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I had a PCB board printed that has some relays that are connected to 220 VAC circuit. Now unfortunately some traces passes near the relays and are affected by this high voltage causing the circuit to fail.
Is there a way to stop the effect of this high voltage on the near traces?
Regards
If you are just trying to make your current board work, can you just solder an RC Snubber circuit across the actual contacts switching the AC?
For 220VAC, I'd go about 150-250 ohms in series with .1uF. That might help clean up some switching noise (and reduce contact wear).
Move the traces.
There are separation and creepage distances for a reason. Mostly to do with safety, but EM interference sounds like the problem you're experiencing.
General answer:
If the high voltage is "tracking" across the surface of the circuit board then make physical slots in the PCB to make the surface path much longer. If the problem is induced emf due to currents then try using some ferrite sheet but make sure it's insulated against the AC voltages (ferrite can conduct a little). Small decouplers on the sensitive tracks to ground may also help.
If high AC voltage is capacitively coupling to the sensitive tracks small decouplers on those tracks to ground may alleviate the problem. The problem may also be alleviated by adding series resistance to the sensitive tracks.
However, it sounds to me like you may have to redesign the PCB.
As you have a low and a high voltage part you could perhaps separate them by putting the simpler one on a separate prototype PCB. Then you can connect the two boards with twisted wires, eventually soldering some wires directly to the relais connectors.
As always - keep an eye on security, especially when other persons will use the finished product too.
