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In this paper, we propose a circuit configuration for the low-frequency second-order active RC BPF (band pass filter) which has stable high Q. This proposed circuit is a high Q low-frequency one with a small capacitance, which is realized by applying an output capacitance multiplier to the circuit. Then a detailed circuit analysis is performed for the proposed circuit. From the simulation results of f o and Q for various combinations of circuit element values, we can confirm that the circuit realization of a center frequency of several Hz is possible by employing chip condensers of dozens of nF. The bread-board circuit of this configuration is confirmed to have small temperature dependences of f o and Q by the experiment. It is also clarified from detailed noise analysis and noise measurement that the circuit noise is sufficiently maintained at a low level.

The operation of a self-oscillating switched-mode circuit topology for low-voltage thermal energy harvesting is analysed and experimental efficiency results are presented. Circuit self-start-up function as well as high-efficiency power transfer are obtained by using only one transformer without additional inductors. It is shown that even without using a maximum power point tracking (MPPT) tracking circuit, it is possible to achieve efficiencies up to 65% over a relatively broad input voltage range which can be optimised by properly varying the transformer turns ratio n.

The present letter describes the design of an energy harvesting circuit on a one-sided directional flexible planar antenna. The circuit is composed of a flexible antenna with an impedance matching circuit, a resonant circuit, and a booster circuit for converting and boosting radio frequency power into a dc voltage. The proposed one-sided directional flexible antenna has a bottom floating metal layer that enables one-sided radiation and easy connection of the booster circuit to the metal layer. The simulated output dc voltage is 2.89 V for an input of 100 mV and a 50 Ω power source at 900 MHz, and power efficiency is 58.7% for 1.0 × 107 Ω load resistance.

This paper aims at developing a new design method of the active-shunted hybrid type of piezoelectric damping system for structural vibration suppression. Piezoelements are actively driven with series tuned RL shunting circuits. Considering shunting circuits as compensators (or filters), both shunt resistors and active control gains are designed by using filtered LQ control theory. Experimental test and numerical simulation of a simple cantilevered beam demonstrate the structural damping capability of the hybrid piezoelectric damping system. Control effort by the active control could be reduced by the hybrid piezoelectric damping system.

Design, parameters, and application areas of a superconducting fault current limiter (FCL) are analyzed on the basis of the requirements of power systems. The comparison of resistive and inductive designs is carried out. An example of the effective application of FCLs in distribution substations is considered and the gain from the FCL installation is discussed. It is shown that an FCL not only limits a fault current but also increases the dynamic stability of the synchronous operation of electric machines. The calculation procedure of the parameters of an inductive FCL for a specific application case is described.

On-chip conductors such as clock- and power-distribution networks require accurately modeling skin and proximity effects. Furthermore, to incorporate skin and proximity effects in the existing generic simulation tools such as SPICE, simple-frequency independent-lumped element-circuit models are needed. A rule based RL circuit model is proposed in this paper that is realizable and predicts skin and proximity effects accurately in the frequency range of interest. With this circuit model, wires are characterized by a few parallel branches of resistors and inductors while proximity effect is captured by mutual inductance between inductors in different RL circuits.

In this paper, a novel voltage generator circuit using a ferroelectric capacitor is described. This circuit consists of two metal-oxide-semiconductor (MOS) transistors, a ferroelectric capacitor and a dielectric capacitor, which can convert a positive input voltage into a negative output voltage. We describe in detail the design and operation principles of the circuit. We have demonstrated the expected circuit operation and evaluated its performance characteristics such as voltage efficiency and verified, using an experimental circuit, that a negative voltage is continuously generated. The magnitude of the measured output voltage value was smaller than that of the simulation result, possibly due to the existence of parasitic resistance in the experimental circuit. The simulation results suggest that our circuit is suitable for reducing the standby leakage current of MOS transistors, one of the most serious power consumption-related problems in advanced CMOS LSIs.

A new current-mode analog circuit configuration that implements the function ln (x/y) is proposed. The circuit uses bipolar transistors and resistors and is suitable for integration. In the proposed circuit the ratio (x/y) can be larger or smaller than unity. Simulation results are included.

A novel voltage sensorless control technique for a bidirectional AC/DC converter is presented. Only a single current sensor that measures the inductor current is needed in the whole system. The sensed inductor current is used for two functions. The first one is for shaping the current waveform at the AC side and the second one is for deriving the inductor voltage by determining the rate of change of the inductor current. The AC-side and DC-side voltages, which are used for AC current synchronization and DC voltage regulation, respectively, are obtained by extracting the envelopes of the derived inductor voltage. Apart from reducing the number of sensing elements, the proposed method has additional advantages of: (1) inherent electrical isolation and reducing noise coupling between the power circuit and the controller; (2) wide operating range. Design criteria for the differentiator and the envelope detector circuit has been described. The applicability of the proposed method is verified with the experimental results of a laboratory prototype.

General modelling of a resonant shunting damper has been made from piezoelectric sensor/actuator equations. It is found that an additional damping, which is augmented to a system, is generated by the shunt damping effect. The transfer function of the tuned electrical absorber is derived for both series and parallel shunt circuit. The governing equations and associated boundary conditions are derived using Hamilton's principle. The shunt voltage equation is also derived from the charge generated in PZT due to beam vibration. The frequency response function of the obtained mathematical model is compared with that of the tuned electrical absorber and experimental work. The vibration amplitude is reduced about 15 dB at targeted second mode frequency.

The design and equivalent circuit of an inductor with a ferromagnetic film is described. High-frequency circuit simulation including inductance is carried out by two methods: 1) a SPICE-based simulation in which the distributed linear circuit is converted into a GCRL equivalent circuit and 2) an harmonic balance method in which the nonlinear active part of the circuit is solved in terms of sinusoidal harmonics in the frequency domain. High-frequency circuits including inductors and active elements such as low noise amplifiers are analyzed by these methods.

Several realizations of Chua's circuit have been proposed in the literature. The methodologies used in these realizations can be divided into two basic categories. In the first approach, a variety of circuit topologies have been considered for realizing the nonlinear resistor, NR in Chua's circuit. The main idea in the second approach related to the implementation of the circuit is an inductorless realization of Chua's circuit. For this purpose, several circuit topologies serving as a synthetic inductor, i.e. inductance simulator, are used instead of the inductor element in Chua's circuit. In this study, after comparing the circuit topologies proposed for Chua's diode and the inductor element in the circuit, we will present six alternative hybrid realizations of Chua's circuit combining circuit topologies proposed for the nonlinear resistor and the inductor element in the literature. The PSpice simulation experiments confirm that the six alternative hybrid realizations of the circuit exhibit the original chaotic behavior of Chua's circuit.

A novel Impedance Generation Circuit is proposed in this paper and is also implemented. The need for this is the lack of availability of such a device in the market at an affordable price and also the versatility it provides. Decade boxes such as DRB, DCB or DLB use switching of the corresponding passive elements (R, C, L variations) whereas the device proposed in this paper uses only variations in resistors to vary the Capacitance and Inductance, thus making it more compact compared to the other passive elements box. The Impedance generation circuit proposed here uses an inductor simulation circuit which is the Antoniou's circuit as explained in [4,5]. The Design was done using the well know Antoniou Inductance simulation circuit, and a novel modification which gives Capacitance simulation circuit along with resistor switching circuits. The implementation used OP-Amps, CMOS switches and the micro-processor TI MSP430 for switching of the resistors which in turn was used for varying Inductance and Capacitance at a given frequency. The Prototype of the proposed circuit was developed and tested; the results obtained were found to be accurate within a range of frequencies.

In this article, a piezo-based tuned vibration absorber is proposed and theoretically analysed. The proposed device consists of a proof mass, a piezoelectric actuator and a resilient element (spring). An equivalent mechanical model where the piezoelectric element is connected to a general circuit composed of a resistor, an inductor and a capacitor in series ( RLC) is presented to illustrate the coupling of the electrical components with the mechanical systems. Based on the mechanical replacement model, a C or L circuit can be used to realise a piezo-based tuned vibration neutraliser, while with an RC or RL circuit the piezo-based tuned vibration absorber can be considered as a piezo-based tuned mass damper. For the C and L circuits, tuning strategies are derived to adjust the shunt capacitance and inductance to track the disturbance frequency. In the case of RC and RL shunt circuits, an ℋ2 optimisation criterion is used for tuning the piezo-based tuned mass damper. Closed-form expressions for the optimal tuning parameters are provided in this article.

Marine electromagnetic transmitter transmits electromagnetic waves with large power frequency conversion to the seabed to obtain the submarine structure and mineral resources. However, the current transmitter presents several problems, such as low efficiency, serious heat, and poor adaptability to the load. Soft-switching controlled-source circuit is used to reduce circuit losses. The mathematical model of controlled-source circuit should be established to realize a closed-loop control for increasing the output transient performance of electromagnetic waves. Given that the soft-switching controlled-source circuit has more status and that direct modeling is difficult, small-signal model of soft-switching controlled-source circuit is established based on that of hard-switching controlled-source circuit by analyzing the effect of output filter inductor current transformer leakage inductance and input voltage soft-switching controlled circuit on change in the duty cycle. Finally, experiments verify the accuracy and validity of the model.

The design procedure for a fast-response control circuit for resonant inverters is presented. The input to the circuit is a signal proportional to the load current, sensed through a Hall-effect sensor or a current transformer. The heart of the circuit is based on a phase-shift and attenuation network, followed by a comparator. In order to obtain reliable operation of the circuit, the design procedure takes into account factors such as the conditioning and slew rate of the differential voltage applied to the comparator. The additional logic used to implement a full control circuit, capable of operating either in open loop or in a resonance-tracking mode, is also described. This logic includes the dead-time generator needed to avoid the simultaneous turn-on of both transistors in the same inverter leg. The circuit was adjusted to provide a slightly inductive response, and tested in a bridge inverter with a maximum operating frequency of 250kHz. Test results show that the circuit provides good performance du...

A general equivalent circuit for the modeling of a system of magnetically coupled coils including the losses is presented. This equivalent circuit includes two parts: a subsystem of primary branches whose terminals correspond with those of the real coils, and a secondary network which allows the representation of frequency-dependent inductances and resistances. An analysis of the equations of the proposed circuit is carried out and an expression of the frequency-dependent impedance matrix as seen by the primary coils is determined. The properties of the mathematical expression are analyzed. The proposed equivalent circuit allows representing the dependence of inductances and resistances on the frequency. The expression of the impedance is the starting point for the synthesis of an equivalent circuit, which is carried out in a separate article.

We study and formulate the Lagrangian for the LC, RC, RL, and RLC circuits by using the analogy concept with the mechanical problem in classical mechanics formulations. We found that the Lagrangian for the LC and RLC circuits are governed by two terms i. e. kinetic energy-like and potential energy-like terms. The Lagrangian for the RC circuit is only a contribution from the potential energy-like term and the Lagrangian for the RL circuit is only from the kinetic energy-like term., Comment: 6 pages, conference

In this study, a passive suppression scheme for nonlinear flutter problem of composite panel, which is believed to be more reliable than the active control methods in practical operations, is proposed. This scheme utilizes a piezoelectric inductor-resistor series shunt circuit. The finite element equations of motion for an electromechanically coupled system is derived by applying the Hamilton’s principle. The aerodynamic theory adopted for the present study is based on the quasi-steady piston theory, and von-Karrnan nonlinear strain-displacement relation is also applied. The passive suppression results for nonlinear panel flutter are obtained in the time domain using the Newmark-β method. To achieve the best damping effect, optimal share and location of the piezoceramic (PZT) patches are determined by using genetic algorithms. The effects of passive suppression are investigated by employing in turn one shunt circuit and two independent shunt circuits. Feasibility studies show that two independent inductor-resistor shunt circuits suppresses flutter more effectively than a single shunt circuit. The results clearly demonstrate that the passive damping scheme that uses piezoelectric shunt circuit can effectively attenuate the flutter.

The theoretical analysis has demonstrated that the width of a pulse from a detector can be reduced by using an inductive-resistive load. A criterion for selecting parameters of the electric load based on the shape of the frequency characteristic has been suggested. Optimal resonant frequencies and Q-factors for transducers from the TsTSNV-1 ceramics have been determined.

It is well–known that arbitrary interconnections of passive (possibly nonlinear) resistances (R), inductances (L) and capacitances (C) define passive ports, with port variables the external sources voltages and currents, and storage function the total stored energy. In this brief note we establish some new passivity properties of RC and RL circuits under the more restrictive assumption that the characteristic functions of the capacitances and inductances are nondecreasing. In particular, we prove that for this class of nonlinear RC circuits passivity is preserved even if we take as port variables the sources currents and the voltage derivatives. We also show that nonlinear RL circuits define passive ports with port variables the sources current derivatives and the voltages. The storage function in both cases is the sum of the resistors co–content, which is a function associated to the power dissipation. The proof of these properties is a direct application of Tellegen's theorem. We illustrate the applicability of these results to generate new Lyapunov functions for nonlinear stabilization problems.

We demonstrate the reduction of characteristic time in resistor-inductor (RL) circuit for fast, efficient magnetic levitation according to Kirchhoff’s circuit laws. The loading time is reduced by a factor of ∼4 when a high-power resistor is added in series with the coils. By using the controllable output voltage of power supply and voltage of feedback circuit, the loading time is further reduced by ∼ 3 times. The overshoot loading in advance of the scheduled magnetic field gradient is equivalent to continuously adding a resistor without heating. The magnetic field gradient with the reduced loading time is used to form the upward magnetic force against to the gravity of the cooled Cs atoms, and we obtain an effectively levitated loading of the Cs atoms to a crossed optical dipole trap.

This paper presents a novel technique for the analysis of looped linear time-invariant electric circuits. This approach works in both time and Laplace domains; any type of elements could hence be incorporated. The circuit elements are partitioned into twofold classes of basic circuit and subsidiaries. The basic circuit is a spanning tree of the network, and the subsidiaries include circuit elements hypothetically removed from the looped electric circuit to open the loops. The subsidiaries include a suit of passive elements which might not even make any interconnected circuit. The circuit governing equations of flow and energy conservation are manipulated so that branch currents in the subsidiaries and branch voltages in the basic circuit are considered as independent variables to calculate passive element properties (impedance of all passive elements) directly. In contrast to existing methods, this technique is tailored for the circuit analysis in a reverse manner. As a complement for conventional circuit analysis techniques, this method can be taught in the undergraduate program to offer the students an alternative tool for the circuit analysis.

This paper presents design and performance validation of 3D printed electronic components, 3D toroidal air-core inductors, fabricated by multi-material based Fused Deposition Modelling (FDM) 3D printing technology and electroless copper plating. Designs of toroidal inductor is investigated with different core shapes and winding numbers; circular and half-circular cores with 10 and 13 turns of windings. Electroless plated copper thin film ensures 3D printed toroidal plastic structures to possess inductive behaviors. The inductance is demonstrated reliably with an applied source frequency from 100 kHz to 2 MHz as designs vary. An RL circuit is utilized to test the fabricated inductors’ phase-leading characteristics with corresponding phase angle changes.

This paper presents a double half bridge resonant inverter for induction heating (IH) system composed of two partly coupled coils. Induction coils are electrically characterized by their electrical equivalents, usually a series RL circuit, where the inductance is determined by the magnetic energy stored in the system and the resistance is associated with the power dissipated in the load. Pulse width modulation based control strategy for double half bridge resonant inverter based power supply circuit is presented. The aim of this work is to simulate and obtain the electrical equivalent of the inductor system for accurate power study with two concentric coils by considering the frequency dependent eddy current losses associated with both the pan and the coil. This paper gives an idea about the in new control modes taking advantage of the coupling between coils in order to provide the target output power. The performed analysis includes the description of the operation and principle of the control strategy. The power converter system is designed and the simulation results are presented to prove the performance of the double half bridge inverter for partly coupled induction heating coil.

The article discusses the method of solving random differential equations of the first order. Random factors cause that only some methods for solving stochastic differential equations enable to obtain efficient results . In addition to the differential equation (together with the initial condition) the output equation should be given. If the output equation is not given, solution of the differential equations are not useful from the viewpoint of the moments of the output process (as opposed to stochastic differential equations in which the coefficients are not random variables). It was assumed that the coefficients are functions of two random variables (A and B) and the force does not contain irregular processes (Winner processes, white and colored noise). The considered equations describe electrical dynamical systems of the first order. The expected value of response of the system, cross-correlation function of the force process and response process and the correlation function of the system response have been determined. It was considered RL series circuit as an example of a solution the problem, where the response is the voltage at the resistance. An example of the problem solution has been presented for a series RL circuit assuming that the voltage across the resistor is the response of the system.

Series connections of the cells of energy-storage devices such as electric double-layer capacitor (EDLC) and lithium-ion battery result in voltage imbalance in each cell because of the nonuniform properties of the individual cells. In previous work, the authors proposed a novel cell voltage equalization circuit using an LC series circuit. In the proposed circuit, the differences of the convergence time and the efficiency had occurred according to the value of the cell change cycle T cc - Therefore, the characteristics when T cc was changed were verified by the simulation and the experiment in this paper. The simulation results and the experimental results showed that shorter convergence time with high efficiency can be obtained by setting T cc to T rs /4, where T rs is resonance period of LC series circuit used in the proposed circuit.

An equivalent circuit of a photovoltaic (PV) panel for transient analysis is proposed in this paper. The circuit is based on a conventional equivalent circuit consisting of a photo current and a non-linear resistor for expressing DC characteristic of the PV panel. The transient characteristic is modeled by linear lumped-elements additional to the model. The equivalent internal inductance of the panel is theoretically derived by reducing a multi-phase inductance matrix. The parameters of the lumped circuit are derived from a measured transient responses of a voltage and a current at a short-circuit fault. A program estimating the circuit parameters from the measured result is developed in this paper. In the program the equivalent circuit is divided into two for avoiding instability and for reducing the calculation time. The circuit parameters are obtained by iterative approximations for each circuit. The proposed equivalent circuit can express a high frequency characteristic as well as DC characteristic.

Considering the importance of modeling the electri- cal power system behavior under high frequency transients, this paper aims to present a practical methodology to obtain a RL lumped parameters model of an air-cored reactor. Firstly, the RL frequency responses are obtained using the Finite Element Method (FEM). Thus, the frequency response is converted into a RL circuit in accordance with the classical series Foster model and its parameters values are calculated through Least Square (LS) fitting algorithm. Finally, the lumped parameters circuit is converted to an ATP network model. For validation purposes a well-known air-cored reactor is modeled for a frequency range from 10 Hz to 100 kHz and the frequency responses obtained with FEM, LS fitting and ATP are compared. Index Terms—Frequency response, Finite Element Method, Least Square, ATP, Air-cored reactor

This paper presents a new voltage-mode universal filter with three-input and four-output using two differential difference current conveyors, two grounded capacitors and two resistors. The proposed filter is suitable for integrated circuit by using only grounded capacitor. Low-pass, band-pass, high-pass and band-stop voltage responses can be obtained simultaneously into one single topology and without component-matching condition requirements. The natural frequency and the quality factor can be controlled orthogonally by setting the passive components. PSPICE simulation results using 0.5 μm CMOS technology form MIETEC are included to confirm the theoretical analysis. The simulation results can be expressed that the proposed circuit agrees well with theory.

A novel equivalent circuit model for a spiral inductor is proposed based on a unified coplanar waveguide (CPW) transmission line model. The spiral inductor can be treated as a network of several individual conductor paths. The individual conductor loss is similar to the loss in CPWs, which can be explained by the unified model. The coil current of the inductor induces an eddy current in the silicon substrate which is magnetically coupled with the metal line. The substrate eddy current loss and coupling with the spiral line are modeled by an RL ladder structure and mutual inductance. Single turn spiral inductors have been designed and fabricated on various resistivity substrates. A good agreement is obtained between the measurement and the equivalent circuit even above the self-resonance frequency. This work demonstrates that the performance of spiral inductors can be predicted and investigated by the proposed equivalent circuit.

CNC constant voltage power is composed by the analog power circuit, MCU control circuit , pulse width modulation circuit, a power driver amplifier , analog to digital conversion circuit , the input voltage setting circuit and the output voltage display circuit. The power possesses the functions of digital regulator, high precision output, short-circuit & over-current protection and alarm functions, especially for a higher accuracy requirements for various occasions. DOI: http://dx.doi.org/10.11591/telkomnika.v12i6.5443 Full Text: PDF

The dc-link pole to pole short circuit is one of the most serious fault of a modular multilevel converter. Because of this, it is also one of the most important research objects for institutes and companies. However, there are not so many papers about this experiment published yet. Actually, the short circuit current before blocking the sub modules is the combination of the ac injection current and the capacitor discharge current. This paper analyzes the model of the capacitor discharging circuit and demonstrates the results of the experiment done with a ±10 kV prototype MMC.

It has been shown that piezoelectric materials can be used as passive electromechanical vibration absorbers by shunting them with electrical networks. Semi-active piezoelectric absorbers have also been proposed for suppressing harmonic excitations with varying frequency. However, these semi-active devices have limitations that restrict their practical applications. The approach presented here is a high performance active-passive alternative to semi-active absorbers. By utilizing a combination of a passive electrical circuit and active control actions, the system is synthesized for adaptive variable frequency narrowband disturbance rejection. The active control consists of three parts: an inductor tuning action, a negative resistance action, and a coupling enhancement action. In the current paper (Part 1), the control algorithm is developed and analyzed. Part 2 of the paper contains experimental investigations and parametric studies of the new absorber design.

In Part 1 of the paper, a new high-performance active-passive hybrid piezoelectric absorber concept was presented. This design is an attractive alternative to semi-active absorbers for the purpose of suppressing harmonic excitations with variable frequency. In this paper (Part 2), the effectiveness of the new absorber design is first demonstrated through experimental investigations. Parametric studies are then carried out to illustrate how the performance of the new design is affected by the design parameters and excitation characteristics. In these studies, two state-of-the-art control methods are used as baselines for comparison with the new absorber design, and it is shown that the proposed design offers superior performance and efficiency compared to these methods.

This paper presents an analytic solution for the transient response of a parallel RL network with piecewise linear inductance. It compares the rise time and zero-crossing pulse compression of the nonlinear network with a corresponding linear network. It shows that there is a rise time and compression improvement in the nonlinear circuit as the amplitude of the input current increases. It provides analytic expressions as well.

This letter presents a broadband medium power amplifier in 0.18-μm CMOS technology. The Darlington cascode topology is used to achieve wide bandwidth, flat gain and power frequency response. For wideband matching consideration, an interstage inductor and series peaking RL circuit are adopted. An output high pass matching circuit is used to maintain gain and power flatness at high frequency. The measured results show that the proposed PA demonstrates a gain of 10 dB from 4 to 17 GHz with less than 2-dB ripple, and a saturation output power of 16 to 18 dBm with PAE of better than 10% and power consumption of 306 mW. The chip size is only 0.67 mm2 .

A CMOS current-mode nth-switchable-root circuit composed of a compact logarithm circuit, a divide-by-n circuit, and a compact exponential circuit is proposed. The n can be selected from 5 values by three switches. Simulation results indicate that the compact nth-switchable-root circuit has a wide input-current range for relative errors less than 3%, low power dissipations below 630 μW, and high bandwidth over 330 MHz.

We present a systematic approach to the synthesis of R–L (resistor–inductor) and C–D (capacitor–frequency-dependent negative resistance) configurations by using a single third-generation current conveyor (CCIII) and a minimum number of passive elements. All the simulated immittance values can be orthogonally adjusted, there are no requirements for any certain element matching or cancellation constraints. The test filter circuits, constructed with the derived R–L immittances, are used to verify the theory by HSPICE simulations. The simulation results corroborating all our theoretical predictions are incorporated in the work. This methodology can be extended to the immittance synthesis based on different active elements.

In this paper, there is shown the existence of limits to output voltage and power in a boost power factor correcting circuit operating in discontinuous inductor current mode. Like in the continuous case, the limits result from input current distortions that appear when the output power and voltage are not chosen properly for given circuit elements. There are presented graphs and numerical data which allow determining the proper values of circuit parameters and elements to ensure the proper operation of the whole circuit.

SUMMARY A voltage-controlled oscillator (VCO) tolerant to process variations at lower supply voltage was proposed. The circuit consists of an on-chip threshold-voltage-monitoring circuit, a current-source circuit, a body- biasing control circuit, and the delay cells of the VCO. Because variations in low-voltage VCO frequency are mainly determined by that of the current in delay cells, a current-compensation technique was adopted by using an on-chip threshold-voltage-monitoring circuit and body-biasing circuit techniques. Monte Carlo SPICE simulations demonstrated that variations in the oscillation frequency by using the proposed techniques were able to be suppressed about 65% at a 1-V supply voltage, compared to frequencies with and without the techniques.