| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electronic watthour meter which can measure electric power pulses accurately. <P>SOLUTION: An electric energy frequency changing circuit 3 multiplies an input voltage and an input current together, and outputs power pulses proportional to electric energy. Pulse intervals are measures by using a time measuring means 4d. A shunt running judgement part 4f decides whether the pulse interval is longer than a prescribed time T. When the pulse interval is shorter than the prescribed time T, one electric power pulse is measured. When last pulse interval is longer than T and this time pulse interval is shorter than T, two electric power pulses are measured. <P>COPYRIGHT: (C)2004,JPO |
