| 摘要 |
PURPOSE:To effectively restart by specially connecting the first and second series circuits with a transistor and a pulse width modulation controller, thereby reducing the size of a starter. CONSTITUTION:A switching regulator starter has a pair of input terminals Ti, the first series circuit including a resistor 17 and the first - third Zener diodes 24-26, a pulse width modulation controller 14, the first and second transistors 3, 22, the second series circuit including a resistor 20 and a capacitor 23, and a resistor 18 connected in parallel with the capacitor 23 as shown. Thus, after a power source is turned ON, when the input voltage becomes a voltage of higher determined by Zener diodes 24-26, power is supplied through the transistor 3 to the controller 14. Simultaneously, the capacitor 23 is charged, and the transistor 22 is turned ON after the prescribed time. As a result, the transistor 3 is turned OFF, and since power is not supplied to the controller 14, it can operate as a protecting circuit. |
