一台Olympus双目显微镜,因电源插头插入插座达数日之久,保险丝烧损,致使光源不亮。换用同型(1.5A)保险丝,开机后仍烧毁。初步判断故障在电源插头与电源开关间。经查,该区间除有保险丝外,尚有一黑色圆柱型封闭物体Noise Filter(噪声滤波器)呈短路状态。剥开后,见其中电容已击穿。该噪声滤波器(见图1)系感容去耦网络,用于滤除噪声耦合干扰。其中C_1、C_2是空心电容,对所穿过的导线有屏蔽作用,可减少 An Olympus binocular microscope, because the power plug into the socket for several days, the fuse burns, resulting in light is not bright. Switch to the same type (1.5A) fuse, burned after boot. The initial judge fault between the power plug and the power switch. The investigation, in addition to the range of fuses, there is a black cylindrical obstruction Noise Filter (noise filter) was short-circuit state. Peel open, see where the capacitor has been breakdown. The noise filter (see Figure 1) is a capacitive decoupling network used to filter out noise-coupled interference. Which C_1, C_2 is a hollow capacitor, the wire through the shielding effect can be reduced