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在现代化城市或工厂里大部分采用埋地电缆输送电能。时间一长,一旦电缆出了故障,在查找故障或在电缆经过的地方增加其它设施时,都需先找到电缆的确切位置。这里介绍一种小仪器,所用元件不多,灵敏度却较高,在需要的时候随时就可装配使用。原理:探测器由音频振荡器,放大器和高频振荡器三部分组成(如图)。单结晶体管BG_1和电容C_1及电阻R_1,R_2,R_3等元件组成驰张振荡器,产生的音频电流经BG_2进行放大后,加到由BG_3和振荡线圈L等元件组成的高频振荡器上,由
In modern cities or factories, most of them use buried cables for power transmission. Over time, once the cable fails, find the exact location of the cable in the troubleshooting or other facilities where the cable passes. Here introduce a small instrument, the use of small components, but higher sensitivity, when needed, can be assembled at any time. Principle: The detector consists of audio oscillator, amplifier and high-frequency oscillator composed of three parts (pictured). The unidirectional transistor BG_1, the capacitor C_1 and the resistors R_1, R_2 and R_3 form a relaxation oscillator. The generated audio current is amplified by the BG_2 and then added to the high-frequency oscillator composed of the BG_3 and the oscillation coil L, by