Abstract: An object is to provide a driving controller for an AC motor that can prevent generation of an excessive voltage between lines of a motor and between contacts of a motor cut-off contactor and a continuous arc between contacts of the motor cut-off contactor, regardless of the type of a fault occurred, even when a phase in which a current zero point is not generated and a phase in which a current zero point is generated coexist in a fault current that flows between an inverter and the motor. A control unit is configured to open a motor cut-off contactor not at a time when a state of a detected current is determined to be abnormal but at a time when the state of the current is determined to be normal, even when a basic contactor-close command MKC0 becomes off (L level).

Abstract: When electric discharging occurs inside a gas insulated apparatus in which sulfur hexafluoride is filled, hydrogen-fluoride gas is generated, which abrades a part formed of glass fiber reinforced plastics included in the apparatus. Previously, resin for preventing the abrasion has been coated on the surface of the part; however, a problem has occurred that the coating film peels off. Organic fiber woven cloth woven using organic fiber such as aramid fiber or the like having hydrogen fluoride resistance and mechanical toughness is wrapped around the surface of glass fiber reinforced plastics, and thermosetting resin is wettably impregnated into weave patterns of the organic fiber woven cloth and then heat cured; thereby, an abrasion-preventing protection layer that does not peel off is formed.

Abstract: When electric discharging occurs inside a gas insulated apparatus in which sulfur hexafluoride is filled, hydrogen-fluoride gas is generated, which abrades a part formed of glass fiber reinforced plastics included in the apparatus. Previously, resin for preventing the abrasion has been coated on the surface of the part; however, a problem has occurred that the coating film peels off. Organic fiber woven cloth woven using organic fiber such as aramid fiber or the like having hydrogen fluoride resistance and mechanical toughness is wrapped around the surface of glass fiber reinforced plastics, and thermosetting resin is wettably impregnated into weave patterns of the organic fiber woven cloth and then heat cured; thereby, an abrasion-preventing protection layer that does not peel off is formed.

Abstract: A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.

Abstract: An object is to provide a driving controller for an AC motor that can prevent generation of an excessive voltage between lines of a motor and between contacts of a motor cut-off contactor and a continuous arc between contacts of the motor cut-off contactor, regardless of the type of a fault occurred, even when a phase in which a current zero point is not generated and a phase in which a current zero point is generated coexist in a fault current that flows between an inverter and the motor. A control unit is configured to open a motor cut-off contactor not at a time when a state of a detected current is determined to be abnormal but at a time when the state of the current is determined to be normal, even when a basic contactor-close command MKC0 becomes off (L level).

Abstract: An actuator used in a safety stop device for an elevator has: a movable portion displaceable between an actuation position where the safety stop device for the elevator is actuated and a normal position where the actuation of the safety stop device is released; and an electromagnetic coil for displacing the movable portion when a current flows through the electromagnetic coil. A device for inspecting operation of the actuator has a feeder circuit for supplying an amount of electricity required for a semi-operation which is less than that required for a full operation for displacing the movable portion from the normal position and the actuation position to the electromagnetic coil.

Abstract: An actuator has a driving first coil and a driving second coil. A capacitor is electrically connected to both the first coil and the second coil through a discharge switch using electric power accumulated in a capacitor which can be selectively supplied. An operation portion for operating the discharge switch is electrically connected to the discharge switch. For example, when an electric power supplied to the operation portion is cut due to a power failure, the second coil and the capacitor are electrically connected to each other through the discharge switch.

Abstract: A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.

Abstract: An actuator has a driving first coil and a driving second coil. A capacitor is electrically connected to both the first coil and the second coil through a discharge switch using electric power accumulated in a capacitor which can be selectively supplied. An operation portion for operating the discharge switch is electrically connected to the discharge switch. For example, when an electric power supplied to the operation portion is cut due to a power failure, the second coil and the capacitor are electrically connected to each other through the discharge switch.

Abstract: An actuator used in a safety stop device for an elevator has: a movable portion displaceable between an actuation position where the safety stop device for the elevator is actuated and a normal position where the actuation of the safety stop device is released; and an electromagnetic coil for displacing the movable portion when a current flows through the electromagnetic coil. A device for inspecting operation of the actuator has a feeder circuit for supplying an amount of electricity required for a semi-operation which is less than that required for a full operation for displacing the movable portion from the normal position and the actuation position to the electromagnetic coil.

Abstract: A magnetic actuator includes a first yoke, an armature which is provided inside the first yoke and made movable in reciprocating motion along a first direction inside the first yoke, first and second coils fitted inside the first yoke, a pair of second yokes affixed to the first yoke along a second direction, and permanent magnets affixed to the second yokes in a manner that the permanent magnets are positioned face to face with the armature. In the magnetic actuator thus constructed, fluxes generated by the first and second coils pass through first magnetic circuits whereas fluxes generated by the permanent magnets pass through second magnetic circuits differing from the first magnetic circuits.

Abstract: In an actuator, coils are kept from being displaced along a y-axis direction as projections of coil bobbins are sandwiched between first and second iron cores along the y-axis direction. Also, the coils are kept from being displaced excessively along x- and z-axis directions due to shocks, for instance, because they are fitted in groovelike channels fitted in the first and second iron cores. Since two bearings are sandwiched and fixed between third and fourth iron cores along the x-axis direction, the bearings can be easily set on a common axis with high accuracy. It is therefore possible to prevent displacement of the coils during operation of the actuator. Slidable support plates ensure smooth movements of an armature and thereby provide improved reliability, even when the distance between the support plates and the first to fourth iron cores is reduced.

Abstract: A displacement sensor includes a ferromagnetic member for forming a magnetic path, a coil for generating a magnetic field in the magnetic path when fed with a high-frequency current, and a low-resistance magnetic-shielding member that moves across magnetic flux passing through the magnetic path. The sensor is excellent in production is, robust, and useful in high speed operation.

Abstract: A magnetic actuator includes a first yoke, an armature which is provided inside the first yoke and made movable in reciprocating motion along a first direction inside the first yoke, first and second coils fitted inside the first yoke, a pair of second yokes affixed to the first yoke along a second direction, and permanent magnets affixed to the second yokes in a manner that the permanent magnets are positioned face to face with the armature. In the magnetic actuator thus constructed, fluxes generated by the first and second coils pass through first magnetic circuits whereas fluxes generated by the permanent magnets pass through second magnetic circuits differing from the first magnetic circuits.

Abstract: In an operation circuit of an electromagnetic switching device, when electric energy is discharged by discharge switches connected in series, respectively, to opening coils and closing coils, an induction current flowing in a direction opposite to a current of the coil of the excitation side is generated. The current flows through the coil on the non-excitation side due to magnetic coupling, and a magnetic flux necessary for driving is cancelled, thereby inhibiting generation of a driving force. The operation circuit includes first and second opening and closing coils, so that a moving element may be driven between those coils. This circuit includes a circuit for suppressing an over-voltage at the moment of interrupting an excitation current of a first coil and for interrupting an induction current generated through the first coil at the time of exciting the second coil.

Abstract: In an operation circuit of an electromagnetic switching device when electric energy is discharged by discharge switches connected in series, respectively, to opening coils and closing coils, an induction current flowing in a direction opposite to a current of the coil of the excitation side is generated. The current flows through the coil on the non-excitation side due to magnetic coupling, and a magnetic flux necessary for driving is cancelled, thereby inhibiting generation of a driving force. The operation circuit includes first and second opening and closing coils, so that a moving element may be driven between those coils. This circuit, includes a circuit for suppressing an over-voltage at the moment of interrupting an excitation current of a first coil and for interrupting an induction current generated through the first coil at the time of exciting the second coil.

Abstract: In an actuator of the invention, coils are kept from being displaced along a y-axis direction as projections of coil bobbins are sandwiched between first and second iron cores along the y-axis direction. Also, the coils are kept from being displaced excessively along x- and z-axis directions due to shocks, for instance, as they are fitted in groovelike channels formed in the first and second iron cores. Since two bearings are sandwiched and fixed between third and fourth iron cores along the x-axis direction, the bearings can be easily set on a common axis with high accuracy. It is therefore possible to prevent displacement of the coils during operation of the actuator. Slidable support plates ensure smooth movements of an armature and thereby provide improved reliability even when the distance between the support plates and the first to fourth iron cores is reduced.

Abstract: The displacement sensor includes a ferromagnetic member for forming a magnetic path, a coil for generating a magnetic field in the magnetic path when feeding a high-frequency current thereto, and a low-resistance magnetic-shielding member that moves across magnetic flux passing through the magnetic path, which is excellent in production, robust, and adaptable for the high speed operation of devices as well.

Abstract: A switching apparatus for multiphase electric power includes switching units corresponding to different phases. Each switching unit includes an operating mechanism having a movable coil disposed between two fixed coils, and a switch portion having a movable contact operatively connected to the movable coil. A separate power supply may be provided for each switching unit to permit individual control of the different phases.

Abstract: A switching device includes a pair of fixed coils and a pair of movable coils, with one pair being disposed between the other pair. Two of the coils may be connected back to back on opposite sides of a support plate to increase the stiffness of the coils and reduce damage due to impact between the fixed and movable coils. The coils include two sets of coils, each set including one of the fixed coils and one of the movable coils. The coil sets can be driven simultaneously or at different times to effect contact opening and closing.