Capacitor Circuit Research Articles

Appropriate Selection of Frequency Range and Damping Ratio to Reduce the Resonance Effect, Lower Power Consumption, and Improve the Accuracy of the Capacitive Accelerometer

Introduction: In this work, we explored the capacitive accelerometer in depth by highlighting its advantages over other accelerometers. However, a major challenge associated with using capacitive accelerometers lies in choosing the appropriate frequency range. Method: Incorrect selection of the frequency range can cause several problems. It can decrease the accuracy of the accelerometer, increase the measurement error, and increase power consumption. To overcome these challenges, we undertook detailed modeling of the physical behaviour of the capacitive accelerometer. This modeling takes into account the mechanical and electrical properties of the sensor, including its mass, its rigidity, and the characteristics of its capacitive circuit. By simulating the developed model, we analyzed how the accelerometer reacts to different frequencies of vibratory movements. Result: This analysis led to the extraction of an important mathematical relationship that links the natural frequency of the accelerometer to the frequency of the vibratory movements to which it is subjected. Using this mathematical relationship, we determined the optimal frequency range for capacitive accelerometer operation. This precise determination of the frequency range makes it possible to significantly reduce the measurement error by avoiding resonance regimes and ensuring that the sensor operates in its maximum precision zone. Conclusion: Additionally, this approach helps improve overall measurement accuracy and minimize sensor power consumption by avoiding inefficient operating conditions.

Spiking Neural Network Pressure Sensor.

Von Neumann architecture requires information to be encoded as numerical values. For that reason, artificial neural networks running on computers require the data coming from sensors to be discretized. Other network architectures that more closely mimic biological neural networks (e.g., spiking neural networks) can be simulated on von Neumann architecture, but more important, they can also be executed on dedicated electrical circuits having orders of magnitude less power consumption. Unfortunately, input signal conditioning and encoding are usually not supported by such circuits, so a separate module consisting of an analog-to-digital converter, encoder, and transmitter is required. The aim of this article is to propose a sensor architecture, the output signal of which can be directly connected to the input of a spiking neural network. We demonstrate that the output signal is a valid spike source for the Izhikevich model neurons, ensuring the proper operation of a number of neurocomputational features. The advantages are clear: much lower power consumption, smaller area, and a less complex electronic circuit. The main disadvantage is that sensor characteristics somehow limit the parameters of applicable spiking neurons. The proposed architecture is illustrated by a case study involving a capacitive pressure sensor circuit, which is compatible with most of the neurocomputational properties of the Izhikevich neuron model. The sensor itself is characterized by very low power consumption: it draws only 3.49 μA at 3.3 V.

Dynamic control of elastic wave transmission by a digital metalayer

Piezoelectric materials with shunt circuits have aroused much research interest due to flexible parameter adjustment. However, shunted piezoelectric elements are difficult to respond to the dynamic changes in the whole system due to the absence of autonomous control ability, which constrains their practical applications. Here, we propose a digital metalayer to control the wave energy transmission across different materials in real time. This digital metalayer comprises a stack of multiple piezoelectric lead zirconate titanate (PZT) disks connected with shunt capacitance circuits (SCCs). The external digital control system adjusts the effective acoustic impedance of the PZT disks through digital potentiometers and microprogrammed control unit, thereby enabling digital manipulation of wave transmission. Utilization of optimized SCCs further enhances adjustment accuracy, supporting both negative and positive capacitance values. The experiments demonstrate that this digital metalayer exhibits remarkable performance in controlling wave transmission. Moreover, the distinct variations in transmitted amplitudes, precisely controlled by the digital metalayer, are harnessed as binary signals for information transmission. An image of letters is encoded into a series of amplitude-modulated waves by the digital metalayer and clearly transmitted. The proposed digital metalayer shows great promise for applications in intelligent impedance matching and the real-time modulation systems.

Investigating the Effects of Induction Heating on a Submerged Hollow Cylindrical Element

ABSTRACTThis article proposes an induction heating element that addresses heat transfer and thermal homogenization while being fully submerged in a liquid, specifically focusing on heating of water as a case study. The design calculations, fabrication, and realization of a resonant induction heating system that heats the proposed heating element are presented. The geometric shape of proposed heating element is a hollow cylinder that maintains structural strength while delivering required thermal energy because of an external time‐varying magnetic field. Detailed mathematical modeling of the proposed heating element's equivalent electric circuit has been presented while considering physical parameters including diameter, thickness, height, material properties, magnetic field frequency, and skin effect. A laboratory scale prototype of the induction heating system including the proposed heating element has been built, and experiments have been demonstrated. The experimental results of the working induction heating resonant inverter and RLC resonant circuit inductance and capacitance with induction load are presented. Additionally, the results of thermographic images and temperature–time profile of the water sample, which was heated using the proposed heating element, are provided to demonstrate the heating element's reliability and practicality. This research contributes to the field of induction heating technology by investigating a heating element that is submerged in a liquid medium, resulting in a uniform temperature distribution throughout the liquid. The conventional method of heating water in a stainless steel cup‐shaped container is an inefficient heat transfer process. In stainless steel cup‐shaped containers, a portion of the energy input used to boil the water is lost to the environment through the surface area of the container that is not in direct contact with the water. This heat loss occurs due to the container's design, which exposes a large surface area to the surrounding environment, allowing thermal energy to dissipate through conduction, convection, and radiation.

Real-time non-destructive monitoring of supported liquid membranes using electrochemical impedance spectroscopy

The degradation of supported liquid membranes (SLMs) due to membrane liquid leaching has been a hurdle for their implementation in resource recovery from waste streams. We present a novel approach utilizing four-electrode mode electrochemical impedance spectroscopy (EIS) for real-time, non-destructive monitoring of SLM degradation, providing detailed analysis of SLM's structural changes. We first showed that SLMs may be depicted as an electrical circuit of resistors and capacitors by EIS. The EIS then revealed that SLM degradation progressed over four different phases as a result of varying rates of thickness and area reduction of the SLM. To demonstrate the effectiveness of EIS-based diagnosis, we prepared SLMs designed for selective medium-chain fatty acid (MCFA) extraction in intact, partially, and completely degraded states, determined by the EIS. The intact SLM showed a high selectivity (∼50) for MCFAs over short-chain fatty acids. The selectivity decreased to ∼22 in the partially degraded SLMs, and less than 1 in the completely degraded SLM, indicating the clear linkage between the degree of degradation and the separation performance. Our four-electrode mode EIS method is expected to serve as a key tool for efficient SLM operation and stable SLM development.

Design of non‐contact capacitive displacement detection methods for magnetic levitated sphere

AbstractTo meet the demand for non‐contact displacement detection of magnetic levitation spheres, single‐ended and differential variable electrode distance capacitance displacement detection schemes are designed in this paper. For these two schemes, finite element simulation models are established in COMSOL Multiphysics software to obtain the relationship between the test capacitance and the displacement of the magnetic levitation sphere. In the single‐ended scheme, there is a non‐linear relationship between the test capacitance and the position of the levitated sphere, and this non‐linearity becomes more significant as the sphere moves away from the electrode plate. In contrast, in the differential scheme, the test capacitance and the displacement of the levitated sphere follow a linear relationship, but the test sensitivity decreases with the expansion of the measuring range. The simulation results of the differential scheme have been verified by building a spherical displacement detection simulator, and thanks to the mature development of capacitive detection circuits, the scheme is expected to achieve better than nanoscale displacement detection resolution in the 6.6 mm displacement range of a magnetic levitation sphere in the future.

Feasibility of Remotely Controlled Capsule to Enable Directionality and Higher Dose Rates for Conventional Low Dose Rate Brachytherapy Using Topas

With low dose radiation (LDR) brachytherapy, thus far, only low dose rates could be used with low energy level radiation sources at 30 keV or less due to the risk of radiation to healthy cells, tissue, and organs. The radiation seeds are placed in the location of the tumor and is left in the body for the total dose to be continuously administered throughout the decay period of the radiation seed. However, the amount of time to deliver the total dose can take up to several months depending on the type of radiation source, tumor size and location, due to the low dose rate of <2 Gy/hr. In contrast, high dose radiation (HDR) is defined as a dose delivered at a rate >12 Gy/hr, although usually much higher, often in excess of 1 Gy/min, with a higher energy radiation source close to 0.5 MeV.For the first time, a remotely controllable, implanted radiation capsule is introduced, to enable a very high dose rate of 10 Gy/min for 30 keV I-125 radiation source. Until now, this combination of low energy and high dose rate for implanted radiation seeds for LDR was not possible due to the risk of radiation. The implantable capsule is designed to control this risk of radiation by remotely controlling the opening of the capsule hole. In the open case, the high dose rate of I-125 is delivered for a duration of 1 minute and then closed to stop emission.For feasibility, a simulation study was conducted using TOPAS for Monte Carlo simulation of radiotherapy. In the top right figures, a cylindrical capsule of height 6 mm, diameter 3 mm, and wall thickness 0.9 mm is designed using gold to contain the radiation and prevent leakage radiation. An opening of 30 degrees was made in the middle of the capsule wall where the radiation was to be emitted. For the radiation source, a 30 keV I-125 was used with a specific activity of 6.42 x 1014 Bq/gram. With a wall thickness of 0.9 mm, calculations showed that 4.4 micrograms of I-125 was needed to increase the source activity for 1.454 x 1020 Bq per second for a high dose rate of 10 Gy/min.The yellow and red colors in the capsule are both gold with wall thickness of 0.9 mm. The red portion of the cylinder is where the 30 degree opening was defined. The green lines show the paths of the radiation particles.TOPAS simulation results successfully show that the capsule contains the radiation and the only direction of radiation is through the defined opening in the capsule. The bottom three graphs show the x, y, and z plane cuts showing a directional radiation beam that drops in intensity, from a range of 1.0 to 0, over distance and slightly widens over distance.To control the opening and closing of the hole in the radiation capsule, an inner cylinder and outer cylinder is used, where the inner cylinder can move up and down. A permanent magnet is attached to the bottom of the inner cylinder and an electromagnet is attached to the base at the bottom of the capsule. An implantable inductive coil receives an AC current from the external inductive coil, which is rectified using a diode and capacitor circuit. This DC current powers the electromagnet, which repels the inner cylinder, moving it up to align the windows of the inner and outer cylinders. This alignment opens the hole and radiation is emitted towards the target tumor. After the dose is delivered, the current is turned off, which turns off the electromagnet. With no repelling force from the electromagnet, the permanent magnet reattaches itself to the base, and the inner cylinder slides down and the windows are no longer aligned. This blocks the radiation from being emitted. The dimensions of the capsule and the windows depend on the radiation source and tumor size. Micromachining and micro 3D printing techniques can be applied for fabrication of the device.In conclusion, a feasibility study using TOPAS demonstrated that a 0.9 mm gold wall with a hole can contain a very high source activity of I-125 radiation for a very high dose rate of 10 Gy/min and emit a directional beam through the hole. A remotely controllable capsule can enable a high dose rate with LDR brachytherapy that combines the advantages of LDR and HDR, which is minimum radiation risk and minimum treatment time, simultaneously. Potential applications for this is intracavitary cancer treatment such as esophageal or cervical cancer. Figure 1

A novel capacitive sensor interface based on a simple capacitance-to-phase converter

Abstract A novel room temperature capacitive sensor interface circuit is proposed and successfully tested, which uses a modified All-Pass filter architecture combined with a simple series resonant tank circuit with a moderate Q-factor. It is fashioned from a discrete inductor with small dissipation resonating with a grounded capacitor acting as the sensing element to obtain a resolution of ∆C ~ 2 zF in a capacitance range of 10 – 30 pF. The circuit converts the change in capacitance to the change in the phase of a carrier signal in a frequency range with a central frequency set up by the tank circuit’s resonant frequency and is configured to act as a close approximation of the ideal All-Pass filter. This cancels out the effects of amplitude modulation when the carrier signal is imperfectly tuned to the resonance. The proposed capacitive sensor interface has been specifically developed for use as a front-end constituent in ultra-precision mechanical displacement measurement systems, such as accelerometers, seismometers, gravimeters and gravity gradiometers, where moving plate grounded air gap capacitors are frequently used. Some other applications of the proposed circuit are possible including the measurement of the electric field, where the sensing capacitor depends on the applied electric field, and cost effective capacitive gas sensors. In addition, the circuit can be easily adapted to function with very small capacitance values (1 - 2 pF) as is typical in MEMS-based transducers.

A MEMS resonant vacuum gauge for high vacuum measurement

In this paper, a MEMS resonant vacuum gauge (MRVG) based on the squeezed film damping is proposed and its theoretical measurement model is established. The sensitive structure and electrodes of the MRVG were fabricated on SOI wafers and were wafer level packaged including intake hole. An resonance excitation and capacitive detection circuit consists of capacitive voltage converter (C/V) module, PLL and modulation and demodulation module was designed. Experimental tests were carried out in a standard vacuum calibration chamber, and the measurement results verified the theoretical model. The indication accuracy of the MRVG is less than ±20% in the vacuum range of 9×10−5 Pa ∼ 1 Pa. Moreover, the output voltage is still not saturated at the highest vacuum level (9×10−5 Pa), which lays the foundation for subsequent measurement of higher vacuum levels.

Anti-Disturbance Bumpless Transfer Control for a Switched Systems via a Switched Equivalent-Input-Disturbance Approach

This paper concentrates on the issue of anti-disturbance bumpless transfer (ADBT) control design for switched systems. The ADBT control design problem refers to designing a continuous controller and a switching rule to ensure the switched system satisfies the ADBT property. First, the concept of the ADBT property is introduced. Then, via a switched equivalent-input-disturbance (EID) methodology, a switched EID estimator is formulated to estimate the impact of external disturbances within the switched system. Second, a bumpless transfer control is then constructed via a compensator integrating an EID estimation. Finally, the effectiveness of the presented control scheme is verified by controlling a switching resistor–inductor–capacitor circuit on the Matlab platform. Above all, a new configuration for ADBT control of switched systems is established via a switched EID methodology.

High-performance anti-series diode ring amplifier for switched capacitor circuits

Ring amplifiers enable efficient amplification with less power consumption. These are characterized by fairly power requirements, and innate rail-to-rail output swing and are robust against PVT variations. In this paper, we are presenting an improved self-biased anti-series diode-based ring amplifier (ASD-RAMP) design, implemented on 45-nm CMOS technology. The design uses two diode-connected PMOS transistors that are connected in an anti-series manner to generate a large resistance because of which a high dead-zone voltage is generated. The ASD-RAMP has a settling time of only 4.05 ns, which is nearly half of the conventional self-biased ring amplifier (CSB-RAMP). In comparison to CSB-RAMP, the proposed ASD-RAMP improves the dead-zone voltage by 1.1× while requiring 6.76% less power. The circuit is durable and suitable for high-performance applications since it exhibits great resilience to PVT variations in addition to the improved dead zone voltage and reduced settling time.

A peak enhancement of frequency response of waveguide integrated silicon-based germanium avalanche photodetector

Avalanche photodetectors (APDs) featuring an avalanche multiplication region are vital for reaching high sensitivity and responsivity in optical transceivers. Waveguide-coupled Ge-on-Si separate absorption, charge, and multiplication (SACM) APDs are popular due to their straightforward fabrication process, low optical propagation loss, and high detection sensitivity in optical communications. This paper introduces a lateral SACM Ge-on-Si APD on a silicon-on-insulator (SOI) wafer, featuring a 10 μm-long, 0.5 μm-wide Ge layer at 1310 nm on a standard 8-inch silicon photonics platform. The dark current measures approximately 38.6 μA at −21 V, indicating a breakdown voltage greater than −21 V for the device. The APDs exhibit a unit-gain responsivity of 0.5 A/W at −10 V. At −15 V, their responsivity reaches 2.98 and 2.91 A/W with input powers of −10 and −25 dBm, respectively. The device's 3-dB bandwidth is 15 GHz with an input power of −15 dBm and a gain is 11.68. Experimental results show a peak in impedance at high bias voltages, attributed to inductor and capacitor (LC) circuit resonance, enhancing frequency response. Furthermore, 20 Gbps eye diagrams at −21 V and −9 dBm input power reveal signal to noise ratio (SNRs) of 5.30. This lateral SACM APD, compatible with the stand complementary metal oxide semiconductor (CMOS) process, shows that utilizing the peaking effect at low optical power increases bandwidth.

ВПЛИВ ВЕЛИЧИНИ ЄМНОСТІ ПОСЛІДОВНОГО РЕЗОНАНСНОГО КОНТУРУ НА ПОТУЖНІСТЬ ЕЛЕКТРОТЕХНІЧНИХ СИСТЕМ РЕЗОНАНСНОГО ТИПУ ДЛЯ МОНІТОРИНГУ ІЗОЛЯЦІЇ ВИСОКОВОЛЬТНОГО ОБЛАДНАННЯ

It were analyzed the processes of charging the capacitive electro-technical storage (CES), which can be the electrical insulation of modern high -voltage equipment (in particular power cables) during the current monitoring of its techni-cal condition by the value of leakage currents when applying high voltage to insulation. The transformerless electro-technical system (ETS) of a resonance type, in which resonant inductive-capacitive circuit (ICС) with a high Q -factor carried out a multiple increase in AC voltage, was used to generate such voltage. Analytical expressions were obtained for the steady-state voltage on such CES and transient currents in the ETS circuit its charging. Simulation modeling of transient processes in the circuits of such ETS during CES charging was performed using the LTSpice software pack-age. It is shown that the dependences of the output voltage and current of the ETS on time, obtained by analytical ex-pressions, practically coincide with the results of simulation simulations. The influence of the ratio of the load capaci-tance and the resonant circuit capacitance on the relative load charging time and, accordingly, on the ETS power was studied. It was found that in order to increase the power of high -voltage transformerless ETS of the specified reso-nance type, it is necessary to increase the ratio of the CES capacity to the ICС capacity of the resonant circuit of the ETS. This approach can be used when using ETS with resonant ICCs to create powerful electric discharge installations (EDIs) for the implementation of technologies for obtaining electro-spark micro- and nanopowders with unique opera-tional properties. When creating powerful EDIs, it is suggested to use the value of the above-mentioned ratio at least 10. References 31, figures 5.

APPLICATION OF SOFT SWITCHING IN THREE-PHASE VOLTAGE INVERTERS OF TRACTIONAL ROLLING STOCK

Autonomous voltage inverters with PWM, which are used in electric drive systems with brushless motors, occupy an important place in the complex of electrical equipment of modern traction rolling stock of railways. The article presents the results of the research of the traction three-phase bridge voltage inverter with soft switching of power switches. Using the soft switching mode allows you to reduce the switching losses in the power transistors of the keys, increase the PWM frequency and improve other performance indicators of the converter. It is advisable to implement soft switching in the key transistors of the three-phase voltage inverter using soft switching nodes with fast-acting four-quadrant switches based on IGBT. It is proposed to consider the possibility of using transistor switches of a voltage inverter with capacitive non-dissipative snubbers at high PWM frequencies. For this purpose, a synthesis of the scheme and algorithm for the implementation of soft switching in a three-phase bridge voltage inverter with bipolar sinusoidal PWM with soft switching nodes with high-speed four-quadrant switches based on IGBT was performed. An analysis of the characteristics of the three-phase voltage inverter was carried out when using high-speed switches in the soft switching nodes to implement soft switching in the power transistors of the inverter switches.On the basis of the study, it is proposed to modernize the scheme of the soft switching unit in order to provide better preparation for the switching of the power transistors of the keys at large load currents. The improved soft switching unit includes low-voltage sources of constant voltage, which will compensate for energy losses in the recharging circuit of the snubber capacitors and contribute to the soft switching on of the power transistors of the voltage inverter keys. The performance test was carried out and the characteristics of the converter were analyzed when using a modernized soft switching node using simulation modeling in the MATLAB package.

A comprehensive study of crystal structure, UV–visible study, electric-dielectric properties of a recently developed Hybrid Material [(C6H5N2)2ZnCl4]

The advanced hybrid material, [(C6H5N2)2ZnCl4] was prepared using the gradual dehydration process by combining 4-cyanopyridine and ZnCl2 under standard ambient temperature conditions. The compound underwent various characterization techniques, including single crystal and Powder X-ray diffractions (SXRD, PXRD), Scanning Electron Microscopy (SEM) and EDX Energy-Dispersive X-ray, FT-IR spectroscopy, UV–Visible absorption analysis, Hirshfeld surface analysis (SHG), and thermal analysis. The molecular composition of the examined chemical substances was determined to belong to the orthorhombic P212121 space group through single crystal X-ray analysis. analysis. Its molecular arrangement was characterized by alternating layers of tetrahedral [ZnCl4]2- and 4-cyanopyridinium planes (C6H5N2)+. These layers are connected through NH···Cl and CH···Cl hydrogen bonds, which contribute to their cohesion and overall adherence. The UV–visible spectrum using Tauc plot relation, has unveiled the energy ratio of an optical band gap, which is measured at 4.80 eV. Additionally, thermal analysis has demonstrated that [(C6H5N2)2ZnCl4] exhibits thermal stability up to a temperature of 475 K. SHG study was employed to examine the interactions between molecules. Additionally, 2D finger plots were utilized to quantitatively assess the impact of these interactions on the crystal structure. This work discusses various electrical characteristics obtained through impedance measurements, including dielectric constants and electric modulus. To shed light on the electrical resistance and dielectric characteristics, we conducted complex impedance spectroscopy at different frequencies with temperature ranging between 313 and 423 K. The elaborate Nyquist curve revealed a solitary semicircle, indicating that the signal was generated by a single capacitive circuit associated with the grain. We also researched ac conduction to figure out how electricity is transmitted. The diagram unveils that the conduction mechanism is thermally activated. The activation energy value obtained from the dc conductivity is approximately 0.768 eV. The analysed material allows for the movement of space charge through a hopping mechanism. Finally, the dielectric constant estimate demonstrates that this title compound is a suitable candidate for the fabrication of opto-electronic materials. Modulus analysis demonstrated that the mobile charge carriers exhibited mobility both at low and high frequencies, covering short and long distances.

A 2.5–8V input range peak-current-control non-inverting buck-boost DC-DC converter with high efficiency and automatic mode transition for Ni-MH battery application

In portable electronic devices, the output voltage of the Ni-MH cell battery gradually decreases with the extension of run time, eventually leading to an inability to provide the required operating voltage. As a result, this paper proposed a non-inverting buck-boost converter with automatic switching of operating modes to extend the run time of Ni-MH batteries connected in series, which is peak current controlled. By comparing the input and output voltages, the DC-DC converter is placed in either buck, boost, or buck-boost mode. Of the three modes, the buck-boost mode is designed to have the smallest operating range due to its lowest power conversion efficiency. The converter is characterised by a wide input range of 2.5–8 V, which exceeds the maximum voltage leading to oxide breakdown. In order to prevent the breakdown of the gate oxide layer, a capacitive coupling level shift circuit is proposed to control voltage between gate and source of the power transistor below 5 V. The proposed converter is manufactured using a 180 nm BCD process and occupies an effective chip area of 1.44 mm × 0.73 mm. Experimental results demonstrate that the maximum power conversion efficiency of the proposed buck-boost DC-DC converter is 93%, marking a significant 11% enhancement compared to the traditional buck-boost DC-DC converter operating in only buck-boost mode (84% efficient). In addition, the converter achieves a maximum output current of 500 mA, which improves the output maximum current by 67% compared to the traditional DC-DC converter (max. output current 300 mA).

Input currents of CMOS SAR ADC in microcontroller, their measurement and behavior model from users point of view

The article introduces the possible issue of internal CMOS Successive Approximation Register microcontroller’s Analog-to-Digital Converters (ADC) input currents. It describes the nature of the ADC input current and its dependence on the sampling frequency but also explains the issue when the ADC input appears to the user as a voltage source. Methods for measurement of parameters such as input charge, residual voltage, and equivalent capacitance of sample-hold circuits are presented and used in the proposed simplified model of ADC input behavior. These parameters, which are not listed in the datasheets, if not respected in the data acquisition design, can adversely affect how the ADC is used when measuring signal sources with non-negligible internal resistance. The article also explains how to solve a voltage measurement on a source with high internal resistance even in a situation where, according to datasheets, it should already have limitations. If the microcontroller contains a dynamically switched multiplexer, it can lead to other consequences, such as changing the input current or residual voltage. The proposed simplified CMOS SAR ADC input behavior model in an MCU can help users in an MCU-based data acquisition system design.

The collector current model of the IGBT based on the gate charge

In this study, a dynamic and static collector current (IC) model of the IGBT based on the gate charge is proposed. The gate charge could be easily obtained by measuring the voltage across the gate mirror circuit capacitance, and the transconductance obtained from the IC–VGE curve is mainly used. This model does not need the device structure parameters such as doping concentration, length, and thickness, thus is low cost and highly convenient. First, the gate charge is derived by integrating the currents of the variable capacitors CGE and CGC during the turn-on and turn-off transients, and an analytical relationship between the dynamic IC and QG is researched. Second, a static collector current IC is established, and the gate charge is obtained through current integration during the period of the Miller capacitance plateau. The influence of the temperature on the static transconductance is studied, and the accuracy of the static current model is improved. Finally, the performance of the model is optimized with various voltages, temperatures, and currents. The experimental results reveal that the proposed model achieves a collector current error of less than 5.6 % under various operating conditions, which verifies the accuracy of the proposed model.

Analysis of Energy During Spark Discharge in Short Circuit of Capacitive Circuit

ABSTRACT In the explosive environments, the electrical sparks with short circuit of capacitor output will ignite the surrounding explosive medium, and the relationship between effective ignition energy, capacitance energy conversion rate, capacitor capacitance and capacitor terminal voltage is unclear. Based on the three stages of breakdown, discharge and attenuation of the discharge characteristic curve of capacitive circuit, this paper deduces the expressions of spark resistance and discharge current including voltage, capacitance and polar distance parameters. Based on the programmable micro-nano gap discharge experimental platform, experiments under different voltages and different capacitances were carried out. It is found that the theoretical voltage-current curve and spark energy conversion rate are in good agreement with the experimental fitting curve and spark energy conversion rate. And with the increase of capacitance or voltage, the peak current and discharge time increase, which leads to the increase of energy. The conversion rate of spark energy decreases with the increase of capacitance or voltage, and the conversion rate changes between 20% and 30%. The change of spark energy conversion rate is also related to spark resistance, and with the decrease of spark resistance, the spark energy conversion rate also decreases. This study can further understand the energy variation in the discharge gap and is of great significance for the research of intrinsically safe circuits.

Protocol-based state estimation of two-time-scale complex networks with nonhomogeneous sojourn probabilities

This paper is dedicated to researching the problem of the state estimation for two-time-scale complex networks (TTSCNs) subject to sojourn probabilities (SPs) under channel fadings and false data injection attacks (FDIAs). The network’s switching topology is governed by a novel switching law that incorporates time-varying SPs, with the variation of SPs being regulated through a persistent dwell-time (PDT) switching signal. Meanwhile, for the sake of achieving energy savings and mitigating data congestion, the dynamic probabilistic event-triggered weighted try-once-discard (DPEWTOD) policy is innovatively developed by integrating with the major merits of the dynamic probabilistic event-triggered mechanism (DPETM) and WTOD protocol (WTODP) based on hybrid compensation. Different from the traditional communication rules, this DPEWTOD concept not only captures stochastic behavior of the dynamic triggering threshold (DTT), but also enables a compensatory measurement that closely approximates the actual value. Subsequently, we construct time delay-, DTT-, and PDT-dependent Lyapunov functionals to analyze the stability of error dynamic systems in the presence of fading and malicious FDIAs. By employing a separation technique, our proposed solving algorithm transforms non-convex analysis conditions into tractable ones. Eventually, the rationality and effectiveness of the proposed method are demonstrated by an resistance–capacitance (RC) circuit example.