Capacitors pass high frequencies like the 130khz from the KQ-130. So the capacitors in the EN460 will short out the signals from the KQ-130.
Here I made a filter using two inductors which will open up at high frequencies. Now the signals from the KQ-130 will not pass back into the power line. All KQ-130s going to the right can talk just fine.
Capacitor C1 is optional. It will short out any 130khz signal that leaks through the inductors.
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QUESTION: Why keep the signals off the power line? I am using X-10 power line communication which is about the same thing. It works with out filters.
What load is on the line with the KQ-130s?