Abstract: This invention is a tape drive which includes a transducer head, a tape carrier, and a tape displacement structure. The tape carrier is provided in association with the transducer head, and is configured to support and move a tape along a tape travel path within the tape drive. The tape carrier moves the tape in contact with the transducer head along the tape travel path during at least one of a read operation and a write operation. The tape displacement structure is provided in association with the transducer head, and is configured to engage and bias a received tape from the tape travel path to a retracted tape travel path. The retracted tape travel path is spaced apart from the transducer head. The tape carrier is operative to move the retracted tape across the tape displacement structure, spaced apart from the transducer head. The tape carrier prevents at least one of transducer wear and transducer contamination caused by contact of the tape moving against the transducer head. A method is also provided.

Abstract: In a magnetic tape cartridge, the tape is transported so as to be wound and unwound from two hubs disposed in a housing by direct contact of said tape with a drive puck. A roller wheel is disposed on an opposite side of said drive puck, with the tape disposed between the drive puck and the roller wheel, so as to maintain the tape in contact with the drive puck during rotation of the drive puck. A braking force can be applied to one or both hubs during winding and unwinding, so as to tension the tape. The components can be dimensioned to make the cartridge compatible with various existing drives for existing cartridge formats.

Abstract: A disk cassette including a cassette housing having upper and lower shells in which a freely rotatable disc is accommodated. A shutter is slidably secured in parallel relation to the side surfaces of the cassette housing and opens/closes a head insertion hole formed in the cassette housing. The disk cassette further includes a shutter spring assembly which has one end thereof hooked to the cassette housing and the other end thereof hooked to the shutter and thereby urges the shutter so as to close the head insertion hole. An insertion groove is provided in the cassette housing for inserting the shutter spring assembly thereinto and be covered by the shutter when the shutter closes the head insertion hole.

Abstract: An apparatus and system for improving the contact between the heads of a disk drive and the storage media of the disk by improving disk stability. The apparatus comprises a disk having a disk stability pattern disposed proximate a center region of the disk. The disk stability pattern improves disk stability by reducing vibration modes in the spinning disk, thereby minimizing the formation of standing waves in the spinning disk media, and by improving disk compliance, thereby minimizing disk anisotropic curl and tilt.

Abstract: The method for producing a magnetic recording medium, includes the steps of (a) subjecting surfaces of a substrate to grinding by a ductile-mode grinding with a grinding wheel having a setting depth of cut of from 0.05 to 20 .mu.m, to give a surface-worked substrate having grinding marks of arc patterns; and (b) forming recording medium-constituting layers at least comprising an under layer, a magnetic layer, and a protective layer on the surface-worked substrate, or on a mirror-polished substrate obtained by further subjecting the surface-worked substrate to a finish polishing. The resulting magnetic recording medium is constituted by (a) the surface-worked substrate or the mirror-polished substrate; and (b) recording medium-constituting layers at least comprising an under layer, a magnetic layer, and a protective layer, wherein the recording medium-constituting layers are formed on the surface-worked substrate, or on a mirror-polished substrate.

Abstract: An actuator block for supporting suspension assemblies of a data storage system for read or write operations. The suspensions assemblies are coupled to an actuator arm of the actuator block via a mounting plate. The mounting plate is formed of a generally flat planar member coupled to a first end of the suspension assembly and defining upper and lower surfaces and sides. The mounting plate is coupled to the actuator arm along sides of the mounting plate to secure the suspension assemblies to the actuator block for operation without imparting a significant force to the suspension assembly along a load axis of the suspension assembly.

Abstract: A magnetic head unit is provided in which the distance between a surface of the gimbal plate put touching the pressing member and a surface of the magnetic head facing the first or second disc-shaped recording medium is set to fall in a range of 0.3 to 0.8 mm and thus the coil winding concavity can be formed in the intermediate portion of the magnetic head in the direction of the head thickness and the magnetic heads can be kept stably in place in relation to the disc-shaped recording medium. Also, a recording and/or reproducing apparatus using the magnetic head unit is provided.

Abstract: An FPC cable which is excellent in noise resisting property, manufacturing cost, mounting operability to a carriage, and maintenance. The FPC cable includes a spacer and a reinforcing plate. In the patterned surface of the FPC, a head pad to which a head wire is bonded is formed on a pad forming portion and a preamplifier chip is mounted on a device mounting portion. Wiring patterns are linearly connected between the head pad and the preamplifier chip and between the preamplifier chip and an I/O-side end portion, respectively. In the spacer, a cavity is formed for storing the preamplifier chip. The reinforcing plate is inserted into the space formed by folding back the pad forming portion, and the spacer is engaged with the device mounting device, thereby constituting a magnetic-head-side end portion.

Abstract: To provide a floppy disk device wherein positioning members of the PM type stepper motor are unitized with the base frame (3), the base frame comprises a housing fabricated in the same body of the same material with the base frame (3) wherein a coil assembly (13, 14) of the PM type stepper motor is fixed, and frame stator-teeth (3c) configured by punching out parts of the housing. An inner housing cap (21) having inner-housing-cap stator-teeth (21a) is put inside the housing for covering the coil assembly (13, 14). To an opening of the housing, a first pivot bearing (2') retained by a plate spring (22) is inserted. To an opening of a frame pivot-fixed face (3a) fabricated by punching out a part of the base frame (3), a second pivot bearing (2) is fixed. A lead-screw shaft (1) is set between the first and the second pivot bearing (2'and 2) compressing the plate spring (22).

Abstract: A method and apparatus for providing cross track positioning of a disk drive head relative to a formatted track on a disk platter. A load beam is attached via a living hinge to a cradle. Piezo crystals are mounted on the cradle in plane with the load beam. The crystals are attached to levers formed into a proximal end of the load beam and activated with electric signals from a microactuator control to elongate or contract. Activated simultaneously the crystals exert a push force on one lever and a pull force on the other lever causing the load beam to pivot about the living hinge acting as a fulcrum. The load beam is attached to the cradle via cradle panels located at the distal end portion of the load beam. The cradle panels are preferably perpendicular to the load beam thereby providing low resistance in the cross rack direction and support in the vertical direction.

Abstract: A magnetoresistive read sensor fabricated on a substrate includes a ferromagnetic layer that is exchange coupled with an antiferromagnetic layer made of a defined composition of iridium manganese. A tantalum layer is used so that the exchange field and coercivity do not change with variations in annealing temperature. The antiferromagnetic layer is formed with a material composition of Ir.sub.x Mn.sub.100-x, wherein x is in the range of 15<.times.>23. In an embodiment of a spin valve structure, the tantalum layer is disposed over the substrate and the antiferromagnetic layer is in direct contact with a pinned ferromagnetic layer. In another embodiment, the IrMn layer is formed over a soft active layer. In a third embodiment using exchange pinning, spaced IrMn regions are formed over the active magnetoresistive layer to define the sensor track width.

Abstract: An electrical connector includes an insulative housing retaining signal and power contacts therein. A resettable power regulation device is attached to the housing and electrically connected to the power contact whereby an excessive-power condition caused by an excessive-current or excessive-voltage power signal transmitted through the power contact triggers a shut-down operation of the regulation device thereby terminating transmission of the power signal to protect an electrical device connected to the connector. The resettable power regulation device resumes transmission when the power condition decreases to an operational level.

Abstract: A load driver circuit (10) includes an output driver (11) suitable for driving an inductive load (13). An output clamp circuit (15) clamps the output (12) to a high voltage during turn-off of the output driver (11). An open load detect circuit (26) clamps the output (12) to a lower voltage when the load (13) has an open circuit fault. A power fault voltage detect circuit (28) clamps the output (12) to another low voltage during a power fault condition.

Abstract: A protector cartridge circuit arrangement which permits more robust line protection. The circuit arrangement has high-capacity and large-sized components staggered across the surface of a printed circuit board such that high-capacity components can be used in the cartridge to protect plural, adjacent lines. Such devices cannot be used in pair-at-a-time protectors because of space constraints. A preferred industrial application is the protection of communication lines.

Abstract: A patch cord and method for installing new hardware in a remote terminal of a telecommunications system. Hardware installed inside remote terminal cabinets require lightning protection systems to prevent damage from sudden power surges. The patch cord and method allow new hardware to be installed in the remote terminal using existing lightning protection systems.

Abstract: A method of increasing a cast-off speed of an armature from a pole of an electromagnet of an electromagnetic actuator, includes the following steps: holding the armature at the pole against a force of a resetting device by maintaining an electric holding current flow through a coil of the electromagnet; and launching the armature from the pole by switching off the holding current; and at a predetermined moment during a release period of the armature from the pole, passing a cast-off current for a predetermined period through the coil. The cast-off current has a polarity opposite to the polarity of the holding current.

Abstract: The static chuck apparatus includes a metal substrate, a first adhesive layer provided on the metal substrate, a ceramic insulating plate provided on the first adhesive layer, a second adhesive layer provided on the ceramic insulating plate, an insulating film provided on the second adhesive layer, and an electrode provided between the second adhesive layer and the insulating film.

Abstract: A plasma erosion resistive clamping ring is provided for clamping a wafer in a plasma treatment chamber. The plasma erosion resistive clamping ring comprises a ring and one or more tips secured to, and mutually spaced apart about, a circumference of the ring. Each of the tips projects away from the ring, in a radial direction, towards an interior of the ring. Each tip has plural side surfaces that taper to, and meet, a single, continuous surface of rotation. The surface of rotation is located in the interior of the ring at a location of the tip which is radially most distant from the ring. The meeting of the tapered sides at the single continuous surface of rotation has a cross-section, taken in a plane of the ring, as follows. The cross-section comprises first and second line segments, on lines that intersect at an acute angle, and an arc of a convex ellipse, that begins at an end of the first line segment most distant from the ring, and ends at an end of the second line segment most distant from the ring.

Abstract: And electrolytic capacitor having excellent high temperature life characteristics and excellent low temperature properties, an aluminum electrolytic capacitor having excellent high temperature life characteristics and moisture resistance, a low dielectric loss and good low temperature properties, and an electrolyte therefor. A first electrolyte which includes a mixed solvent of sulfolane and at least one 3-methyl sulfolane and 2,4-dimethyl sulfolane, a second electrolyte in which a quaternized imidazolinium salt or a quaternized pyrimidinium salt is dissolved in a mixed solvent containing sulfolane and .gamma.-butyrolactone, and a third electrolyte which includes a mixed solvent containing .gamma.-butyrolactone and at least two of sulfolane, 3-methyl sulfolane and 2,4-dimethyl sulfolane and a quaternized imidazolinium salt or a quaternized pyrimidinium.

Abstract: A vibration dampening mechanism for operative arrangement with a data storage media drive canister, having: a cantilevered dampening spring secured to a surface of, or integral with, a side of a housing for the drive canister. The spring has a free end that can extend over an aperture through the housing side. The spring can comprise a bent portion, having an outer bend surface, between a secured end and the free encl. When installed in a canister support structure, this outer bend surface will contact an under surface of the structure causing the bent portion to at least partially flatten; the free end may deflect into the aperture. Also, a storage media drive vibration dampening system for operation with a media drive canister support structure having: a cantilevered dampening spring secured to, or integral with, a side of a drive canister housing.

Abstract: A "hot-pluggable" hard disk drive is mounted in a removable hard disk drive tray. The hard disk drive tray has a vibration dampening system for reducing vibration between the hard disk drive, the hard disk drive tray, and a hard disk drive docking bay located within a computer system. The vibration dampening system has three primary components. The first component is a strip of polymeric material located between an end of the hard disk drive tray and the docking bay. The second component of the vibration dampening system is a set of polymeric strips located between an inner surface of the tray and the hard disk drive. The third component of the vibration dampening system is a set of spring assemblies. Each spring assembly is located between the sides of the tray and the docking bay.

Abstract: A CPU module for compactPCI-based computer, including a fixing board having a first surface and a second surface opposite to the first surface is disclosed. A first fixing member is disposed on the first surface for fixing a first peripheral equipment of the computer. A second fixing member is disposed on the second surface for selectively fixing a second peripheral equipment of the computer. The first fixing member includes two sets of fixing plates spaced from each other by a distance sufficiently long for receiving therein the first peripheral equipment. Each of the fixing plates is formed with a hole for a screw to pass there through for fixing the first peripheral equipment on the fixing board. The second fixing member also includes multiple holes for screws to pass there through for fixing the second peripheral equipment on the fixing board. Multiple spacing posts are disposed on the fixing board for supporting and fixing a main board thereon.

Abstract: The invention relates to an electronic power module comprising electronic power components (1) each having at least one contact face (2), control connections (4) for connecting the components to a control module, power connections (5) for conveying power between the components and/or other modules, and at least one metal heat exchanger (6) for removing power dissipated by the Joule effect in the electronic power components (1). According to the invention the contact faces (2) of the electronic power components (1) are mounted directly on the metal heat exchanger (6), the metal heat exchanger (6) being at the same potential as the contact faces (2) of the electronic power components (1).

Abstract: A heat generating cooling device including a heat sink with a plurality of fins and a cooling fan unit mounted on and above the fins and having a motor. At least one auxiliary blade is provided on the bottom surface of the motor and extends in toward the thickness direction of the heat sink. The fins can be formed short to provide blade clearance.

Abstract: A sealed type casing comprises a casing body 10, a cover 9, one motor 12 fixed to a rear face plate 10a of the casing body, a plurality of inner and outer heat exchange fins 11a, 11b integral with and formed on inner and outer surfaces of the rear face plate so that the heat exchange fins are arranged vortically in an overlapping manner around a rotary shaft 12a of the motor, a first centrifugal fan 13 adapted to be rotated inside the casing body by the motor and sending the air to the inner heat exchange fins, and a second centrifugal fan 13 adapted to be rotated outside the casing body by the motor and sending outside air to the outer heat exchange fins. When the motor is rotated, the centrifugal fans apply a centrifugal force to the air sucked from a region close to the rotary shaft of the motor, and send out the air toward the heat exchange fins.

Abstract: A heat-dissipating module for dissipating heat generated by an electronic component includes a fan base formed with a fan mounting cavity, a heat-dissipating fan mounted in the fan mounting cavity, a heat-conducting plate adapted to contact a heat-dissipating side of the electronic component, and a connecting shaft having a mounting section that is mounted on the heat-conducting plate and a pivot section that extends from the mounting section and that is mounted pivotally on the fan base, thereby permitting movement of the heat-conducting plate toward and away from the heat-dissipating side of the electronic component.

Abstract: A CPU cooling system for dissipating heat from a CPU in a computer which includes a water cooling type CPU heat dissipating unit fastened to the CPU of the computer for carrying heat away from the CPU, the water cooling type CPU heat dissipating unit defining a water circulation channel, a rack installed in the computer, a water and air cooling type heat dissipating unit mounted in the rack, the water and air cooling type heat dissipating unit including a water tank holding a liquid coolant, a heat sink mounted in the water tank, at least one first radiator each defining a water circulation channel, at least one cold discharge device each having a cold side disposed in contact with the at least one first radiator and a hot side disposed in contact with the heat sink, at least one fan disposed behind front air vents on the rack, and a second radiator disposed between the at least one fan and the at least one first radiator, the second radiator having evaporator coils a water-circulation pipe assembly for circu

Abstract: An integrated circuit cartridge has been described. The cartridge includes a heat pipe lid that comes in thermal contact with at least one integrated circuit die. The integrated circuit die is mounted on a substrate that is held in a cavity of a pin chassis that has a grid array of pins for interconnection with a socket. The integrated circuit die can be mounted on a secondary substrate that is mounted to a primary substrate. The substrate has an edge connector to supply power to the integrated circuit die, freeing the grid array of pins to be used for signal interconnects. The substrate has a grid of connections soldered to the grid array of pins on the pin chassis. The pin chassis also supplies key structures that aid in alignment of the pins and a socket.

Abstract: A switch box for a vehicle has a substrate, an electricity distribution bus bar mounted on the substrate and at least one intelligent power switch mounted on the bus bar. To provide good heat dispersal from the switch, the bus bar is mounted to be upstanding from the substrate with its side surfaces extending away from the substrate. The intelligent power switch is mounted on one side surface of the bus bar. The bus bar may be shaped so as to lie against at least two sides of the intelligent power switch.

Abstract: The invention relates to security apparatus for computer equipment and, more particularly, to a device for securing a computer casing and its contents, i.e. the CPU and/or docking station, to a surface to prevent its theft and/or to prevent tampering with or pilfering of its internal components. In one embodiment, the device comprises an open-ended base (12) which is mountable on a surface by fasteners such that the unfastening elements therefor are contained generally within the base. A containment structure (14) comprising a frame (18) and a plurality of connecting members (20a, 20b, 20c, 20d) is fastenable to the base by fasteners whose unfastening elements therefor are likewise contained within the base.

Abstract: Provided is a semiconductor assembly, comprising a circuit board (1) including a conductor circuit (4), the conductor circuit including connecting pads, a semiconductor chip (2) provided with connecting terminals provided on a first surface thereof, and mounted on the circuit board, a casing (5) covering the circuit board, wherein the connecting pads of the conductor circuit and the connecting terminals of the semiconductor chip are disposed in mutually opposing relationship, and are connected with each other by an electroconductive bonding agent, a neutral plane of the semiconductor chip substantially coinciding with an overall neutral plane of the semiconductor assembly.

Abstract: There is provided an IC card and manufacturing method thereof assuring a highly reliable fixed portion in fixing upper and lower panel members to a frame made of resin as well as an advantage in terms of manufacturing cost. In the IC card in which a pair of upper and lower panel members covering card planar portions are respectively fixed to the upper and the lower surfaces of a resin frame which supports a peripheral portion of an electric circuit board and a connector attached to an end portion of the electric circuit board, the panel members have their peripheral edge portions which are provided with a bent portion extending along the peripherial edge portions and are formed by bending the panel material at a specified angle, and a welding use resin layer is formed on the surface of the bent portion and the periphery of the planar portion of the panel member.

Abstract: A casing for enclosing a circuit board comprises pair of symmetrical halves assembled together. Each said half forms plurality of retaining means on a first longitudinal side thereof and plurality of receiving means at a second longitudinal side opposite said first longitudinal side whereby said halves are fixedly assembled together by the interlocking engagement between said retaining means and said receiving means.

Abstract: In an IC card in which an IC module constituted by a terminal plate 1 having a connection terminal pattern(3), arranged on a surface of an insulating substrate (2), for external power supply, signal connection, and grounding, an IC chip (4) mounted on the rear surface of the terminal plate 1 and electrically coupled to the connection terminal pattern (3), a sealing member (5) for the IC chip, and a reinforcing member (6) for reinforcing the sealing member (5) is mounted on a card base, the reinforcing member (6) consists of a conduction material, and integrally constituted by a ring portion (7) for covering the outer periphery of the sealing member (5) and a flange portion (8), having almost the same shape as that of the outer periphery of the terminal plate (1), for covering the rear surface of the insulating substrate (2).

Abstract: A method of forming a circuit board includes, a) providing a temporary substrate; b) depositing an uncured electrically insulative circuit board material over the temporary substrate, the circuit board material adhering to the temporary substrate; c) substantially curing the uncured circuit board material into at least one self supporting sheet; d) providing circuit traces atop the cured self supporting sheet; e) mounting an electronic circuit component atop the cured self supporting sheet in electrical communication with the circuit traces; and f) peeling the temporary substrate and cured self supporting sheet from one another.

Abstract: An adjustable circuit board support frame utilizes an adjustable frame assembly for receiving various size circuit boards having the desired interface connectors and logic circuits thereon so as to allow for necessary repair, expansion, or upgrade of the computer system. The present invention provides for the removability and replacement of any size circuit board within the computer housing at any time during manufacturing or in the field. A base computer system may be easily upgraded when more features are desired by interchanging the circuit board within the system and adjusting the frame assembly to the desired position.

Abstract: A technique for installing circuit cards on a motherboard in an electronic device. A motherboard, having a plurality of keyhole apertures and locking apertures, mounts in the electronic device. Cardguide pairs mount on the motherboard to form expansion ports for receiving circuit cards. Each cardguide pair has two parallel card guides. Each card guide has an elongated body with a bottom member and a longitudinal groove. Entrance ports and ramps located at either end of the body communicate with the groove. Mushroom mounting lugs and resilient locking hooks mount on the bottom member. A cardguide installer places each card guide on the motherboard while passing each mushroom lug into a wide segment of a keyhole aperture. The installer then slides the card guides parallel to the plane of the motherboard to move the mushroom lugs into a narrow segment of the keyhole apertures, while the hooks couple to the locking apertures.

Abstract: The present invention relates to a protective shield (1) of EMC-type, for e.g. electrical components (40) on a circuit board (30). The protective shield (1) comprises a frame (10) with associated lid (20), where said frame (10) at the end facing towards the circuit board (30) comprises a flange (12). The frame is arranged to be fastened to the circuit board (30) by means of gluing, welding or soldering. The frame (10) is intended to surround at least one component (40) so that electrical contact is formed between said circuit board (30) and said frame (10) and between said frame (10) and said lid (20).

Abstract: A filler module is slidably mountable in an otherwise unused slot of a multi-slot, multi-module electronic system housed in a casing. The filler module includes a relatively compact housing which engages an EMI gasket and an electric connector in an unused slot at the backplane of a shelf in the casing. The module also includes a non-conductive, rigid extension element which facilitates air flow between adjacent modules within the rack. The extension element may include electrically conductive strips which provide ESD protection during the insertion of the module through intimate contact with a grounded, resilient contacting surface. The module may also comprise a non-conductive bulkhead with pivoted latches which engage the casing to secure the housing to the backplane. In this way, a filler module is achieved in which EMI containment is accomplished in a modular fashion and air flow is maintained in the shelf independent of the number or position of used and unused slots.

Abstract: A retention member for securing a dual processor card retention module to a circuit board is provided. In accordance with an embodiment of the present invention, the retention member includes a base portion. A first securement portion is disposed at a first end of the base portion and defines a first bore that extends therethrough. A second securement portion is disposed at a second end of the base portion and defines a second bore that extends therethrough.

Abstract: An integrated circuit includes a converter for converting a first DC voltage from a DC voltage source to an AC signal. The converter include an inductor and a transistor. The inductor and an intrinsic capacitance of the transistor provide an oscillating circuit without a need for a transformer. The integrated circuit also includes a rectifier for rectifying the AC signal to form a second DC voltage which has a sign opposite to the sign of the first DC voltage.

Abstract: A current detecting circuit detects amplitude of a current flowing toward the connecting point of a first transistor and a serial circuit through a second transistor and a comparing circuit compares amplitude of the current detected by the current detecting circuit with the reference value. An oscillation control circuit controls a control current supplied to an oscillating circuit in order to raise the oscillation frequency of the oscillating circuit when amplitude of the current detected by the current detecting circuit is smaller than the reference value as a result of comparison by the comparing circuit in view of preventing the oscillation frequency to be further lowered. Therefore, it is no longer required to design the apparatus by giving allowance to take into consideration the temperature characteristics and fluctuation of parts unlike the related art in which the minimum oscillation frequency of the oscillating circuit is set. Accordingly, variable range of the oscillation frequency can be expanded.

Abstract: The switched-mode power supply comprises a secondary winding and four diodes for producing two rectified voltages of the same polarity, one of which can be regulated. A connection of the unregulated voltage has connected to it a variable Zener diode as an error amplifier for transmitting a regulating signal to the primary side. The driver stage provides a pulse-width-modulated square-wave signal for driving the switching transistor which is arranged at a high potential between the operating voltage on the input side and a first connection of the primary winding. The second connection of the primary winding is connected with a Zener diode and provides a stabilized voltage for the driver stage. Arranged between the driver stage and the control electrode of the switching transistor there is a differentiating element which produces positive and negative switching voltages for controlling the switching transistor.

Abstract: In an arrangement for supplying energy from an a.c. voltage source that includes a rectifier bridge (D1) and a converter (TR1, D5, C4), an inductor means (L1) is connected between a first output terminal on the rectifier bridge and a valley-fill circuit (10) that includes at least two capacitors (C1, C2). The converter includes a transformer (TR1) having a primary winding which together with a controllable switch means (SW1) is included in a loop that extends from a second output terminal on the rectifier bridge to the interconnection junction between the inductor means and the valley-fill circuit (10). When the absolute value of the source voltage is greater than or approximately equal to a highest intermediate voltage including the voltage across at least one capacitor in the valley-fill circuit, energy is supplied from the source to the inductor means and to the valley-fill circuit.

Abstract: A DC converter for stepping down DC voltage having two input terminals (E1, E2) to be connected to an input DC voltage source with a high voltage level; two output terminals (A1, A2) for taking a regulated low output DC voltage; a coil (TS) having a center tap (MA) and connected at one end (TA1) with a first one (E1) of the input terminals via an electronic switch device (MOS) and at the other end (TA2) with the second input terminal (E2) via a first capacitor (C1); the charging voltage of the first capacitor (C1) forming the output DC voltage; a second capacitor (C6) connected at one end with a node located between switching device (MOS) and coil (TS) and at the other end with the center tap (MA) via a first diode (D2); a control device (EV, PWM for comparing the charging voltage of the second capacitor (C6) with a reference voltage (REF) and rendering the switch device (MOS) conductive and non-conductive with a pulse-frequency modulated and/or pulse-width modulated switching pulse sequence depending on the

Abstract: In a tuned switch mode power supply, a supply inductance is coupled to a capacitance to form a tuned, resonant circuit. A transistor switch is coupled to the resonant circuit for generating current pulses in the inductance, coupled to a load circuit to provide an output of the power supply. Resonant voltage pulses are developed between a pair of main current conducting terminals of the transistor switch. A controller is coupled to the transistor switch for generating a switch control signal, during a run mode of operation. The transistor switch is turned on periodically, when the resonant voltage pulses reaches a zero voltage, to provide for zero voltage switching. The generation of the current pulses is disabled to provide for a burst mode operation, in a standby mode operation.

Abstract: A push-pull converter for converting an input voltage to a selectable output voltage is disclosed. The push-pull converter includes a pair of primary switches and a pair of primary windings of a transformer. The voltage stress across the primary switches is regulated by means of a clamp capacitor. The clamp capacitor clamps the voltage of the primary switches during the reset of the primary windings of the transformer. An alternate embodiment is also disclosed in which the voltage stress across the primary switches is regulated by means of two clamp capacitors. The clamp capacitor clamps the voltage of the primary switches during the reset of the primary windings of the transformer. The clamp capacitors extend the transformer reset period to include the lagging dead time for the corresponding switches, as well as the complementary powering stage. Current in the output section during the dead times is permitted by means of an additional diode, therein.

Abstract: In a method for open-loop and closed-loop control of an electrical drive, which comprises an asynchronous motor (18) which is supplied by a DC-AC invertor (14) with a downstream sine-wave output filter (15) with an AC voltage at a predetermined circular frequency (.omega.), stable operation with a good control response and reliable damping of natural filter oscillations is achieved in that the voltage at the output of the sine-wave output filter (15) is measured, in that the measured filter voltage is assigned a complex filter voltage vector (E) in a complex reference system rotating at the circular frequency (.omega.), and in that the DC-AC invertor (14) is actuated in such a manner that the complex filter voltage vector (E) corresponds to a predetermined required voltage vector (E*).

Abstract: A multi-motor drive in which the resonance existing between one or more output filter capacitors of a current source inverter and an a.c. induction motor is reduced. The inverter features a switching pattern generator which controls the power switches of the inverter based on a reference current. A control loop, connected to the switching pattern generator, measures the load current or voltage and generates a nominal reference current based on an error therein; determines a damping current based on the voltage at the terminal; and determines the reference current supplied to the switching pattern generator by subtracting the damping current from the nominal reference current. The invention essentially simulates the use of a physical damping resistor connected in parallel with each output filter capacitor, but without the corresponding energy loss.

Abstract: A DC matrix converter having six forward current conducting power switches and six reverse current conducting power switches has the on time duration of each power switch within each pulse width modulation period controlled by relationships between d, q components of a modulation index determined by the ratio of a voltage command to the instantaneous voltage of the AC mains expressed in stationary d, q coordinates, the selection of which is made based on inequalities between the AC mains voltage components expressed in dq coordinates, and relationships of the AC main voltage components expressed in d, q coordinates. Zero vectors are related to the one AC main having lower line-to-neutral voltage than the other AC mains, using relationships between the instantaneous AC mains voltage in d, q coordinates.