Power line disturbance detector circuit

摘要

A power line disturbance (PLD) detector circuit includes a digital counter which is driven by pulses provided by a clock in an associated data processing system. The PLD detector circuit includes a comparator amplifier for comparing primary AC power to a DC reference voltage on a cycle-by-cycle basis. The amplifier generates a reset pulse once during each AC cycle as long as the AC voltage exceeds the DC reference voltage. When a decoder circuit detects a count outside the range of counts attained by the digital counter between normally occurring reset pulses, the decoder circuit responds by generating a PLD signal. The PLD signal is provided both to the associated data processing system and to a Power On Reset circuit. The Power On Reset circuit is initialized by the PLD signal, permitting the circuit to respond consistently upon subsequent restoration of power.