Abstract: It is an object to integrate storing functions at a high density and make it possible to perform a stable operation even at a low power supply voltage. A MOS transistor including a gate electrode and an n-type impurity region serving as a source-drain has a memory capacitor comprised by a dielectric film, a conductor, and an n-type impurity region opposing to the conductor through the dielectric film in a first trench formed in a p-type epitaxial layer beneath the gate electrode. With this structure, an area occupied by the MOS transistor and the memory capacitor can be minimized. Each unit memory cell is a two-transistor memory cell in which the drain and source of a MOS transistor supply a pair of complementary signals to a detection circuit. For this reason, a storing operation can be made reliable, and a stable operation can be realized, especially, at a low voltage.

Abstract: A laser trimming link is provided on a field oxide film. An N well is formed below the field oxide film and in the surface of a semiconductor substrate. N well is formed of a retrograde well.

Abstract: The present invention provides for a shielded capacitor in a digital CMOS fabrication process. The shield capacitor comprises a first surface (also known as a top plate) and a second surface (the bottom plate). The bottom plate has two portions which are connected, and the two portions of the bottom plate are positioned to sandwich the top plate in between the portions. A polysilicon layer is fabricated between the plates and the substrate of the semiconductor to isolate the plates from the substrate. To build the shielded capacitor, the polysilicon layer is fabricated first, then the plates are built on top of the polysilicon layer. The polysilicon layer is silicized and is often connected to the ground.

Abstract: A lateral PNP bipolar electronic device integrated monolithically on a semiconductor substrate together with other NPN bipolar devices capable of being operated at high frequencies. The PNP device is incorporated to an electrically insulated multilayer structure which comprises a semiconductor substrate, doped for conductivity of the P-type, a first buried layer, doped for conductivity of the N-type to provide a base region, and a second layer, overlying the first and having conductivity of the N-type, to provide an active area distinguishable by a P-doped emitter region within the active area being located peripherally and oppositely from a P-doped collector region. The lateral PNP device can be operated at high frequencies with suitable collector current values and good amplification, to provide a superior figure of merit compared to that typical of conventional lateral PNP devices.

Abstract: A semiconductor device comprising a silicon substrate is provided with semiconductor elements on a first side, a metallization with connection pads for external contact, and a passivation layer which leaves the connection pads of the metallization exposed. The integrated circuit thus formed is also provided with a ceramic security coating having a matrix of monoaluminium phosphate which also leaves the connection pads of the metallization exposed. The protective layer can be deposited so as to have a thickness in the range from 2 to 10 &mgr;m, and hence is suitable for protecting integrated circuits used in smart cards. As a result, the information stored therein is not accessible.

Abstract: A bipolar power transistor intended for radio frequency applications, especially for use in an amplifier stage in a radio base station, and a method for manufacturing the bipolar power transistor are provided. The power transistor includes a substrate (13), an epitaxial collector layer (15) on the substrate (13), a base (19) and an emitter (21) formed in the collector layer (15). The degree of doping Nc(x) of the collector layer varies from its upper surface (24) and downwards to at least half the depth of the collector layer, essentially according to a polynom of at least the second degree, a0+a1x+a2x2+ . . . , where a0 is the degree of doping at the upper surface (24), x is the vertical distance from the same surface (24) and a1, a2, . . . are constants. The transistor can further include an at least approximately 2&mgr; thick insulation oxide (17) between the epitaxial collector layer (15) and higher situated metallic connections layers (31, 33).

Abstract: To improve the gettering performance by ion implanting boron and improves the production yield of the semiconductor device by using an epitaxial wafer of good quality suppressing the occurrence of dislocations. For this purpose, an epitaxial wafer in which an epitaxial layer of about 1 &mgr;m is formed to a CZ semiconductor substrate implanted with boron ions which are dopant and carbon ions which are not a dopant is provided, and transistors are formed on the surface of the epitaxial layer.

Abstract: A semiconductor structure includes a first substrate portion having a surface and a first active region disposed in the first substrate portion. An insulator region is disposed on the first substrate portion outside of the first active region and extends out from the surface. A second substrate portion is disposed on the insulator region, and a second active region is disposed in the second substrate portion. Thus, by disposing a portion of the substrate on the isolation region, the usable substrate area is dramatically increased.

Abstract: A bonded wafer in which silicon wafers and an amorphous heat fusion bonding polyimide are used, a process for producing the same, and a substrate which is prepared by variously processing the bonded wafer.

Abstract: A semiconductor device of surface-mount type includes a circuit strip tailored to have patterns projected, a semiconductor element fixedly joined to the circuit strip, and pads on the semiconductor element electrically connected by wires to the corresponding patterns on the circuit strip and sealed with a resin material. While the surface-mount type semiconductor device is adapted to be simple in structure and capable of high-density mounting, an appliance on which the semiconductor device is mounted and a method of producing the semiconductor device are also provided.

Abstract: This semiconductor device comprises a semiconductor package having a first wiring substrate and a semiconductor element disposed or mounted thereon, a mounting second wiring substrate, and a protrusion electrode terminal and a receiving terminal portion for connecting an external connecting terminal of the semiconductor package and an external connecting terminal of the second mounting wiring substrate. The protrusion electrode terminal coated with a conductor layer is disposed on the external connecting terminal of the semiconductor package. An aggregated electrode layer having a plurality of fiber electrodes that are bound or tangled is disposed on the external connecting terminal of the mounting wiring substrate. The protrusion electrode terminal on the semiconductor package side is detachably inserted into the aggregated electrode layer on the mounting wiring substrate side. Thus, the protrusion electrode terminal and the aggregated electrode layer are mechanically secured and electrically connected.

Abstract: A semiconductor apparatus and method of manufacture therefor comprises a printed circuit board (PCB) having a plurality of pads with each pad adapted to receive a bond wire and a plurality of holes through the PCB. The apparatus further comprises a semiconductor die associated with each hole, each semiconductor die having a circuit side with bond pads on the circuit side, wherein the circuit side of each said die is attached to the printed circuit board. The apparatus also comprises a plurality of bond wires each having first and second ends, wherein the first end is attached to one of the bond pads and the second end is attached to one of the PCB pads and each bond wire passes through one of the plurality of holes.

Abstract: A thin, small-outline semiconductor package, and a thermally enhanced leadframe for use in it, comprise a plurality of electrically conductive leads held together in a spaced, planar relationship about a central opening defined by the leads, and a thick, plate-like heat sink made of an electrically and thermally conductive metal attached to the leads such that it is centered within the opening and parallel to the plane of the leads. The heat sink has a lower surface exposed through the outer surface of a molded resin envelope encapsulating the package for the efficient dissipation of heat therefrom, and an upper surface having a recess formed into it. The recess has a planar floor with a semiconductor die attached to it, and defines a grounding ring around the periphery of the upper surface of the heat sink immediately adjacent to the edges of the die for the down-bonding of grounding wires from the die and the leads.

Abstract: A semiconductor package and method for fabricating same is provided that includes a printed circuit board having an electrical circuit formed therein, a plurality of semiconductor chips vertically attached at fixed intervals to the printed circuit board and conductive connecting members that couple bonding pads on each semiconductor chip to pads on the printed circuit board. An encapsulation body encapsulates the semiconductor chips and the conductive connecting members above the printed circuit board. External connection terminals can be attached on a lower side of the printed circuit board for electrical connection to the semiconductor chips through the electrical circuit in the printed circuit board. The semiconductor package and method has increased mechanical and electrical reliability. The semiconductor package is preferably an ultra high density integrated circuit semiconductor package.

Abstract: A semiconductor device includes a wiring substrate having wiring and a solder resist for protecting the wiring, which are provided on an insulating substrate, a semiconductor chip which is mounted via the wiring protective film on the wiring substrate on a surface on the other side of the surface on which a circuit is provided to face a side of the wiring substrate on which the wiring is formed, and a wire for electrically connecting the circuit provided on the surface of the semiconductor chip and the wiring of the wiring substrate, and the surface of the solder resist and the semiconductor chip are firmly adhered to each other. In this semiconductor device, because the solder resist and the semiconductor chip are firmly adhered to each other, there arise no bubbles due to a spacing at a portion where the solder resist and the semiconductor chip are bonded with each other.

Abstract: A package for mounting a power semiconductor device to a printed circuit board comprises a dielectric ceramic plate having an upper and lower surface and a grid array of holes penetrating the plate. A plurality of conductive metal contact pads that provide electrical contact for the power semiconductor device are disposed on the upper surface of the ceramic plate, and a conductive metal fills the holes. The metal-filled holes are connected to the conductive metal contact pads and provide vias from the pads to the lower surface of the ceramic plate. An array of solder balls, each ball being attached to a via at the lower surface of the ceramic plate, provide connection terminals to the printed circuit board. Sidewalls are sealably connected to the ceramic plate at its perimeter, and a lid is sealably connected to the sidewalls. The lid comprises, together with the sidewalls and ceramic plate, a hermetically sealed cavity that encloses the power semiconductor device and conductive metal contact pads.

Abstract: A semiconductor structure of reduced contact resistance is provided by providing a layer of amorphous silicon-derived material on an epitaxial silicon substrate having an average dopant concentration of at least about 1020 atoms/cm3 in the contact material within about 500 Å of the substrate.

Abstract: An integrated circuit and method for forming the same. The integrated circuit includes a semiconductor wafer with first and second surfaces. A functional circuit is formed on the first surface of the semiconductor wafer. Further, a metallization layer is formed outwardly from the first surface of the semiconductor wafer. The integrated circuit also includes at least one high aspect ratio via that extends through the layer of semiconductor material. This via provides a connection between a lead and the functional circuit.

Abstract: A semiconductor device excellent in bonding strength of bumps with respective protruded electrodes and having high reliability wherein a wiring pattern 28 to be connected to an electrode 22 of a semiconductor chip 20 is formed on an insulting film 23 formed on the semiconductor chip 20 in which the electrode 20 is formed, protruded electrodes 32 are formed on the wiring pattern 28, the wiring pattern 28 is covered with a protective film 36, and a bump 38 for external connection is formed on the end portion of each of the protruded electrodes 32 exposed from the protective film 36, the bump 38 is formed in such a manner that the bump is bonded to the at least entire end face of each of the protruded electrodes 32.

Abstract: A copper bonding pad is directly supported by a copper via pad structure, the copper via pad structure having substantially the same geometry and dimensions as the copper bonding pad. The combination of the copper bonding pad and the copper via pad structure results in an increase in effective thickness of the copper bonding pad. Due to this effective increase in the bonding pad thickness, the bonding pad is more tolerant to the potential dishing problem caused by the CMP process. Additional metal pad structures and via pad structures are used below the bonding pad. The additional metal pad structures and via pad structures comprise alternating segments of interconnect metal and dielectric fillers, and alternating segments of via metal and dielectric fillers, respectively. The alternating segments of interconnect metal and dielectric fillers and the alternating segments of via metal and dielectric fillers prevent or reduce the potential dishing problem that otherwise exists in damascene and CMP processing.

Abstract: A thermally enhanced quad flat non-lead package of semiconductor comprises a chip a plurality of leads, and a molding compound. The chip has its active surface bonded to the top surface of the die pad, and the area of the die pad is smaller than that of the chip in order to expose the bonding pads on the active surface of the chip. The leads are disposed at the periphery of the die pad wherein the bottom surface of the lead has a stepped structure with a relatively thin portion to form a wire-bonding protruded zone. A plurality of bonding wires is used to electrically connect the wire-bonding protruded zone of the leads to the bonding pads of the chip. The molding compound encapsulates the chip, bonding wires, the die pad, and a portion of the surface of the leads, but exposes the bottom surface of the die pad.

Abstract: An improved semiconductor chip package capable of independently aligning with testing equipment during the manufacturing phase of electrical testing. Independent alignment is realized by directly connecting the semiconductor chip package to the test alignment apparatus by fitting together two substantially conforming surfaces, one on the chip package and one on the alignment apparatus. The conforming surfaces are arranged so that only one matable position is achievable. The substantially conforming surfaces equate to three substantially conical indentations on the chip package and three substantially conical protrusions or protuberances of substantially conforming size and depth extending from the alignment apparatus.

Abstract: A method of forming an SRAM transistor cell on a doped semiconductor substrate with a halo region in transistors thereof by the steps including well formation, field isolation formation, threshold voltage implant, gate oxidation; deposition of polysilicon and patterning thereof into gate electrode; post etching anneal; N type LDD photolithography and ion implanting NMOS transistor devices; ion implant halo regions in a transistor; P type LDD photolithography and ion implanting PMOS transistor devices; spacer formation; N+ source/drain photolithography and ion implanting; and P+ source/drain photolithography and ion implanting.

Abstract: A microturbine power generation system includes an electrical generator, a turbine and a compressor intermediate the generator and the turbine. The turbine, compressor and electrical generator are secured together by a tieshaft. The tieshaft is prestressed such that faces of the turbine, electrical generator and compressor maintain contact during high-speed, high-temperature operation of the system.

Abstract: A switching device and process for external force-actuated driving devices in a motor vehicle, especially windows and sliding roofs. Depending on the dynamics and/or degree of displacement of an actuating component, control signals are generated which code the displacement speed and travel, the position, the displacement duration and/or direction of the item to be displaced. The actuating component is preferably an unrestrictedly rotatable component which, during its rotation, generates control signals for an electronic control unit. The device and process give a user the greatest possible control over the displacement of the component.

Abstract: An improved UPS/CPS system employs a high-efficiency uninterrupted power supply function integrated with an engine-generator set that combines both short term protection against momentary power interruptions with longer term power generation. Feedback from a controller provides for improved voltage regulation during abrupt load changes and flexibility of application. A number of features and operating modes are disclosed. In one embodiment, the system is useful as a kit to retrofit existing backup power facilities.

Abstract: A power supply that provides a source of backup AC voltage and a method of operating thereof. In one embodiment, the power supply includes a transformer having main power and backup power windings and a secondary winding. The power supply also includes multiple stages, namely, (1) a primary power stage coupled to the main power winding, (2) a backup power stage coupled to the backup power winding and having a backup battery, one of the primary and backup power stages acting as a current fed source and (3) an AC power stage, coupled to the secondary winding, that provides a source of AC voltage. The power supply is operable in a normal mode of operation in which the primary power stage supplies power to the secondary winding and further supplies power to the backup power winding to allow the backup power stage to charge the backup battery.

Abstract: A single- or multi-phase step wave power converter includes multiple transformers configured to receive DC voltage from one or more power sources. Each of the transformers includes a primary winding and a secondary winding. The transformers are each configured to supply a step for a step wave AC output. Bridge circuits are supplied for controlling input of DC voltage into the primary windings of the transformers. Steps for the step wave AC output are output from the secondary windings based upon the input provided to the primary windings. DC source management circuitry manages which DC power source(s) supplies DC voltage input to each of the bridge circuits. The management circuitry provides seamless power switching between the plurality of DC power sources based on each power source's performance characteristics. A pulse-width modulator can also be provided to the step wave power converter to modulate the input into a selected primary winding.

Abstract: A linear actuator can obtain a roughly fixed load within a stroke range. The linear actuator comprises a fixed element, comprising a yoke and a magnet which is magnetized in the radial direction, and a moving element, comprising an electromagnetic coil and a bobbin which surrounds the magnet. A spring is provided for applying a force acting in opposition to the thrust direction acting on the moving element. A constant load stroke area is provided so that the characteristics of the opposite force of this spring balance the characteristics of the thrust force acting on the moving element. The constant load stroke area is an area where one end of the coil in the stroke direction is located in an outside position from one end of the magnet in the stroke direction, and the other end of the coil in the stroke direction is located in an inside position from both ends of the magnet in the stroke direction.

Abstract: A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

Abstract: A motor which has optimal performance along with minimal performance sensitivity with respect to manufacturing variations is described. Performance is defined by a critical-to-quality relationship. A process for designing such a robustly optimal, yet manufacturable, motor also is described.

Abstract: A two-phase electro-mechanical stepper motor has a first and second rotor fixed on a shaft. Permanent magnets are mounted on each of the rotors. The magnets each have several north and south pole magnet regions that are oriented such that the magnet's north and south pole magnet regions are misaligned with respect to the other magnet's north and south pole magnet regions. A first and second stator are mounted around the shaft and positioned adjacent to the permanent magnets. The stators have coils that are wrapped around poles to allow the formation of electromagnets by passing electrical current through the wire coils. A gear train is positioned between the first and second rotors to obtain a higher torque output.

Abstract: An electric drive unit includes an electronic control and monitoring module integrally connected to an electric motor. The housing of the electric motor has a double-walled construction to form a water jacket with cooling water passages therein. The electronic module includes at least one high power component that requires cooling. This component is mounted directly on a cooling insert that extends through a recess in the electronic module housing and is inserted in an opening provided in the outer wall of the motor housing. In this manner, the cooling insert is integrated into the water jacket of the motor housing and is directly cooled by the cooling water flowing in the cooling passages. A very compact and reliable construction is achieved, in which the electric motor and the electronic module share a common water cooling circuit. External water hoses and external electrical connections between the electric motor and the electronic module are avoided.

Abstract: In order to protect a brushless motor, heat generated at a switching device, in response to an abnormality, activates a protection device. The protection device includes a connecting line communicating between a source supply line and the switching device. The protection device is provided near the switching device such that it can sense heat at the switching device with a high degree of sensitivity. Thus, when excessive heat is generated at the switching device, the protection device reaches a specific temperature, whereby the source supply line becomes cut off from the switching device, thereby immediately stopping the operation of the brushless motor.

Abstract: A magnetic ring (1) is provided, comprising a magnetic disc (2) and an annular disc (10). The annular disc (10) is coated, by injection molding or die-casting, with a magnetizable material so that two spring tongues (20,21) protrude from the inner rim of the magnetic disc (2) which are able to exert a clamping effect on a shaft or rod (30).

Abstract: An electric motor includes a stator having a plurality of conductive windings radially spaced about a central axis. A rotor is located radially inward up the stator and is rotationally fixed with respect to a shaft along the central axis. The rotor and the stator are disposed in a frame. A heater is in operative communication with the windings. A thermostat is in operative communication with the heater and is configured to activate and deactivate the heater responsively to a motor temperature.

Abstract: A positive-side heat sink and a negative-side heat sink are both disposed on a generally flat plane perpendicularly intersecting a shaft, the longitudinal direction of the positive-side diodes secured to the radially inner positive-side heat sink being disposed along the radial direction of the positive-side heat sink, and the longitudinal direction of the negative-side diodes secured to the radially outer negative-side heat sink being disposed along the circumferential direction of the negative-side heat sink.

Abstract: A vehicle AC generator includes a pair of front and rear frames fastened by a plurality of stud bolts at peripheral portions thereof, a stator having a multi-phase armature winding supported by the pair of frames, a rotor disposed radially inside the stator, a rectifier unit having a positive cooling fin holding a plurality of positive diodes, a connection member, and a negative cooling fin holding a plurality of negative diodes. The positive cooling fin is fastened by the plurality of stud bolts together with the pair of frames separate from the negative cooling fin, and the connection member is disposed between the positive cooling fin and the negative cooling fin. The connection member has a circuit for electrically connecting the armature winding and the rectifier unit, which is covered by an insulation member.

Abstract: In a motor driven device, a yoke of a motor has a flange at a side of its opening. An end plate sized smaller than the flange is formed with tongues on its outer circumferential periphery so that the end plate is press-fit in position in the yoke through the tongues. An annular packing is disposed around an annular ring part of the end plate so that the packing encircles the end plate when the flange of the yoke is fixed to a housing of a pump. The packing fluid-tightly seals the inside of the yoke from an outside.

Abstract: The present invention provides a compact, efficient and noiseless alternator for an automotive vehicle which employs a double-layer coil arrangement in a slot for eliminating coil end interference as well as improving the space factor. An automotive alternator comprises a Lundel-type core rotor with 16 poles, and a stator with toothed portions of 96 poles spaced by slots. U-shaped conductor segments are installed in the slots. One portion of the conductor is accommodated in an outer layer portion of a predetermined slot, while the other portion is accommodated in an inner layer portion of a slot phase shifted by an electric angle of 180°. In this manner, all of the slots are separated into the inner and outer layers to accommodate a plurality of conductor segments. These conductor segments are connected only at one side of the stator to form a total of twelve wavy winding coils.

Abstract: The present invention relates to a replacement alternator constructed to replace an existing CS-130 alternator in a vehicle where the CS-130 alternator was disposed in a predetermined alternator space within the vehicle. The alternator space has a predetermined length, width and height. The alternator comprises a housing defining an alternator interior space. The housing is sized to fit within the predetermined alternator space. A rotor coil having a plurality of wire windings wound thereabout is disposed in the alternator interior space of the housing and rotatably supported by the housing. The wire windings of the rotor coil have an electrical current flowing therethrough for generating a rotating magnetic field as the rotor coil rotates. Means are provided for selectively rotating the rotor coil at a speed of at least 1600 revolutions per minute. The alternator includes a stator positioned in the rotating magnetic field generated by the rotor coil and supported by the housing.

Abstract: The invention relates to a brush-holding device for electric motors comprising carbon brushes, a conductive stamped grid as a printed circuit board, a base to which the printed circuit board is attached and components for monitoring temperature or for radioshielding. The printed circuit board is a single part and has several levels, at least one of which is staggered axially and in alignment with the commutator. The brush-holding device has a small overall length and the electric bonding of the components can take place simply without any additional parts.

Abstract: A configuration for supporting a first part of a stator of an electric machine, in particular a turbogenerator, at a second part of the stator, in which the first part and the second part are at a distance from one another and at least partially surround an axis of rotation of a rotor shaft in a rotation direction. The two parts are each supported against one another by an integral supporting element at least at three locations distributed around the axis of rotation. The supporting elements each have a material strip which is bent in a single plane, between their ends, so that the distance between the two parts is variable when the material strip is subjected to bending deformation in the axial direction and radial direction of the turbomachine. The support is rigid in the tangential direction due to the stiffness of the material strips transversely with respect to the bending course. Due to the bent metal strips, the configuration can be produced in such a way that it saves space and is cost-effective.

Abstract: A rotor (10) for an electric machine (40) includes a first elongated rotor segment (12) having a plurality of axially extending rotor poles (20) arranged in a circular array about a central axis (18) that extends longitudinally through the first rotor segment(12). A second axially extending rotor segment (14) engages and is fixed relative to the first rotor segment (12). The second rotor segment (14) has a plurality of axially extending rotor poles (38) arranged in a circular array about the central axis (18). The poles (38) of the second rotor segment (14) are rotated in a first direction about the central axis relative to the poles (20) of the first rotor segment (12). Preferably the rotor (10) also includes a third axially extending rotor segment (16) that engages and is fixed relative to at least one of the first and second rotor segments (12, 14). The third rotor segment (16) also has a plurality of axially extending rotor poles (44) arranged in a circular array about the central axis (18).

Abstract: A high efficiency motor for low velocity and high volume fans and other applications includes an armature, a stator and a motor shaft. The armature is made from plates that collectively have a stack height that give the armature a thickness. The plates are keyed with a keyway and the motor shaft has a key to increase alignment accuracy and armature assembly efficiency. An armature aspect ratio is determined by the armature diameter divided by the armature thickness. Similarly a stator aspect ratio is determined by a stator diameter divided by a stator thickness. The armature and the stator aspect ratios are selected to increase torque output and lower rotational speed of the motor for various power output levels. Magnetic permeability properties of the armature and stator is selected to increase operating efficiency of the motor and decrease motor size.

Abstract: An electrical machine with a discoidal structure comprising rotor and stator discs disposed coaxially and having at least two axial air gaps between the rotor and stator discs. The widths of the axial air gaps are measured and sent to a control unit for being compared so that an offset signal can be generated based on the difference between the widths of the axial air gaps. The offset signal is supplied to a drive module for driving a balancing means in order to cancel an axial magnetic force exerted on either the rotor or stator discs. The deterioration of the electrical machine can be reduced.

Abstract: A surface acoustic wave functional element is provided that includes a piezoelectric substrate or a multilayer piezoelectric substrate having a large electromechanical coupling coefficient. Semiconductor layers are formed on the piezoelectric substrate. The semiconductor layers include an active layer and a buffer layer. The buffer layer is formed of a structure that has a lattice constant that is the same as or similar to that of the active layer. In addition, input and output electrodes are formed on both sides of the semiconductor layers. The surface acoustic wave functional element attains a large amplification gain at low voltage, and can be used as part of a transmitting/receiving circuit in a high frequency portion of a mobile communication device.

Abstract: When an input voltage rises, (the amplitude of) a sine-wave voltage for driving a piezoelectric transformer (1) increases, so that a detection voltage (Vti) rectified by a rectifying circuit (9) also increases. An output voltage from an error amplifier (10) for comparing the detection voltage (Vti) with a reference voltage (Vref2) rises. If the output voltage from the error amplifier (10) rises, a voltage-controlled oscillation circuit (11) decreases the duty ratio of an oscillation signal to be output. In a driving circuit (7), as the duty ratio of the oscillation signal decreases, the amplitude of a fundamental wave contained in a rectangular wave to be output decreases to be a small driving voltage to the piezoelectric transformer (1).

Abstract: A short circuit between a negative pole GND and a capacitive actuator in a circuit with a charging capacitor, a recharging capacitor, a recharging coil and a selector switch is determined by calculating a value corresponding to the quantity of charge QL flowing off from the recharging capacitor during a charging operation. The quantity of charge is compared with an integral of current i flowing during the charging operation via the selector switch assigned to the actuator. A short circuit of the actuator to the negative pole is diagnosed when the integral is smaller than k*QL (k<1).

Abstract: A thickness extensional vibration piezoelectric resonator includes a strip-type, substantially rectangular plate-shaped piezoelectric body, first and second excitation electrodes disposed on both sides of the piezoelectric body, the back side and the front sides thereof being opposed to each other with the piezoelectric body disposed therebetween, and an internal electrode disposed in the piezoelectric body. The resonator portion where the first and second excitation electrodes and the internal electrode are opposed to each other define a resonance portion. In the longitudinal direction (a first direction) of the piezoelectric body, vibration-attenuating portions are provided on both sides of the resonance portion. The ratio L/D is within the range of about 9.0 to about 14.0, in which L is the length in the longitudinal direction of the piezoelectric body, T is the thickness, and wherein D=T/N.