Zero crossing detection circuit and a high power factor rectification circuit

摘要

PROBLEM TO BE SOLVED: To detect an accurate zero-cross point of AC power supply voltage even when noise such as instantaneous power failure occurs, in a zero-cross detection circuit or a high power factor rectification circuit.;SOLUTION: In addition to a conventional method for detecting a zero-cross point of power supply voltage by external interruption of a microcomputer, the zero-cross point is detected by sampling the power supply voltage also with an A/D converter of the microcomputer. By using both detection results, determination for eliminating a zero-cross point detection signal erroneously detected by the external interruption is performed.;COPYRIGHT: (C)2014,JPO&INPIT