I'm using a PIC to do some zero-cross detection on the AC mains using a similar double-diode voltage clamp that is used for ESD protection. I need to connect the AC neutral to the logic ground so that the logic has something to reference the AC to.
In some app notes, they connected the AC neutral to the logic ground through a 1MOhm resistor, but I was wondering if there was a way to connect neutrals together but filter out noise. Like could I connect the two together with an inductor and the inductor might filter out high frequency AC mains noise from disrupting the logic ground and introducing noise into the logic?
In some app notes, they connected the AC neutral to the logic ground through a 1MOhm resistor, but I was wondering if there was a way to connect neutrals together but filter out noise. Like could I connect the two together with an inductor and the inductor might filter out high frequency AC mains noise from disrupting the logic ground and introducing noise into the logic?