简介：AnewFB-ZVT-PWMconverterisproposed.ThenewconverteroperatesatafixedfrequencyandimplementsZVSforpowerdeviceswithoutincreasingvoltageinbothturn-onandturn-offtransient.A80kHz/50WFB-ZVT-PWMboostconverterusingMOSFETsisanalysedtheoretically.

简介：Thezero-voltagequasi-resonantboostswitchingDC-DCconverterhasbeeninves-tigatedbyusingthetimeaveragingequivalentcircuitapproachofperiodicallyswitchinglinearnetworks.TheDCsteadystateandACsmallsignalcharacteristicsoftheconverterarealsogiven.

简介：飞兆半导体公司推出具高效率和出色热性能，并有助实现更薄、更轻和更紧凑的电源解决方案的MOSFET产品系列，可应对工业、计算和电信系统对更高效率和功率密度的设计挑战。

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简介：文中对宜普电源转换公司（EPC）Buck转换器EPC9107进行参数测试与分析。测试结果表明,当EPC9107电源模块工作于开关频率1000kHz、宽幅输入电压12-28V时,输出电压恒定3.3V,输出电流约为0-16A,效率最高约为96.1%,功率密度约为14W·cm^-3,转换时间小于4ns,具有良好的抗干扰度和瞬态响应,纹波小于20mV。该模块的整体性能均优于当前硅基DC/DC电源模块。

简介：目前,开关电源以小型、轻量和高效率等特点被广泛应用于几乎所有的电子设备,电源系统通常被称为＂心脏系统＂,有着其他系统不可比拟的重要地位。随着科学技术的发展,各种用电装备系统对于电源的要求也越来越高,电源组件直接影响着装备系统的体积、重量和可靠性。文章以一个小型化隔离型双路输出DC/DC变换器作为设计实例,通过对实际电路的分析,详细说明其工作原理及主要器件的取值或计算方法。

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简介：<正>凌力尔特推出同步降压-升压型DC/DC控制器LT3790,采用单个器件就可提供高达250W功率。LT3790的4.7V至60V输入电压范围使其非常适合多种汽车和工业应用。其输出电压可设定在0V至60V,从而非常适合用作电压稳压器或电池/超级电容器充电器。LT3790的内部4开关降压-升压型控制器采用高于、低于或等于输出电压的输入电压工作,使其成为汽车等应用

简介：BasedontheanalysisofDCcharacteristicsofsiliconbipolartransistorsatlowtemperature,DCanalyticmodelsofECLcircuitatlowtemperaturearederived,thencomparedwiththeexperimentaldataandcomputersimulationresults.ThemodificationofSPICEBJTmodelabouttemperatureanddesignoflowtemperatureECLcircuitarediscussed.

简介：Inordertorealizethemodulardesignofthemicrogrid,thispaperproposedanewmodulartopologyfortheAC-DCmixedmicrogrid.Inthattopology,theACmicrogridunitandtheDCmicrogridunitwerepackagedtogetherbytheback-to-backconverter.Thebattery-supercapacitorhybridenergystoragesystemwasconnectedtotheDCbusofback-to-backconverter.Bythereasonabledesignonthebattery-supercapacitorhybridsystem,theenergystoragesystemcouldsupplytherapidpowerandenergysupportforthemicrogridspontaneously.Themathematicalmodelandthecontrolalgorithmofthatmicrogridtopologywerestudied.Bythesimulationanalysis,itcanbeconcludedthatAC-DCmixedmodularmicrogridtopologycouldoperatesteadilyonboththegrid-connectedmodeandtheisolatedmode.Furthermore,wecanconcludebythesimulationthatthedesignedmodularmicrogridcouldoperateuninterruptedwhenthemicrogridtopologyswitchedfromthegrid-connectedmodetotheisolatedmode.Theseamlessswitchingbecamethenaturalpropertyforthemodularmicrogrid.Asaresult,themodularmicrogridtopologycanbeconsideredasausualpower/loadmoduletorealizethefriendlypowerinteractionwiththepowergrid.

简介：In_2O_3∶SnO_2(ITO)thinfilmswerefabricatedonthesubstrateofflexiblepolyethyleneterephthalate(PET)byDCmagnetronsputteringfromaceramictargetofIn_2O_3/SnO_2(90∶10).PropertiesofthethinfilmswerecharacterizedbyX-raydiffraction(XRD),four-pointprobe,Hall-effectmeasurement,UV-Visspectrophotometer,andscanningelectronmicroscopy(SEM).Theeffectsofsputteringpressure,oxygenpartialpressureanddepositiontemperatureonpropertiesofmicrostructureandoptoelectronicspropertiesofPET/ITOthinfilmswereinvestigatedindetail.High-qualityITOthinfilmsonPETsubstrateswiththeresistivityaslowas8.5×10-4Ω·cmandtheopticaltransmittanceover80%inthevisiblespectrumrangewereobtained.

简介：WeproposeaBPNNbasedadaptiveslidingmodecontrolschemeforspeedtrackingofaDCmotorwithunknownsystemnonlinearities.Theinput-outputlinearizationtechniqueisusedtocancelthenonlinearities,andoutputoftheBPNNisincorporatedintothecontrollerintheproposedscheme.ItisshownthattherotorspeedofaDCmotorcanfollowanyarbitrarilyselectedtrajectoriesundervariableloadtorque.Thentheapplicationoftheapproachistestedviacomesimulations.

简介：Soft-switchingtechniquesareattractivetounity-power-factorAC/DCconverterintheviewofthesizereductionandEMIsuppression.Asoft-switchedboostPFCconverterhasbeenstudiedbasedonitstopologyanalysis,PSIMsimulationandcircuitexperiment.Aspeciallimitationofsoft-switchingtechniqueshasbeenfoundintheirAC/DCapplications.

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简介：Aneworganicsemiconductortartaricaciddopedsaltofemeraldinepolyaniline(PANI-C4H6O6)hasbeenobtainedbythemethodofoxidativepolymerizationofmonomericanilinewithammoniumpersulfateinacidicsolution.ThestructurewascharacterizedbyFourierTransformInfraredtechnique(FTIR)andX-raydiffraction(XRD).Thetemperaturedependencedcconductivityδdc(T)showsasemiconductorbehaviorandfollowsthequasionedimensionalvariablerangehopping(Q1D-VRH)model.Dataonδdc(T)arealsodiscussed.

简介：Thisletterstudiesandanalyzestheworkingfeaturesofmaincircuitoftri-levelboostPowerFactorCorrect(PFC)converterandtheadvantagesoftri-levelswitchconverterinaspectsofbearinghigh-voltageofpowercomponents,overallsystemlossandmagneticcomponentselectionbaseduponthesingle-levelboostPFCswitchconverter.Besides,relyingontheapplicationofmi-croprocessorinpowerconvertertechnologyandDSP(DigitalSignalProcessing)chip'sstrongcal-culatingcapacity,theletterpresentstheadoptionofmodifiedschemeoftri-levelboostPFCconverterunderthecontrolofpredictivecontrolalgorithm.Moreover,theoperatingprincipleandcontrolmethodarespecified,theresultsofcircuittestandanalysisareprovidedandtheadvantagesofpre-dictivecontroltechnology-basedmulti-levelboostPFCconverterisverified.

简介：从数码印刷作为一个前沿技术出现在印刷类杂志上为人所津津乐道．到如今彩色短版印刷被企业用户耳熟能详．成为商务及印刷领域中促使生产发生质变的催化剂，上海康伟商务有限公司通过使用富士施乐DC2060数码印刷机．亲身经历了这一过程。

简介：为了解决动目标检测过程中的盲速问题,通常采用参差周期法设计参差滤波器组来达到同时抑制杂波和推远盲速的效果。提出了一种基于梯度免疫算法的参差MTI滤波器优化设计。该算法利用免疫算法搜索最优参差码,有效地避免了传统遗传算法中的早熟问题。针对传统的遗传算法运算量较大的问题,引入了梯度算子缩小初始种群规模,使运算量大大减少。仿真结果验证了算法的可行性和有效性。

简介：<正>曾在2003年12月日本东京松下表面实装技术展上引起轰动的"细胞"概念贴片机(CellMount)MC111／MC211,已开始对外销售。"细胞"式贴片机顾名思义,是具有超小型体积,但能独立完成贴装任务,功能强大的小型贴片单元。SMT贴片生产线由若干超小型"细胞"单元组

简介：<正>吴军在《浪潮之巅》中总结硅谷的成功经验时写道,"世界很多国家都在学硅谷的经验,办起了自己的科技园,但却无法孕育出像思科和雅虎这样具有开创性的公司。这里面的原因有很多,其中一个是缺乏新的产业的孵化器。"毋庸置疑,孵化器在培育创新型企业集群、营造产业创新氛围、完善产业链整体实力上,具有十分重要的作用。而生物医药产业恰恰是一个比较特殊的产业。从其发展规律看,重大生物产品研发周期需要5-10年,大规模产业化则需要更长的时间。这就使得初创型的生物企业如何熬过漫长的