| 摘要 |
PURPOSE:To detect the crest value of an AC sine wave with high precision with a simple constitution by processing crest values of an AC sine wave, sampled with a 90 deg. time difference, by addition, etc. according to the number of samples, and determining a crest value. CONSTITUTION:Alternating-current sine-wave signals is and ic sampled at intervals of 30 deg., i.e., with a 90 deg. time difference are passed through an absolute value circuit 1 and the number of samples, or 3 is processed by adding circuits 2-4 which perform multiplication by coefficients 15/4, 11/4, etc. The counting results of those circuits 2-4 are multiplied by an arithmetic circuit 5 and their maximum value is selected to determine a crest value I from equationI. Therefore, an AC sine-wave current crest value is detected with high precision by the simple constitution which eliminates the need to square and add sampled values with the 90 deg. time difference and to perform square root processing. |
