US5256979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring an unknown voltage, and power meter employing the same
Assignee: Elster Solutions LLC
•
Filing: 1992-02-21
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Granted: 1993-10-26
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Expires: 2012-02-21
Abstract
Abstract A method for measuring an unknown voltage (V IN ) using a voltage divider network in such a way that uncertainties in the values of the resistances do not affect the measurement. The unknown voltage is divided into three fractional voltages, the fractional voltages are measured, and the unknown voltage is computed on the basis of the fractional voltages. The unknown voltage is divided with a voltage divider comprising first, second and third resistors, and a first voltage (V o1 ) is measured across the first resistor, a second voltage (V o2 ) is measured across the second resistor and a third voltage (V o3 ) is measured across the third resistor. The unknown voltage V IN is computed in accordance with the equations disclosed in the specification.
Inventors
- 👤 Michael C. Moorman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:03
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/04
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
115 words
A method for measuring an unknown voltage (V IN ), comprising the steps of: (a) dividing said unknown voltage into at least three fractional voltages; (b) measuring said fractional voltages; and (c) computing said unknown voltage on the basis of said fractional voltages; wherein: step (a) comprises the step of dividing said unknown voltage with a voltage divider comprising first, second and third resistor means; and step (b) comprises the steps of measuring a first voltage (V o1 ) across said second resistor means, measuring a second voltage (V o2 ) across said third resistor means and measuring a third voltage (V o3 ) across a parallel combination of said second and third resistor means.
Claim 2
Independent Claim
115 words
A method for measuring an unknown voltage (V IN ), comprising the steps of: (a) dividing said unknown voltage into at least three fractional voltages; (b) measuring said fractional voltages; and (c) computing said unknown voltage on the basis of said fractional voltages; wherein: step (a) comprises the step of dividing said unknown voltage with a voltage divider comprising first, second and third resistor means; and step (b) comprises the steps of measuring a first voltage (V o1 ) across said second resistor means, measuring a second voltage (V o2 ) across said third resistor means and measuring a third voltage (V o3 ) across a parallel combination of said second and third resistor means.
Claim 3
Dependent Claim
30 words
The method recited in claim 1, wherein step (c) comprises the step of computing said unknown voltage in accordance with the equation: V.sub.IN =V.sub.o1 *V.sub.o2 *V.sub.o3 /{(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}.
Claim 4
Dependent Claim
62 words
The method recited in claim 1, wherein step (c) comprises the step of computing said unknown voltage in accordance with at least one of the following equations: V.sub.IN =V.sub.o1 /K1 V.sub.IN =V.sub.o2 /K2 V.sub.IN =V.sub.o3 /K3 V.sub.IN =V.sub.o1 *V.sub.o2 *V.sub.o3 /{(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}, where K1, K2 and K3 are each functions of V o1 , V o2 and V o3 .
Claim 5
Dependent Claim
37 words
The method recited in claim 3, further comprising the step of computing K1, K2 and K3 in accordance with the following equations: K1={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o2 *V.sub.o3) K2={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o1 *V.sub.o3) K3={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}(V.sub.o1 *V.sub.o2).
Claim 6
Dependent Claim
59 words
The method recited in claim 3, further comprising the step of computing K1, K2 and K3 in accordance with the following equations: K1=R.sub.2 /(R.sub.1 +R.sub.2) K2=R.sub.3 /(R.sub.1 +R.sub.3) K3=R.sub.2 *R.sub.3 /(R.sub.1 *R.sub.2 +R.sub.3 *R.sub.3 +R.sub.2 *R.sub.3), wherein R 1 , R 2 and R 3 respectively represent the approximate resistance values of said first, second and third resistor means.
Claim 7
Dependent Claim
35 words
The method recited in claim 3, further the step of measuring a plurality of samples of each of V o1 , V o2 and V o3 during a plurality of cycles of said unknown voltage.
Claim 8
Dependent Claim
28 words
The method recited in claim 6, further comprising the step of reordering the sequence in which the samples V o1 , V o2 and V o3 are measured.
Claim 9
Dependent Claim
19 words
The method recited in claim 6, further comprising the step of computing average values of K1, K2 and K3.
Claim 10
Dependent Claim
23 words
The method recited in claim 6, wherein each of V o1 , V o2 and V o3 are sampled at approximately 2.4 kHz.
Claim 11
Dependent Claim
14 words
The method recited in claim 6, further comprising the step of interleaving said samples.
Claim 12
Dependent Claim
17 words
The method recited in claim 6, further the step of low pass filtering K1, K2 and K3.
Claim 13
Dependent Claim
70 words
The method recited in claim 3, further comprising the steps of: measuring a plurality of samples of each of V o1 , V o2 and V o3 during a plurality of cycles of said unknown voltage; computing K1, K2 and K3 in accordance with the following equations: K1={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o2 *V.sub.o3) K2={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o1 *V.sub.o3) K3={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}(V.sub.o1 *V.sub.o2); and low pass filtering K1, K2 and K3.
Claim 14
Independent Claim
113 words
An apparatus for measuring an unknown voltage (V IN ), comprising: (a) voltage divider means for dividing the said unknown voltage into at least three fractional voltages; (b) measuring means for measuring said fractional voltages; and (c) computing means for computing said unknown voltage on the basis of said fractional voltages; wherein: said voltage divider means comprises first, second and third resistor means; and said measuring means comprises means for measuring a first voltage (V o1 ) across said second resistor means, measuring a second voltage (V o2 ) across said third resistor means and measuring a third voltage (V o3 ) across a parallel combination of said second and third resistor means.
Claim 15
Independent Claim
113 words
An apparatus for measuring an unknown voltage (V IN ), comprising: (a) voltage divider means for dividing the said unknown voltage into at least three fractional voltages; (b) measuring means for measuring said fractional voltages; and (c) computing means for computing said unknown voltage on the basis of said fractional voltages; wherein: said voltage divider means comprises first, second and third resistor means; and said measuring means comprises means for measuring a first voltage (V o1 ) across said second resistor means, measuring a second voltage (V o2 ) across said third resistor means and measuring a third voltage (V o3 ) across a parallel combination of said second and third resistor means.
Claim 16
Dependent Claim
30 words
The apparatus recited in claim 13, wherein said computing means comprises means for computing said unknown voltage in accordance with the equation: V.sub.IN =V.sub.o1 *V.sub.o2 *V.sub.o3 /{(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)].
Claim 17
Dependent Claim
62 words
The apparatus recited in claim 13 wherein said computing means comprises means for computing said unknown voltage in accordance with at least one of the following equations: V.sub.IN =V.sub.o1 /K1 V.sub.IN =V.sub.o2 /K2 V.sub.IN =V.sub.o3 /K3 V.sub.IN =V.sub.o1 *V.sub.o2 *V.sub.o3 /{(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}, where K1, K2 and K3 are each functions of V o1 , V o2 and V o3 .
Claim 18
Dependent Claim
36 words
The apparatus recited in claim 15, further comprising means for computing K1, K2 and K3 in accordance with the following equations: K1={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o2 *V.sub.o3) K2={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o1 *V.sub.o3) K3={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}(V.sub.o1 *V.sub.o2).
Claim 19
Dependent Claim
58 words
The apparatus recited in claim 15, further comprising means for computing K1, K2 and K3 in accordance with the following equations: K1=R.sub.2 /(R.sub.1 +R.sub.2) K2=R.sub.3 /(R.sub.1 +R.sub.3) K3=R.sub.2 *R.sub.3 /(R.sub.1 *R.sub.2 +R.sub.1 *R.sub.3 +R.sub.2 *R.sub.3), where R 1 , R 2 and R 3 respectively represent the approximate resistance values of said first, second and third resistor means.
Claim 20
Dependent Claim
35 words
The apparatus recited in claim 15, further comprising means for measuring a plurality of samples of each of V o1 , V o2 and V o3 during a plurality of cycles of said unknown voltage.
Claim 21
Dependent Claim
27 words
The apparatus recited in claim 18, further comprising means for reordering the sequence in which the samples V o1 , V o2 and V o3 are measured.
Claim 22
Dependent Claim
18 words
The apparatus recited in claim 18, further comprising means for computing average values of K1, K2 and K3.
Claim 23
Dependent Claim
25 words
The apparatus recited in claim 18, further comprising means for sampling each of V o1 , V o2 and V o3 at approximately 2.4 kHz.
Claim 24
Dependent Claim
13 words
The apparatus recited in claim 18, further comprising means for interleaving said samples.
Claim 25
Dependent Claim
17 words
The apparatus recited in claim 18, further comprising means for low pass filtering K1, K2 and K3.
Claim 26
Dependent Claim
73 words
The apparatus recited in claim 15, further comprising: means for measuring a plurality of samples of each of V o1 , V o2 and V o3 during a plurality of cycles of said unknown voltage; means for computing K1, K2 and K3 in accordance with the following equations: K1={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o2 *V.sub.o3) K2={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o1 *V.sub.o3) K3={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}(V.sub.o1 *V.sub.o2); and means for low pass filtering K1, K2 and K3.
Claim 27
Dependent Claim
97 words
An electronic power meter, comprising: (a) voltage divider means for dividing an unknown voltage into at least three fractional voltages (V o1 , V o2 , V o3 ); (b) measuring means, including an analog-to-digital converter, for measuring and digitalizing said fractional voltages; and (c) computing means for computing said unknown voltage in accordance with at least one of the following equations: V.sub.IN =V.sub.o1 /K1 V.sub.IN =V.sub.o2 /K2 V.sub.IN =V.sub.o3 /K3 V.sub.IN =V.sub.o1 *V.sub.o2 *V.sub.o3 /{(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}, where K1, K2 and K3 are each functions of V o1 , V o2 and V o3 .
Claim 28
Dependent Claim
97 words
An electronic power meter, comprising: (a) voltage divider means for dividing an unknown voltage into at least three fractional voltages (V o1 , V o2 , V o3 ); (b) measuring means, including an analog-to-digital converter, for measuring and digitalizing said fractional voltages; and (c) computing means for computing said unknown voltage in accordance with at least one of the following equations: V.sub.IN =V.sub.o1 /K1 V.sub.IN =V.sub.o2 /K2 V.sub.IN =V.sub.o3 /K3 V.sub.IN =V.sub.o1 *V.sub.o2 *V.sub.o3 /{(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}, where K1, K2 and K3 are each functions of V o1 , V o2 and V o3 .
Claim 29
Dependent Claim
37 words
The power meter recited in claim 25, further comprising means for computing K1, K2 and K3 in accordance with the following equations: K1={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o2 *V.sub.o3) K2={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}/(V.sub.o1 *V.sub.o3) K3={(V.sub.o1 *V.sub.o3)+(V.sub.o2 *V.sub.o3)-(V.sub.o1 *V.sub.o2)}(V.sub.o1 *V.sub.o2).
Claim 30
Dependent Claim
72 words
The power meter recited in claim 25, wherein said voltage divider means comprises first, second and third resistor means, and further comprising means for computing K1, K2 and K3 in accordance with the following equations: K1=R.sub.2 /(R.sub.1 +R.sub.2) K2=R.sub.3 /(R.sub.1 +R.sub.3) K3=R.sub.2 *R.sub.3 /(R.sub.1 *R.sub.2 +R.sub.1 *R.sub.3 +R.sub.2 *R.sub.3), where R 1 , R 2 and R 3 respectively represent the approximate resistance values of said first, second and third resistor means.
Claim 31
Dependent Claim
34 words
The power meter recited in claim 26, further comprising means for measuring a plurality of samples of V o1 , V o2 and V o3 during a plurality of cycles of said unknown voltage.
Claim 32
Dependent Claim
28 words
The power meter recited in claim 28, further comprising means for reordering the sequence in which the samples V o1 , V o2 and V o3 are measured.
Claim 33
Dependent Claim
19 words
The power meter recited in claim 29, further comprising means for computing average values of K1, K2 and K3.
Claim 34
Dependent Claim
26 words
The power meter recited in claim 30, further comprising means for sampling each of V o1 , V o2 and V o3 at approximately 2.4 kHz.
Claim 35
Dependent Claim
14 words
The power meter recited in claim 31, further comprising means for interleaving said samples.
Claim 36
Dependent Claim
29 words
The power meter recited in claim 32, wherein said means for computing average values of K1, K2 and K3 comprises means for low pass filtering K1, K2 and K3.
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