| 摘要 |
PURPOSE:To stabilize the operation as well as realize a small size for the power circuit without using the relay or the like, by carrying out the make-break sequence for the power circuit possessing the logic (for logic circuit driving) power source and the stabilized driving power source by controlling the stabilized transistor of the driving power source via the voltage value of the logic power source. CONSTITUTION:The AC voltage supplied to transformer 1 is rectified through rectifying circuits 2 and 3, and the DC output rectified at circuits 2 and 3 is stabilized through stabilizing circuits 5 and 8 to be delivered in the form of the logic power output and the driving power output each. Detection circuit 7 is connected to circuit 5 at the side of the logic power output in order to detect the voltage value of the logic power source. When the stabilized voltage of the logic power source is detected by comparator 7a provided at circuit 7, the output of comparator 7a is applied to the base of control transistor TR2. And the base of stabilized TR1 is controlled by the voltage of TR2 to cut off the current flowing to the load. |
