EquipmentforswitchingpowersupplytestingFile:AC003.docPageofNUMPAGES11Date:28-Dec-20011.引言/Introduction此文件描述一般开关电源供应器的测试仪器及其特性。Thisdocumentdescribesgeneralequipmentusedinswitchingpowersupplytestingandtheircharacteristics.-示波器/Oscilloscope.-电压探头/Voltageprobe.-交流电流探头/ACcurrentprobe.-数字式电压表/DVM.-有效值表/RMSmeter.-功率表/Powermeter.-温度测量表/Temperaturemeasurement.-电子负载/Electronicload.-交流电源/ACsource.-台式直流电源/BenchtopDCpowersupply.2.示波器/Oscilloscope是用来显示一个或多个随时间快速变化的电量的设备。这个电量通常是指开关电源测试中的电压或电流。大多数示波器是用CRT(阴极射线管)显示的﹐数字存储型示波器也有用液晶显示的。Aninstrumentthatproduceavisibleimageofoneormorerapidlyvaryingelectricalquantitieswithrespecttotime.Thequantitiesareusuallyavoltageorcurrentinswitchingpowersupplytesting.ThemostusualtypeofoscilloscopeuseCRT(cathoderaytube)display,LCDdisplayisalsoavailablefordigitalstoragetype.2.1示波器类型/Typeofoscilloscope模拟示波器﹕不能存储。水平扫描是在示波器内部产生的(除用XY模式)。射线束在垂直方向的位置﹐随CH1或CH2的输入信号而变化。Analogscope:Nostorage.Thehorizontalsweepisgeneratedinternallyintheoscilloscope(exceptinXYmode).TheverticalpositionofbeamonthedisplaywillvaryaccordingtheinputsignaltoVERT(CH1orCH2).数字存储示波器﹐矢量显示(Tektronix2232)﹕对于非存储模式﹐类似仿真示波器。对于存储模式﹐首先﹐输入信号经模/数转换并存储在存储器中﹐存储后的信号再经数/模转换﹐然后调整光束的垂直位置。这种类型的示波器现在已经逐步被淘汰。Digitalstoragescope,vectordisplay,(Tektronix2232):﹐Innon-storemode,thiskindofscopeissameasananalogscope.Instoragemode,theinputsignaltoVERTisfirstconvertedwithA/Dandstoredinmemory,thenthecontentofthememorywillbeconvertedbacktoanalogsignalwithD/Aandmodulatetheverticalpositionofthebeam.Thistypeofscopeisphasingoutnow.数字存储示波器﹐监控显示(TektronixTDS3012)﹕这种显示是监控显示(类似计算机显示)。首先﹐输入信号必须由模/数转换并存储在存储器中。这类示波器没有类似仿真示波器的功能。Digitalstoragescope,monitordisplay(TektronixTDS3012):Thedisplayisamonitordisplay(similartocomputerdisplay).TheinputsignalmustbeconvertedwithA/Dandstoredinmemoryfirst.Thiskindofscopecannotfunctionasananalogscope.2.2重要的控制/Importantcontrol2.2.1垂直/Vertical.垂直增益(伏/格)/Verticalgain(V/div).垂直位置/Verticalposition直流耦合/DCcoupling交流耦合/ACcoupling2.2.2水平/Horizontal时间/格/Time/div.水平位