AC voltage detection circuit and method, charging circuit and method, chopper circuit and chopping method, chopper charging circuit and method, electronic apparatus, and timepiece

摘要

In an AC voltage detection circuit, a chopper charging circuit converts an induced voltage of an AC generator to a chopper voltage and charges a main capacitor. When the chopper voltage becomes a predetermined voltage or less, the chopper charging circuit charges an auxiliary capacitor and detects a power generation state of the AC generator at an early stage based on a potential obtained by adding the potential between output terminals of the AC generator and the auxiliary capacitor and starts the charging.