A drill bit having a bit body, at least one blade extending radially from the bit body, a plurality of blade cutting elements disposed on each blade, at least one journal extending downwardly and radially outward from a longitudinal axis of the drill bit, a roller cone or roller disc mounted rotatably to each journal, and a plurality of cutting elements disposed on each roller cone or roller disc, and methods for making the drill bit are disclosed.

A spacer fluid comprises a fluid and a viscosity agent. The viscosity agent is a mixture of at least two polyvinylalcohol compositions. A first polyvinylalcohol composition comprises polyvinylalcohols having a first degree of hydrolysis and a second polyvinylalcohol composition comprises polyvinylalcohols having a second degree of hydrolysis. The first and second degrees of hydrolysis are substantially different such that the rheology of the spacer fluid is stable during temperatures changes.

Method for identifying CVD diamond comprises (1) placing a clean diamond on a fixed platform; (2) illuminating the diamond with light having various wavelengths; (3) receiving reflected light from the diamond; (4) calculating a reflectance value at each wavelength based on a light intensity at each wavelength of the reflected light, generating a spectral reflectance curve; (5) determining whether the spectral reflectance curve has a sharp trough, then storing the diamond if the spectral reflectance curve thereof does not have the sharp trough, while selecting the diamond for a further identification if the spectral reflectance curve thereof has the sharp trough; and (6) determining whether the sharp trough of the diamond selected from the step (5) is at a wavelength between 227 nm and 233 nm, and identifying the diamond to be the CVD diamond if the sharp trough is at the wavelength between 227 nm and 233 nm.

A method of bunch length compression method for a free electron laser (FEL) that avoids parasitic compressions by 1) applying acceleration on the falling portion of the RF waveform, 2) compressing using a positive momentum compaction (R56>0), and 3) compensating for aberration by using nonlinear magnets in the compressor beam line.

Systems and methods are disclosed herein to a radiation safety system comprising radiation emitting medical equipment; a radiation safety system controller connected to the radiation emitting medical equipment through a first communication means configured to determine a number of people within a radiation room housing the radiation emitting medical equipment and prevent the radiation emitting medical equipment from performing radiation emitting functions if the radiation safety system controller determines that more people than a maximum allowed number of people are presently in the radiation room; and a scanner connected to the radiation safety controller through a second communication means configured to detect people in the radiation room and communicate to the radiation safety system controller that a person has been detected.

Provided is an A/D converter including an input terminal, a reference signal line for supplying a reference signal which changes temporally, a comparator, a correction capacitor connected to an inverting input terminal of the comparator; and an output circuit which outputs digital data corresponding to an analog signal input to the input terminal. In a first state in which a total voltage of a first analog signal and an offset voltage of the comparator is held in the correction capacitor, a second analog signal input to the input terminal is supplied to a non-inverting input terminal of the comparator, and the second analog signal or the total voltage is changed using the reference signal, thereby outputting, from the output circuit, digital data.

According to one embodiment, a solid state imaging device includes a sensor substrate having a plurality of pixels formed on an upper face, a microlens array substrate having a plurality of microlenses formed and a connection post with one end bonded to a region between the microlenses on the microlens array substrate and with the other end bonded to the upper face.

This invention provides a system and method for efficiently and completely combusting oil in mixture with particulate solids. A furnace (kiln) having a feed nozzle with a lead screw drives the mixture from a feed hopper. This nozzle includes forced-air jets/ports at its tip providing makeup air and allowing atomization of the mixture. The nozzle thereby directs the mixture into a rotating combustion chamber that is tilted downwardly from the front toward a solid waste outlet port at the rear. Uncombusted fuel and air backflow to an upper, secondary chamber near the primary chamber front, and are completely combusted at a high temperature. Gasses exit a flue that can include a heat exchanger. This heat exchanger can be operatively connected to a heating device or other mechanism that converts the heat into usable energy. The nozzle can include a cone with axially tilted air ports about its perimeter.

A slag remover for discharging combustion residues of an incineration plant comprises a trough, which has a trough housing having two side walls, which define the trough width, and having a trough bottom, and which is intended to collect the combustion residues evacuated from a combustion chamber of the incineration plant. The trough further comprises at least two push rams for pushing the combustion residues out of the trough, and a shaft rotatably mounted in two shaft bearings and on which at least one drive lever cooperating with a cylinder-piston unit and at least two output levers connected to respectively one of the push rams are disposed in a rotationally secure manner. The cylinder-piston unit is here designed such that the push rams move back and forth between a retracted position and an extended position. The drive lever is disposed between two output levers.

An ash basket can act as a sieve or strainer, allowing a user to lift out the charcoal from a kamado grill, clean out the ash, and place the ash basket back into the grill for future use. The ash basket retains larger pieces of charcoal that can be reused, while allowing the ash to pass through to a bottom plate of the grill. The bottom plate has openings to permit the ash to fall to an ash collection chamber. Without the ash basket, pieces of charcoal can block the openings in the bottom plate, making ash collection difficult. Moreover, with the openings blocked, proper air flow through the openings. Finally, the ash basket creates and additional air space that covers the entire surface of the interior walls by separating the ash from the wall, improving air flow, which is critical to the kamado grill design.

A fluidized bed reactor includes a bottom portion, a roof portion, and side walls vertically extending between the bottom portion and the roof portion, forming a reaction chamber of the reactor. At least one side wall of the reaction chamber forms at least one vertical indentation in the reaction chamber, which indentation extends from the plane of the at least one side wall towards the reaction chamber. The indentation extending from the plane of the at least one side wall towards the reaction chamber is formed of a portion of the at least one side wall, protruding from the plane of the at least one side wall towards the reaction chamber, and the portion of the at least one side wall includes at least two substantially vertical indenting wall portions deviating from the plane of the at least one side wall at vertical lines within a distance from each other.

The invention relates to solid fuel units having a fuel supply chamber wherein the fuel to be sent for combustion to the combustion region found in the body is placed and the feed mechanism carrying the solid fuel found in the chamber forward. It is characterized in that it includes a main burning block having a fuel and air cell connected to the solid fuel supply chamber and air outlet vents formed on the external wall surface. A preventive surface is positioned on the main burning block external wall surface in a way that it would form a closed volume in a certain distance.

Methods and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells are provided. A photovoltaic (PV) device generally includes a window layer; an absorber layer disposed below the window layer such that electrons are generated when photons travel through the window layer and are absorbed by the absorber layer; and a plurality of contacts for external connection coupled to the absorber layer, such that all of the contacts for external connection are disposed below the absorber layer and do not block any of the photons from reaching the absorber layer through the window layer. Locating all the contacts on the back side of the PV device avoids solar shadows caused by front side contacts, typically found in conventional solar cells. Therefore, PV devices described herein with back side contacts may allow for increased efficiency when compared to conventional solar cells.

Accordingly, a method of forming a metal chalcogenide material may comprise introducing at least one metal precursor and at least one chalcogen precursor into a chamber comprising a substrate, the at least one metal precursor comprising an amine or imine compound of an alkali metal, an alkaline earth metal, a transition metal, a post-transition metal, or a metalloid, and the at least one chalcogen precursor comprising a hydride, alkyl, or aryl compound of sulfur, selenium, or tellurium. The at least one metal precursor and the at least one chalcogen precursor may be reacted to form a metal chalcogenide material over the substrate. A method of forming a metal telluride material, a method of forming a semiconductor device structure, and a semiconductor device structure are also described.

The present invention is that of a solar energy system that uses a light-guide solar panel (LGSP) to trap light inside a dielectric or other transparent panel and propagates the light to one of the panel edges for harvesting by a solar energy collector such as a photovoltaic cell. This allows for very thin modules whose thickness is comparable to the height of the solar energy collector. This eliminates eliminating the depth requirements inherent in traditional concentrated photovoltaic solar energy systems. A light guide solar panel has a deflecting layer, a light guide layer and a solar cell in optical communication with the light guide layer. The deflecting layer receives light at a first surface and inputs the light into the light guide layer. The light guide layer propagates the light to the solar cell, which is aligned generally parallel to the input surface.

Provided is a web guiding apparatus capable of ensuring a smooth operation and durability against a force applied from a web even if the apparatus is used in an environment with airborne paper powder, dust and the like. The web guiding apparatus includes a rocking frame 4 rocking around an axis perpendicular to a reference surface 2s of the base 2, and a support portion 40 supporting movement of the rocking frame 4 with respect to the base 2. The support portion 40 includes a base member 41 provided on the base 2 and having a rolling surface parallel to the reference surface 2s of the base 2, and a roller 46 provided on the rocking frame 4 so as to roll on the rolling surface of the base member 41. The rolling surface of the base member 41 is formed so that an axial direction thereof intersects an arc with a rocking shaft 3 of the rocking frame 4 as a center. A width of the roller 46 is wider than a width of the rolling surface of the base member 41. The roller 46 is provided so as to move along the arc with the rocking shaft 3 of the rocking frame 4 as the center when the rocking frame 4 rocks.

An optical data storage device includes an optical storage tape having one or more optical storage layers. A plurality of optical pickup units reads and/or writes data to the optical storage tape. A feed reel provides the optical storage tape to the optical pickup units. A guiding wheel that guides the optical storage tape when the optical storage tape is in the vicinity of the optical pickup units during read and/or write operations. Finally, a take-up reel receives the optical storage tape from the guiding wheel.

Groups of phase shifted Pulse Width Modulation signals are generated that maintain their duty-cycle and phase relationships as a function of the period of the PWM signal frequency. The multiphase PWM signals are generated in a ratio-metric fashion so as to greatly simplify and reduce the computational workload for a processor used in a PWM system. The groups of phase shifted PWM signals may also be synchronized with and automatically scaled to match external synchronization signals.

In an embodiment, a method of generating a pulse-width modulated signal from an input signal includes calculating a finite number of basis functions of a first pulse-width modulated signal based on the input signal, and forming an electronic output based on the calculated finite number of basis functions.

A PWM circuit that can have two refresh rates, including: a first PWM signal generator and a second PWM signal generator; wherein the first PWM signal generator and the second PWM signal generator respectively control refresh rates in two dimensions of an output data generated from a target apparatus. A PWM signal generation method that can have two refresh rates, including: generating a first PWM signal; generating a second PWM signal; and controlling refresh rates in different dimensions of an output data generated from a target apparatus respectively by using the first PWM signal and the second PWM signal.

A digital pulse width modulation controller includes a pulse width modulation controller, a selection unit having at least one selector, a comparison unit having at least one comparator, and a signal conversion unit having at least one digital-to-analog converter. The digital-to-analog converter generates a reference current and/or voltage. The comparator receives the reference current and/or voltage, and performs a comparison operation to generate a comparison signal based on a feedback signal. The selector selects one selection signal to input into the pulse width modulation controller, which receives other parameters set by a user or the system at the same time so as to control characteristics of the digital pulse width modulation signals, thereby improving the electric properties of a loading circuit.

An example PWM includes a driver and a two-way oscillator. The oscillator includes, a first frequency adjust current source, a second frequency adjust current source, a capacitor, a switching reference and a comparator. The capacitor integrates a frequency adjust current by charging with the first frequency adjust current source. The capacitor subsequently integrates a second frequency adjust current by discharging with the second frequency adjust current source. The switching reference outputs a first reference voltage and a second reference voltage responsive to an oscillator signal. The comparator compares the output of the switching reference with a voltage on the capacitor. The first and second frequency adjust current sources vary the first and second frequency adjust currents to vary the frequency of the PWM signal to spread energy of switching harmonics over a frequency band and to reduce EMI.

In an embodiment, a method of producing a multi-level RF signal includes producing plurality of pulse-width modulated signals based on an input signal. The method further includes driving a corresponding plurality of parallel amplifiers with the plurality of pulse-width modulated signals by setting a parallel amplifier to have a first output impedance when a corresponding pulse-width modulated signal is in an active state and setting the parallel amplifier to have a second output impedance when the corresponding pulse-width is in an inactive state. The method also includes phase shifting the outputs of the plurality of parallel amplifiers, wherein phase shifting transforms the second output impedance into a third impedance that is higher than the second output impedance, and combining the phase shifted outputs.

In various embodiments, systems and methods for generating high-precision pulse-width modulation include a delay-locked loop comprising multiple delay units having time-variable delays, control logic for selecting a subset S of the multiple delay units to thereby generate a time-invariant shift amount having a precision finer than that of a system clock and circuitry for applying the shift amount to rising and falling edges of a pulse-width modulation waveform to thereby generate a high-precision pulse-width modulation waveform.

An ultra-wide band frequency modulator is disclosed. The frequency modulator includes a direct modulation phase lock loop that receives a small component. The frequency modulator also includes a delay module that produces a plurality of delay lines. The frequency modulator further includes an edge selector that receives a large component and the plurality of delay lines.

The present invention provides a digitally controlled, current starved, pulse width modulator (PWM). In the PWM of the present invention, the amount of current from the voltage source to the ring oscillator is controlled by the proposed header circuit. By changing the header current, the pulse width of the switching signal generated at the output of the ring oscillator is dynamically controlled, where the duty cycle can vary between 50% and 90%. A duty cycle to voltage converter is used to ensure the accuracy of the system under process, voltage, and temperature (PVT) variations. The proposed pulse width modulator is appropriate for dynamic voltage scaling systems due to the small on-chip area and high accuracy under process, voltage, and temperature variations.

This disclosure relates to methods and systems to reduce high voltage breakdown jitters in liquid dielectric switches. In particular, dielectric liquids have been produced that contain a suspension of nanoparticles and a surfactant to reduce the breakdown jitter. In one embodiment, the suspended nanoparticles are Barium Strontium Titanate (BST) nanoparticles.

The present invention relates to contactors for unidirectional DC operation with permanent magnetic arc extinguishing. In addition to the blow magnets, the contactors are equipped with compensatory permanent magnets for compensating the magnetic field in the vicinity of the contact bridge in order to prevent contact levitation, i.e., an uncontrolled opening of the contacts that is due to a magnetic force generated by a strong current flowing through the contact bridge. To this end, the compensatory permanent magnets are arranged in the vicinity of the contact bridge and polarized in the opposite direction of the blow magnets. The magnetic field of the compensatory magnets and the current flowing through the contact bridge are generating a magnetic force that acts on the contact bridge and tends to keep the electrical contacts closed.

A sealed solenoid, magnetically operated electric power switch is suitable for use as capacitor, line and load switch operating at transmission and distribution voltages that includes no dynamically moving seals through the sealed container housing the contactor portion of the switch. The sealed solenoid switch includes a magnetically operated drive system with an actuator that magnetically couples across the container wall to avoid the use of a moving or sliding seal as part of the drive system. The sealed solenoid switch may also include a ballast resistor and resistor contact located inside the sealed container to avoid another seal as part of the ballast system. A magnetic latch holds the switch in a closed position, and a spring holds the switch in the closed position, to avoid the need for an energizing current to maintain the switch in either position.

A circuit protection device is provided for use with a circuit that includes at least one pair of conductors. The protection device is configured to generate an arc. The protection device includes at least a pair of electrode assemblies electrically coupled to the at least one pair of conductors and a conductor base to support the pair of electrode assemblies. The protection device includes a cover coupled to the conductor base and defining at least one isolation chamber, wherein the electrode assemblies are disposed within the isolation chamber. The protection device includes a containment shield moveably coupled to the cover. The containment shield defines a containment chamber configured to contain charged particles produced by the arc. The containment shield is operative to move relative to the cover in response to a change in pressure produced by the arc within the containment chamber. An isolation assembly is coupled to at least one of the cover and the containment shield and configured to prevent the cover from contacting the containment shield.

A guide assembly for a switchgear assembly is provided. The guide assembly includes an elongated support member and a passage. The support member is coupled to and extends from a housing assembly rear sidewall. The support member extends in the circuit breaker assembly direction of travel. The passage is disposed on the circuit breaker assembly base and also extends in the circuit breaker assembly direction of travel. The support member is substantially aligned with the passage. In this configuration, as the circuit breaker assembly moves between a withdrawn position and an installed position, the support member moves between a first position, wherein the support member is not disposed in the passage, and a second position, wherein the support member is partially disposed in the passage. When the support member is in the second position, the support member bears a portion of the weight of the circuit breaker assembly base.

The present invention provides an assembly for the preparation of a medical device having a porous coating comprising hydrogen peroxide. Particularly interesting medical devices are catheters (such as urinary catheters), endoscopes, laryngoscopes, tubes for feeding, tubes for drainage, guide wires, condoms, urisheaths, barrier coatings e.g. for gloves, stents and other implants, extra corporeal blood conduits, membranes e.g. for dialysis, blood filters, devices for circulatory assistance, dressings for wound care, and ostomy bags. The coating is in particular a hydrophilic coating formed from cross-linked polyvinylpyrrolidone. In one embodiment, the assembly holds a dry catheter element in one compartment of a package and an aqueous hydrogen peroxide solution in another compartment. The solution may also comprise stabilizers, e.g. chelators, and osmolality increasing agents. The catheter for insertion in the urethra is useful for the treatment, alleviation or prophylaxis of microbial infections such as urinary tract infections (UTI).

Tamper-evident package comprises a container, a primary cap, and a secondary cap. The container comprises a sidewall defining a chamber and a rim defining a mouth to the chamber. The primary cap is removably-attachable to the rim of the container to selectively close the mouth of the container. The secondary cap is positioned over the primary cap to prevent removal of the primary cap when positioned thereover. The secondary cap includes a single-use lock, such as a cable tie, to secure the secondary cap in position over the primary cap. The package thus provides evidence that someone has tampered with or attempted to tamper with the container if the single-use lock is removed or damaged. Method of using the tamper-evident package is also disclosed.

A tactile orientation indicator is positioned along the periphery of a bill, and a tactile denomination indicator is positioned elsewhere along the periphery of the bill. The user of the bill may then use their tactile senses to feel along the edges of the bill to orient the bill to a pre-determined orientation based on the location of the orientation indicator. The user then feels along the periphery of the bill to locate the denomination indicator. Using a predetermined system associating the location of the denomination indicator with a particular bill denomination, the user may then identify the denomination of the bill even if blind or otherwise visually impaired.

An improved learning aid in the form of a book, the book includes a front cover, a back cover, and a plurality of pages intermediate the front cover and the back cover. The plurality of pages, front cover, and back cover are conventionally bound together along one longitudinal side by a binding means. The back cover includes an outer side disposed with a plurality of sections. Each of the sections printed text framed by a text identification and sequence indicator, wherein the printed text is a complete reproduction of the text printed on a particular numbered page of the plurality of pages of the book.

A book protection apparatus and method are provided, that include a pair of substantially right angled sheets configured in a parallel fashion, the sheets being joined by a joining mechanism having a tension setting mechanism configured between the pair of sheets, to enable forcibly coupling the binding device to a coupled corner of a book.

An inside leaflet of a book is provided which is bond-bound with pages of the book to provide an advertisement. The inside leaflet includes an advertisement printed part and a binding part. Catchphrases or illustrations for advertisement are printed on at least one side of the advertisement printed part. The binding part is configured to be bound with the pages along an edge of the inside leaflet such that the binding part has less binding portions than those of the pages in order to leave no traces or marks when the inside leaflet is detached from the book. Accordingly, since the inside leaflet is able to be bound to pages of various kinds of books and easily removed from the books without leaving any traces or marks in the books, the inside leaflet contributes to extension of the application range of advertisements and improvement of advertisement efficiency.

An amplifying structure includes a main amplifier configured to amplify a first signal; and a peak amplifier configured to amplify a second signal, each of the main amplifier and the peak amplifier including, respectively, a hybrid power device, the hybrid power device including, a first power transistor die configured to amplify signals of a first frequency, and a second power transistor die configured to amplify signals of a second frequency different than the first frequency.

A power combiner/divider having a waveguide, a plurality of amplifiers disposed on a supporting structure, a plurality of probes, each one having a first end electrically coupled to an output of a corresponding one of the plurality of amplifiers and a second end projecting outwardly from the supporting structure and into the waveguide. The probes are disposed in a common region of the waveguide. The region has a common electric field maximum within the waveguide. A first portion of the probes proximate the sidewalls have lengths different from a second portion of the probes disposed in a region distal from the sidewalls of the waveguide. The waveguide is supported by the support structure. The power combiner is a monolithic microwave integrated circuit structure.

A tunable wide band driver amplifier is disclosed. In an exemplary embodiment, an apparatus includes a first band selection circuit selectively connected between an output terminal of an amplifier and a circuit ground. The first band selection circuit configured to adjust an amplification band from a first frequency band to a second frequency band. The apparatus also includes a first harmonic reduction circuit selectively connected between the first band selection circuit and the circuit ground and configured to reduce 2nd harmonic frequencies associated with the first frequency band when the amplification band is set to the first frequency band.

Systems and methods are provided for generating an amplitude modulation signal to a switchmode power amplifier. A DC to DC switch is configured to receive a DC input voltage and to provide a DC output voltage. A low dropout regulator is configured to provide the amplitude modulation signal according to a modulation control signal received by the low dropout regulator. A control circuit is configured to establish a nominal operating power level for the power amplifier via the amplitude modulation signal and to maintain a minimum voltage difference between the DC output voltage and the low dropout regulator output. A modulator control circuit is configured to provide the modulation control signal to the low dropout regulator. The modulator control circuit provides the transition from a high amplitude to a low amplitude and a transition from the low amplitude to the high amplitude at configurable first and second slopes, respectively.

A workholder to hold a workpiece, including a main body partially defining a fluid chamber, and a bladder carried by the main body with an interference fit, further defining the fluid chamber, and composed of an 80 to 100 durometer Shore A scale hardness polymer of a 12:1 to 18:1 diameter-to-wall-thickness ratio. Annular seals may further define the fluid chamber, and are disposed radially between the bladder and main body and axially adjacent the fluid chamber, and are composed of a 60 to 80 durometer Shore A scale hardness polymer. A collet is carried and driven by the bladder for gripping engagement with the workpiece.

An apparatus having a frame; a shuttle member, adapted to receive and hold a needle blank, and movably mounted to the frame; a clamp member detachably mounted on the frame for supplying needle blanks to the shuttle member; a transfer mechanism mounted on the frame for facilitating the transfer of the needle blanks from the clamp member to the shuttle member; a press mechanism for imparting first flat surfaces to first opposing sides of the needle blanks held by the shuttle member; a mandrel mounted on the frame for imparting an arcuate profile to the needle blanks; a transport mechanism for transporting the needle blanks from the shuttle member to the mandrel; and a needle side press for imparting second flat surfaces to second opposing sides of the needle blanks. A method of forming a curved, rectangular bodied needle from substantially round-elongated needle blanks is also disclosed and comprises the steps of: transferring needle blanks from a clamp to a holding shuttle having die surfaces on needle engaging faces thereof; flat pressing first opposing sides of the needle blanks between die surfaces; transporting the needle blanks from the shuttle onto a rotatable mandrel; curving the needle blanks between the rotatable mandrel and a reciprocable belt; rotating the needle blanks about the mandrel and adjacent side press dies and depositing the needle blanks therebetween; and side pressing second opposing sides of the needle blanks between side press dies.

A liquid flow rate control valve is provided in which since a total area of overlapping sections of a communication hole group (38c, 38d) of a distributor (38) and an outlet opening (37a, 37b) of a sleeve (37) changes when the distributor (38) is rotated by a first electric motor (46), if a rotor (42) is rotated by means of a second electric motor (47), an input port (31e) communicates with an output port (31f) through an inlet opening (42c, 42d) of the rotor (42), the communication hole group (38c, 38d) of the distributor (38), and the outlet opening (37a, 37b) of the sleeve (37) when the inlet opening (42c, 42d) of the rotor (42) passes through the overlapping sections, thereby making it possible to carry out PWM control of a flow rate of liquid. Since a thrust load in an axis (L) direction does not act on the distributor (38) and the rotor (42), supporting the distributor (38) and the rotor (42) becomes easy, thereby enabling the cost and weight to be cut.

A method and apparatus for a fluid damper comprising a first fluid-filled chamber, a second chamber filled with a fluid having variable flow characteristics and at least partially displaceable by the first fluid, and a gas chamber, the gas chamber compressible due to the displacement of the second chamber. In one embodiment, the fluid in the second chamber is a variable rheology fluid.

An apparatus can include a pressure vessel that defines an interior region that can contain a liquid and/or a gas. A piston is movably disposed within the interior region of the pressure vessel. A divider is fixedly disposed within the interior region of the pressure vessel and divides the interior region into a first interior region on a first side of the divider and a second interior region on a second, opposite side of the divider. The piston is movable between a first position in which fluid having a first pressure is disposed within the first interior region and the first interior region has a volume less than a volume of the second interior region, and a second position in which fluid having a second pressure is disposed within the second interior region and the second interior region has a volume less than a volume of the first interior region.

A fluid-working machine has a working chamber of cyclically varying volume, high and low pressure manifolds, and high and low pressure valves for regulating the flow of fluid between the working chamber and the high and low pressure manifolds respectively. A controller actively controls at least one said valve to determine the net displacement of working fluid of the working chamber on a cycle by cycle basis. At least one said valve is a variable timing valve and the controller causes the valve to open or close at a time determined taking into account one or more properties of the performance of the fluid working machine measured during an earlier cycle of working chamber volume.

An arrangement for providing a throttle cross-section for a fluid flow. The throttle cross-section can be varied depending on a pressure difference present across the throttle cross-section. The arrangement is designed such that the polarity of the pressure difference, by which the throttle cross-section can be varied and/or changed. It is thereby possible to use the arrangement for fluid flows that alternate in the flow direction thereof.

In a fluid pressure cylinder, a piston is displaced in an axial direction under the action of a pressure fluid. A circular protrusion, which projects toward the piston along an axial direction of the cylinder tube, is formed on an inner end surface of a collar member constituting part of the fluid pressure cylinder, a concavity, which can be fitted externally over the circular protrusion, is formed on the piston, and an annular groove is formed on an inner circumferential edge of an end plate. By the piston coming into contact with the end plate, a pressure receiving chamber is formed between the piston and the annular groove, together with an opening of a second port on an inner side of the cylinder tube being closed to a maximum of 90%.

A thin film of a low-thermionic-work-function material is maintained on the cathode of a device for producing a high-current, low-pressure gas discharge by means of sputter deposition from an auxiliary electrode. The auxiliary electrode includes a surface with a low-work-function material, such as thorium, uranium, plutonium or one of the rare earth elements, facing the cathode but at a disposition and electrical potential so as to extract ions from the gas discharge and sputter the low-work-function material onto the cathode. By continuously replenishing the cathode film, high thermionic emissions and ion plasmas can be realized and maintained over extended operating periods.