Topic
Electrical impedance
About: Electrical impedance is a research topic. Over the lifetime, 36015 publications have been published within this topic receiving 371891 citations. The topic is also known as: electrical impedance & complex impedance.
Papers published on a yearly basis
Papers
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TL;DR: The relationship between impedance change component and instrumention technique is examined and a method for reducing the subjectrground artifact is presented and the instrumentation techniques discussed also apply to other bioimpedance change measurements.
Abstract: The impedance pneumograph is a bioimpedance recorder for indirect measurement of respiration. Using superficial thoracic electrodes, the impedance pneumograph measures respiratory volume and rate through the relationship between respiratory depth and thoracic impedance change. This paper reviews the development of impedance pneumography, and pneumographic instrumentation techniques. The advantages and disadvantages of the bridge, modulated oscillator, constant voltage, voltage divider, and constant current designs are examined and both the bridge and constant current designs are found to be useful. The relationship between impedance change component and instrumention technique is examined and a method for reducing the subjectrground artifact is presented.
73 citations
TL;DR: In this paper, a filter-based technique was used to extract the four parameters that characterise a single-dispersion Cole-Cole impedance model without direct measurement of the impedance real and imaginary parts.
Abstract: A filter-based technique to extract the four parameters that characterise a single-dispersion Cole-Cole impedance model without direct measurement of the impedance real and imaginary parts is reported. Experimental results in the range 100 Hz-5 MHz using apples, apricots and kiwi fruits are given and results are compared with numerical simulations of the acquired model.
73 citations
Patent•
28 Apr 1989
TL;DR: A two-terminal, alternating current power control device connected in an electrical path between a load and a remote switch, comprising a current switching device, a controlling device and a direct current power supply device, is described in this paper.
Abstract: A two-terminal, alternating current power control device connected in an electrical path between a load and a remote switch, comprising a current switching device, a controlling device and a direct current power supply device. The current switching device provides a low impedance electrical path in response to the application of triggering signals thereto, and provides a high impedance electrical path in the absence of the triggering signals. A control circuit is provided for applying triggering signals to the current switching device as the proper time in the AC cycle, and is responsive to a momentary interruption in the applied AC voltage so as to effect change in the power intensity or timed duration of power delivered to the load. A remote switch in the electircal path can be the source of a momentary power interruption. The entire power control device can be constructed to directly attach to the electrical screw shell base of a gas dischage lamp, so the lamp and power control device can be mounted into the normal accommodating electrical fixture without the need for an intermediary fixture or additional electrical wiring.
73 citations
18 May 1992
TL;DR: In this paper, a technique for the equivalent circuit modeling of interconnects having discontinuities such as bends, steps, and junctions in high-speed circuits and packages is developed.
Abstract: A technique for the equivalent circuit modeling of interconnects having discontinuities such as bends, steps, and junctions in high-speed circuits and packages is developed. The circuit models are extracted from time domain reflection (TDR) measurements. The simulated results for the circuit models are compared with the measured data to validate the accuracy of the circuit model. The proposed method can be used to help validate circuit models based on field-theoretic techniques as well as used as an independent tool to synthesize circuit models for general nonuniform or interacting two- and three-dimensional interconnects. >
73 citations
TL;DR: This article proposes a parameter identification method based on the high frequency (HF) equivalent impedance model of permanent magnet synchronous motor with HF signal injection at both the dq-axes, which identifies the resistance and the dQ-axis inductances offline and online, along with the flux linkage online.
Abstract: Existing online motor parameter identification methods mostly depend on the fundamental frequency voltage equations, which lead to the unsatisfactory identification effect at low current and low speed operation. This article proposes a parameter identification method based on the high frequency (HF) equivalent impedance model of permanent magnet synchronous motor with HF signal injection at both the dq -axes. This method identifies the resistance and the dq -axis inductances offline and online, along with the flux linkage online. In order to improve the identification accuracy, the parameter sensitivity analysis-based algorithm is proposed to detect the resistance and the flux linkage. Meanwhile, the inverter nonlinearities and the HF influence on parameter identification are compensated effectively. In order not to affect the normal operation of the motor drive, the selection of the amplitude, and the frequency of the injected signal is investigated. The proposed method is validated on a 2.2-kW motor and confirmed by finite element analysis. The experimental results show the good identification effect in different operation conditions.
73 citations