeth on each end of the jaws, wherein the jaws and teeth are adapted to engage and hold the clamp on the cathode ray tube, and wherein the clamp has a second ring and stand-off which is adapted for removably securing a printed circuit board on but spaced apart from the first ring and cathode ray tube. The first split ring may be connected to but independent from the second ring and standoff so that movement of the clamp will not affect the position of the stand-off.

Abstract: A mounting assembly includes a chassis having a rear wall, a cover slidably mounted to the chassis in a first direction, and a clamping member mounted on the cover. The rear wall has a positioning portion thereon. The clamping member has a cantilever thereon. The cantilever has a locking portion at a free end thereof for engaging with the positioning portion, and a pressing portion at an opposite end thereof for urging the locking portion to disengage from the positioning portion. When the pressing portion of the clamping member is pressed downward in a second direction perpendicular to the first direction, the locking portion is raised, thereby disengaging the locking portion from the positioning portion of the chassis.

Abstract: A portable computer has a base supporting a keyboard and a cover with a display screen, with the cover being foldable away from the base to an open configuration to view the entire screen and operate the keyboard. The cover can also be folded flush against the base to a closed configuration. A portion of the screen remains viewable in the closed configuration, either by virtue of a window formed in the base or by virtue of the portion of the cover extending past the base.

Abstract: A computer case is surrounded by detachable front, rear, left, right, top, and bottom panels. Ventilation openings and fans are provided on the panels. The case is divided into an upper first compartment for mounting a circuit board section, a lower second compartment for mounting a power supply and a drive section. A plurality of recesses are provided on a plate dividing the first and second compartments such that wires and busses are adapted to pass to electrically interconnect components of the first compartment and that of the second compartment and communicate signals between them. The invention can facilitate heat removal during the computer operation and is easily assembly or disassembly.

Abstract: A latch mechanism is provided for locking a cover unit to a base unit. The latch mechanism includes a locking member slidably installed in the cover unit, a button movably attached to the cover unit, and a pivot member pivotably connected to the cover unit. The locking member includes a hook for engaging with the base unit, and an engaging portion formed thereon. The button forms a pushing portion. The pivot member is capable of being driven by the pushing portion of the button to rotate and in turn to slide the locking member for disengaging the hook from the base unit.