Hello everyone,
I have a sensor which is disturbed by my mains earth frequency lucky me I have a sync Pin to sync the sensor with 50/60 Hz So I tried that to sync the sensor IC with a zero crossing circuit on a rather crude setup and it worked way better than anticipated. But on my actual circuit I only have
1 AC line to switch a Triac available
https://www.onsemi.com/pub/Collateral/FODM3083-D.pdfat page 8.
So the ZC circuit I used can't be implemented, and I doubt I can get L and N of mains earth on my PCB due to various resons.
One Solution would be if I could have a zero crossing triac driver which would have an output for when the ZC is- I couldn't find any so far that would have this ability (and I doubt I will find one)
I have found a workaround for this probelm, but I'm not really happy with it.
I probed my analog signal going to my sensor IC and noticed that the AC line noise is really huge (around 1V PP ) when the sensor IC is disconected/ turned off. So I used this signal and amplified and filterd it and to my surprise I coud actually do a zero crossing with that signal. I only can use this signal to get the sync started with a µC and then disconnect my circuit and connect the measurement IC but that would be feasable...I think.
So I have this solution which worked in a quick and dirty test but I doubt this will really work all the time.
So I'm a bit of a loss right now how to make that work other than this method?
Any Ideas would be welcome.
cheers.