| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a small-sized inexpensive built-in power measuring device independent of a power consumption state of an apparatus to be measured. <P>SOLUTION: This power measuring device 1 is equipped with: a voltage measuring circuit 3 for measuring a voltage supplied to the apparatus 2 to be measured; a current measuring circuit 4 for measuring a current supplied to the apparatus 2; an operation part 6 for calculating values measured by the voltage measuring circuit 3 and the current measuring circuit 4; communication parts (8, 12) for outputting a result from the operation part 6; and internal power source parts (7, 9, 10, 11) for supplying driving power to each part. The voltage measuring circuit 3 uses one neutral line 17 of power supply lines of the apparatus 2 as a ground potential and measures a voltage to another power supply line therefrom, and the internal power source parts supply power in the insulated state from a power source part 14 of the apparatus 2 without using an expensive transformer or a new power source. <P>COPYRIGHT: (C)2011,JPO&INPIT |
