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Precise temperature control is crucial for the development of sensitive instruments, as temperature fluctuations will introduce many negative effects. In temperature control systems, $1/{f}$ noise is dominant in the low-frequency range, which limits the temperature control precision. To suppress the $1/{f}$ noise, AC bridges based on the modulation-demodulation method are commonly used. While the $1/{f}$ noise is suppressed, other types of noise rise to domination, further limiting the precision of the temperature control system. The response of the AC-bridge readout circuit to temperature fluctuation is the most serious. This paper proposes a method for suppressing the response of the AC-bridge readout circuit to temperature fluctuations. Using this method, the temperature coefficient of the readout circuit is reduced by matching the temperature coefficients of the used electro-components according to their weights of impact. This method has been verified in the test of a precise temperature control system designed for a superconducting gravimeter. The temperature coefficient of the AC-bridge circuit was reduced by approximately 57.4 times compared with the unmatched AC-bridge circuit, and the temperature fluctuation in the vacuum chamber of the superconducting gravimeter was controlled within $\pm 5~\mu \text{K}$ .

Bidirectional associative memories (BAMs) have been extensively applied in auto and heteroassociative learning. However, the research on the hardware implementation of BAM neural networks is relatively few. Memristor, a nanoscale synaptic-like element, provides a new perspective for the circuit implementation of neural networks. In this work, we improve a threshold memristor bridge circuit (T-MBC) and design a novel memristive bidirectional associative memory (MBAM) network circuit on this basis. T-MBC is capable to achieve positive, negative, and zero synaptic weights without any switches, inverters, transistors, and current–voltage conversion processes. The validity of T-MBC is illustrated by PSPICE. MBAM has a simpler structure and gains excellent effects in flexibility, and reconfigurability. Besides, it is shown that MBAM can be trained to recall both disturbed binary images and incomplete/noisy grey-scale images robustly. Meanwhile, a more complex application of emotion classification based on MBAM is also accomplished. Experimental results verify the effectiveness of the MBAM neural network and demonstrate that the MBAM neural network has high recognition accuracy and strong noise immunity.

Magnetoresistive sensors are considered as part of bridge circuits for measuring magnetic field strength and electric current value. Normalized or relative expressions are introduced to change the resistance of the sensor and the measured bridge voltage to increase the information content of the regime to provide the possibility of comparing the regimes of different sensors. To justify these expressions, a geometric interpretation of the bridge regimes, which leads to hyperbolic straight line geometry and a cross ratio of four points, is given. Upon a change in the sensor resistance, the bridge regime is quantified by the value of the cross ratio of four samples (three characteristic values and the current or real value) of voltage and resistance. The cross ratio, as a dimensionless value, is taken as a normalized expression for the bridge voltage and sensor resistance. Moreover, the cross ratio value is an invariant for voltage and resistance. The proposed approach considers linear and nonlinear dependences of measured voltage on sensor resistance from general positions.Se analizează utilizarea senzorilor magnetorezistivi ca parte componentă a circuitelor în punte pentru măsurarea intensității câmpului magnetic și a curentului electric. Pentru a spori capacitatea informativă a regimului de lucru, a oferi posibilitatea de a compara regimurile diferitor senzori, sunt introduse expresii normalizate sau relative pentru schimbarea rezistenței senzorului și a tensiunii măsurate a punții. Pentru a fundamenta aceste expresii, se utilizează interpretarea geometrică a regimurilor de punte, ceea ce duce la geometria hiperbolică a liniei drepte și la raportul complex a patru puncte. Atunci când rezistența senzorului se schimbă, regimul de punte este determinat cantitativ de valoarea raportului complex a patru eșantioane (trei valori caracteristice și valoarea actuală) a tensiunii și rezistenței. Raportul complex, ca mărime adimensională, este luat ca expresie normalizată pentru tensiunea punții și rezistența senzorului. În plus, valoarea raportului complex este un invariant pentru tensiune și rezistență. Abordarea propusă ia în considerare, din punct de vedere general, dependențele liniare și neliniare ale tensiunii măsurate de rezistența senzorului.

We propose a novel circuit for the fractional-order memristive neural synaptic weighting (FMNSW). The introduced circuit is different from the majority of the previous integer-order approaches and offers important advantages. Since the concept of memristor has been generalized from the classic integer-order memristor to the fractional-order memristor (fracmemristor), a challenging theoretical problem would be whether the fracmemristor can be employed to implement the fractional-order memristive synapses or not. In this research, characteristics of the FMNSW, realized by a pulse-based fracmemristor bridge circuit, are investigated. First, the circuit configuration of the FMNSW is explained using a pulse-based fracmemristor bridge circuit. Second, the mathematical proof of the fractional-order learning capability of the FMNSW is analyzed. Finally, experimental work and analyses of the electrical characteristics of the FMNSW are presented. Strong ability of the FMNSW in explaining the cellular mechanisms that underlie learning and memory, which is superior to the traditional integer-order memristive neural synaptic weighting, is considered a major advantage for the proposed circuit.

A discrete GaN power transistor’s substrate is typically connected to its source electrode. However, on the GaN-on-Si power IC platform, the high-side transistor (HS-transistor) and low-side transistor (LS-transistor) share a common substrate that cannot be simultaneously connected to both source electrodes of the two transistors. Thus, the termination of the common substrate remains an undecided issue. In this work, comprehensive TCAD simulations are exploited to reveal the influences of various substrate termination schemes. It is found the common substrate inevitably leads to severe degradation in the dynamic ${R} _{\mathrm{ ON}}$ due to back-gating effects. The mechanisms for the degradations vary with the substrate termination scheme, and will be discussed in detail. To address these issues, we propose a new GaN power IC platform on an engineered bulk silicon substrate, and study the new platform with TCAD simulations. The proposed platform provides a local electrical substrate (a p+ island) for each GaN power transistor. The source electrode of each GaN transistor is connected to its local electrical substrate, while all devices share a common mechanical substrate. The junctions between the local substrates and the underlying n-layer provide an effective isolation between GaN transistors. The back-gating effects are completely suppressed for the GaN integrated bridge circuit.

In variable parameter transducers, the small change in passive parameters such as resistance, capacitance, and inductance, generally changes linearly with the process variable in process plant. The classical method of measurement of passive parameters generally uses an ac bridge circuit. However, this type of bridge measurement technique suffers from errors due to the effect of stray capacitances in between bridge output terminals and ground. These errors can be minimized by using the Wagner-earth technique, but the limitation is the repetition of bridge balance, which is required in every observation so that continuous measurement is not possible, which is the basic needs of a transducer. In this article, a modified De’ Sauty bridge network has been developed by using a high-gain operational amplifier to minimize the stray capacitances in case of measurement of the small change in resistances or capacitances. A potentiometer has been used to adjust the sensitivity of the bridge. For a particular value of bridge sensitivity factor, the change of passive parameters of sensor equivalent and the change of actual process variables have been observed and found good linearity and repeatability.

Nowadays most used technology is Wireless sensor network which provides increasing efficiency of data collection and processing, which controls the flow of data applications. Rectenna is a device that converts Radio waves into Electrical signal by utilize of rectifying bridge circuit which is directly connected to the normal antenna. The common purpose of antenna is used in transmission of microwave energy. The purpose of rectenna is to receive RF energy from the atmosphere and transmit through the circuit. This provide high efficiency while conversion of microwaves into the Electrical energy.

High-frequency bipolar high-voltage pulsed electric field can be used in tumor ablation to uniform the electric field distribution in the ablated region and inhibit muscle contraction effectively. Developing a high-frequency bipolar pulsed power generator (HBPPG) with wide range of specifications, such as voltage magnitude, waveform, repetition rate, and pulsewidth, is of great significance for promoting the clinical application of irreversible electroporation. Hence, in this article, a novel modular high-voltage HBPPG circuit topology is proposed for such application. Each module consists of an H-bridge and an isolated inductor. Theoretical analysis, simulation, and experimental results show that this generator perfectly combines the advantages of solid-state Marx and bridge circuit, with high stability and redundancy. The pulse frequency, pulse duration, and waveform can be flexibly adjusted by a controller software algorithm according to load parameters. The viability of the proposed HBPPG is demonstrated by PSpice simulation and equal-scale prototype. The key parameters of the developed HBPPG are as follows: voltage amplitude up to ±10 kV with 500 ns–5 μ s pulsewidths, 500 kHz within the burst, and 10 kHz within the continuation limited by the input high-voltage dc power supply. All the pulse parameters can be programmed arbitrarily.

Earlier, when studying with the help of instrument-technological simulation of the silicon-on-insulator field-effect Hall sensor (SOI FEHS) in the partial depletion mode, the effect of increasing its magnetic sensitivity was discovered. In this paper, we study the parameters of SOI-FEHS samples in various operation modes to experimentally confirm the discovered effect. To increase the measurement accuracy in the partial depletion mode, the FEHS design with a split drain is used. The optimal values ​​of the load resistances of the bridge circuit are determined. An analysis of the results of studying the experimental SOI-FEHS samples shows that the peak of the increased magnetic sensitivity is observed in the partial depletion mode. At a load resistance of 1 MΩ and a supply voltage of –9 V, the maximal magnetically induced signal approximately triples in the partial depletion mode compared with the full depletion mode. When recalculating the ΔU voltage difference on the load resistances to the magnetic sensitivity, the specific magnetic sensitivity of the FEHS in the partial depletion mode can reach values ​​of about 105 V/(A T), which is significantly higher than that of semiconductor Hall elements.

Pulsed eddy current testing is widely used because of its richness in spectral components. However, the degrading sensitivity as lift-off increases poses a challenge to its application in thick insulation or buried structures and weld areas. In the transmitter-receiver probe, self-impedance (offset) of receiver coil dominates the output signal, reducing the signal-to-noise ratio, especially at high lift-off. This limits the subsequent amplification of the output signal by the signal conditioning circuit. In practice, bridge-based measurements are used to mitigate this challenge but result in small linear range input-output characteristics. Electromagnetic interference and stray capacitance effects also cause measurement errors. This paper investigates a modified Maxwell’s inductance bridge based on operational amplifier configuration for high lift-off testing. The receiver coil self-impedance is removed to improve signal-to-noise ratio and to make output signal proportional to impedance change only. Experiments are performed to evaluate the performance of the circuit in crack detection. The results show improved signal-to-noise ratio with maximum linearity deviation of 0.30%, and a higher crack detection sensitivity at 30mm high lift-off, in comparison to the conventional bridge circuit with maximum linearity deviation of 0.53%.

Объект исследования – мощный современный импульсный источник вторичного питания резонансного типа с корректором коэффициента мощности и подстройкой Ð²Ñ‹Ñ Ð¾Ð´Ð½Ð¾Ð³Ð¾ напряжения для дальнейшей разработки одного из блоков подобного улучшенного устройства. Цель работы – разработать следующие принципиальные ÑÑ ÐµÐ¼Ñ‹: ÑÑ ÐµÐ¼Ð° Ð²Ñ Ð¾Ð´Ð½Ð¾Ð¹ части с защитой от ÑÐµÑ‚ÐµÐ²Ñ‹Ñ Ð¿ÐµÑ€ÐµÐ½Ð°Ð¿Ñ€ÑÐ¶ÐµÐ½Ð¸Ð¹ и Ð¿Ð¾Ð¼ÐµÑ Ð¸ ограничением пускового тока; ÑÑ ÐµÐ¼Ð° блока корректора коэффициента мощности с составным ключом. В результате исследования изучались вопросы перестройки на другие рабочие напряжения и особенности работы инвертора, а также применяемые Ñ‚ÐµÑ Ð½Ð¾Ð»Ð¾Ð³Ð¸Ð¸ снижения нагрузки сети. Исследование Ð¿Ñ€Ð¾Ð¸ÑÑ Ð¾Ð´Ð¸Ð»Ð¾ экспериментальным путём с последующим соотнесением с теоретическими данными, извлечёнными из Ð°Ð²Ñ‚Ð¾Ñ€Ð¸Ñ‚ÐµÑ‚Ð½Ñ‹Ñ Ð¸ÑÑ‚Ð¾Ñ‡Ð½Ð¸ÐºÐ¾Ð². Поскольку сейчас требования к качеству питания и возможностям Ð¿Ð¸Ñ‚Ð°ÑŽÑ‰Ð¸Ñ ÑƒÑÑ‚Ñ€Ð¾Ð¹ÑÑ‚Ð² довольно высоки, такие устройства применяются в промышленном оборудовании, ÑÐ¿ÐµÑ†Ð¸Ð°Ð»ÑŒÐ½Ñ‹Ñ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ñ‚ÐµÐ»ÑŒÑÐºÐ¸Ñ ÑƒÑÑ‚Ð°Ð½Ð¾Ð²ÐºÐ°Ñ Ð¸ Ñ‚ÐµÐ»ÐµÐºÐ¾Ð¼Ð¼ÑƒÐ½Ð¸ÐºÐ°Ñ†Ð¸Ð¾Ð½Ð½Ñ‹Ñ ÑÐµÑ‚ÑÑ . Результатом работы являются достигнутые цели, т. е. один из блоков. Данные результаты стали начальным этапом разработки всего устройства., The object of study is a powerful modern switching resonant-type secondary power supply with a power factor corrector and output voltage adjustment for further development of one of the blocks of such an improved device. The purpose of the work is to develop the following schematic diagrams: input circuit diagram with protection against mains surges and interference and inrush current limitation; block diagram of the power factor corrector with a composite key. As a result of the study, the issues of restructuring to other operating voltages and features of the inverter, as well as the technologies used to reduce the network load, were studied. The study took place experimentally with subsequent correlation with theoretical data extracted from authoritative sources. Since the requirements for power quality and the capabilities of power devices are now quite high, such devices are used in industrial equipment, special research facilities and telecommunication networks. The result of the work is the achieved goals, i. e. one of the blocks. These results became the initial stage in the development of the entire device.

Объектом исследования являются Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸ÐºÐ¸ современной элементной базы ÐºÐ»ÑŽÑ‡ÐµÐ²Ñ‹Ñ Ñ‚Ñ€Ð°Ð½Ð·Ð¸ÑÑ‚Ð¾Ñ€Ð¾Ð² из Ñ€Ð°Ð·Ð»Ð¸Ñ‡Ð½Ñ‹Ñ Ð¼Ð°Ñ‚ÐµÑ€Ð¸Ð°Ð»Ð¾Ð²: карбид кремния, нитрид галлия, кремний. Рассмотрены ÑÑ ÐµÐ¼Ñ‹ ÐºÐ»ÑŽÑ‡ÐµÐ²Ñ‹Ñ ÑƒÑÐ¸Ð»Ð¸Ñ‚ÐµÐ»ÐµÐ¹ мощности: D, E, DE, FE1 и FE2. Целью исследования является возможность повышения энергетической эффективности ключевого усилителя мощности за счёт Ð¿ÐµÑ€ÐµÑ Ð¾Ð´Ð° на элементную базу из Ð½Ð¾Ð²Ñ‹Ñ Ð¼Ð°Ñ‚ÐµÑ€Ð¸Ð°Ð»Ð¾Ð². В результате исследования была проанализирована современная элементная база для Ð½Ð¸Ð·ÐºÐ¸Ñ Ð¸ Ð²Ñ‹ÑÐ¾ÐºÐ¸Ñ Ñ‡Ð°ÑÑ‚Ð¾Ñ‚ в диапазоне от 1 кГц до 10 МГц. Для оценки достоверности результатов было проведено имитационное моделирование, при котором значения формирующего контура и нагрузки были рассчитаны для усилителя классов D и DE с учётом Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸Ðº Ð²Ñ‹Ð±Ñ€Ð°Ð½Ð½Ñ‹Ñ ÐœÐžÐŸ и IBGT транзисторов. Задание на выпускную квалификационную работу выполнено в полном объёме., The subject of the graduate qualification work is the characteristics of the modern element base of switch transistors made of different materials: silicon carbide, gallium nitride, silicon. Circuits of switching mode power amplifiers: D, E, DE, FE1 and FE2 are considered. The given work is devoted to the possibility of improving the energy efficiency of a switching mode power amplifier by switching to an element base of new materials. As a result of the study the modern element base for low and high frequencies in the range from 1 kHz to 10 MHz was analyzed. To assess the validity of the results a simulation was carried out, in which the values of the shaping circuit and load were calculated for an amplifier of classes D and DE, taking into account the characteristics of the selected MOS and IBGT transistors.

In our earlier work we proposed a method to measure the temperature of the coal pipe of Coal Mills in PF Boiler by a continuous basis, In order to achieve, accurate measurements of coal pipe temperature, using the resistive transducers like resistance temperature detector (RTD), the small resistance changes linearly with temperature, but resistance measurement by using RTD using normal Wheatstone bridge circuit would have errors for the stray capacitance presents in between bridge nodal points and the ground. Hence, by the use of a modified operational amplifier based Wheatstone bridge network, these effects can be minimized. The bridge performance has been studied experimentally with RTD. It has been observed good linearity, repeatability and variable sensitivity over the wide range of temperature.

The paper present the results of studying the process of forming the commutating voltage of a compensation converter, implemented to the three-phase combined bridge circuit, are presented. It is shown that the transition of the converter from the non-compensation mode of operation to the compensating one requires the research of three modes: 1) starting, in which the commutating voltage has an insignificant value, 2) transient mode characterized by increased values of the commutating voltage, and 3) compensating. The results of the study of the process of forming the commutating voltage in three situations of the starting mode are given because the volume of publication is limited. A conclusion is made about the optimal conditions for recharging the capacitors of the commutating link.

Nowadays, condition monitoring of gearboxes is based on analyzing vibration signal (mostly acceleration, velocity; fewer strain) measured from mechanical components or on analyzing acoustic emission and temperature data. Strain sensors are rarely used because of their high cost, mounting difficulties and their sensitivity harsh environment. They are based on strain gage technology which implements ‘Wheatstone Bridge Conditioner’ to be able to measure strain values. This bridge circuit, unfortunately, becomes non-linear out of the measurement range resulting in significant errors. To avoid those errors, a new technology of piezoelectric strain sensors, relatively new to condition monitoring, emerges: they have good precision since the accuracy is improved and provide good results especially when attempting to do measurements at extremes of the range. In this work, a piezoelectric strain sensor mounted on an industrial planetary gearbox (PG) in vertical direction is used to acquire time domain signals. This latter is introduced to focus on the importance of the new time domain representation of a gearbox dynamic behavior by a such sensor. Finally, an analysis of the RHM sensor time domain data is conducted to identify the PG characteristic frequencies.

The parasitic inductance of transmitting coil in transient electromagnetic transmitter causes some serious problems like the overlong falling edge time, overshoot and oscillation of the emission current. In order to solve these above problems, this paper proposes a design scheme of passive constant voltage clamping circuit of highly speeding shutoff based on TVS (Transient Voltage Suppressor) and switch. In this design scheme, resistance, TVS and switch are configured in parallel and then connected into the main launch bridge circuit. During the earlier stage of the shutoff of the emission current, TVS is utilized to form the high voltage clamping and thus realize the highly speeding shutoff of the emission current. At the later stage of the emission current decline, the energy of the load inductance is set free by the resistance to prevent the overshoot and oscillation of the emission current. In this paper, the operating procedure and principle of the circuit, the influence of the parameters of core devices on the circuit performance, and the effectiveness of this design scheme is verified by simulation and experiment. The results of simulation and experiment show that this circuit is effective to reduce the shutoff time of the emission current, restrain the overshoot and oscillation meanwhile, and hence improve the wave quality of the emission current.

Gallium-nitride-field-effect transistors (GaN-FETs) are expected as a key component to the power density improvement of switching power converter for electric vehicles (EVs) because of their low on-resistance and fast switching capability. It is well known that the switching loss is influenced by the drain inductance, which is the parasitic inductance of the power loop, and can be minimized in principle by an appropriate design of the drain inductance. However, in switching power converters using Si-based power devices such as the Si-MOSFET and the Si-IGBT, it is usually difficult to design the drain inductance so that the switching loss minimizes because an appropriate drain inductance becomes too large, thus resulting in large surge voltages of the switching device. On the other hand, this may not be the case when using the GaN-FETs because the inductance that can minimize the switching loss may become small due to the high-di/dt switching. Therefore, the purpose of this study is to show the feasibility of the parasitic drain inductance design that the switching loss of the GaN-FET in the bridge circuit can be minimized while keeping the surge voltage of the GaN-FET within acceptable limits. The appropriateness of this insight is verified by simulation.

The material removal of hard material is difficult. The conventional tools are failure to remove the metal from the hard surface. Electrical Discharge Machining (EDM) is the best non-traditional process utilized for hard material machining purposes. It is difficult to achieve the high material subtraction rate in the EDM method. In present work includes that the Material Subtraction Rate (MSR) is improved or increased through alteration of electrical circuits. The capacitor, resistance, and bridge circuit are included in a controlled pulse circuit. The sample of Eglin steel was considered as workpiece material for the EDM process. The peak current, pulsation time on and off is chosen for the process control parameter. The material subtraction rate and its efficiency are determined and compare with and without modification of the circuit.

The analysis has been carried out on the disadvantages of regulating power flows in electric networks and systems using intermediate DC links, which are based on traditional current sourced converters with natural switching thyristors. It has been noted that due to modern advances in the field of power electronics, power static current sourced converters can operate in the modes with leading current, i.e. not consuming, but generating reactive shear power. The possibilities of phase regulation of the converter by the thyristors have been shown, in which the power converter can operate in the modes with the generation of reactive shear power into an alternating current network. The mode of the artificial switching of the valves, in which the converters operate with the leading current, is achieved by opening the thyristors without time delay, and by closing them before the natural moment of their closing. We have carried out the analysis of electromagnetic processes in a static power current sourced converter with fully controlled thyristors according to a three-phase bridge circuit in the rectifier and dependent inverter modes, which can be used to build an intermediate DC link as components of flexible AC transmission systems with the capabilities of four-quadrant control of inter-system power exchange. We have created the conditions under which a three-phase bridge rectifier and a grid-controlled inverter with closing thyristors as a part of a direct current insert will not consume reactive power from the AC network, which is not provided for by the classical theory of their operation. The analytical expressions have been provided that can be used to obtain the basic energy characteristics of a DC insert made on the basis of current sourced converters, which not only does not need an additional resource of reactive power for its functioning, but can itself generate reactive power in an alternating current network. We have obtained analytical expressions for electromagnetic parameters, which can be the basis for further research and design of a prototype DC insert with new properties.

At the moment, almost any electronic product incorporates measuring sensors for converting physical quantities. These devices produce a signal of measurement information in a form suitable for transmission and further conversion. As a rule, the output signal from the measurement sensors undergoes first preprocessing such as amplification, filtering, modulation, etc. After preprocessing the prepared signal, various architectures of analog‑to‑digital converters (ADC) are used. The choice of ADC depends on the parameters of the conversion signal and the dynamic characteristics of the sensors used. This paper considers converting a square‑amplitude modulated signal from a current sensor to a pulse width using a phase‑locked loop (PLL). The architecture of the ADC based on the PLL circuit allows obtaining a linear dependence of the output signal duty cycle on the value of the measured input current. The layout of the device is implemented on a printed circuit board, the main components of which are: current sensor, which is a bridge circuit of magnetoresistive conductors; phase‑sensitive rectifier and microcircuit of a two‑channel PLL circuit made inTechnological Center.

A simplified economical liquid level measurement technique has been developed for measuring the level of any type of liquid. A fabricated inter digital capacitor (IDC) is used as a primary sensor that transduces the liquid head into corresponding variation in the capacitance. This variation in the capacitance changes to an electric signal, using a modified De Sauty bridge circuit. In this paper, different types of water, such as mineral water, tap water, distilled water, and river water, are used as process liquid. This sensor can be relied for the detection of the water level, independent of the water type. The theoretical analysis of the work has been illustrated in this paper to describe the working of the proposed transmitter. The proposed sensor has been developed and laboratory tested. It is found that this transmitter exhibited the linear characteristics and followed the theoretical equations. It has 12.8-mV resolutions for measurement of water level from 0 to 15 cm range.

An independent metering valve control hydraulic system (IMVCHS) adopts two independent valves to separately control the meter-in and meter-out orifices. This structure increases the degree of freedom of the control, and improves its flexibility and energy-saving performance. In this study, an IMVCHS was established that applies a control system developed to research the pressure and flow compound control performance. A two-level fuzzy control algorithm based on the calculated flow rate feedback from the spool displacement was proposed to realize high precision flow control, and the two-level fuzzy control algorithm based on the pressure feedback was also adopted to enhance the pressure performance under a dynamic load. A simulation model was established, and its key parameters identified experimentally using the simulated load of a hydraulic bridge circuit. The experimental results show that the proposed flow controller has higher control accuracy with an error of less than 2%, and the flow adjustment time for 40 L/min step control is 320 ms. The pressure controller with a two-level closed-loop fuzzy algorithm can significantly improve these pressure dynamic and static performances, and achieve a step response time of less than 180 ms. Combining the pressure and flow controllers, the pressure and flow compound control of the IMVCHS is realized, and the capacity for coping with load fluctuations is also identified, with compound adjustment times of generally less than 200 ms, and occasionally less than 100 ms. This control system therefore achieves a good performance for pressure and flow compound control, and is able to widen the application of independent metering control technology.

This paper presents a quasi-Z-source based isolated bidirectional DC-DC converter (qZIBDC) for renewable energy applications. The converter utilizes a dual active bridge circuit with a quasi-Z-source network on both sides, so the converter works as buck/boost converter from either side. It has a wider input/output voltage operating range, soft-switching capabilities without additional devices, and higher boost capability than a traditional dual active bridge circuit. Apart from that, shoot-through states are incorporated in its operating cycle to boost the input voltage resulting in high reliability of the proposed converter. Due to the symmetrical structure of the circuit, there is no defined high voltage or low voltage side as in traditional isolated bidirectional DC-DC converter. The operating principle and control strategy of the proposed converter are presented. Simulation and experimental results are provided to verify the effectiveness of the proposed converter topology and its control strategy.

The performed analysis of known capillary flowmeters for low gas flows reveals the prospect of constructing the primary measuring transducers of flowmeters with a linear output signal. Owing to the stability of dimensions of the pass-through channels in glass capillaries channels such flowmeters can demonstrate high metrological characteristics. In this regard, we have investigated the capillary as a sensing element in the primary transducers of flowmeters for low gas flows. Different circuits of capillary primary transducers for the measuring instruments of low gas flow rate have been examined. Our study makes it possible to select the optimal circuit of a primary measuring transducer based on the measurement range, as well as the number and size of the pass-through channels in capillaries. For example, the flow meter based on a package of capillaries demonstrates a wider measurement range compared to other schemes. We have derived analytical dependences that enable the design of single- capillary, package, and bridge transducers. Comparative characteristics of the specified primary measuring transducers are provided. We have constructed algorithms for calculating dimensions of channels in the capillaries of transducers with a linear output signal. The influence of temperature and barometric pressure on a deviation in the static characteristic of the transducer has been estimated. It was established that the bridge circuit, unlike others, ensures partial compensation for the influence of external factors. We have designed and investigated a capillary oxygen flowmeter, constructed using the bridge measurement circuit with a linear conversion function, intended for an automated system of the manufacturing process of workpieces for fiber light guides. The upper limit of measurement by the flowmeter is at the level of 54 l/h, its basic relative error is 0.8 %

It has been demonstrated before that human skin can be modeled as a memristor (memory resistor). Here we realize a memristor bridge by applying two voltages of opposite signs at two different skin sites. By this setup it is possible to use human skin as a frequency doubler and half-wave rectifier which is an application of the non-linear electrical properties of human skin. The corresponding electrical measurements are non-linear since these are affected by the applied stimulus itself.

Ambient energy harvesting using piezoelectric material needs a rectifier for ac to dc conversion. Piezoelectric energy harvester (PZEH) generates very low level output and therefore, the rectification efficiency of the rectifier needs to be high. The voltage drop across the rectifier components which commonly use diode connected MOSFETs, is a major source of power loss. To reduce the voltage drop, in this paper we propose use of active diode as the rectifier component of the bridge rectifier circuit used for PZEH. The active diode minimizes the forward voltage drop to 21 mV. The proposed bridge rectifier circuit can extract maximum 91% of the power provided by the piezoelectric energy harvesting device. The use of active diode in the bridge circuit improves the power conversion efficiency by 49% to that of the diode connected MOS based BR.

The performance of silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) is better than silicon devices in terms of switching speed, switching loss and temperature tolerance. Due to the higher di/dt and dv/dt during the switching process and the combined effect of various parasitic parameters, serious bridge-leg crosstalk will be generated in the SiC MOSFET bridge circuit. This paper firstly analyzes the mechanism of crosstalk, and based on the parameters extracted from the device data sheet and experiments, the maximum values of the bridge-leg crosstalk voltage under different operation conditions are calculated. Secondly, a passive Miller clamp circuit on crosstalk suppression in SiC MOSFET bridge-leg configuration is proposed in this paper. When the crosstalk occurs, the proposed driver circuit shunt the Miller current to the ground, and the gate-source parasitic capacitance of SiC MOSFET is bypassed. The advantages of the proposed crosstalk suppression circuit are that the switching speed is not sacrificed, the circuit topology is relatively simple, and it is easy to be integrated into the driver circuit of SiC MOSFETs. Finally, experimental results prove the effectiveness of the proposed crosstalk suppression circuit.

12. 76MHz discrete crystal filter adopts AT cut quartz resonator and differential bridge circuit design. The bandwith of 3dB passband is up to 60kHz at the operting temperature range of -20°c ∼ 60°C. The filter features advanced circuit design, reasonable component application, voltage standing wave ratio less than 2.0. The components are mounted and sealed with tin, and the whole structure is shielded and isolated. The successful development of this product provides a frequency selection device for electronic systems such as tactical mission and radar systems which require extremely high signal reception and transmission under severe conditions. The electrical performance test data and result analysis of the 12. 76MHz discrete crystal filter are given.

In this paper, development of the mobile platform for the spherical robot is considered. A three-omni-wheeled mobile robot was selected as a driving mechanism. The actuators of the mobile robot are DC motors with a transistor bridge circuit as a driver. The results of testing motors for determining linearity of the system are presented as well as a closed-loop speed control system for each motor is implemented. The paper presents a description of the architecture of hardware level and related software.

Данная работа посвящена процессу разработки устройства питания для автомобилей на микроконтроллере STM32. В Ñ Ð¾Ð´Ðµ работы были исследованы особенности использования микроконтроллеров STM32 с таймером высокого разрешения. Были исследованы и выбраны основные компоненты для создания устройства: микроконтроллер STM32F334, драйвер FAN73901MX, драйвер UCC27519, преобразователь интерфейса FT232RL, изолятор интерфейса ISO7221BD. Результатом данной работы является разработка принципиальной ÑÑ ÐµÐ¼Ñ‹ устройства и платы прототипа для дальнейшей работы. Устройство предназначено для питания Ñ‚Ñ€ÐµÐ±Ð¾Ð²Ð°Ñ‚ÐµÐ»ÑŒÐ½Ñ‹Ñ Ðº стабильности напряжения устройств, использует бортовую сеть 12В, увеличивает срок службы аккумуляторов., This work is devoted to the process of developing a power supply device for cars on the STM32 microcontroller. In the course of the work, the features of using STM32 microcontrollers with a high-resolution timer were investigated. The main components for creating the device were studied and selected: the STM32F334 microcontroller, the FAN73901MX driver, the UCC27519 driver, the FT232RL interface converter, and the ISO7221BD interface isolator. The result of this work is the development of a schematic diagram of the device and the prototype board for further work. The device is designed to power devices that are demanding for voltage stability, uses an on-board 12V network, and increases the battery life.

Данная работа посвящена исследованию Ñ€Ð°Ð·Ð»Ð¸Ñ‡Ð½Ñ‹Ñ ÑÐ»ÐµÐºÑ‚Ñ€Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Ñ†ÐµÐ¿ÐµÐ¹, Ñ‚Ð°ÐºÐ¸Ñ ÐºÐ°Ðº делитель напряжения, делитель тока, мостовая ÑÑ ÐµÐ¼Ð°. Задачи, которые решались в Ñ Ð¾Ð´Ðµ исследования: 1. Анализ Ñ€ÐµÐ·Ð¸ÑÑ‚Ð¸Ð²Ð½Ñ‹Ñ Ð¿Ñ€ÐµÐ¾Ð±Ñ€Ð°Ð·Ð¾Ð²Ð°Ñ‚ÐµÐ»ÐµÐ¹ и Ñ€Ð°Ð·Ð»Ð¸Ñ‡Ð½Ñ‹Ñ ÑÑ ÐµÐ¼ включения. 2. Моделирование работы реостатного преобразователя в ПО Multisim с различными ÑÑ ÐµÐ¼Ð°Ð¼Ð¸ включения. 3. Разработка структурной ÑÑ ÐµÐ¼Ñ‹ и выбор компонентов информационно измерительной системы. 4. Разработка программного обеспечения для информационно измерительной системы. 5. Экспериментальное исследование информационно измерительной системы для реостатного преобразователя. Работа была поделена на две части. Первая часть работы проведена на базе ПО Multisim, где собирались теоретические сведения о ÑÐ»ÐµÐºÑ‚Ñ€Ð¸Ñ‡ÐµÑÐºÐ¸Ñ ÑÑ ÐµÐ¼Ð°Ñ . Вторая часть работы проведена в лаборатории. Была собрана информационно-измерительная система и разработано ПО, которое предназначено для обучения студентов, имеет в себе минимальный набор функций, отвечающий требованиям Ñ‚ÐµÑ Ð½Ð¸Ñ‡ÐµÑÐºÐ¾Ð³Ð¾ задания научного руководителя., This work is devoted to the study of various electrical circuits, such as voltage divider, current divider, bridge circuit. Tasks that were solved during the study: 1. Analysis of resistive converters and various switching circuits. 2. Simulation of the operation of a rheostat converter in Multisim software with different switching schemes. 3. Development of the block diagram and selection of components of the information and measurement system. 4. Development of software for the information and measurement system. 5. Experimental study of the information measuring system for a rheostat converter. The work was divided into two parts. The first part of the work was carried out based on Multisim software where theoretical information about electrical circuits was collected. The second part of the work was carried out in the laboratory. For teaching students were assembled an information and measurement system and developed software which has a minimum set of functions that meets the requirements of the technical task of the adviser.

The performance of power amplifiers for active magnetic bearings (AMB) is closely related with their main power circuits and control algorithms used. A three-phase bridge circuit is selected as a main power circuit of an AMB power amplifier. Through a space vector pulse width modulation (SVPWM) algorithm, two electromagnet coils can be driven simultaneously by the three-phase bridge circuit. However, when the coil current command signal for the amplifier fluctuates sharply, a specially designed duty ratio restriction strategy is required. In this paper, two duty ratio restriction strategies, which are Period Bisection Strategy and Proportional Reduction Strategy, are proposed for the situation that the coil current command signal exceeds the tracking range in one PWM period. Experiments show that when the change rate of the coil current command signal is large, the Proportional Reduction Strategy makes the distortion of the current in each coil (i.e. the difference between the required current change and the actual current change in one PWM period) proportional to the change rate of the command signal. And the Period Bisection Strategy significantly reduces or even eliminates the distortion of the current in the coil with a slower change rate of the command signal, but at the cost of increasing the distortion of the current in the coil with a faster change rate of the command signal.

This paper proposes a circuit configuration of LLC converter that achieves both wide output voltage gain and high efficiency operation. The primary side of the proposed circuit is composed of six switches to form a bridge circuit and has two transformers with different parameters. Thus, the proposed circuit has six operation modes, those modes realize a wide output voltage gain range. In addition, two different resonant tanks allow a large magnetizing inductor and a small resonant inductor, so that it is possible to design reducing for the circulating current. The validity of the proposed system is verified by built a 1.0 kW prototype with an input voltage of 360V. The proposed circuit shows that an output voltage gain of over 2 can be obtained. In addition, the proposed circuit also exhibits high efficiency characteristics with a maximum efficiency of 96.6%.

In the position control system using the piezoelectric actuators, a feedback control system is indispensable to improve the positioning/tracking accuracy by compensating for nonlinearities in the actuator. However, a high-resolution displacement sensor poses the problems of cost and installation space. In this paper, a feedback control system without the displacement sensor is designed by combining displacement estimation based on capacitance detection with vibration control by a bridge circuit. The superimposed signal with a high frequency component is injected to the actuator. Based on the voltage and the current generated by the injection signal, the capacitance is computed by performing the discrete Fourier transform. The displacement is estimated using linear relationship between the capacitance and the displacement. In addition, a minor-loop is designed to suppress the resonant vibration using a detected signal through the bridge circuit. The designed control system is evaluated by conducting numerical simulations and experiments using a piezoelectric cantilevered actuator.

In this work, the substrate effects in GaN-on-Si power ICs are systematically investigated, and a novel GaN power IC platform on engineered bulk silicon substrate is proposed to effectively address these negative effects. For the GaN-on-Si power ICs, the integrated high-side (HS-) transistor and low-side (LS-) transistor have to share a common conductive silicon substrate. The termination of the substrate cannot be optimized for both the HS- and LS-transistors, so one of the transistors has to suffer a significant degradation in the dynamic R ON . The proposed engineered bulk silicon substrate provides a common mechanical substrate for both the HS- and LS-transistors. For each of the transistors, the engineered substrate also provides a localized electrical substrate region. The electrical substrate region is isolated from the mechanical substrate by a reversely biased PN junction. TCAD simulations show that the substrate effects are completely eliminated in the novel GaN power IC on engineered bulk silicon substrate.

Electric drives are used in industrial installations for the mechanical movement of various kinds of goods, in pumps, as well as in transport installations to bring them into motion. An electric drive includes an actuator (motor) and a frequency converter, as well as a control system that provides soft start, reverse and speed control. The most complex part of the electric drive is the frequency converter, so the probability of the occurrence of a failure of the entire system depends on its reliability. Currently, inverters are used, based on a three-phase bridge with IGBT transistors; its circuitry has made it possible to minimize the number of elements, which was especially relevant earlier when using thyristors with forced switching. Currently, they are replaced by fully controllable insulated gate transistors, which reduced the number of elements in power circuits, and also simplified control algorithms - thereby increasing the reliability of electric drives in general. However, a further improvement in the characteristics of the electric drive is still associated with the improvement of the frequency converter. In this paper it is proposed to replace the three-phase bridge circuit in the inverter with three single-phase channels according to the full-bridge circuit in each of them; the phase outputs are connected in series according to the star circuit. The main difference between this option is the presence of a common neutral at the inverter output, the tap from which is not present in three-phase bridge circuits. In this case, in the event of an accident in one of the phases, it is possible to connect the corresponding phase of the motor to the inverter neutral, which, when correcting the shift angle between the remaining two phases of the inverter by an angle of 60°, ensures the formation of a symmetric three-phase voltage system on the motor stator. This made it possible to abandon the reservation of a three-phase bridge circuit, requiring two sets of 3 phases each on the motor stator, provided that their neutrals were isolated, and such systems are essentially six-phase. The electric drive described in this article has redundancy that is not inferior to the currently used systems and has several advantages - these include maintaining 2/3 of the rated power during emergency phase shutdown, and the operation of the electric motor in symmetric mode; also the advantages include the possibility of forming a three-level voltage without capacitors in the DC link. In general, the proposed solution has a low cost while maintaining reliability, as well as the quality of voltage and currents in nominal mode.

The possibility of sensitivity increasing of magnetic field sensors by combining different types of sensitive elements in one sensor circuit is experimentally investigated. For this purpose, four new sensor constructions are proposed: based on bridge circuit, based on magnetotransistor in combination with magnetodiode or with second magnetotransistor and with frequency output. More thermostable and radiation-resistant sensor with 10 times greater sensitivity than in conventional two-diode bridge sensor is obtained with four polar magnetodiodes in bridge circuit, instead of two non-polar ones. Sensor constructions with two-collector magnetotransistors in combination with two polar magnetodiodes or one additional magnetotransistor are described. The sensitivity of such devices is 6 and 4 times higher compared to single-transistor sensors, while their temperature stability and radiation resistance increase. Relaxation generator circuit based on unijunction transistor is proposed as magnetic field sensor with frequency output. Inclusion of additional magnetodiode in generator circuit increases sensitivity by 2.3 times in comparison with single-transistor sensor and improves environmental stability. The described devices can be used as effective magnetic field sensors in wireless communication networks.

In this paper, a hybrid flexible current limiter is proposed to solve the problem of short circuit between positive pole and negative pole in DC distribution network. The current limiter consists of superconducting resistance and self-excited current limiter. In normal operating condition, the current limiter and self-excited current limiter are bypassed by the bridge circuit, so that the current limiter has no impact on DC distribution network. When a short-circuit fault happens between positive pole and negative pole, the bypass function of bridge circuit is failed. With the help of the current limiter, the fault current and the voltage drop of interelectrode capacitance can be quickly suppressed by superconducting resistance. For fully remove the negative effect of fault on interelectrode capacitance, through offering a controlled linearly rising current to an inductor in the set time, the self-excited current limiter can provide a positive clamping voltage, so as to keep the interelectrode capacitance’s voltage in its rated value. Finally, based on the theoretical derivation and simulation results, it can be proved that the major problems troubling a DC distribution network’s fault ride-through technologies can be resolved by the proposed method.

The accurate detection and demodulation of mechanical oscillations is crucial for the performance of miniaturized resonant sensors and scanners. Demodulation by external instruments such as lock-in amplifiers or spectrum analyzers is not always desired due to their large size, complexity and cost. The demodulation technique proposed in this paper enables a simplified measurement of the oscillation amplitude of a mechanical oscillator with integrated deflection sensors, such as piezoresistive or capacitive elements. Configuring the sensors in an AC bridge circuit operated at the oscillator resonance frequency leads to a direct demodulation at the output of the bridge circuit. The presented method is experimentally verified on an AFM cantilever with integrated piezoresistive elements.

The bridge-type pneumatic system is to control the intake and exhaust time sequences of an air cylinder with four switch valves by applying the expansion energy of air for work to save energy. However, the system is often sensitive, and thus, the control accuracy can be rather poor. Therefore, the applicability of this system remains to be further tested. A nonlinear dynamic optimization model with the air consumption as the objective function was established. A simultaneous collocation method was used to obtain the on–off time sequences. The concept of optimization performance rating to evaluate the system's energy-saving performance and the stability was introduced. Experiments were done to validate the applicability of the circuit. The results showed that the bridge circuit was applicable to a certain range of working conditions under each given action system and that instability, such as rebound or impact, could occur outside this range., Mechanical Engineering; Dynamical System; Mathematical Optimization; Energy Conservation; Fluid Mechanics; Compressed air; bridge-type pneumatic system; energy-saving; dynamic optimization; applicability range

Research on a contact induction displacement sensor over short distances is presented. A ferrite core with a winding and a movable armature is used as a sensor. There is an air gap between the core and the armature.To solve the problem of improving the accuracy of measurement, the sensor is included in the bridge measuring circuit, which is powered by high-frequency alternating current. To increase the sensitivity of the indicated sensor to movement, a differential circuit for its inclusion is proposed. Also, in order to increase sensitivity, the resonant mode of operation of the bridge measurement circuit is used. To maintain a constant voltage of the power generator, a phase-locked loop is used.As a result of the study of the induction displacement sensor, practical results were obtained with a maximum displacement of ±0.6 mm. The sensor has not been studied for large displacements, since with an increase in the indicated displacement, the nonlinearity of the displacement-current transformation appears.The maximum sensitivity of the differential sensor in the indicated range of movement 2.44 μA/μm is obtained without the use of a phase-locked loop.The use of a phase-locked-loop frequency adjustment system increased the sensitivity to 3.48 μA/μm.During the study, the dependence of the sensitivity of the sensor on the frequency of the power generator was determined, which allows to determine the optimal power frequency of the measuring bridge circuit.Studies have shown that the use of contact inductive meters have the prospect of application and reserves for improvement. And the use of differential inclusion of the sensor and the resonant mode of operation gives a significant increase in the sensitivity of the primary transducer at small displacements.An inexpensive sensor has been developed that will be useful for many applications where it is necessary to measure displacements and linear dimensions by contact methods, Представлены исследования контактного индукционного датчика перемещения на небольшие расстояния. В качестве датчика применен ферритовый сердечник с обмоткой и подвижным якорем. Между сердечником и якорем существует воздушный зазор.Для решения задачи повышения точности измерения датчик включен в мостовую измерительную схему, которая питается переменным током высокой частоты. Для повышения чувствительности указанного датчика к перемещению предложена дифференциальная схемы его включения. Также, с целью повышения чувствительности, использованный резонансный режим работы мостовой схемы измерения. Для поддержания постоянного напряжения генератора питания применена схема фазовй автоматической подстройки частоты.В результате исследования индукционного датчика перемещения получены практические результаты при максимальной величине перемещения ±0,6 мм. На большие перемещения датчик не исследовался, так как при увеличении указанного перемещения появляется нелинейность преобразования перемещения-ток.Получена максимальная чувствительность дифференциального датчика в указанном диапазоне перемещения в 2,44 мкА/мкм без применения системы фазового автоматической подстройки частоты.Применение системы фазового автоматической подстройки частоты позволила повысить чувствительность до 3,48 мкА/мкм.В ходе исследования была определена зависимость чувствительности датчика от частоты генератора питания, что позволило определить оптимальную частоту питания измерительной мостовой схемы.Проведенные исследования показали, что использование контактных индуктивных измерителей имеют перспективу применения и резервы по совершенствованию. А использование дифференциального включения датчика и резонансный режим работы дает существенное повышение чувствительности первичного преобразователя на малых перемещениях.Разработан недорогой датчик, который будет полезен для многих применений, где необходимо измерять перемещения и линейные размеры контактными методами, Представлені дослідження контактного індукційного датчика переміщення на малі відстані. В якості датчика застосований феритовий сердечник з обмоткою та рухомим якорем. Між сердечником та якорем існує повітряний зазор.Для вирішення завдання підвищення точності вимірювання датчик ввімкнутий в мостову вимірювальну схему, яка живиться змінним струмом високої частоти. Для підвищення чутливості вказаного датчика до переміщення запропонована диференційна схема його включення. Також, з метою підвищення чутливості, використаний резонансний режим роботи мостової схеми вимірювання. Для підтримання сталої напруги генератора живлення застосована схема фазового автоматичного підстроювання частоти.В результаті дослідження індукційного датчика переміщення отримані практичні результати при максимальній величині переміщення в ±0,6 мм. На більші переміщення датчик не досліджувався, так як при збільшенні вказаного переміщення зꞌявляється нелінійність перетворення переміщення-струм.Отримана максимальна чутливість диференційного датчика в вказаному діапазоні переміщення в 2,44 мкА/мкм без застосування системи фазового автоматичного підстроювання частоти.Застосування системи фазового автоматичного підстроювання частоти дозволила підвищити чутливість до 3,48 мкА/мкм.В ході дослідження була визначена залежність чутливості датчика від частоти генератора живлення, що дозволило визначити оптимальну частоту живлення вимірювальної мостової схеми.Проведені дослідження показали, що використання контактних індуктивних вимірювачів мають перспективу застосування і резерви по вдосконаленню. А використання диференційного включення датчика та резонансний режим роботи дає суттєве підвищення чутливості первинного перетворювача на малих переміщеннях.Розроблений недорогий датчик буде корисний для багатьох застосувань, де необхідно вимірювати переміщення і лінійні розміри контактними методами

Locomotive electric drives with DC commutator motors and smooth voltage regulation systems usually apply reversible power rectifiers based on partially or fully controllable semiconductor devices. The paper presents theoretical analysis of working processes of different single-phase bridge circuits. Reviewed circuits include: initial (or type) half-period thyristor-based circuit; asymmetrical circuit with two thyristor arms and two diode arms; half-period thyristor circuit with a shunting diode arm in parallel with the rectified sub-circuit; contemporary transistor-based bridge circuit. Detailed time diagrams of working processes of the circuits demonstrate that application of different schematic solutions and new control algorithms allows for a significant decrease or complete elimination of phase shift between current and voltage curves on AC side of the electric drive (i.e. power transformer primary winding), making it possible for power coefficient of the rectifier to increase up to a maximum of 1.

This paper presents a way for endeavoring cable fault distance location by using an optimizing technique. The proposed scheme aims to model and test the two popular cable fault location methods i.e. Murray and Varley loop. The modelling of the bridge circuits of Murray and Varley loop are implemented in MATLAB environment. Using optimization algorithms, both implemented platforms of Murray and Varley loop test, locate the earth faults and short circuit fault in underground cables accurately. The proposed platforms are useful to study the concept of optimization techniques in combination with the conventional cable fault location methods. Here Box’s evolutionary multivariable optimization technique is used for calculating two resistance variable function of the Murray Loop and Bisection Method which converges to a single optimum root is used for calculating single resistance variable of the Varley Loop for balancing the bridge circuit. The simulation results confirm that the proposed scheme assess the fault location with minimum error and is unaffected to variation in fault distance, fault resistance, and fault inception angle.

The article presents the development of a continuous attenuator with a minimum number of sequential stages, with digital control for microwave operation. The use of continuous attenuators reduces the number of sequential cascades. This allows for a broadband attenuator in the frequency range from 1 GHz to 6 GHz, with a minimum loss of not more than 1.9 dB and a maximum isolation of not less than 31 dB. The use of a bridge circuit gives a significant gain in providing isolation, as it compensates for the influence of parasitic capacitances on any technological processes in a wide frequency range. For digital control, you can build a discrete attenuator with a given resolution, by using a high-bit DAC. The article presents a topological scheme and assesses the influence of parasitic components on the characteristics of the microwave attenuator.

The paper presents principle scheme of wireless torque sensor on rotary shafts, for example truck cardan shaft, to measure dynamic torque of transmission in range of 0…10 kNm, also describes designing and manufacturing method. Recommendations on selecting, arranging and gluing strain-gauge in manufacturing, and on calculating signal amplifier are given. A simulation of sensor modules was carried out in software package Proteus to confirm working efficiency of assembled schema of electronic components. Experiment was conducted to confirm working efficiency and to collect performance specifications of the sensor.

This paper introduces a new Multilevel STATCOM for Medium Voltage (MV) applications which has low component count compared to other multilevel configurations. The converter consists of a three phase bridge circuit, bidiectional switches and wave-shapers. The wave-shaper consists of series connection of half-bridge submodules, and provides necessary wave shape, so that the converter generated voltage approaches near to sinusoid. As a result, passive filter is not required which reduces the foot-print and minimizes magnetic interference. A Part of the circuit is operated at fundamental frequency and hence reduces the losses in the converter and increases efficiency. The converter is configured in such a way that only two arms of the wave-shaper is sufficient to make three phase circuit which minimizes component count to a large extent. As an example, only 52 switches are required for the proposed converter whereas the switch count is 120 for Cascaded H-bridge Converter (CHB) considering similar voltage levels (say 21). The control methods are developed for the proposed converter including balanced and unbalanced operations. The performance of the converter is checked through PSCAD simulation and the results show satisfactory performance.

When the characteristics of the input vibrations change with time, also the optimal operating point of a Resonant Piezoelectric Vibration Energy Harvester (RPVEH) changes with time. Such an optimal operating point is characterized by the highest value of the extracted electrical power and is called Maximum Power Point (MPP). This paper is focused on MPP Tracking (MPPT) techniques for RPVEHs. In the most widespread RPVEH AC/DC architecture, which is based on the use of a diode bridge rectifier cascaded by a DC/DC converter, MPPT requires that the voltage V0 at the output of the bridge rectifier is properly regulated. The first issue that is addressed in this paper is the derivation of a simple closed form expression of the power extracted by a RPVEH as a function of the voltage V0 as well as of the optimal value of V0. Moreover, a complete set of general guidelines leading to the proper choice of the values of the parameters of the two most widely used MPPT techniques for RPVEHs applications (the Perturb & Observe technique and the Open Circuit Voltage technique) are provided and experimentally validated. It is experimentally shown that, if the above MPPT techniques are not properly and carefully customized to the particular RPVEH application of interest, they may lead to very poor performances of the system. © 2018 Elsevier B.V.