49results about How to "Eliminate dead time" patented technology

A system for seismic data acquisition has been invented having, in certain aspects, one or multiple distributed data acquisition subsystems that are independent of energy source controller and/or of navigation system operation. Thus the distributed acquisition system(s) do not require a complicated and burdensome interface to the energy source controller or navigation systems. The seismic data acquisition system supplies a continuous flow of data which is buffered within a centralized data repository for short term storage until required by non-real-time processes. A seismic data acquisition method has been invented that replaces conventional closely coupled interaction between seismic acquisition systems and the energy source controller and the navigation systems by utilizing GPS time stamps on both the data as well as cycling events of the energy source controller and/or navigation systems to insure precise association of seismic data with cycling events. By continuously acquiring data with no interruption in the acquired data flow, association with energy source or navigation events may be accomplished at a latter point in time and not in the real-time operation of the acquisition subsystem.

The invention relates to a standard Z source three-level T-shaped inverter and an SVPWM method thereof. A topology has boost features identical to boost features of a standard Z source network three-level NPC inverter, however, few switching elements are utilized, and efficiency is high. Compared with a three-level T-shaped inverter, functions of boost and voltage reduction of the topology can be achieved, direct connection of an upper bridge arm and a lower bridge arm is allowed, reliability is improved remarkably, dead time is eliminated, and waveform distortion is prevented. Compared with a Z source three-level diode clamped inverter, current at an input end is continuous, ripple waves are small, and the input end does not need to be connected with a large-capacitance array set in parallel. Compared with a standard Z source two-level inverter, output voltage has neutral point electric potentials, therefore, high frequency harmonic waves are small, a required filter is small, a switching frequency can be reduced, and switching loss is less. The SVPWM method is adopted to control the inverter, so that switching frequencies are decreased, switching loss is reduced, and harmonic contents of the output voltage are reduced.

The invention is intended to replace three-colour traffic lights or STOP signs in order to enable motorists to benefit from an alternation of right of way at intersections, without any prolonged or superfluous waiting times in the cases where concurrent lanes are either congested or free of vehicles. The invention comprises an illuminated signal (3) controlled by a traffic light controller and representing a STOP or give-way sign post in force in the highway code. The illuminated signal remains lit for as long as the lights of concurrent lanes, where applicable, are green (1), yellow (2), or for as long as the STOP/give-way signals of concurrent lanes are off, where applicable. It is advantageous to combine three-colour traffic lights with the signal (3) on the same sign post so as to render the right of way explicit.

The invention discloses a method for controlling a phase shifting stagger angle of a doubly salient motor. The method comprises the following steps of: forming a phase-lock doubling circuit by using a duodecimal counter and a logic phase-lock loop chip; performing m times frequency doubling process on any phase position signal of three phase position signals by the phase-lock doubling circuit to acquire a doubling signal; connecting the three phase position signals and the doubling signal to a DSP processor acquisition port; establishing an angle pulse relation table of a phase shifting angle alpha, a stagger angle theta and the doubling signal pulses and importing the table into a DSP microprocessor; acquiring falling edges, which serve as the reference signal of switching on and switching off a power transistor, of every phase position signals of the doubly salient motor by the DSP processor acquisition interface; and resetting a phase conversion control by calling the angle pulse relation table to realize an on-off signal of the power transistor of the doubly salient motor and calculate the phase shifting angle alpha and the stagger angle theta. The method eliminates dead time between the upper and the lower power transistors, not only can ensure that the doubly salient motor realizes large output torque but also can reduce the torque of the output torque, and effectively improves the motor output.

In a method and magnetic resonance apparatus for slice-selective magnetic resonance imaging, read partitions in a cyclical sequence of slices are read out. At least two slices have a different number of read partitions. The same predefined number of read partitions for the slices is read out in all cycles of the sequence. SEMAC techniques are used.

The invention relates to a Z-source three-level T-type inverter and a neutral-point balance control method thereof. A topology has an identical step-up characteristic with a Z-source network three-level neutral-point clamped (NPC) inverter, but uses comparatively fewer switching devices and has higher efficiency. Compared with a three-level T-type inverter, the topology is capable of realizing a step-up/step-down function and allows direction connection of upper and lower bridge arms so that the reliability is improved obviously, dead time is eliminated and waveform distortion is prevented. Compared with a Z-source two-level inverter, an output voltage has a neutral-point level so that high-frequency harmonic waves are low and a needed filter is smaller. Because three levels are closer to sine waves than two levels, switching frequency can be reduced and switching loss is lower. An SVPWM control strategy is adopted and a three-level SVPWM is converted into a two-level SVPWM and then neutral-point balance and step-up are realized on the basis of the two-level SVPWM. The method is capable of simply eliminating neutral-point balance and direct-connection coupling.

A timepiece includes a chime mechanism (1) having an hours component (2), a quarters component (4) and a minutes component (6), the hours (2), quarters (4) and minutes (6) components being pivot-mounted about one and the same spindle (3), the quarters component (4) and the minutes component (6) being kinematically linked by a first driving member collaborating with a first driving toothset (34). Out of the hours component (2) and the quarters component (4), one includes a second driving toothset (21) and the other includes a second driving member designed to be capable of collaborating with the second driving toothset (21) and of kinematically linking the hours component (2) and the quarters component (4), thereby eliminating the dead time between the chimes for the hours and those for the quarters, or between those for the hours and those for the minutes when there isn't a quarter to chime.

By adding silica to ceria-based CMP slurries the polish process starts much faster than without silica thereby eliminating dead time in the polish process and eliminating process instability caused by changes in the dead time with operating conditions. A slurry for performing chemical mechanical polishing (CMP) of patterned oxides (e.g., STI, PMD, ILD) on a substrate, comprises: ceria particles having a concentration of 1.0-5.0 wt % and silica particles having a concentration of 0.1-5.0 wt %. A ratio of ceria concentration to silica concentration (ceria:silica) is from approximately 10:1 to nearly 1:1 by weight. The ceria particles have a particle size of 150-250 nm, and the silica particles have a particle size of greater than 100 nm. The silica may be fumed or colloidal. The slurry has a pH of approximately 9.0.

The invention relates to a Z-source three-level PWM (pulse width modulation) rectifier and a method for controlling the same. The Z-source three-level PWM rectifier comprises three phases of bridge arms which are connected with one another in parallel. Each phase of bridge arm comprises four switch tubes which are serially connected with one another, and middle points of the various phases of bridge arms are connected with power grids or alternating-current sources by inductors to be used as input sources of the rectifier; output ends of the various bridge arms which are connected with one another in parallel are connected with an input end of a Z-source network; the switch tubes S<W1> and S<W2> are respectively serially connected to the upper side and the lower side of an output end of the Z-source network; a rear output end of the Z-source network is connected with a serial connection branch of a capacitor C1 and a capacitor C2 in parallel, and the serial connection branch of the capacitor C1 and the capacitor C2 is connected with a direct-current load. The Z-source three-level PWM rectifier and the method have the advantages that reduced voltages can be outputted by the Z-source three-level PWM rectifier with the topology, the upper and lower bridge arms can be directly connected with one another, the reliability can be obviously improved, dead time can be eliminated, and waveform distortion can be prevented; alternating-current harmonic voltages and currents can be effectively reduced by the Z-source three-level PWM rectifier while withstand voltage level can be upgraded, the quality of network-side waveforms of the Z-source three-level PWM rectifier can be improved in identical switch frequency and control modes, and distortion can be decreased.

A method for transmitting data between a master modem and at least one slave modem of a master-slave network in orthogonal frequency-division multiplexing, including assigning to each slave modem at least one transmit frequency band and at least one receive frequency band chosen in a range of frequencies likely to be processed by the master modem; and in each slave modem: oversampling, respectively undersampling, each transmitted or received symbol; and filtering upstream of the oversampling, respectively of the undersampling, by a band-pass filter of the corresponding assigned frequency band.

If an instruction to move a ram (5U) is issued, a ram instructed speed is instructed to be suppressed to a certain warming-up speed not higher than a target speed until a release speed determination section (75) determines that a moving speed of the ram (5U) calculated by a ram moving speed calculation section (51) reaches a predetermined warming-up release speed; if the release speed determination section determines that the moving speed of the ram (5U) reaches the predetermined warming-up release speed, the warming-up speed is released to accelerate the ram (5U) to the target speed.

Devices and corresponding methods are provided to operate a hot cathode ionization pressure gauge (HCIG). A transistor circuit can be configured to pass the electron emission current with low input impedance and to control cathode bias voltage. Emission current and cathode bias voltage can be controlled independently of each other, without a servo settling time. HCIGs can be calibrated with respect to leakage current.

A method for producing a shaped body from a curable material, in particular from a mineral binder composition, wherein the curable material is applied layer by layer in an additive method, in particular in an additive free-space method, by a printing head that can be moved in at least one spatial direction and wherein an application rate of the curable material and the temporal development of strength of the curable material are coordinated with each other.

Using a chemical vapor-phase deposition (CVD), physical vapor phase deposition (PVD) process or similar, novel directionally-oriented piezoelectric materials are created from zinc oxide (ZnO) and similar materials with innovative features that enhance their performance as ultrasonic transducers. Applications for these enhanced piezoelectric materials and transducers include: underwater sonar devices, non-destructive testing devices, tank level indicators, eddy current detectors, ultrasonic wellfield characterization devices, and in-fluid imaging devices (e.g., under-water and under-sodium viewing devices).

The invention discloses a ground magnetic resonance detection device and method for shallow groundwater and hydrocarbon substances, and belongs to the field of geophysical exploration. The device is composed of an upper computer, a main control module, a DC-DC converter, an H-bridge transmitting module, a switch driving module, an acquisition card, a storage battery, a transmitting coil Tx, a receiving coil Rx1, a receiving coil Rx2, a switch group, a pre-amplification module, a band-pass filtering module, a sliding rail driver and a supporting rod sliding rail. The two receiving coils are distributed on the two sides of the transmitting coil at equal intervals to form a symmetrical structure, the influence of the transmitting coil on the receiving coils is counteracted in an ultra-shallowlayer or short relaxation fine detection mode, dead time generated by coupling can be completely eliminated, and complete magnetic resonance signals are obtained. In an ultra-shallow layer or short relaxation fine detection mode, the difference between induction signals of the two receiving coils is obtained, effective magnetic resonance signals are reserved, meanwhile, far-end environment noiseis suppressed from the source, and the signal-to-noise ratio is effectively increased.

The invention discloses a T-shaped rectifying circuit and a corresponding three-phase rectifying circuit, By utilizing an internal circuit topology, A first controllable switch and a second controllable switch are both soft-switched. Namely, zero voltage switch, zero current switch or zero voltage zero current switch, or on-off switch with limited dv/dt and di/dt, which reduces the on-off power consumption of controllable switch, and makes the on-off power consumption of T-type rectifier circuit can be very small when the working frequency is relatively high, so that the on-off power consumption of T-type rectifier circuit is very low. In addition, the present application builds on conventional T-type rectifying circuits, Only one inductor is added, Four diodes and two capacitors do not require additional controllable switches and control circuits, and devices can be added without substantially changing the internal circuit layout of the traditional T-type rectifier circuit, so that the circuit topology structure is compact and the bus bar design is simple, thereby facilitating the electrical layout and structure design, and reducing the reconstruction cost.

A method for transmitting data between at least three nodes of an orthogonal frequency-division multiplexing network, including assigning to each node at least one transmit frequency and one receive frequency, the assigned frequencies being different from one node to the other; forming data symbols to be transmitted all having the same duration whatever the transmission node; and adding, to each transmitted symbol, a cyclic prefix and a cyclic suffix reproducing a predetermined number of samples, respectively of the end and of the beginning of the symbol.

A digital/analog amplifier includes the following coupled in series: a pulse-width modulator, a control circuit, a power inverter and a filter. The power inverter comprises two transistors series-connected between a power supply terminal and a ground of the amplifier. The control circuit drives the transistors of the power inverter. One output of the filter forms an output of the amplifier to which a load is connected. The amplifier also comprises a capacitive circuit parallel-connected to the output of the power inverter.

The invention discloses a T-type conversion circuit and a corresponding three-phase conversion circuit and a conversion device. In the T-type conversion circuit, by adding an inductor, four diodes andtwo capacitors in a T-type conversion circuit in the prior art, a controllable switching device and a diode device of the T-type conversion circuit can realize soft switching, and the power consumption of power devices and diode devices is reduced. The conversion device adopting the above-mentioned T-type conversion circuit combines components in the prior art with the newly-added components in the technical scheme into a circuit module, so that in a case that the internal circuit layout of the inverter/rectifier is not changed, the reconstruction cost is greatly reduced, the topological structure is compact, and the busbar design is simple, which is extremely advantageous for electrical layout and structural design.

The invention discloses a T-shaped rectifying circuit and a corresponding three-phase rectifying circuit, by utilizing an internal circuit topology, A first controllable switch and a second controllable switch are both soft-switched. Namely, zero voltage switch, zero current switch or zero voltage zero current switch, or on-off switch with limited dv/dt and di/dt, which reduces the on-off power consumption of controllable switch, and makes the on-off power consumption of T-type rectifier circuit can be very small when the working frequency is relatively high, so that the on-off power consumption of T-type rectifier circuit is very low. In addition, the present application builds on conventional T-type rectifying circuits, Only one inductor is added, Four diodes and two capacitors do not require additional controllable switches and control circuits, and devices can be added without substantially changing the internal circuit layout of the traditional T-type rectifier circuit, so that the circuit topology structure is compact and the bus bar design is simple, thereby facilitating the electrical layout and structure design, and reducing the reconstruction cost.