摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electric water heater system capable of accurately integrating electricity charges by acquiring accurate time zone information relating to the electricity charges with a simple constitution. <P>SOLUTION: This electric water heater system comprises a signal generating circuit 12 disposed on an electricity meter 10, synchronizing with the start of integration of at least one of a daytime meter 15 integrating power consumption in daytime hours, and a nighttime meter 16 integrating power consumption in midnight hours, and superposing a prescribed integration switch signal informing a time of switching to the integration of the nighttime meter 16 to the electric water heater 20, to a commercial power source. A microcomputer 22 as a control circuit for the water heater detects the prescribed integration switching signal superposed by the signal generating circuit 12 to discriminate the midnight hours. Thus the electricity charges can be accurately integrated. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |