Switching power source circuit


PURPOSE: To protect a switching power source circuit and load circuit by stopping the operation of the switching power source circuit when the value of a current signal continuously exceeds a prescribed reference voltage by at least two times. CONSTITUTION: The inverted output signal FFQ of a flip flop circuit 19 opens or closes a switch 34 and connects a constant-current source 35 with an external capacitor 37 and external resistor 38. The capacitor 37 is set so that it can exceed the reference voltage VL of a comparator 36 when a comparator 20 is continuously inverted five times. When the value of the voltage signal V 1 S of a transistor 25 exceeds a reference voltage VS the output signal FFQ of the flip flop circuit 19 becomes a high level through the comparator 20 and a charging current is supplied to the external capacitor 37. When the charging is continuously made to the capacitor 37 more than five times, a switching power source circuit stops its operation and the transistor 25 is turned off. COPYRIGHT: (C)1992,JPO&Japio




Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (0)


Cited By (5)

    Publication numberPublication dateAssigneeTitle
    JP-2006223038-AAugust 24, 2006Hanshin Electric Co Ltd, 阪神エレクトリック株式会社Device and method for protecting switching power circuit
    JP-2006340414-ADecember 14, 2006Mitsumi Electric Co Ltd, ミツミ電機株式会社Dc/dcコンバータおよびその過電圧防止方法
    JP-2011083079-AApril 21, 2011Shindengen Electric Mfg Co Ltd, 新電元工業株式会社スイッチング電源の制御回路
    JP-2015104305-AJune 04, 2015株式会社デンソー, Denso Corpスイッチング電源装置および電子制御装置
    US-9531268-B2December 27, 2016Denso CorporationSwitching power supply and electronic control unit