| 摘要 |
PURPOSE:To improve the efficiency of a power source and reduce its size by arranging separately the base current limitation resistors of a switching transis tor, connecting a capacitor therebetween, and connecting a transistor to which offset voltage is applied from input voltage through the resistors. CONSTITUTION:When a driving transistor TR2 is turned on by a control signal (m) from a switching controller 3, a base current IB1 (n) to turn a switching transistor TR1 on is passed through current limitation resistors R5 and R1. A capacitor C2 is charged by resistors R5 and R7 and the transistor TR1. The current IB1 to which the charging current of the capacitor C2 is added is passed to shorten the turn-on time of the transistor TR1. When the transistor TR2 is turned off, a transistor TR3 is biased by the voltage stored in the capacitor C2 through the resistors R1, R6, R7 and the transistor TR3 is turned on. The discharge current of the capacitor C2 is passed to accelerate emission of the carriers stored in the transistor TR1 and shorten the turn-off time of the transistor TR1. |
