Multi-core cable disconnection inspection circuit composed of only one electric test pen
This article will introduce to the readers the simplest multi-core cable disconnection inspection circuit composed of a test pen. It is fast and simple, and can make it easier for telecommunications maintenance personnel to judge whether the cable is disconnected and determine where it is. The root thread is broken.
The circuit is mainly composed of a 220V power supply and a test pen (see Figure 1). When checking, first strip off all the wire end insulation of the other end of the multi-core cable to be tested, and then short-circuit them together and ground them. Then peel off all the insulation of the multi-core cable at this end of the cable under test, and then insert the test head of the electric test pen into the 220V mains phase line jack to make good contact with the internal metal. Then hold the test pen with your left hand, and use your right hand to touch all the metal parts of the multi-core cable with the metal parts of the tail of the test pen (such as pen hook) one by one. If the small neon bulb in the electric test pen glows 1, it means that the wire is connected. If the small neon bulb does not light up when the wire end of a certain wire touches the metal part of the tail of the electric test pen, it means that the wire is broken, and mark it ( For example, the wire can be tied into a knot. In fact, the energy color of each wire inside some cables is marked differently, so the color of this wire can also be used as a mark). Finally, reverse the operation, that is, ground the test end just now, go to the other end of the cable to repeat the above test with a test pen, and also mark the broken core wire. In this way, the specific disconnected wires can be found out one by one conveniently and quickly.
The beauty of this circuit is that it uses the earth as the current loop, and it has two advantages; one is that it is not necessary to remove the entire cable (because some communication cables are as long as one kilometer, it is laborious and time-consuming to remove them all) The inspection is done in one place, so the circuit is suitable for long-distance inspection; the second is to save manpower and material resources, only one person, one electric test pen and one rake wire stripper can complete the operation.
