| 摘要 |
PURPOSE:To stabilize the output voltage of a DC/DC converter and to improve the stability to the variations in the load and temperature by providing self- excited and separately-excited drive circuits in parallel and switching them by a switch circuit. CONSTITUTION:A forward diode D2 is connected in series between the connecting point of a bias circuit having a resistor R1 and a feedback circuit having a condenser C1, a resistor R2, a diode D1, and a feedback coil Nf and the base of a switching transistor Q. A switch circuit 2 is connected between the anode side of the forward diode D2 and (-) pole. An auxiliary rectifying the smoothing circuit 3 is provided at the output side of a converter transformer T1 as the power source of a pulse width control circuit 4. The control circuit 4 detects the output of a main rectifying and smoothing circuit 1 by an output voltage detector 5, supplies the pulse of the pulse width in response to the output voltage to the switching transistor Q and to the switch circuit 2. |
