“This project provides AC voltage zero-cross timing detection and a DC voltage after diode rectification with high accuracy. Possible applications for such circuits are AC motor controllers, AC lamp controllers, AC Dimmer Controllers, Home Appliances. The circuit outputs a zero-cross signal from 90 Vac to 264 Vac input. The project is based on BM1Z102FJ chip which outputs a high precision zero-cross timing of targeted AC voltage and a DC voltage after diode rectification of high accuracy. The project also includes high voltage offline AC to DC converter chip BM2P129TF.
AC VOLTAGE ZERO CROSS DETECTION
By monitoring the voltage between the VH_AC1 and VH_AC2 pins, this IC outputs the zero-cross point of AC voltage from the ACOUT pin. These pins have a built-in monitor circuit that tolerates 600 V and they realize high reliability and low power consumption. The ACOUT pin performs an N channel open-drain output and this makes it possible to support various applications. It is necessary for the VH_AC1 pin to be connected to the N side of the AC input and for the VH_AC2 pin to be connected to the L side of the AC input”