EP0058050A1
Expired / Lapsed
EP
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Measuring method
Assignee: Mitsubishi Electric Corp
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Filing: 1982-02-03
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Granted: —
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Expires: 2002-02-03
Abstract
Abstract A frequency detection system samples a sinusoidal input V(t) with a predetermined constant sampling period h to form four sampled values V(t0 - 2h), V(t0 - h), V(t0 + h) and V(t0 + 2h) and calculates …<CHEM>… where omega is the angular frequency of the sinusoidal input. The sinusoidal input is converted to corresponding digital values. The absolute value of the frequency may be obtained by computing the arc-cosine of y(h)/2.
Inventors
- 👤 Sunao Suzuki
- 👤 Koji Maeda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 19:38
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
82 words
A frequency detection system comprising sampling means for sampling, with a predetermined constant sampling period h, an AC input V(t) having a frequency to be detected, thereby forming sampled values ( V (t o - 2h), V(t o - h), V(t o + h) and V(t o + 2h) where t o designates any desired time point, and calculating means for calculation from the sampled values a quantity y(h) given by: thereby providing a measure of said frequency of said AC input.
Claim 2
Dependent Claim
82 words
A frequency detection system comprising sampling means for sampling, with a predetermined constant sampling period h, an AC input V(t) having a frequency to be detected, thereby forming sampled values ( V (t o - 2h), V(t o - h), V(t o + h) and V(t o + 2h) where t o designates any desired time point, and calculating means for calculation from the sampled values a quantity y(h) given by: thereby providing a measure of said frequency of said AC input.
Claim 3
Dependent Claim
38 words
A frequency detection system as claimed in claim 1 wherein there is provided another calculating means for calculating an arc-cosine function of the quantity y(h) thereby to detect the absolute value of said frequency of said AC input.
References Cited (Backward Citations)
No citation records indexed.
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