| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching regulator capable of improving power efficiency and realiability at a low cost by reducing heat generated by power loss in a switching device without the need for the additional installation of a trigger winding of a converter transformer. SOLUTION: In this switching regulator, a delay drive circuit of FET Q1 is constituted as follows: a first resistor R1, a second resistor R2 and a FET Q2 are conneced with each other in series between a positive terminal and a negative terminal on the DC side of a primary rectifying bridge diode D1. A third resistor R3 is connected between the gate and source of the FET Q2, a fourth resistor R4 is connected between the drain and source of the FET Q2, a DC side (-) terminal of the primary rectifying bridge diode D1 is connected to the source of the FET Q2, and the junction point of the first resistor R1 and the second resistor R2 and the source of the FET Q2 are connected through a capacitor C2. Input AC power is inputted to the delay driving circuit, and after an inrush current is finished to flow, the FET Q1 is turned on, thus reducing power loss. COPYRIGHT: (C)2004,JPO
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