AC Zero Crossing Detect
AC Mains Detection + Zero Crossing Detection
- http://bbs.elecfans.com/jishu_1936706_1_1.html
- https://www.hackster.io/hesam-moshiri/how-to-build-an-isolated-digital-ac-dimmer-using-arduino-b25aa1
Common Solutions
Bidirectional Detector
- H11AA1
- LTV8241 - WV
Single Direction + Diode Bridge
- DB107 + EL817