Title:
AC MEASURING APPARATUS
Document Type and Number:
Japanese Patent JP3248845
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an AC measuring apparatus for highly accurate and fast measurement of an effective value at a low cost with a simple circuitry.
SOLUTION: An analog signal to be measured is full-wave rectified to obtain an input voltage Vin. A sigma delta converter 10 is used to generate a modulation signal MR=Vin/-Vref indicating the size of the input voltage Vin to the reference voltage Vref by a digital stream. A voltage VD=Vin MR modulated by the signal MR is passed through a low pass filter 12 and a DC component VOUT thereof is outputted by a gain -GLP. The output VOUT obtained is inputted into the sigma-delta converter 10 as reference voltage Vref while being taken out as effective value of the analog signal to be measured as indicated by a value obtained by multiplying the input voltage Vin by -GLP-2.
Inventors:
Yasuo Miyake
Garry Walker
Garry Walker
Application Number:
JP14318796A
Publication Date:
January 21, 2002
Filing Date:
June 05, 1996
Export Citation:
Assignee:
Takemoto Denki Co., Ltd.
Texmate Inc.
Texmate Inc.
International Classes:
G01R21/127; G01R19/02; G06G7/20; (IPC1-7): G01R19/02; G01R21/127; G06G7/20
Attorney, Agent or Firm:
Shogo Ebara (2 outside)
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