Dear expert,
can any body give me a help in a project.Is there any possibility that a circuit detects three different reading of AC voltages like 180,200,220 and operates a single relay(12vdc) on its behalf but one relay at a time.lz help me
You can scale the AC input down with a transformer. Use a diode rectifier and capacitor filter to render the AC from the transformer into DC. A voltage comparator (more like 3) can signal when those voltage levels (scaled down) are reached.
You statement -
operates a single relay(12vdc) on its behalf but one relay at a time