| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply equipment of high efficiency by reducing a loss generated when a switching element is driven. SOLUTION: A connection between the emitters of transistors Q2, Q3 for driving a driving circuit 4 is connected to the base of a switching transistor Q1, and a connection between the bases of the transistors Q2, Q3 is connected to a pulse output terminal PO of a control circuit 3. The collector of the transistor Q3 is connected to a main current path of a control transistor Q4 which constitutes a limiter circuit 5. Furthermore, a current detecting circuit 6a for detecting the output current of the power supply equipment is installed, and a signal corresponding to the output current detected by the current detecting circuit 6a is supplied to the base of the control transistor Q4 of the limiter circuit 5. Between the base of the switching transistor Q1 and the pulse output terminal PO of the control circuit 3, a resistor 7 which constitutes a bias circuit 7 is connected.
|
