| 摘要 |
PURPOSE:To quicken the rise or fall of an output even to a long delay time by using an FET having a high input impedance so as to ulitize positive feedback. CONSTITUTION:When a switch 16 is closed, since a capacitor 14 is not charged and a gate potential of the FET7 is equal to a supplied voltage, and the internal impedance of the said FET7 is high by an electric field applied between the gate and source of the said FET7 in comparison with the said resistors 8 and 9. As time is elapsed, since the said capacitor 14 is charged through a resistor 15, the gate potential of the said FET7 is lower, and when it reaches a voltage to break down a Zener diode 10, the TR11 transits to the On state and the TR11 is turned on quickly through regeneration. |
