Hello Forum,
I am working on a micro based project which controls inductive loads like trafos, etc using phase angle control. the following are two circuits which will be used : one is voltage 0 crossing circuit and second is current 0 cross circuit.
the mains input is between 120VAC t0 240VAC, i know that both the circuits employ Resistor dividers to scale down the mains voltage, i just need explanation on role these components especially the 4V7 zener in second circuit
Thanks & Regards
Arun