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Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,2024/11/26,1,开关电源原理与维修,Leon Liu,Jackie Qin,Salcomp R&D 22-Aug-2021,1,2024/11/26,2024/11/26,2,内容,开关电源维修人员的根本要求,开关电源原理,开关电源维修,维修台和设备,开关电源的维修本卷须知,开关电源维修案例AC-16,考试,2024/11/26,3,开关电源维修人员的根本要求,高中或电子技校学历,会使用以下仪表：,万用表？,示波器？,爱好电子技术,2024/11/26,4,开关电源原理,充电器,交流电压,90V-264V,直流电压,/,电流：,5V/1A,充电器功能：,交流变直流,隔离，得到平安输出电压,开关电源原理,-,输出特性,充电器的输出电压电流,CC,负载：,0 1000mA,CV,负载：,CV=2.0V 4.75V,充电器的输出电压纹波,70%,充电器的待机功耗,150mW,2024/11/26,5,2024/11/26,6,开关电源原理,波形,交流输入电压,整流滤波,C2,电压,开关管上,T2,电压,变压器输出电压 F,S),直流输出电压,/,电流,2024/11/26,7,开关电源原理,-,电路,整流电路,滤波电路,储能隔离电路,开关电路,启动电路,输出稳压电路,输出恒流电路,VCC,电路,整流滤波电路,输入,AC 220V,输出,5V/1A,热地,冷地,开关电源原理,-,电路,电路启动,AC 输入电压经D1整流和C1C2滤波好，得到DC电压。,DC 电压通过R3 电阻和IC 内部二极管Vin 脚和Vcc脚之间的，对VCC 脚上的电容C8 充电。,当C8上电压到达开启电压12V时，IC开始工作,IC开始工作后，变压器绕组6，3通过D5 R10给C8供电，维持IC 工作。,当C8上电压低于6V时，IC 进入欠压保护状态。,2024/11/26,8,开关电源原理,-,电路,输出电压控制,输出电压Vo由变压器输出绕组F,S耦合到初级检测绕组6.3,此信号经R11,R12 和R5分压后，送入IC的VS脚，与IC内部的基准电压做比较，,从而调整IC OUT脚输出的脉冲宽度或开关频率来实现输出电压的稳定。,2024/11/26,9,开关电源原理,-,电路,输出电流控制,由开关管T2上串联的电阻R4R15R13,可以检测到初级的电流,此电流信号送入IC的IS 脚，与内部的电流基准比较。,从而调整IC OUT脚输出的脉冲宽度或开关频率来实现输出电流的稳定。,2024/11/26,10,开关电源维修,维修台和设备,认真阅读仪器说明书,接地要牢固可靠,2024/11/26,11,开关电源维修,看懂电路图,看懂PWB的走线,看懂产品测试规格 电流，电压，纹波电压,先不通电检查,目视,用万用表测量两点间阻抗,通电检查,空载低压90V 开机，注意AC输入功率的大小,慢慢增加负载，看输出电压电流的变化,用万用表测量两点间电压,用示波器测量两点间电压波形,2024/11/26,12,开关电源维修,2024/11/26,13,示波器,开关电源维修,进一步阅读资料,电路根底,电子技术根底,IC规格书,电子零件规格和测量,AC-16 的维修案例,考试,2024/11/26,14,
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