| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic watt-hour meter with a good characteristic of unbalanced load, realizing a small size, a low price, and low power consumption, and capable of employing measurement items corresponding to various charge systems. SOLUTION: The outputs of voltage detectors 109 to 111 are multiplied by the outputs of current detectors 112 to 114, respectively, by using multiplying circuits 201 to 203, added up and integrated by an adding circuit 204, and displayed on an active watt-hour display 205. Reactive watt-hour is computed from outputs obtained by 90 deg. shifting the phases of the outputs of the detectors 109 to 111 by using voltage phase shifters 206 to 208 and from the outputs of the detectors 112 to 114, and displayed on a reactive watt-hour display 213. A power factor computed by a power factor computing circuit 214 is displayed on a power factor display 215. This electronic watt-hour meter with a small size, a low price, and low power consumption, can be realized by this configuration.
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