Parallel Resistor-inductor Research Articles

VCII‐Based Immittance Simulators: Generalized Parallel Configurations

ABSTRACTIn this paper, four new generalized configurations of grounded parallel‐type immittance simulators are proposed. These circuits implement parallel resistor–inductor (RL), parallel resistor–capacitor (RC), parallel capacitor–frequency‐dependent negative resistance (CD), and capacitance multiplier configurations utilizing only two second‐generation voltage conveyors (VCII±) as active elements along with three impedances, without the need for specific matching conditions. The applicability of the proposed parallel RL and capacitance multiplier configurations as a second‐order high‐pass filter (HPF) and a first‐order low‐pass filter (LPF), respectively, is also demonstrated. These applications illustrate the versatility and utility of the proposed structures. Frequency, transient, and Monte Carlo analysis utilizing the CMOS VCII± in the SPICE simulation tool have also been performed to validate the feasibility of the presented circuits. Further validation is carried out through layout design in Cadence Virtuoso, employing 0.18‐μm CMOS technology. Both presimulation and postsimulation results are presented for a thorough assessment of the proposed circuits. Also, the claimed theory is verified by experimental results based on the VCII implementation with commercially available IC AD844.

Increasing signal amplitude in electrical impedance tomography of neural activity using a parallel resistor inductor capacitor (RLC) circuit

Objective. To increase the impedance signal amplitude produced during neural activity using a novel approach of implementing a parallel resistor inductor capacitor (RLC) circuit across the current source used in electrical impedance tomography (EIT) of peripheral nerve. Approach. The frequency response of the impedance signal was characterized in the range 4–18 kHz, then a frequency range with significant capacitive charge transfer was selected for experiment with the RLC circuit. Design of the RLC circuit was aided by in vitro impedance measurements on nerve and nerve cuff in the range 5 Hz to 50 kHz. Main results. The frequency response of the impedance signal across 4–18 kHz showed maximum amplitude at 6–8 kHz, and steady decline in amplitude between 8 and 18 kHz with −6 dB reduction at 14 kHz. The frequency range 17 ± 1 kHz was selected for the RLC experiment. The RLC experiment was performed on four subjects using an RLC circuit designed to produce a resonant frequency of 17 kHz with a bandwidth of 3.6 kHz, and containing a 22 mH inductive element and a 3.45 nF capacitive element with +0.8/− 3.45 nF manual tuning range. With the RLC circuit connected, relative increases in the impedance signal (±3σ noise) of 44% (±15%), 33% (±30%), 37% (±8.6%), and 16% (±19%) were produced. Significance. The increase in impedance signal amplitude at high frequencies, generated by the novel implementation of a parallel RLC circuit across the drive current, improves spatial resolution by increasing the number of parallel drive currents which can be implemented in a frequency division multiplexed (FDM) EIT system, and aids the long term goal of a real-time FDM EIT system by reducing the need for ensemble averaging.

Design and analysis of floating inductance simulators using VDDDAs and their applications

This contribution introduces the design of new electronically controllable floating inductance simulators including lossless inductor, parallel resistor-inductor and series resistor-inductor circuits. The proposed simulators consist of two voltage differencing differential difference amplifiers (VDDDAs) as active function block with one resistor and one grounded capacitor. For real practical test and cheap cost, the VDDDA employed in this paper is constructed from commercially available ICs. The proposed active inductors don’t require any critical matching condition of passive element. If second port of the proposed inductors is assigned as output voltage, it can be simply adapted to achieve low impedance output voltage node with unity or double gain amplifier which is beneficial feature. Moreover, the third order low-pass and fourth order band-pass ladder filters are designed using proposed simulators. Low impedance output voltage node and double output voltage gain of ladder filters with electronic controllability of pass-band frequency are obtained. The performances of the presented simulator circuits and ladder filters are tested by Pspice simulation and experiment using VDDDA constructed from ICs, AD830 and LM13700. The simulation and experimental results confirm with theoretical behavior. Moreover, the recommended design for chip implementation to reduce number of VDDDA is included. The recommended lossless inductor, parallel resistor-inductor and series resistor-inductor circuits consist of single VDDDA which contains plus and minus z terminals along with single resistor and single grounded capacitor.

Rotor Balancing Via an Enhanced Automatic Dynamic Balancer With Inductively Coupled Shunt Circuit

Despite the elegant nature of the automatic balancing principle for passive imbalance vibration control, the co-existence of undesired whirling limit-cycles is a major impediment to the more widespread application of automatic dynamic balancing devices also called automatic dynamic balancer (ADB) in industry. To enlarge the region of stable perfect balancing and to eliminate whirling limit-cycles, we develop an innovative enhanced ADB system. This new idea harnesses the automatic balancing principle via moving permanent magnet balancer masses which are inductively coupled to a parallel resistor–inductor–capacitor (RLC) circuit. It is found that the circuit parameters can be adjusted properly to suppress the whirling limit-cycle to enlarge the perfect balancing region. We start from a Lagrangian description of the system and get nonlinear autonomous equations-of-motion. We then solve two dominant steady-state solutions for the enhanced ADB system. One solution is for the perfect balancing equilibrium points (EPs), which can be solved analytically. While the other solution is for the whirling limit-cycle which is solved via a harmonic balance method. The stability of these solutions is then evaluated through eigenvalue analysis and Floquet theory. The newly involved electrical parameters, such as coupling coefficient, equivalent capacitance, and equivalent resistance, are designed via an arc-length continuation method to destabilize the limit-cycle solutions to then guarantee stable rotor balancing.

Dissipation, voltage profile and Lévy dragon in a special ladder network

A ladder network constructed by an elementary two-terminal network consisting of a parallel resistor–inductor block in series with a parallel resistor–capacitor block sometimes is said to have a non-dispersive dissipative response. This special ladder network is created iteratively by replacing the elementary two-terminal network in place of the resistors. In this paper, it will be demonstrated that, in fact, non-dispersive dissipative response conclusion of this special ladder network is not accurate for steady-state condition. Furthermore, the voltage profile of this special ladder network exhibits a fractal form called the Lévy C curve or Lévy dragon in a certain condition. Therefore, this special ladder network may be called the Lévy ladder network. This ladder network might be interesting for physics and electrical engineering students and they may encounter when dealing with this network series and parallel combinations of impedances.

Energy transduction analyses of piezoelectric based vibration control of smart structures

Passive vibration shunt control using piezoelectric materials and an electrical network can remove vibration energy from structures. However, the vibration shunt control efficiency relies on the optimization of the vibration energy transfer between a structure and a Lead-Zirconate-Titanate piezoelectric ceramic material. We present an analytical study of a parallel resistor-inductor piezoelectric vibration shunt control on a beam structure using Hamilton's principle and Galerkin's method. The influence of the material's mechanical property on vibration energy transfer between the structure and the Lead-Zirconate-Titanate is discussed. The results of the vibration shunt control with various materials obtained from numerical modeling and experiments are discussed and corroborated.

Method for Multiple Mode Piezoelectric Shunting with Single PZT Transducer for Vibration Control

We report a method for passive piezoelectric shunt-damping of multiple vibration modes using a single piezoelectric transducer (PZT). The method, which is different from other multiple-mode shunting (Edberg et al., 1992; Hollkamp, 1994), is to employ a blocking circuit in series with each parallel resistor-inductor shunt circuit designed to control one structural mode. The blocking circuit consists of one parallel capacitor-inductor antiresonant circuit or a series of them. The number of the antiresonant circuits in each shunt circuit depends on the number of the structural modes to be controlled simultaneously. These antiresonant circuits are designed to produce infinite electrical impedance, or antiresonance, at the natural frequencies of all other shunt circuits. Each shunt circuit with the addition of the blocking circuit is functional for its own mode yet blocks or causes open circuit for all other frequency modes. Therefore, when the individual shunt circuits are all connected to the two terminals of the PZT to form a composite shunt circuit for the multiple-mode shunting, they will not interfere with each other. The method is also easier and more reliable for finetuning and damping control. We analyze first the multiple-mode shunt-damping circuit with both the generalized circuit and the modified circuit. The latter derived from the former is intended to reduce the number of the antiresonant circuits and to make the composite shunt circuit simpler to operate. Experimentally we have designed two modified shunt circuits and successfully demonstrated vibration reduction of two and three structural modes with a single PZT transducer bonded on a two-wing aluminum cantilever beam. For three-mode shunt damping, the resonant amplitudes at 206, 348.5, and 484.5 Hz are reduced for 13.28, 7.30, and 9.45 dB, respectively.