ELECTRONIC WATT-HOUR METER - MITSUBISHI ELECTRIC CORP

Title:

ELECTRONIC WATT-HOUR METER

Document Type and Number:

WIPO Patent Application WO/1994/016334

Kind Code:

A1

Abstract:

In a method for digitizing the voltage signal and current signal of an electronic watt-hour meter to calculate electric power by digital multiplication, the circuit has a small analog scale, signals are mainly digitally processed in the circuit, and the circuit can be composed of ICs, thus enhancing the accuracy of calculating the power. A voltage signal (v) and a current signal (i) are respectively inputted into analog-digital converting means comprising sigma-delta modulation circuits (10 and 11) and others. The outputs are averaged by running by the running-averaging means (12, 13, 14 and 15) which are low-pass filters. Then the voltage is multiplied (18) by the current. The analog scale in the sigma-delta modulation is small. Also, the scale of circuit is small by the adoption of low-pass filters provided for the running average. Further, the power calculation can be made at a high accuracy.

More Like This:

JP5661812	Table tap and power measurement method
JPH04212073	SAMPLING TYPE WATTMETER

Inventors:

YOSHINAGA TOORU (JP)
TAKAHASHI KATUHIKO (JP)
TAMAI SHINZOU (JP)

Application Number:

PCT/JP1994/000008

Publication Date:

July 21, 1994

Filing Date:

January 06, 1994

Export Citation:

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Assignee:

MITSUBISHI ELECTRIC CORP (JP)
YOSHINAGA TOORU (JP)
TAKAHASHI KATUHIKO (JP)
TAMAI SHINZOU (JP)

International Classes:

G01R21/133; G01R22/00; (IPC1-7): G01R21/133; G01R22/00

Foreign References:

JPH02173576A	1990-07-05
JPH02222843A	1990-09-05
JPH05333067A	1993-12-17
JPH04320972A	1992-11-11
JPS61292067A	1986-12-22

Other References: