ac-mains-and-zero-crossing-detector

FlameIT - AC Mains and Zero Crossing Precision Detector

Caution!

!!! Caution !!!

 This module was design to connect directly to the AC grid power. 
 Its misuse might cause ELECTRIC SHOCK or FIRE.

 !!! Caution !!!

Features

• very accurate mains zero crossing detection
• fully isolated (5kV optoisolation)
• low voltage, safe output (low side can be supplied with voltages from 1V up to 16V)
• ultra-low power consumption; worst case power dissipation < 120mW
• produces symmetrical pulses around the zero crossing
• very low parts count, no precision components required
• all components can be low voltage SMD
• works over all mains voltage ranges (100VAC…240VAC), without any modification
• both 50Hz (1,2ms ZC pulse) and 60Hz (1ms ZC pulse) mains frequency compatible
• highly stable with varying temperature
• ROHS compliant (Pb-free)
• extra AC input protection (fuse and varistor)
• 4 independent AC inputs on one module
• 2 low side outputs for each AC input
  • ZCD - Zero Crossing Detection pulse (HIGH level pulled to GND)
  • MDL - Mains Detection Logic (HIGH when mains is detected)
• spring clamp system terminal blocks on input and output
• extra goldpin outputs on low side

Use cases

• Mains detection (logical output HIGH when phase is available)
• ZCD - Zero Crossing Detection
• Mains frequency monitoring
• Checking of connection order of three phase systems
• Checking shift between phases
• Detection of power failures
• AC motor monitoring
• other…

Simulation

Real module testing

Phase Order Detection

Phase Order Detection

Turn ON / OFF

Mains Detection Logic

Zero Crossing

Zero Crossing with Mains Detection Logic

Different designs

• https://www.electroschematics.com/detector-module/

• https://create.arduino.cc/projecthub/andrzejco/sensor-230v-ac-for-arduino-1b1109

• https://www.electronicsweekly.com/blogs/engineer-in-wonderland/improved-isolated-wide-range-zero-crossing-detector-needs-no-power-switch-2020-07/

• https://www.eevblog.com/forum/projects/mains-zero-crossing-detection/

• https://sound-au.com/appnotes/an005.htm

Idea

This project was created using Dextrel idea: https://dextrel.net/dextrel-start-page/design-ideas-2/mains-zero-crossing-detector

Author

• Paweł ‘felixd’ Wojciechowski - FlameIT - Immersion Cooling