Precision universal AC bridges with phase controlled dividers

Surdu, M. N.; Surdu, D.; Koffman, Andrew D.

doi:10.1109/cpem.2010.5543800

Cited by 3 publications

(8 citation statements)

References 2 publications

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“…The accurate high impedance bridge using described approach and two pair terminal connection of the standards being compared was described in [10]. In this report we describe the automatic bridge with four terminal (pair) connection for measurements in wide range of impedances and frequencies.…”

Section: Solutionmentioning

confidence: 99%

“…To balance the bridge we change the phases of the output signals of the synthesizer S 11 and S 21 by the algorithm described in [10].…”

Section: Solutionmentioning

confidence: 99%

“…The resulting total balancing signals (vectors 1 U + and 1 U − ) are described by equations: � � � � �|� � |�� |� � |�� To create signals U 0 , U 11 and U 21 synthesizers, based on fast digital-to-analog converters, are used [3, 4, 5, 7.]. In [10] possible variational calibration procedures of the bridge, based on synthesizers and phase control balancing, are described. After these calibrations the dependence of the complex ratio of the vectors U 1 and U 0 on their phase ψ and φ changes can be calculated strictly, with uncertainty less than 10 -7 .…”

Section: Solutionmentioning

confidence: 99%

“…The approach to the synthesis of two voltages sources with very accurate ratio (10 -7 or less) based on the phase control was described in [10]. On this base there was developed the accurate two terminal bridge for high impedance measurement on audio-, low and ultralow frequencies.…”

Section: Introductionmentioning

confidence: 99%

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Wide range bridge-comparator for accurate impedance measurements on audio- and low frequencies

Surdu¹,

Surdu

2014

29th Conference on Precision Electromagnetic Measurements (CPEM 2014)

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The accurate (uncertainty -better than 1 ppm, sensitivity -better than 0.1 ppm on main ranges) bridge-comparator, balanced by phase control only, is described. Bridge is aimed to measure any impedance in wide dynamic range (from 10 -7 to 10 17 Ohm). It operates in wide frequency range (from 10 -2 to 10 kHz). Bridge balancing and uncertainty correction use the variational method and measurements of unbalance signals.Bridge compares the impedances with arbitrary phase angle, i.

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Section: Solutionmentioning

confidence: 99%

“…To balance the bridge we change the phases of the output signals of the synthesizer S 11 and S 21 by the algorithm described in [10].…”

Section: Solutionmentioning

confidence: 99%

Section: Solutionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Wide range bridge-comparator for accurate impedance measurements on audio- and low frequencies

Surdu¹,

Surdu

2014

29th Conference on Precision Electromagnetic Measurements (CPEM 2014)

Self Cite

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“…Such bridge will be balanced by changing of the signals phases only. This approach was proposed in [12]. It should be noted that control of the electromagnetic field magnitude by phase control is widely used on high frequencies in radio-instruments for astronomic observations, in ground-based and airplane radar systems, etc [13,14], but not for accurate impedance measurements.…”

Section: Phase Controlled Voltage Dividermentioning

confidence: 99%

Peculiarities of the accurate ac phase controlled bridge realization

Surdu¹,

Surdu²

2017

Ukrainian Metrological Journal

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Рассматривается новый метод построения мостов переменного тока, в которых используются делители напряжения с фазовым управлением, основанные на синтезе сигнала с регулируемой амплитудой посредством суммирования сигналов с регулируемой фазой. The new method of building of AC bridges, in which phase-controlled voltage dividers are used, based on the synthesis of a signal with a controlled amplitude by summing signals with a controlled phase.

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Fast balancing method for an AC bridge based on a novel phase matching technique

Ida

Pasdar

2016

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

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Purpose Development of a method of balancing an AC bridge with minimum computation time. The applications envisioned are in power system monitoring and sensing Design/methodology/approach The method is based on a recursive algorithm, first matching the phase followed by that of amplitude. Each phase step requires three samples per steps.Voltage matching is based on halving the range of measured amplitudes in each step, resulting in an n-step recursive algorithm. Findings Computation is minimal - only requires 4 phase matching steps for an error of 1º. Further steps improve on this error. Matching of amplitude is equally fast. The resolution in amplitude is directly proportional to the number of steps. An example and experimental results demonstrate the efficiency of the method. Research limitations/implications Balancing of AC bridges in conjunction with automated measurement systems is a fairly complex process requiring either extensive computation or dedicated hardware (tunable devices, microprocessors, etc.). The current method is recursive and very light on computation. This means the method can be used in sensing systems where neither extensive hardware nor computational resources are readily available. Practical implications The method has been developed for power line AC impedance sensing as part of a power line monitoring system. It is however a general method that can be used in any AC bridge application. Originality/value The methods used as well as the implementation are entirely original. These have been developed as part of a research in instrumentation of power line monitoring.

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Precision universal AC bridges with phase controlled dividers

Cited by 3 publications

References 2 publications

Wide range bridge-comparator for accurate impedance measurements on audio- and low frequencies

Wide range bridge-comparator for accurate impedance measurements on audio- and low frequencies

Peculiarities of the accurate ac phase controlled bridge realization

Fast balancing method for an AC bridge based on a novel phase matching technique

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