| 摘要 |
PURPOSE:To make it possible to execute the stable operation by high supply voltage, by forming the structure so that the blocking oscillator can be connected in series to the supply voltage. CONSTITUTION:Each blocking oscillator 1, 2 uses in common the primary winding L1 of the transformer T1, also has the feedback windings Lf1, Lf2 coupled with the primary winding L1, respectively, and the time when the transistors Q1, Q2 are turned on and off is almost same. The supply to load through the output terminals A, B is executed by switching the primary side of the transformer T1, inducing voltage to the secondary winding L2, and rectifying and smoothing this voltage by the diode D5 and the capacitor C3. In this case, since the flyback voltage proportional to the DC output voltage E0 is generated in the feedback winding Lf2, the DC negative voltage Ec proportional to the DC voltage E0 is obtained by the control circuit 3 by rectifying said voltage, and the base of the transistor Q2 is controlled through the constant-voltage diode ZD1. |
