| 摘要 |
PURPOSE:To enhance switching frequency of a self-oscillating type switching regulator by a method wherein electric power loss of an output transistor in OFF time is reduced, and storage time thereof is shortened. CONSTITUTION:Respective control windings T2, T5 are connected in series, and out of them, the control winding T5 is connected with a capacitor C10 in parallel, discharging time of the capacitor C10 is controlled by an error amplifying transistor Q5 to make pulse length to veriable. Therefore because when the transistor Q5 conduct, the voltage between the base and the emitter of an output transistor Q1 is biased to negative, and electric charge stored in the base thereof transfers through a small resistor R20. Accordingly the base current of the output transistor Q1 is not affected by the error amplifying circuit and the driving circuit, electric power loss of the output transistor Q1 becomes extremely small, and electric charge stored through low impedance can be cleared away. |
