i am wondering if there is a way to find a break in a very long cable (up to 500 mtrs) i thought of using a pwm signal but am not shaw if an arduino could recive some sort of back emf from where the crack or break is if it could then i should be able to measure distance using an arduino
thanks for any idears
The theory is sound but the implementation requires careful electrical design (fast-rise-time signals are needed, and fast, sensitive detectors). Specialized test equipment exists for this purpose, though you can build it from lab equipment:
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The MegaRAM shield: add 128 kilobytes of external RAM to your Arduino Mega/Mega2560
Hi,
Hmmm. Signals travel about 9ns per meter in most cables..
First, what kind of cable? Test that it has no power applied!!! !!
WhatIf: You use an Arduino output to put a very short pulse into the cable, then "look" at the signal coming back.
Looking is the hard part, it's so fast. If the far end of the cable is shorted a signal will return in about 500*9=4500 Ns (Times 2 again for the round trip).
So that's only 9000 ns or 9 Microseconds. Probably not time enough for Arduino to look, I think. You need an oscilloscope to look at the signals.
If you are going to be digging this cable up, you need to be sure what the actual propagation velocity of the real cable is.
Also, most power and telephone and cableTV companies have a TDR (Time Domain Reflectometer) cable tester and might help you out.