| 摘要 |
PURPOSE:To reduce current loss and to improve the input/output characteristics of a switching regulator by mounting a constant current supplying means set at the DC output side at the reference voltage point, and supplying the constant current from the means to a transistor for driving and controlling the switching transistor. CONSTITUTION:A switching transistor (TR) 8 is connected between the input and output terminals 2A, 6A of high voltage side, and a DC current reproducing circuit 10 which reproduces the DC by rectifying the AC voltage formed by the TR8 is provided. In the circuit 10, a choke coil 12 is connected in series with the TR8, one terminal of the secondary coil 12S is connected to the base of the TR8 through a differentiating capacitor 18, thereby applying the differentiated waveform to the base of the TR8. On the other hand, the base of the controlling TR 26 for controlling the drive TR32 of the TR8 is connected to the connecting point of the resistors 22, 24 for detecting the variation in the output voltage, and a constant-voltage diode 28 is connected at the cathode to the emitter side between the emitter and the reference voltage point of the TR26. |
