524results about How to "Increase duty cycle" patented technology

The invention relates to a radar detection technology, and provides a method and a device for detecting radar acquiring low-altitude wind profiles through combination of a frequency-modulated continuous-wave radar technology and a wind profile radar technology against the poor low-altitude detection capability of the existing equipment. One phased-array antenna is adopted to transmit serrated linear frequency-modulated continuous waves, and the other phased-array antenna is adopted to receive echo signals, thus forming a dual-antenna working mode of continuous-wave radar. The array surfaces of the two antennas are horizontally placed side by side with opening surfaces facing upward. Time-sharing scanning is carried out to form five detection wave beams which are the same with wind profile radar, and detection signals and data of the five wave beams are processed in the same way that signals and data of wind profile radar are processed so as to obtain a low-altitude wind profile of which the smallest height can be as small as 50m to 10m and other basic data products. A low-altitude continuous-wave wind measuring radar manufactured by adopting the method and the device of the invention has a wide range of applications.

An electrosurgical system includes a generator for generating radio frequency power, an electrosurgical instrument including at least first and second electrodes carried on the instrument, and a monopolar patient return electrode separate from the instrument. The generator comprises at least one source of radio frequency (RF) power, and has a first supply state in which the RF waveform is supplied between the first electrode and the patient return electrode, and a second supply state in which the RF waveform is supplied between a second electrode and the monopolar patient return electrode. A controller is operable to control the generator such that, in at least one mode of the generator, feeding means within the generator is adapted to alternate between the first and second supply states.

Methods and apparatus for analyzing ions by pipelining data acquisitions with an orthogonal time-of-flight (OTOF) mass spectrometer. A predetermined push sequence is established for launching packets of ions from a source region into a flight tube towards a detection region within the OTOF mass spectrometer such that ions which are launched in adjacent packets do not overlap prior to reaching the detection region. These discrete packets of ions do not intermingle and are launched in accordance with the predetermined push sequence along a propagation path from the source region toward the detection region such that portions of the packets of ions are simultaneously in-flight within the flight tube of the OTOF mass spectrometer. The times of arrival of ions are detected at the detection region to produce time-of-flight scans with signals corresponding to times of arrival for the ions in the launched packets of ions to provide a mass spectrum derived from pipelined data acquisitions.

The invention discloses a light mixing method based on three-primary-color LEDs. The light mixing method comprises the following steps: acquiring spectral power distribution of single-color light by using a spectrograph, and calculating tristimulus values corresponding to the single-color light; and testing through the spectrograph to obtain photometry and colorimetry performance parameters and the like of RGB three-primary-color LEDs. Red light, green light and blue light are mixed, the light is adjusted by a PWM mode. By the established three-primary-color light mixing mathematic model, the ratio of the theoretical three primary colors is obtained. Due to influence of junction temperature, chromaticity coordinate and color temperature of synthesized white light can deviate, and the relation between the chromaticity coordinate of the synthesized light and duty ratio of the three primary colors is found out by respectively adjusting duty ratios of bulbs R, G and B in the synthesized white light. The light mixing method based on three-primary-color LEDs has the characteristics of wide adjustable color temperature range and simple mathematic model. Light quality of illumination of white light LEDs can be improved, so that a light environment can be comfortable, healthful and intelligently adjustable, and demands of people to light are met.

Provided are an electronic device including a bank structure and a manufacturing method thereof. Methods of fabricating electronic devices require a relatively small number of steps and include the possibility of direct patterning of insulating layers such as fluorinated organic polymer layers using cost-effective techniques such as inkjet printing.

The invention discloses a Ka-frequency-band fixed-orientation dual-polarization all-solid-state millimeter-wave cloud radar. The millimeter-wave cloud radar comprises an all-solid-state transmitter (1), an antenna housing (5), an ortho-mode transducer (3), a dual-channel receiver (10) and the like. Output signals of the all-solid-state transmitter (1) reach an antenna (4) through a circulator (2) and the ortho-mode transducer (3) and are radiated towards the sky through the antenna housing (5); echo signals are processed by the dual-channel receiver (10), a digital receiver (11), a signal processor (12) and a display control computer (13) and provided for a far-end computer (15) through a communication system (14); a power distribution system (16) provides needed power; and test signals generated by a frequency synthesizer (9) pass through a power divider (6), a coupler A (7) and a coupler B (8) to be used for testing. According to the millimeter-wave cloud radar, a novel tool is provided for cloud observation, the size is small, the structure is simple, the reliability is high, and radar is applicable to long-time continuous observation to cloud.

The invention provides a rotating speed control method and device of a brushless DC fan, the brushless DC fan and a refrigerator. The rotating speed control method of the brushless DC fan comprises the following steps: detecting the real-time rotating speed of the brushless DC fan; comparing the real-time rotating speed with a target rotating speed; adjusting the current duty ratio of the driving voltage of the brushless DC fan according to the comparison result, so as to adjust the real-time rotating speed to be matched with the target rotating speed. According to the technical scheme, the rotating speed control method of the brushless DC fan has the advantages that the duty ratio of the driving voltage of the fan can be accurately controlled, thus the output voltage of the fan can be accurately controlled, and as a result, the accurate control of the rotating sped of the fan is realized, and the noise of the refrigerator is minimized.

The invention discloses a display panel and a display device. Display areas of the display panel comprise a first area and a second area, wherein the quantity of pixel units in each row in the first area is smaller than the quantity of pixel units in each row in the second area; a scanning line in electrical connection with a first shifting register is positioned in the first area, and a scanningline in electrical connection with a second shifting register is positioned in the second area; the first shifting register and the second shifting register are electrically connected with a first clock signal line; the first shifting register is electrically connected with the first clock signal line by using a resistance compensation unit; or the first shifting register is electrically connectedwith a second clock signal line; the second shifting register is electrically connected with a third clock signal line; an effective signal duty ratio of the second clock signal line is greater thanan effective signal duty ratio of the third clock signal line. According to the technical scheme in the invention, delay time of enabling the first shifting register to output a scanning drive signalto the scanning line positioned in the first area is prolonged, and display uniformity of the display panel is improved.

The invention relates to a method for controlling a piezoelectric valve positioner capable of changing PWM (pulse-width modulation) duty ratio. A software system is formed by a main monitoring program module, an initializing module, a parameter self-tuning module, a valve position control module, a man-machine interaction module, an interrupt processing module, an EEPROM (electrically erasable programmable read-only memory) storage module and a watchdog module. Positive PWM duty ratio is changed by adding a five-step switch method with negative PWM into a sectional PI method or a linearization method, and when the control method is applied to small-range step control, positive PWM pulses with big duty ratio can be obtained, valve position starting process can be accelerated, the number of positive PWM pulses and adjusting time of small-range step control can be reduced, and small-range step control process can be accelerated.

The invention relates to a control method for switching power supply, whose specific practices are as following: a voltage checking electric circuit (VCC) examines the output voltage V<0> of a converter then delivered to an error amplifier (VA), the error amplifier (VA) carries on the comparison with an output reference voltage V and the output voltage V<0> to get an error voltage value delta V at the start time of each switching period; an error interval judgment (VC) compares the error voltage value delta V with error interval delta n, n=1,2,... N (N=2-5) of the output voltage, control pulse selection signals are outputted to cause a multistage pulse generator (MPG) to generate multistage control pulse with different dutyfactors according to the comparison result, so that the switch tube (TD)of the converter is carried on multistage control. When using the control method, the output voltage ripple of the converter is small, the dynamic response is good, anti-interference capability is strong, and the method is suitable for converters of various topologies.

The invention relates to a method for the multi-pulse sequence control of a switch power supply working in a pseudo continuous mode, which comprises the following steps that: a voltage detection circuit (VCC) detects the output voltage V0 of a convertor and transmits the output voltage to an error amplifier (VA); at the beginning time of each switch cycle, the error amplifier (VA) compares an output reference voltage Vref with the output voltage V0 to generate an error voltage value delta V; and an error burst judger (VC) compares the error voltage value delta V with a preset error burst value deltan ( n is an integer from 1 to N) of N(N is more than or equal to 1) output voltages, and outputs a control pulse selection signal according to the result of the comparison to make a multi-pulse generator (MPG) generate control pulses Pn1 and Pn2 with different duty cycles to control the switching tubes S1 and S2 of the a converter TD respectively, wherein the n is an integer from 1 to N+1. The method can realize the multi-pulse sequence control of the switch power supply working in a pseudo continuous mode. The converter adopting the control method has current critical condition limitation-free output power, small output voltage ripples, excellent dynamic response and high disturbance resistance, and is applicable to convertors of various topological structures.

The invention relates to the technical field of infrared and discloses an electromodulation MEMS (Micro-electro-mechanical Systems) infrared source and fabrication method thereof. According to the infrared source and the method, a four-side fixed support structure is adopted, heating electrodes fixed on a support film are used for generating external infrared radiation energy, so that the electromodulation MEMS infrared source is secure in structure, stable in working performance, and high in duty ratio, a fabrication technology is simple, the cost is low, and massive production with low cost is realized.

The invention relates to a solar control system capable of providing a direct-current (DC) power supply and a control method thereof. The solar control system comprises a solar controller and a solar cell plate array. The solar control system is characterized in that the output of the solar cell plate array is connected with the solar controller; the output of the solar controller is directly connected with an electrical appliance requiring a DC power supply and in parallel connection with a high voltage storage electrolytic capacitor on the DC power supply side of the electrical appliance; the solar controller comprises a main control MCU (microprogrammed control unit), a DC-DC isolated converter circuit, a DC voltage isolation sampling unit circuit and a DC voltage sampling unit circuit; the solar cell plate array consists of more than two control and conversion units; and each control and conversion unit contains a solar cell plate and an MPPT (maximum power point tracking) and BOOST control unit. By adopting the solar control system, the solar energy after DC-DC conversion, is in parallel connection with the rectified DC of the city power directly; and the solar control systemhas the characteristics of flexible operation, stable performance and wide application range.

The invention relates to a medical proton synchrotron which comprises the components of a first deflecting two-pole magnet, a second deflecting two-pole magnet, a third deflecting two-pole magnet, a fourth deflecting two-pole magnet, a fifth deflecting two-pole magnet, a sixth deflecting two-pole magnet, a seventh deflecting two-pole magnet and an eighth deflecting two-pole magnet, wherein the deflecting two-pole magnets are successively connected, and furthermore the first deflecting two-pole magnet is connected with the eighth deflecting two-pole magnet for forming an annular structure; a first long linear junction, a second long linear junction, a third long linear junction, a fourth long linear junction; a first miniature linear junction, a second miniature linear junction, a third miniature linear junction and a fourth miniature linear junction. According to the medical proton synchrotron, through utilizing the deflecting two-pole magnets with ultrahigh field strength and horizontal focusing and horizontal defocusing four-pole magnets, an envelope function is kept in a relatively low level, and furthermore the medical proton synchrotron has advantages of effectively improving acceptance degree of the proton synchrotron, increasing number of stored protons, increasing proton utilization rate and duty ratio, and shortening treatment time. Furthermore each magnet element in the medical proton synchrotron has relatively high strength for reducing perimeter of the whole synchrotron, thereby effectively utilizing the space of the medical proton synchrotron and furthermore reducing treatment cost.

The invention relates to an electric heating device and provides an electric heating control method with continuously adjustable power. The method comprises the following steps: firstly, a system receives a target temperature input by a user and calculates target power according to the target temperature, and the target temperature is in direct proportion to the target power; then the system detects real-time input voltage value, calculates the real-time power difference according to the real-time input voltage value and the target power and calculates the real-time duty cycle according to the real-time power difference, and the real-time power difference is in direct proportion to the real-time duty cycle; finally, the system modulates the output power of a power module according to the real-time duty cycle. The power output of the heating device is adjusted in real time according to the difference change of the current temperature and the target temperature, so that the effects of improving the heating comfort, improving the energy efficiency of an air conditioner, prolonging the service life of the product and reducing the energy consumption are realized, and the method is applicable to air conditioners, electric heaters and electric blankets.

A clock oscillator system for use in providing the switching regulator duty cycle control in a fixed frequency (no cycle skipping) operation is provided. In one embodiment, the circuit according to the invention uses an analog feedback loop to extend the switch ON time of the clock cycle by controlling the oscillator charging current and, thereby, increase the duty cycle. Preferably, this circuit can achieve very high switching duty cycle and/or very low switching duty cycle in a PWM switching regulator operated in very low drop-out operation when very high duty cycle is required or in other conditions when very low duty cycle is required.

The invention discloses a terahertz microbolometer based on a metamaterial and a preparation method of the terahertz microbolometer. The terahertz microbolometer is composed of two parts including a metamaterial terahertz absorber and a thermal detector, wherein the thermal detector comprises four layers of materials, namely a microbridge supporting layer, a thermistor film, a metal electrode and a passivation layer. The metamaterial terahertz absorber comprises three layers of materials, namely a bottom-layer metal film, an intermediate medium layer and a top-layer metal film. According to the terahertz microbolometer, the metamaterial terahertz absorber and the thermal detector are integrated, heat generated by the metamaterial absorbing terahertz radiation is transmitted to the thermal detector, and then, the electrical property of the thermistor film is changed, so that the terahertz room-temperature detecting and imaging are realized. Due to the adoption of the microbridge structure and the preparation method disclosed by the invention, the problems of microbridge deformation caused by adding the metamaterial and the like are solved, and the microbolometer is high in mechanical stability and terahertz absorptivity. The defect that terahertz waves are difficultly detected by using the traditional microbolometer is overcome; and the terahertz microbolometer is prepared by using the traditional micromachining technology so as to be suitable for industrial production.

The invention provides an electromagnetic resonance control circuit, an electromagnetic heating device and a method for controlling a transistor. The electromagnetic resonance control circuit comprises a power module, a resonance circuit, the transistor and a controller, the resonance circuit is connected to the power module, the transistor is arranged between the resonance circuit and the ground, and used for executing the power-on or power-off operation according to pulse width modulation signals sent by the controller to control the work state of the resonance circuit, and the controller is connected to the power module and the control end of the transistor, and used for adjusting the duty ratio of the pulse width modulation signals sent to the transistor according to the change condition of voltages output to the resonance circuit by the power module to control the power-on time of the transistor. According to the technical scheme, the power-on time of the transistor can be controlled according to the voltages output to the resonance circuit, power output is increased in a low-voltage area, power output is reduced in a high-voltage area, the peak voltage and the peak current of the transistor are reduced under the condition of identical power, and therefore the transistor is effectively protected.

An adaptive clock throttle 600 interfacing a clock generator 601 generating a high speed clock and a processing engine 602 operating in response to a processing clock. Adaptive clock throttle 600 generates a plurality of lower speed clocks from the high speed clock, estimates a duty cycle of the processing engine, and selectively gates one of the lower speed clocks to the processing engine as the processing clock to increase the duty cycle of the processing engine.

The invention relates to a double-closed-loop feedback-control module, wherein two closed-loop control loops are formed in the starting process and the holding stage of a contactor to directly and accurately control the coil current of the contactor, so that the optimizing control for the integral action characteristic of the contactor can be carried out, and the integral performance index of the contactor is comprehensively improved. The double-closed-loop feedback-control module has low hardware cost, the voltage-adjusting rate of a system can be improved, the transient response speed of the system is increased, and the stability of the system is enhanced.

The invention discloses a back light source drive circuit directly driving a lamp strip circuit by using a primary half-bridge resonance circuit. The back light source drive circuit comprises a primary resonance circuit, a secondary lamp strip circuit and an optical isolating feedback circuit having an optical coupling feedback function, wherein the primary resonance circuit generates a driving pulse signal according to the received external voltage and a current signal fed back by the optical isolating feedback circuit, and provides needed work voltage for the secondary lamp strip circuit according to the driving pulse signal; and the optical isolating feedback circuit samples the loaded current in the secondary lamp strip circuit in real time, and feeds back the current signal to the primary resonance circuit. The back light source drive circuit directly lightens and controls the back light source by using the primary half-bridge resonance circuit; and optical coupling is used as the feedback control from the secondary level to the primary level. The drive circuit is simplified so as to eliminate a secondary side LED driving chip, and reduce device number of the whole system.

The invention discloses a photovoltaic air conditioning system. The photovoltaic air conditioning system comprises a photovoltaic battery, a direct current air conditioner, an energy storing apparatus and a photovoltaic converter. The photovoltaic converter comprises a photovoltaic charging circuit, a DC/DC switching circuit and a controller. The photovoltaic charging circuit transmits electricity output by the photovoltaic battery to a low voltage direct current bus; a DC/DC converter converts the electricity on the low voltage direct current bus into an electric signal required by working of the direct current air conditioner; when the controller meets a charging condition and the direct current air conditioner is in a non-running state, the photovoltaic charging circuit is controlled in a four-phase charging mode; and in the first charging phase, the controller gradually increases the duty cycle of a control signal of the photovoltaic charging circuit from the permissible minimum to the permissible maximum. The photovoltaic air conditioning system can charge the energy storing apparatus reasonably, so as to guarantee the service life of the energy storing apparatus. The invention also discloses a charging control method of the photovoltaic air conditioning system.

A stator core for a rotating electric machine includes a plurality of split cores. Each of the plurality of split cores includes a back yoke, a tooth, and a single caulking portion. When each of the plurality of split cores is seen in an axial direction, two inner circumferential-side intersections and two outer circumferential-side intersections are defined, both circumferential-end surfaces of the tooth intersect an inner circumferential surface of the back yoke at the two inner circumferential-side intersections, virtual lines drawn by extending both the circumferential-end surfaces of the tooth intersect an outer circumferential surface of the back yoke at the two outer circumferential-side intersections, a central position of the caulking portion is disposed in an opposing angular region on a radially outer side out of four opposing angular regions defined by lines diagonally connecting the two inner circumferential-side intersections to the respective two outer circumferential-side intersections.