cable test

Posted on Feb 6, 2014

Imagine being faced with a dozen or more cable ends, all the same colour and bearing no identification. The other ends emerge in another part of the building, and you have no way of knowing which is which. You could use a continuity tester and a long length of wire to extend one of the probe leads. But if you had fifty wires, and a five minute walk from one end to the other,

cable test
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it would take you a good working day just to trace them all through! The Multi-core Cable Tracing System presented here is designed to make this sort job less of a nightmare! The Sender unit is connected to up to 64 wires at one end, and then the Readout unit is used to indicate which is which from the other end. The Readout is simply connected to any two wires at the other end, and the display indicates which wire number the positive lead is connected to. Unlike some commercial systems, this system does not require a separate known common connection between the two units. The two units are both battery powered, allowing them to be used in situations where mains power is not readily available. A red LED on each unit indicated that the battery is OK. If the LED does not light or is very faint, the battery should be replaced. PP3 batteries were used in the prototype, but for more regular use larger capacity 9V batteries would be a better choice, for example six AA cells in a suitable holder. Low cost 9V plug-in mains adaptors could also be used. The 2 digit seven segment LED display on the readout unit is blanked whenever it is not connected to a cable, to conserve battery life. This system must never be used on live cables. Ensure both ends of the cables to be traced are disconnected before using this system. If in any doubt, check with a test meter. Connection to live cables will cause damage to this system, and could...

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