56results about How to "Increased power range" patented technology

A power amplifier (1) for receiving and amplifying an input signal (10) and outputting an output signal (11) is disclosed. The power amplifier comprises: N power amplifying units (12) (N is an integer larger than 1) connected in parallel so as to output amplified signals in response to the input signal (10); an output combining unit (14) for combining the output signals from the N power amplifying units (12) and outputting a combined signal as the output signal (11) of the power amplifier; and an amplitude controlling unit (15) for selectively turning ON each of the N power amplifying units (12) based on an amplitude of the input signal (10). In the power amplifier, the amplitude controlling unit (15) may comprise N amplitude adjusters (113) connected in parallel for adjusting the amplitude of the input signal (110) of the power amplifier; and a controller (115) for selectively turning ON each of the N power amplifying units (112) and controlling the amplitude adjusters (113) so that an amplitude of the output signal (111) becomes a substantially continuous function with respect to the amplitude of the input signal (110). The power amplifier may further comprise a local oscillator (222) outputting an constant envelope signal, receiving a modulation signal (210) as the input signal of the power amplifier and outputting an amplified modulated signal (211) as the output signal of the power amplifier; wherein the N power amplifying units comprise N saturation amplifying units connected in parallel so as to amplify the constant envelope signal from the local oscillator; and the amplitude controlling unit comprises an amplifying controller (215) for selectively turning ON each of the N saturation amplifying units (212) based on an amplitude of the modulation signal (210).

A frequency converters used in communications receivers. Such frequency converters can be used for converting a signal from a Radio Frequency (RF) to a low frequency suitable for processing such as demodulation. The inventors have made the unexpected discovery that when the gates of the MESFETs of a double-balanced mixer are left open-circuited and allowed to self-bias, the drop in mixer linearity at high LO power levels is reduced thereby increasing the LO power range of operation. This invention can be used as an improved scale-down mixer as well as an upconverter mixer.

A pedal lever type bicycle includes a pedal lever having a front portion and a rear portion, with an intermediate pivot point located substantially above the center of the rear wheel, and to the rear of the front of the rear wheel. The rear portion of the pedal lever has dog-leg configuration with a slider that is attached to a drive chain. The slider is mounted on a straight section of the rear portion of the pedal lever which extends slightly above and to the rear of the rear wheel hub, so that the chain exerts a force to move the slider outwardly on the rear portion of the pedal lever when it is in a lower position, and in the opposite direction when it is raised. Changes of mechanical advantage of 3 or 4 to 1 are available with this configuration of the pedal lever. The bicycle incorporates positive intuitive gear controls and quick release mechanisms for all major components of the propulsion system.

A digital transmission circuit and method providing selectable power consumption via multiple weighted driver slices improves the flexibility of an interface while reducing transmitter power consumption, area and complexity when possible. A cascaded series of driver stages is provided by a set of parallel slices and a control logic that activates one or more of the slices, which combine to produce a cascaded active driver circuit. The power consumption/drive level selectability of the slice combination provides a driver that can be fine-tuned to particular applications to provide the required performance at a minimum power consumption level.

The invention provides a high-frequency vertical spring probe card structure including a plurality of probes. Each of the probes includes at least one conducting layer and at least one insulating layer. The conducting layer includes a first contact end and a second contact end used for electrically contacting an external component while the probe is compressed and includes a probe body including at least one plate portion and at least one resilient portion connected to each other. The plate portion is used for supporting deformation of the resilient portion while the resilient portion is compressed vertically. The insulating layer includes at least one plate member tightly attached to the plate portion of the conducting layer correspondingly. The probe structure of the invention is simple and can be formed as multi-layer stack structure by electroplating through Lithographie GaVanoformung Abformung (LIGA) technology.

The invention relates to a variable capacitor array which has excellent controllability on a capacitance value and has variable and high tunability. The variable capacitor array includes a first variable capacitor (C1) having a capacitance which is varied according to application of voltage; a first terminal (O1) connected to one side of the first variable capacitor; a second variable capacitor (C2) having a capacitance which is varied by application of voltage; a second terminal (O2) connected to one side of the second variable capacitor; and a third terminal (I) connected to both of the other side of the first variable capacitor and the other side of the second variable capacitor, wherein a state can be selected by switching between at least two selection states among three selection states of a first selection state that the first terminal (O1) and the third terminal (I) are selected, a second selection state that the second terminal (O2) and the third terminal (I) are selected, and a third selection state that the first selection state and the second selection state are selected simultaneously.

A power converter configured to improve power capture in a wind turbine during low wind speed operation is disclosed. The power converter converts the power generated by the alternator of the wind turbine into a suitable AC current for delivery to a utility grid or to an electric load independent of the utility grid. The power converter is configured to operate in multiple operating modes, utilizing both synchronous and non-synchronous control methods, to extend the operating range of the power converter. During non-synchronous operation, the power converter utilizes a modulation routine that may either vary the dead-time compensation period during a constant modulation period or vary the modulation period with a constant on-time. A seamless transfer between non-synchronous and synchronous control methods with low total harmonic distortion (THD) improves the range of power generation for wind generators.

The invention discloses a fuel cell stack test board and a back pressure control method thereof. The test board comprises a hydrogen system and an air system. The hydrogen system is communicated witha hydrogen inlet of a fuel cell stack through an air inlet pipeline; the air system is communicated with an air inlet of the fuel cell stack through an air inlet pipeline; flow meters for detecting the flow of the air inlet pipelines are arranged on the air inlet pipelines; a hydrogen outlet and an air outlet of the fuel cell stack are respectively provided with an air outlet pipeline; first backpressure valves and second back pressure valves are arranged on the air outlet pipelines in parallel; the back pressure range of the first back pressure valve is smaller than that of the second back pressure valve; and pressure sensors used for detecting the pressure are arranged on pipeline sections between the air inlet pipeline or/and the air outlet pipeline and the first back pressure valve and between the air inlet pipeline or/and the air outlet pipeline and the second back pressure valve. According to the back pressure control method, double back pressure valves and two-way control are utilized, and back pressure control is rapidly achieved through different flow, higher-precision control is realized, and meanwhile, the coverage of a larger power range is realized, and the cost of the test board of a client is saved.

A control device, in particular an electrical switch for use for an electrical tool such as a rechargeable-battery and/or plug-powered electrical tool having an electric motor. The switch has a housing for holding at least one heat-generating component such as a power transistor, a MOSFET, a triac or the like, which is arranged in particular in an electrical circuit arrangement which, for example, is used for open-loop and/or closed-loop control of the electric motor by appropriate open-loop and/or closed-loop control of the electrical load current flowing through the component to the electric motor. A means for thermal conduction is connected on the one hand to the housing of the electrical switch, and/or to the heat-generating component, in particular to the power semiconductor which is located in the housing, and on the other hand to a cooled area which is associated with the switch.

An energy generation apparatus uses centrifugal force to generate energy in a controlled manner. The apparatus includes a dual function input shaft and output shaft rotatably attached to opposite sides of a housing defining an axis of orbit, an output gear fixed upon the output shaft, an input sprocket rotatably mounted on the output shaft, and at least two frame gear assemblies, each having a frame gear and at least two weight gears. The frame gears rotate about their centres and also orbit around the output gear in response to an input from the input sprocket.

With a method for controlling a gas burner, the latter is supplied with gas by an electronically controllable gas valve, wherein it is supplied with gas by the gas valve in a low power range and in a high power range. Only one of the power ranges is available at any point in time, wherein in each of the power ranges a power from a minimum power to a maximum power can be preset at the gas burner using an operating element. The low power range and the high power range differ here by more than 50%.

A method for operating a high-pressure discharge lamp outside the nominal power range thereof is provided. The method may include: providing the high-pressure discharge lamp; and varying relative to operation at nominal power, one of at a lamp power of less than 85% of the nominal power and at a lamp power of greater than 110% of the nominal power at least one or more of the following parameters: lamp frequency, lamp current in a commutation pulse, length of the commutation pulse, and the commutation pattern.

The invention discloses an ion-implanted one-dimensional electron gas GaN-based HEMT (high electron mobility transistor) device and a preparation method. The problems of poorer high-temperature high-voltage characteristics, frequency characteristics and power characteristics of the conventional one-dimensional electron gas device are mainly solved. The device comprises a substrate, buffer layer, a potential barrier layer, a passivation layer and a protective layer from bottom to top, wherein a source and a drain are arranged at two ends on the potential barrier layer respectively; the passivation layer is positioned on the potential barrier layer between the source and the drain; a gate trough is formed in the passivation layer, and a gate is arranged in the gate trough; the buffer layer is made from GaN, and the potential barrier layer is made from AlGaN; anions are implanted into local areas on the potential barrier layer, and the areas where the anions are implanted are a plurality of spaced strips; the widths of areas where the anions are not implanted between the strips are at a nanometer order of magnitude, and a one-dimensional electron gas is formed in heterogeneous junctions below the areas where the anions are implanted. Compared with Si-based and GaAs-based devices, the device has good high-temperature high-voltage characteristics, good frequency characteristics and good power characteristics, and a one-dimensional electron gas device with super-high speed and low power consumption can be manufactured.

A multi-voltage output linear power amplifier includes at least one single-voltage range linear power amplifier, a switching unit connected to each of the single-voltage range linear power amplifiersfor outputting a plurality of AC voltages and/or a plurality of DC voltages. The technical scheme can expand the voltage output range or the power range, and realize the AC/DC output of different voltage levels.

The invention relates to a preparation method of an all-ceramic oral cavity repairing composite material with machinable zirconia/lanthanum phosphate, belonging to an inorganic composite material preparation field. The method of the invention is essentially characterized by adjusting the strength and toughness of compound ceramic of zirconia and lanthanum phosphate through controlling the content of zirconia and lanthanum phosphate; the preparation technology of the invention comprises the following processes: lanthanum phosphate powders are prepared; mixture powders of yttrium oxide, lanthanum phosphate and zirconia are prepared by a certain mass ratio; isostatic pressing and sintering is carried out for the mixture under 150 to 250MPa and 1,500 to 1,650 DEG C respectively; and finally the dental composite ceramic material with machinable zirconia and lanthanum phosphate of the invention is obtained. The composite of the invention is suitable for all-ceramic dental repair of oral cavity clinic.

The invention provides an electromagnetic heating device and a power control method; the electromagnetic heating device comprises an AC power supply circuit (10), a rectification circuit (20), a filter circuit (30), a heating loop (40), a controller (50), an electronic switch (60), and a zero cross detection circuit (70); the filter circuit (30) comprises a filter capacitor (31); the filter capacitor (31) is connected in series with the electronic switch (60) and connected in parallel between the rectification circuit (20) and the heating loop (40); the input end of the zero cross detection circuit (70) is connected between the AC power supply circuit (10) and the heating loop (40); the controller is respectively electrically connected with the heating loop (40), a control end of the electronic switch (60) and an output end of the zero cross detection circuit (70). The method can reduce the heating of the IGBT in a low power heating process, thus improving the power range of low powerheating.

The invention discloses a hydraulic slide valve mechanism provided with a force-balance channel. The mechanism is characterized in that: a pressure-balance channel I is arranged on a slide valve core and leads pressure oil close to the I surface of a throttle side in an inlet square-cavity to the left end surface of the slide valve by a keyhole I; the valve core is provided with a pressure-balance channel II that leads pressure oil close to the II surface of the throttle side in the inlet square-cavity to the right end surface of the slide valve by a keyhole II. By the balance of the internal hydraulic pressure of the valve core, the hydraulic force compensation mechanism provided with the pressure-balance channel reduces the effect of hydraulic thrust and the requirements of the slide valve on external control power, improves the power range which can be controlled by a directly driving hydraulic slide valve and mainly aims at laying a foundation for the realization of direct control over a hydraulic valve with large latus rectum and large flow and being capable of directly controlling the hydraulic valve of large power, thereby broadening the application range of the hydraulic slide valve mechanism.

The invention discloses a voltage-reducing and electricity-saving controller of a motor, comprising a power supply circuit, a microprocessor circuit and a power factor angle acquisition circuit, wherein the power supply circuit is connected with the microprocessor circuit; the controller also comprises a current acquisition circuit, a synchronous information acquisition circuit, a silicon-controlled drive circuit, a silicon-controlled circuit and a control signal input circuit which are respectively connected with the microprocessor circuit, wherein the silicon-controlled circuit comprises a first silicon-controlled group, a second silicon-controlled group and a third silicon-controlled group; each silicon-controlled group comprises two pieces of one-way controlled silicon which are reversely connected in parallel; one end of each group of three silicon-controlled groups is the input end of the controller and the other end is the output end of the controller; and the silicon-controlled drive circuit comprises a first drive circuit, a second drive circuit and a third drive circuit which are connected with the trigger ends of the first, the second and the third silicon-controlled groups in sequence. The invention has the advantages of favorable real-time property, high accuracy and commonality.

An operation control method and system of a fuel cell (stack) are provided and extend the operation field of the fuel cell in a fuel cell electric vehicle and ensure power performance in the initial stage of starting of the vehicle. In an operation control method of a fuel cell having improved reverse voltage durability, in which an oxygen evolution catalyst is added to the anode electrode, a cell voltage of the fuel cell during normal operation of the fuel cell is monitored. The monitored cell voltage of the fuel cell is compared with a first setting voltage. When the cell voltage is less than the first setting voltage as the cell voltage decreases, a fuel cell operation control process for increasing the humidity in a cell of the fuel cell is performed.