| 摘要 |
PURPOSE:To obtain a circuit tolerant to a high-voltage noise by obtaining a period when a load is not powered up for a certain time when a power source is put to work again, by using a PUT. CONSTITUTION:When a switch 4 is closed to supply electric power, a PUT40 turns on and a transistor (TR) 27 turns on to power up a load 30. At this time, a capacitor 17 is charged via a route of a diode 34, a resistance 35, a capacitor, a diode 41, and the TR27. When the switch 4 is turned on and turned off immediately, the PUT40 is still off and the charging voltage of the capacitor 17 is applied to the gate of the PUT40 by being superposed upon a power voltage, so the PUT40 holds itself off. When the capacitor 17 is discharged and the gate voltage of the PUT40 drops below its anode voltage, the PUT40 turns on to supply electric power to the load 30. |
