A low resistivity interface material is provided between a self-aligned vertical heater element and a contact region of a selection device. A phase change chalcogenide material is deposited directly on the vertical heater element. In an embodiment, the vertical heater element in L-shaped, having a curved vertical wall along the wordline direction and a horizontal base. In an embodiment, the low resistivity interface material is deposited into a trench with a negative profile using a PVD technique. An upper surface of the low resistivity interface material may have a tapered bird-beak extension.

Provided is a novel coated phosphor capable of effectively suppressing the adverse effects of hydrogen sulfide gas generated by the reaction between a sulfur-containing phosphor and moisture in the air. Provided is a sulfur-containing phosphor having a configuration in which ZnO compound containing Zn and O is present on the surface of a sulfur-containing phosphor having a host material which includes sulfur.

The present invention relates to a swim chair that allows a mobility challenged individual to be transported across the sand with exceptional ease, to lounge on the chair and enjoy the company and sights, to be pulled into the water and, if able, to slip off the chair to go for a swim, remount the chair and return to shore. The chair includes a main frame, defined by a top frame member and two side frame members; two axle support plates, at or in communication with the side frame members of the main frame, the axle support plates having a plurality of openings to receive a wheel axle and optionally a pull rod axle; a wheel assembly; a drop seat; a footrest and a backrest.

According to an embodiment, a drilling fluid comprises: water and a set accelerator, wherein the drilling fluid has a 10 minute gel strength of less than 20 lb*ft/100 sq ft, wherein the drilling fluid has a density in the range of about 9 to about 14 pounds per gallon, wherein the drilling fluid remains pourable for at least 5 days, and wherein when at least one part of the drilling fluid mixes with three parts of a cement composition consisting of water and cement, the drilling fluid cement composition mixture develops a compressive strength of at least 1,200 psi. According to another embodiment, a method of using the drilling fluid comprises the steps of: introducing the drilling fluid into at least a portion of a subterranean formation, wherein at least a portion of the drilling fluid is capable of mixing with a cement composition.

One embodiment relates to an apparatus for electron beam lithography which includes a linear array of reflection electron beam lithography columns and a rotary stage. Each column is separately controllable to write a portion of a lithographic pattern onto a substrate. The rotary stage is configured to hold multiple substrates and to be rotated under the linear array of reflection electron beam lithography columns. Another embodiment relates to a method of electron beam lithography which includes simultaneously rotating and linearly translating a stage holding a plurality of wafers, and writing a lithography pattern using a linear array of reflection electron beam lithography columns over the stage. Each said column traverses a spiral path over the stage as the stage is rotated and linearly translated. Other embodiments, aspects and feature are also disclosed.

An approach is disclosed for acquiring multi-sector computed tomography scan data. The approach includes activating an X-ray source during heartbeats of a patient to acquire projection data over a limited angular range for each heartbeat. The projection data acquired over the different is combined. An image having good temporal resolution is reconstructed using the combined projection data.

The invention relates to a device (10; 10a;10b; 10c; 50) for checking pharmaceutical products (1), in particular hard gelatin capsules, by means of at least one radiation source (30; 60) preferably embodied as an X-ray source, and a conveying device which conveys the products (1) in a clocked manner in a radiation area (31) of the radiation source (30; 60). The radiation emitted by the radiation source (30; 60) penetrating the products (1) preferably perpendicular to the longitudinal axes thereof (2), and the radiation is captured on the side of the products (1) opposite the radiation source (30) by means of at least one sensor element (35) which is coupled to an evaluation device (36). The invention is characterized in that the conveyor device is embodied as a conveyor wheel (15; 15a; 51) which can rotate in a stepped manner about an axis (12; 52), and the products (1) are arranged, while being conveyed in the radiation area (31), in receiving areas (28; 37; 56) of the conveyor wheel (15; 5a; 51).

It is an object to provide a photoelectric conversion device whose power consumption and a mounting area are reduced and yield is improved and further to provide a photoelectric conversion device whose number of manufacturing processes and manufacturing cost are reduced. A photoelectric conversion device includes a photoelectric conversion element for outputting photocurrent corresponding to illuminance, and a resistor changing resistance corresponding to illuminance. In the photoelectric conversion device, one terminal of the photoelectric conversion element and one terminal of the resistor are electrically connected in series; the other terminal of the photoelectric conversion element is connected to a high power supply potential; the other terminal of the resistor is connected to a low power supply potential; and a light intensity adjusting unit is provided on a light reception surface side of the photoelectric conversion element or the resistor to adjust illuminance.

Improved silicon solar cells, silicon image sensors and like photosensitive devices are made to include strained silicon at or sufficiently near the junctions or other active regions of the devices to provide increased sensitivity to longer wavelength light. Strained silicon has a lower band gap than conventional silicon. One method of making a solar cell that contains tensile strained silicon etches a set of parallel trenches into a silicon wafer and induces tensile strain in the silicon fins between the trenches. The method may induce tensile strain in the silicon fins by filling the trenches with compressively strained silicon nitride or silicon oxide. A deposited layer of compressively strained silicon nitride adheres to the walls of the trenches and generates biaxial tensile strain in the plane of adjacent silicon fins.

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.

Disclosed is a photovoltaic device. The photovoltaic device includes: a substrate; a first electrode placed on the substrate; a second electrode which is placed opposite to the first electrode and which light is incident on; a first unit cell being placed between the first electrode and the second electrode, and including an intrinsic semiconductor layer including crystalline silicon grains making the surface of the intrinsic semiconductor layer toward the second electrode textured; and a second unit cell placed between the first unit cell and the second electrode.

This invention is directed to a flexible solar cell photovoltaic module with high light transmittance based on modified substrate, which belongs to the field of thin-film solar cell technology. The objective of the present invention to provide a technical solution for a transparent flexible solar cell module and its fabrication method. Technical features include using a stainless steel template to mold a modified polyimide PI substrate (the PI substrate). The PI substrate has light-passing through-holes, including draining holes and convergence holes, through and distributed on the PI substrate, a conductive film layer, and various stacked photoelectric conversion film layers. The creativeness of the present invention is obvious, such as reducing the short circuit and current leakage due to crystallization of the photoelectric layer interface caused by a subsequent process of laser etching the conductive film layer, reducing the composition on the surface of the solar cell, reducing steps of the fabrication process, and lowering the production cost. Further, the present invention significantly increases the conversion efficiency and load capacity of the solar cell and the quality-cost ratio. The transparent flexible solar cell photovoltaic module also has a broad range of applications.

A photoelectric conversion element comprising a substrate, a first electrode, a photoelectric conversion layer comprising a semiconductor and a sensitizing dye, a hole transport layer and a second electrode, wherein the hole transport layer comprises a polymer having a repeat unit represented by Formula (1) or (2),

Photo-field-effect transistor devices and associated methods are disclosed in which a photogate, consisting of a quantum dot sensitizing layer, transfers photoelectrons to a semiconductor channel across a charge-separating (type-II) heterointerface, producing a sustained primary and secondary flow of carriers between source and drain electrodes. The light-absorbing photogate thus modulates the flow of current along the channel, forming a photo-field effect transistor.

A resin composition, a multi-layered film, a backsheet for photovoltaic modules, a method thereof, and a photovoltaic module are provided. The multi-layered film including a coating layer including a fluorine-based polymer has an excellent durability and weather resistance, and also exhibits high interfacial adhesive strength to a substrate since the multi-layered film is formed by coating a cured product of the resin composition including the fluorine-based polymer, an acrylic polymer including a thermosetting functional group, and a heat-curing agent on the substrate. In addition, drying can be performed at a low temperature during the manufacture of the multi-layered film so that the manufacturing costs can be decreased, productivity can be increased, and the deterioration of the product due to heat modification, heat shock, and the like, can be prevented. The multi-layered film can be effectively used as a backsheet for various photovoltaic modules.

Novel photoactive polymers, as well as related photovoltaic cells, articles, systems, and methods, are disclosed.

An organic compound and a photoelectric conversion device containing the organic compound are disclosed. The organic compound and device realize high photoelectric conversion efficiency, low dark current and high-speed responsivity. It has been found that when this organic compound and an n-type semiconductor are used in combination, high-speed responsivity can be realized while maintaining high heat resistance, an aspect of which has not been seen when the connection part between a donor part and an acceptor part is a phenylene group.

A PV panel uses an array of small silicon sphere diodes (10-300 microns in diameter) connected in parallel. The spheres are embedded in an uncured aluminum-containing layer, and the aluminum-containing layer is heated to anneal the aluminum-containing layer as well as p-dope the bottom surface of the spheres. A phosphorus-containing layer is deposited over the spheres to dope the top surface n-type, forming a pn junction. The phosphorus layer is then removed. A conductor is deposited to contact the top surface. Alternatively, the spheres are deposited with a p-type core and an n-type outer shell. After deposition, the top surface is etched to expose the core. A first conductor layer contacts the bottom surface, and a second conductor layer contacts the exposed core. A liquid lens material is deposited over the rounded top surface of the spheres and cured to provide conformal lenses designed to increase the PV panel efficiency.

The present invention provides a photoelectric conversion material comprising a fullerene derivative represented by the formula C60(R1)5(R2), wherein each R1 independently represents an organic group having a substituent; and R2 represents a hydrogen atom or a substituted or unsubstituted C1-C30 hydrocarbon group. Further, the present invention also provides a photoelectric conversion device having a self-assembled monomolecular film of the photoelectric conversion material, and a solar cell having the photoelectric conversion device.

A method of photoplating a metal contact onto a surface of a cathode of a photovoltaic device is provided using light induced plating technique. The method comprises: a) immersing the photovoltaic device in a solution of metal ions, where the metal ions are a species which is to be plated onto the surface of the cathode of the photovoltaic device; and b) illuminating the photovoltaic device, using a light source of time varying intensity. This results in nett plating which is faster in a direction normal to the surface of the cathode than in a direction in a plane of the surface of the cathode.

A method for fabricating a photovoltaic device includes depositing a p-type layer at a first temperature and depositing an intrinsic layer while gradually increasing a deposition temperature to a final temperature. The intrinsic layer deposition is completed at the final temperature. An n-type layer is formed on the intrinsic layer.

A photovoltaic cell comprises a top subcell having a first band gap; a middle subcell comprising a substrate and having a second band gap, wherein the substrate comprises a first side and a second side opposite to the first side; and a bottom subcell having a third band gap, wherein the top subcell is grown on the first side of the substrate and the bottom subcell is grown on the second side of the substrate, wherein the first band gap is larger than the second band gap and the second band gap is larger than the third band gap.

Hemispheres and spheres are formed and employed for a plurality of applications. Hemispheres are employed to form a substrate having an upper surface and a lower surface. The upper surface includes peaks of pillars which have a base attached to the lower surface. The peaks have a density defined at the upper surface by an array of hemispherical metal structures that act as a mask during an etch to remove substrate material down to the lower surface during formation of the pillars. The pillars are dense and uniform and include a microscale average diameter. The spheres are formed as independent metal spheres or nanoparticles for other applications.

A photovoltaic device including a substrate; a first electrode placed on the substrate; a second electrode which is placed opposite to the first electrode and which light is incident on; a first unit cell being placed between the first electrode and the second electrode, and including an intrinsic semiconductor layer including crystalline silicon grains making the surface of the intrinsic semiconductor layer toward the second electrode textured; and a second unit cell placed between the first unit cell and the second electrode.

A surface of a photovoltaic cell is coated with a solution that includes barium titanate to reduce reflection of sunlight that is incident on the surface. The solution may include a base of polydimethylsiloxane and carbon nanotubes. The process may be used in the fabrication of new photovoltaic cell assemblies, or to retrofit existing assemblies in situ.

Methods of forming a photovoltaic structures including nanoparticles are disclosed. The method includes electrospray deposition of nanoparticles. The nanoparticles can include TiO2 nanoparticles and quantum dots. In an example, the nanoparticles are formed on a flexible substrate. In various examples, the flexible substrate is light transparent. Photovoltaic structures and apparatus for forming photovoltaic structures are disclosed.

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.

Some embodiments relate to a phase shifter that includes an I/Q phase shifter and at least one LC balun. Compared to conventional phase shifters, phase shifter has primarily only LC components, thereby limiting losses relative to conventional solutions. In one embodiment, for example, a phase shifter shows a large bandwidth at 77 GHz center frequency (e.g., 1 dB amplitude error bandwidth is approximately 40 GHz; 1° phase error bandwidth is about 16.5 GHz). The inductors included in phase shifter, in contrast to the quarter wave transmission lines used in conventional phase shifters, reduces chip area compared with conventional solutions. In some embodiments, an emitter follower helps to provide a relatively constant output that is largely independent of temperature, input power, VCC, manufacturing variation, and so on.

A new coded continuous phase modulation (CPM) scheme is proposed to enhance physical layer performance of the current DVB-RCS standard for a satellite communication system. The proposed CPM scheme uses a phase pulse design and combination of modulation parameters to shape the power spectrum of CPM signal in order to improve resilience to adjacent channel interference (ACI). Additionally, it uses a low complexity binary convolutional codes and S-random bit interleaving. Phase response using the proposed CPM scheme is a weighted average of the conventional rectangular and raised-cosine responses and provides optimum response to minimize frame error rate for a given data rate.

A frequency modulator includes a digitally-controlled oscillator (DCO) arranged for producing a frequency deviation in response to a modulation tuning word and a phase-locked loop (PLL) tuning word. In addition, another frequency modulator includes a DCO and a DCO interface circuit. The DCO is arranged for producing a frequency deviation in response to an integer tuning word and a fractional tuning word. The DCO interface circuit is arranged for generating the integer tuning word and the fractional tuning word to the DCO, wherein the fractional tuning word is obtained through asynchronous sampling of a fixed-point tuning word.

Embodiments of digital high-speed bi-phase modulator and method for bi-phase modulation are generally described herein. In some embodiments, the digital high-speed bi-phase modulator comprises a high-speed digital divider, a high-speed digital multiplexer, and matched signal paths provided between the divider and the multiplexer. The high-speed digital divider is configured to receive a carrier signal and generate complementary output signals. The high-speed digital multiplexer is configured to switch between the complementary output signals and generate a bi-phase modulated output at a carrier frequency (fc) modulated with a bi-phase code. The bi-phase code may be provided to control inputs of the multiplexer.

A communications system includes a target receiver having a passband and configured to receive an intended signal within the passband. The communications system also includes a jammer configured to jam the target receiver from receiving the intended signal. The jammer has at least one antenna, a jammer receiver coupled to the at least one antenna, a jammer transmitter coupled to the at least one antenna, and a controller configured to cooperate with the jammer receiver. The controller is configured to detect the intended signal and to generate an interfering signal comprising a continuous phase modulation (CPM) waveform having a constant envelope so that the interfering signal at least partially overlaps the passband of the target receiver.

A method for phase modulation of a carrier signal from a transmitter to a contactless transponder in which data is coded as consecutive symbols, each corresponding to a predefined number of carrier cycles, and in which a symbol time is at least two cycles of the carrier signal includes, at the transmitter, spreading a phase jump of a symbol in relation to a preceding symbol over a first part of the symbol time. The establishment of the phase jump is completed in the first part of the symbol time. The periods of the cycles are constant during a second part of the symbol time.

A pharmacy bottle system includes a bottle and a ring. The bottle is formed as a single piece of molded plastic material and includes a body and a neck. The body defines an interior cavity. The interior cavity extends from a first end to a second end of the interior cavity. The body includes a spine portion covering the first end of the interior cavity. The spine portion defines a spine width measured from a front to a back of spine portion. The neck extends from the second end of the interior cavity and has an opening therethrough providing access to the interior cavity. The ring is secured about the neck of the bottle. The ring defines a ring width measured between a front and a back of the ring. The ring width is larger than the spine width. The neck extends above a top surface of the ring.

A storage case (100) for storing a pharmaceutical syringe unit (4) that is mounted to a pharmaceutical administering device (8) comprises a base body (1) that is open at its upper face, and a cover (2) for covering the opening in the base body (1). The base body (1) has in its interior a concave portion (5) that holds the cylindrical pharmaceutical syringe unit (4). The concave portion (5) has holders (6) that hold two ends of the pharmaceutical syringe unit (4), and a center concave portion (7) for attaching and removing the pharmaceutical syringe unit (4) and being provided in a position that corresponds to the main body portion of a stored pharmaceutical syringe unit (4). The center concave portion (7) further has a bottom part positioned lower than the holders (6), and is formed such that the pharmaceutical administering device (8) can be disposed in an upright position.

A method and an apparatus is disclosed for forming a one-piece introducer needle having a member portion and a needle portion by introducing a photoresist on a substrate. The temperature of the substrate is increased and then decreased. A photomask is deposited onto a substrate.

Graphite and/or carbon surfaces are coated with a titanium nitride coating by exposing the substrate to electric arc thermal spray process wherein titanium wire as the source of titanium and nitrogen is used as the propelling (atomizing) gas.

An electrode assembly for use in an iontophoresis device for the transcutaneous administration of an active therapeutic species has a base layer of including a linking conductive base material which is consumed (oxidizes or reduces) preferentially to water, a first upper layer of sacrificial material coated on a first portion of the base layer wherein the sacrificial material is consumed preferentially to the linking conductive base material of the base layer. A second upper layer of non-conducting material is coated on a second portion of the base layer, the second upper layer being spaced from the first upper layer, connected by a narrow exposed linking area of the base layer material remaining exposed therebetween. During operation of an associated iontophoresis device, the sacrificial material will be sequentially consumed; the first upper layer will be fully consumed followed by the linking conductive base material of the exposed linking area of the base layer which severs the base layer thereby breaking circuit continuity disabling activity in the device. A visual indicator may be provided allowing a wearer to monitor the state of reaction of the linking area.

An electrode assembly for use in an iontophoresis device for the transcutaneous administration of an active therapeutic species has a base layer of including a linking conductive base material which is consumed (oxidizes or reduces) preferentially to water, a first upper layer of sacrificial material coated on a first portion of the base layer wherein the sacrificial material is consumed preferentially to the linking conductive base material of the base layer. A second upper layer of non-conducting material is coated on a second portion of the base layer, the second upper layer being spaced from the first upper layer, connected by a narrow exposed linking area of the base layer material remaining exposed therebetween. During operation of an associated iontophoresis device, the sacrificial material will be sequentially consumed; the first upper layer will be fully consumed followed by the linking conductive base material of the exposed linking area of the base layer which severs the base layer thereby breaking circuit continuity disabling activity in the device. A visual indicator may be provided allowing a wearer to monitor the state of reaction of the linking area.

In a method for correcting a calibration table T(n,k) of a CT apparatus that contains calibration values, the CT apparatus having a detector system with N≧2 rows of detector elements following one another in the z-direction that include a first active row of detector elements in the z-direction and a last active row of detector elements in the z-direction, for correcting the calibration values of the aforementioned first and last active rows of detector elements, a reference vector R(k) is produced, the error is determined with respect to the first and last active rows of detector elements, and the error F(n,k) of the first and last active rows of detector elements is subtracted from the corresponding calibration values of the calibration table T(n,k) for determining corrected calibration values Tcor(n,k) with respect to the first and last active rows of detector elements.

The present invention provides a method of separating nickel bearing sulphides from mined ores or concentrates of mined ores that contain talc particles is disclosed. The method comprises adjusting the Eh of a slurry of mined ores or concentrates of mined ores and making particles of nickel bearing sulphides less hydrophobic than talc particles and floating the nickel bearing sulphide particles from the slurry.

Methods for preventing or reducing the formation of scale in a wet-process phosphoric acid production process by intermixing a water-soluble functional organic reagent with a phosphoric acid at one or more step of the phosphoric acid production process in an amount sufficient to prevent or reduce at least one species of scale are provided.

Adsorptive media for chromatography, particularly ion-exchange chromatography, derived from a shaped fiber. In certain embodiments, the functionalized shaped fiber presents a fibrillated or ridged structure which greatly increases the surface area of the fibers when compared to ordinary fibers. Also disclosed herein is a method to add surface pendant functional groups that provides cation-exchange or anion-exchange functionality to the high surface area fibers. This pendant functionality is useful for the ion-exchange chromatographic purification of biomolecules, such as monoclonal antibodies (mAbs).

The present invention describes a method of optimizing CO2 concentration to increase the specific growth rate of Anammox bacteria and methanogens in wastewater and sludge treatment, as well as novel systems and methods of treating wastewater and sludge. The specific growth rate or doubling time of the Anammox bacteria and methanogens were determined to be sensitive to dissolved CO2 concentration. Optimizing dissolved CO2 concentration increases the specific growth rate of the Anammox bacteria, which may be used as an alternative biological nitrogen removal process for the treatment of domestic wastewater. In the method and system of treating sludge, the CO2 stripper returns biogas with low CO2 concentration to the headspace of an anaerobic digester in order to lower the headspace CO2 concentration and therefore, the soluble CO2 concentration. The lower soluble CO2 concentration increases the specific growth rate of the methanogens for a more efficient anaerobic digestion process.

A semi-automated system suitable for use in a hospital setting for filling patient-specific liquid prescriptions to be administered by oral syringes on a just-in-time basis. The system enables hospital pharmacists to simplify and streamline their task, increasing the number of prescriptions that can be filled in a day, improving patient safety and care by minimizing medication errors and the consequences that ensue.

A pressure-stable cylinder/piston unit which blocks water vapor and oxygen and is designed for a needle-free injector, with a chamber arranged in a cylinder, which blocks water vapor and oxygen, and designed for long-term and sterile storage of an injection solution, an end wall with at least one nozzle bore or one outlet element, a pressure-stable outer cylinder, and a pressure-stable piston arranged movably in the chamber and blocking water vapor and oxygen. Methods for bubble-free, automatic or manual filling of the cylinder/piston unit, also at atmospheric pressure are also disclosed.

The phase margin compensation method according to an exemplary embodiment of the present invention includes: outputting reference voltage (Vout2); outputting a first reference voltage (Vout1) actually supplied to the target circuit; comparing the reference voltage (Vout2) with the first reference voltage (Vout1) by the comparator; counting any section of an output signal (pulse signal) from the comparator by a predetermined frequency by the duty cycle calculator; and controlling a phase margin of a frequency of output voltage supplied to the target circuit by controlling buffer current based on the duty cycle ratios and the output bit information fed back from the duty cycle calculator.

In accordance with one embodiment of the present disclosure, a multi-phase voltage regulator may comprise a plurality of phases, each phase configured to supply electrical current to one or more information handling resources electrically coupled to the voltage regulator. A controller may be electrically coupled to the plurality of phases. The controller may designate at least one of the plurality of phases as a first state phase, and designate each of the plurality of phases not designated as a first state phase as a second state phase. The controller may alternate the designation of at least two of the plurality of phases between a first state phase and a second state phase. Each first state phase may be configured to supply a first electrical current regardless of electrical current demand. Each second state phase may be configured to supply a second electrical current based on the current demand.

Polyphase converter, comprising a plurality of electrical phases (11 to 16), which can each be driven by switching means (21 to 26), wherein at least one coupling means (31 to 39) is provided, which magnetically couples at least one first phase (11) to at least one further phase (12, 14, 16), wherein at least two phases (11, 12) to be coupled are surrounded at least partially by the coupling means (31), wherein at least one insulating body (72) is provided, which on the upper or lower side thereof accommodates the phases (11 to 16) to be coupled and on which at least one fastening means (74, 76, 90) is provided, which interacts with at least one of the phases (11 to 16) for fastening purposes.

There is provided a DC-DC converter which converts an input voltage into an output voltage for supply to a load, in which an input terminal receives the input voltage, an output terminal outputs the output voltage, power stages each includes: a high side switch, a low side switch and an inductor, the control unit executes a first mode and a second mode wherein the first mode controls the high side switch and the low side switch in each of the power stages so that a ratio of an output current in each of the power stages to a load current flowing through the load becomes a set value and the second mode controls the high side switch and the low side switch in each of the power stages so that duty ratios of the high side switch and the low side switch are equalized among the power stages.