摘要
对通信光缆绝缘电阻进行测量的前站所需电源是由监测站通过金属护层与大地构成的回路以负电压远端提供取得,前站系统需要+5V电源工作。使输入前站的负电压以较高的转换效率转换成稳定的+5V电压以供前站正常工作是前站设计要解决的首要问题。设计采用LT1111 DC/DC转换芯片控制驱动的开关电源,完成负电压转正电压来实现前站的供电需要。该电源具有电路简单,体积小,输出稳定等优点。电源可完成任意负电压输入+5V输出,最大输出电流100mA,纹波在2%左右,转换效率达到88%。
Outposts of Measunng fibre optic cables insulation resistance need positive 5V. monitoring center apllyied negtive DC voltage to cable sheath while outposts cepacltors charging. Converting negtive voltage to stable positive voltage is important for outposts design. Design used LT1111 DC/DC converter to control the switching power supply. The switching power supply circuit is simple,smaU and stable. The output is positive 5V, 100mA, dpple is approximately 2%,conversion efficiency is 88%.
出处
《电子质量》
2008年第5期36-39,共4页
Electronics Quality
