| 摘要 |
PURPOSE:To make the delay time at the turning on of power source long without prolonging the delay time when power source is turned off by connecting a detecting capacitor to a DC output through a rectifier. CONSTITUTION:When a power source 1 is turned on, a transistor 7 is turned on and off by AC input voltage but since there is a rectifier 18, the capacitor 11 is not immediately charged until the DC output voltage E0 by a DC power source circuit 17 rises. When the voltage of the capacitor 11 attains reference voltage V1, a power source determination signal E1 is transmitted from a comparator 14. When the power source is cut off, the voltage Vc of the capacitor 11 can attain the reference voltage V1 early, and the power source determination signal E1 ceases. Thereby, the delay time at the turning on is made longer by as much as the time till rising of the DC output voltage E0 when power source is turned on, and the delay time when the power source is cut is made short. |
