| 摘要 |
PURPOSE:To prevent a malfunction by using the negative resistance region of a lambda diode so as to decrease the discharge time of an electric charge in a capacitor thereby turning on a power supply just after power is interrupted and resetting surely even for the occasion requiring the reset state. CONSTITUTION:Since the lambda diode 5 of a circuit shown in figure is in a high impedance state, because a voltage higher than a prescribed voltage Vv is biased and the electric charge is charged fully in a capacitor 1 when a voltage source 3 is turned on, an output terminal has a voltage equal to the power voltage. In turning off the power supply 3, since the lambda diode 5 is in the high impedance state until the voltage is decreased below the voltage Vv, the electric charge stored in the capacitor 1 is fed back to the power supply via a diode 4 connected in parallel with a resistor 2. When the discharge is progressed further and the voltage reaches the prescribed voltage Vv or below, the lambda diode 5 enters the negative resistance region, the impedance is reduced rapidly, the electric charge in the capacitor 1 is discharged rapidly through the lambda diode 5 and the output voltage is turned off soon after the power is turned off.
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