| 摘要 |
<p>PCT No. PCT/CH79/00119 Sec. 371 Date Jun. 25, 1980 Sec. 102(e) Date Jun. 25, 1980 PCT Filed Sep. 5, 1979 PCT Pub. No. WO80/01206 PCT Pub. Date Jun. 12, 1980.In a method of measuring power delivered at an alternating voltage by an alternating current to a load, the steps include comparing the instantaneous alternating voltage and the instantaneous alternating current with a periodically varying reference signal having a relatively high frequency compared to the frequency of the alternating voltage and the alternating current, thereby obtaining a plurality of first voltage-intersection and current-intersection points during the negative-going portions of the reference signal, and a plurality of second voltage-intersection and current-intersection points during the positive-going portions of the reference signal, transforming the measured analog voltage-values and measured the analog current-values into digital voltage-values and digital current-values, respectively, multiplying the digital voltage-values and the digital current values at the first intersection points with one another, so as to obtain a plurality of first instantaneous power outputs, multiplying the digital voltage-values and the digital current-values at the second intersection points with one another, so as to obtain a plurality of second instantaneous power outputs, and continuously integrating the power outputs so as to obtain an average power output.</p> |
