Power brown-out detector
First Claim
1. Apparatus for providing a brownout signal indicating low power in an AC wave having a nominal peak voltage, and comprisinga. voltage detecting means receiving the AC wave, for providing a low half-cycle signal each time the maximum AC wave excursion from 0 falls between a first predetermined voltage level and a second predetermined voltage level greater in magnitude than the first, and a normal half-cycle signal each time the maximum AC wave excursion is at least as great in magnitude as the second predetermined voltage level;
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Abstract
Apparatus for computing an approximation of a running average of the peak voltage of an AC power wave. If this average drops below a predetermined level a brownout signal indicating potential failure of electronic units powered by the AC wave is generated.
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Citations
11 Claims
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1. Apparatus for providing a brownout signal indicating low power in an AC wave having a nominal peak voltage, and comprising
a. voltage detecting means receiving the AC wave, for providing a low half-cycle signal each time the maximum AC wave excursion from 0 falls between a first predetermined voltage level and a second predetermined voltage level greater in magnitude than the first, and a normal half-cycle signal each time the maximum AC wave excursion is at least as great in magnitude as the second predetermined voltage level; - and
b. an accumulator receiving the low and normal half-cycle signals, comprising i. means responsive to an externally supplied reset signal, for setting the accumulator contents to a first preselected value, ii. means responsive to each low half-cycle signal, for changing the accumulator contents to decrease the difference between the accumulator contents and a second preselected value by a third preselected value, iii. means responsive to each normal half-cycle signal, for changing the accumulator contents to increase the difference between the accumulator contents and the second preselected value by a fourth preselected value whenever the accumulator contents are exclusively between the first and second preselected values, and iv. means for issuing the brownout signal whenever the difference between the second and first preselected values is exceeded by the difference between the accumulator contents and the first preselected value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification