| 摘要 |
PROBLEM TO BE SOLVED: To eliminate noise digitally without increasing the number of times of sampling. SOLUTION: This system consists of an A/D converter and a means that eliminates extremely larger (or smaller) data (2), (3) among conversion data (1)-(6) by the number of times of sampling extracted by over-sampling and averages the remaining data (1), (4)-(6). In order to exclude the conversion data having extreme values, the conversion data (1)-(6) are averaged and each of the data (1)-(6) is compared with a value resulting from multiplying a prescribed coefficient with the mean value, adding a prescribed value to the mean value or subtracting a prescribed value from the mean value to exclude the comparison result. In the case that a fluctuation width of an analog input value is known in advance, each of the data (1)-(6) is compared with an upper limit or a lower limit of the fluctuation to avoid the extreme data. Thus, it is not required to provide an analog filter to a pre-stage of the A/D converter.
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