| 摘要 |
A pulse for resetting computing equipment is generated upon a drop in the supply voltage. In a first embodiment of a circuit furnishing such a reset pulse, a comparator is used whose inverting input is connected to the supply line through a capacitor and to ground potential through a parallel diode-resistor combination. The direct input is connected to the tap of a voltage divider and is connected through a feedback resistor to the output. This circuit can detect drops in supply voltage in the order of the forward drop across the diode. Alternatively, a RC oscillator can be used to generate a reset pulse. If the capacitor in the circuit is not recharged in time by a pulse furnished by the computing equipment being controlled, it is assumed that failure to receive the pulse is indicative of a drop in supply voltage.
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