| 摘要 |
PURPOSE:To reduce the capacity and the cost of an auxiliary constant-voltage power source by feeding back the exciting energy stored in a transformer to the power source when a switching transistor is turned OFF. CONSTITUTION:A switching regulator drives the base of a transistor 2 by a drive circuit 9 to generate a voltage at the winding N3 of a transformer 3 and to supply DC voltage energy stabilized at the output side through a rectifying and smoothing circuit made of diode 4. In this case, the winding N1 of the transistor 3 is connected through a diode 1 with an auxiliary constant-voltage power source 8 of the drive circuit 9. When the transistor 2 is turned OFF, the exciting energy stored in the transformer 3 is fed through a diode 1 to the output of the power source 8. Thus, when the drive circuit 9 starts operating, the power supply from the power source 8 can be reduced. |
