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1. (WO2017203687) SWITCHING POWER SUPPLY CONTROL CIRCUIT AND SWITCHING POWER SUPPLY APPARATUS

Pub. No.:    WO/2017/203687    International Application No.:    PCT/JP2016/065718
Publication Date: Fri Dec 01 00:59:59 CET 2017 International Filing Date: Sat May 28 01:59:59 CEST 2016
IPC: H02M 3/28
Applicants: FUJI ELECTRIC CO., LTD.
富士電機株式会社
MEAN WELL ENTERPRISES CO., LTD
ミーンウェルエンタープライズ株式会社
Inventors: SONOBE, Koji
園部 孝二
CHUNG, Yu-Wei
鐘 郁緯
Title: SWITCHING POWER SUPPLY CONTROL CIRCUIT AND SWITCHING POWER SUPPLY APPARATUS
Abstract:
The occurrence of harmonics is suppressed in a switching power supply apparatus. When the value of a voltage applied to a non-inverting input terminal of a comparison circuit (11a) of a switching power supply control circuit (10) exceeds a voltage value (ref_zcd) while a switching element (Q1) included in a switching power supply apparatus (1) for converting an AC power supply voltage into a DC voltage is off, the potential of an output signal of the comparison circuit (11a) becomes an H level. When a prescribed delay time has elapsed since a delay circuit (11b) detects this H level, a pulsed signal is output from the delay circuit (11b), and this becomes a signal with which the bottom of a drain voltage (Vds) of the switching element (Q1) is detected. Because the output of the delay circuit (11b) is connected directly to a set terminal (S) of a flip-flop (13e), the switching element (Q1) is definitely turned on without the bottom being skipped when the bottom of the drain voltage (Vds) of the switching element (Q1) is detected.