| 摘要 |
PURPOSE:To make it possible to output integrated power in real time by determining integrated value of an instantaneous power by multiplying the respective digital signals of AC voltage and current by a digital signal processor(DSP). CONSTITUTION:AC voltage (v) and current (i) are inputted to input circuits 11 and 12 respectively, converted into digital signals by A/D converters 21 and 22 respectively and outputted to DSP 30. The DSP 30 determines an instantaneous power and a power or a current or the like integrated for a prescribed time, by computation, on the basis of the two inputs. An output thereof is displayed in a display unit 50 through CPU 40 and delivered outside by a communications circuit 60. On the occasion, the DSP 30 always determines an integrated value by the computation irrespective of the length of a time of integration, while it determines the value of the integrated power after an arbitrary time passes from some time. Accordingly, the value of the integrated power within a very short unit time such as one second and the value of the integrated power within the arbitrary time can be displayed or delivered outside. |
