| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a watt-hour meter which detects the difference between a current flowing into a load from a power source and a current flowing into the power source from the load. <P>SOLUTION: The current between terminals 1S-1L (the current flowing into the load from the power source: A1) is detected by a current detection unit 102 while the current between terminals 2S-2L (the current opposite to the current flowing into the power source from the load: A2) is detected by a current detection unit 103. The difference between them is calculated by a control unit 109. When the difference does not become nearly zero, a display unit 111 is allowed to display the presence of an abnormality. <P>COPYRIGHT: (C)2010,JPO&INPIT |
