kΩ Resistor Research Articles

Design and experimental investigation of a positive feedback magnetic-coupled piezoelectric energy harvester

A positive feedback magnetic-coupled piezoelectric energy harvester (PFM) is proposed to address the limitations of current piezoelectric energy collectors, including restricted acquisition direction, limited acquisition bandwidth, and low energy output. Firstly, the dynamic theoretical model of the energy harvester was established, and the optimization factors were explored, providing a solid theoretical foundation for subsequent research endeavors. The energy capture characteristics of rectangular beam and compound trapezoidal beam were compared through finite element simulation analysis. Subsequently, an experimental platform was constructed and an optimized experimental methodology was devised to analyze the energy capture characteristics and enhance the performance of the energy harvester. The results demonstrate that the positive feedback magnetic-coupled PFM with a trapezoidal beam exhibits superior energy capture efficiency. Furthermore, it is observed that the optimized energy harvester possesses wide frequency coverage, multi-directional capabilities, low-frequency adaptability, and facilitates easy vibration. When the 45 kΩ resistor is connected in series and subjected to a longitudinal external excitation amplitude of 0.5 g, it is capable of generating an average voltage and power output of 4.20 V and 0.39 mW respectively at a vibration frequency of 9 Hz. Similarly, when exposed to a transverse external excitation amplitude of 1 g, it can produce an average voltage output of 6.2 V and power output of 0.85 mW at a vibration frequency of 19 Hz. When the inclination angle of the energy harvester is set to 35 degrees, the maximum voltage output occurs at a frequency of 18 Hz and the Z-axis to X-axis force ratio of the energy harvester is 1.428. These research findings can serve as valuable references for piezoelectric energy harvesting applications in self-powered microelectronic systems.

The Cascade of High-Voltage Pulsed Current Sources

Currently, pulsed adders are used as pulsed voltage sources maturely. However, their use as pulsed current sources is significantly limited due to circuit impedance and the characteristics of power devices. This paper presents a simple yet effective design for a pulsed current source, incorporating a solid-state Marx pulsed adder as the primary power source and an inductor for energy storage. In the pulsed current source, a Marx pulsed adder produces high voltage to charge the inductor. Then, the stored inductance energy is converted to generate current pulses on the load; the amplitude of the pulsed current is unaffected by the load impedance within a certain range. The pulsed current source can be designed as a standard module, and several modules can form a cascade system for producing current pulses with higher voltage. Finally, a pulsed current source was developed, which can produce adjustable current pulses with high voltage. The design principles, control methods and the effects of the distribution parameters are described. The feasibility of the cascade pulsed power system was validated in experiments. Nine modules were connected to generate pulses of current 10 A on a 15 kΩ resistor.

A voltage mode grounded capacitance multiplier with widely tunable gain for ultra-low cutoff frequency filter.

A voltage mode capacitance multiplier for ultra-low frequency physiological signal processing is designed with a circuit model. With the proposed multiplier, a filter can achieve a cutoff frequency of 12 mHz with a 1 pF basic capacitance and a 10 kΩ resistor. The corresponding multiplication factor will be 1.35 × 109. By changing the controlling terminal, the multiplication factor can be widely tuned from 1950 to 1.35 × 109 and the corresponding filter cutoff frequency will be from 12 mHz to 8.15 kHz. According to the circuit model, to further increase the multiplication factor to decrease the chip area, more multiplication stages can be added to the feedback loop.

Design of a 0.5 V Chopper-Stabilized Differential Difference Amplifier for Analog Signal Processing Applications.

This paper presents a low-voltage low-power chopper-stabilized differential difference amplifier (DDA) realized using 40 nm CMOS technology. Operating with a supply voltage of 0.5 V, a three-stage DDA has been employed to achieve an open-loop gain of 89 dB, while consuming just 0.74 μW of power. The proposed DDA incorporates feed-forward frequency compensation and a Type II compensator to achieve pole-zero cancellation and damping factor control. The DDA has a unity-gain bandwidth (UGB) of 170 kHz, a phase margin (PM) of 63.98°, and a common-mode rejection ratio (CMRR) of up to 100 dB. This circuit can effectively drive a 50 pF capacitor in parallel with a 300 kΩ resistor. The use of the chopper stabilization technique effectively mitigates the offset and 1/f noise. The chopping frequency of the chopper modulator is 5 kHz. The input noise is 245 nV/sqrt (Hz) at 1 kHz, and the input-referred offset under Monte Carlo cases is only 0.26 mV. Such a low-voltage chopper-stabilized DDA will be very useful for analog signal processing applications. Compared to the reported chopper DDA counterparts, the proposed DDA is regarded as that with one of the lowest supply voltages. The proposed DDA has demonstrated its effectiveness in tradeoff design when dealing with multiple parameters pertaining to power consumption, noise, and bandwidth.

Development of Smart UAV (Drone) ozone (O3) monitoring system in Port Harcourt, Rivers State, Nigeria

We hereby report a detailed design and fabrication of our indigenously developed smart UAV (drone) Ozone, O3, monitoring system, using locally sourced materials in Nigeria. Our device is locally built from scratch to finish using materials available to us. Our design comprises a small lightweight (Polystyrene), Rotors, Arduino Joystick, Arduino Nano Board, 434 MHz Transmitter Module, 1 KΩ Resistor, Vero Board, Connecting wires, 9 Volts Battery, Antenna, simple and cost-effective multi-sensor system for multiple measurements of atmospheric phenomena and related climate information. We have used a long-range wireless communication module with real-time monitoring and visualizing software applications embedded on our device to access live data, track trends, and archive historical data for comparisons (data logger). We have also obtained original ozone datasets after conducting test flight measurement experiments at the launch site (Rivers State University Campus) Port Harcourt, Nigeria.

A 177 ppm RMS Error-Integrated Interface for Time-Based Impedance Spectroscopy of Sensors

This paper presents an integrated circuit for time-based electrical impedance spectroscopy (EIS) of sensors. The circuit exploits maximum-length sequences (MLS) in order to perform a broadband excitation of the sensors under test. Therefore, the measured time-domain EIS is obtained by cross-correlating the input with the output of the analog front end (AFE). Unlike the conventional digital approach, the cross-correlation operation is performed in the analog domain. This leads to a lower RMS error in the measured time-domain EIS since the signal processing is not affected by the quantization noise of the analog-to-digital converter (ADC). It also relaxes the sampling frequency of the ADC leading, along with the lack of random access memory (RAM) usage, to a reduced circuit complexity. Theoretical concepts about the circuit’s design and operation are presented, with an emphasis on the thermal noise phenomenon. The simulated performances are shown by testing a sensor’s equivalent model composed of a 50 kΩ resistor in parallel with a 100 pF capacitor. A time-based EIS output of 255 points was obtained with a maximum tested frequency of 500 kHz and a simulated RMS error of 0.0177% (or 177 ppm).

New impedance bridge at LNE for the two terminal-pair AC resistor calibration up to 20 kHz

This paper presents the evolution of LNE’s impedance bridge (Wheatstone bridge) used to calibrate AC resistors defined in the two terminal-pair configuration. A new automated Wheatstone bridge, based on four resistances, was developed to operate in the full complex plane for resistances ranging from 400 Ω to 2 MΩ and for frequencies up to 20 kHz. A commercial dual precision arbitrary waveform generator supplies the bridge and PXI modules achieve the balance. Phase and frequency synchronization solutions between the arbitrary waveform generator source and the PXI modules were used. The choice of these instruments allows the bridge to be easily automated and to benefit from recent progress in the development of digital-analog converters, in particular those with high frequency sampling rates and resolution. The bridge is mainly dedicated to realize the periodic calibration of LNE’s standard resistors, used for routine customer calibrations. The traceability of LNE’s standard resistors is ensured, firstly, by the calibration of a 1 kΩ resistor by comparison to a calculable resistor up to 20 kHz. Then, this resistor is used as a reference element to ensure the traceability of all LNE’s standard resistors using the new bridge. The validation was done by comparing the results obtained, for some resistors with very low drift, with those obtained during calibrations performed in 1983, 1995 and 2009. For resistors of 1 kΩ in a 1:1 ratio, the expanded uncertainty of series resistance variation and argument are, respectively, less than 1.3 µΩ Ω−1 (k = 1) and 1.2 µrad (k = 1), up to 20 kHz.

공통 소스 트랜지스터의 Self-Body-Biasing을 통해 선형성이 향상된 2.45 GHz CMOS 전력증폭기의 설계

This study introduces the design of an RF CMOS power amplifier based on a cascode powercell. self-body-biasing (SBB) of common source (CS) transistors (TRs) was proposed to improve the nonlinearity of power amplifiers. Accordingly, an analysis of the linearization principle of SBB was performed through simulation. The SBB technique is configured by inserting a 4 kΩ resistor between the body and the drain of the CS TRs. Accordingly, using the SBB to the CS TRs could achieve the effect of reducing the third-order intermodulation distortions (IMD3) by changing the third-order transconductance (gm3). Moreover, an effect of reducing AM-PM distortions could be achieved by securing a voltage condition in which the CG TRs could operate in a saturation region, which reduces the variation of parasitic capacitances at the output terminal.

Constructing a capacitive rotating angle sensing system using a hand-made oscillator and testers

In this study, we develop a capacitive rotating angle sensing system using a hand-made 1 kHz oscillator, field-effect transistor (FET) amplifier, and tester through a physics experiment conducted in Ryukoku University. Physics majors of the university can study the fundamentals of electronics through this system because it uses electronic elements, such as transistors and FETs. We fabricated the circuit of a rotation angle sensor system using a fan-type and coaxial variable capacitor. The capacitance of the variable capacitors varied linearly with the rotation angle. Owing to the CR high-pass filter, constructed by capacitors and a 100 kΩ resistor, the output voltage of the system was linear with capacitors and the rotation angle. Not only can this system be used to teach university-level physics, but its applications could extend to various industries.

Research, design, manufacture leakage current protection device for 660V/1140V underground mine electrical networks

This paper presents the results of researching, designing and manufacturing leakage current protection device for 660 V/1140 V ungrounded three-phase electrical networks. The outstanding features of the device are: ability to create wide deformation characteristic; automatically detect and grounded the leakage phase. Device test results show that relay operation time ​​for symmetrical and asymmetric leak resistors are 30 kΩ/60 kΩ per phase and 20 kΩ /50 kΩ for 660 V/1.140 V networks respectively. The total operating time of the device when single phase leaking through a 1 kΩ resistor not exceed 105 ms. The circuit automatically detects and accurately grounded the leakage phase through 100 Ω resistance, the total detection and grounded the leakage phase time does not exceed 110 ms. This research result can be applied in the design and manufacture of high-quality and reliable leakage current protection devices used in underground mines, replacing imported products.

A consistent geometrically nonlinear model of cantilevered piezoelectric vibration energy harvesters

Current theories inconsistently handled the geometrical nonlinearity of cantilevered piezoelectric energy harvesters (PEHs) in two aspects: first, some of the high order terms of the first derivative of deflection were unintentionally omitted in deriving the governing equations; second, the effect of the geometrical nonlinearity on the motion of the tip mass was neglected. In this paper, a consistent geometrically nonlinear model (CGNM) was derived by neglecting the fourth and higher order terms of the first derivative of deflection in the governing equations, and by considering the effect of geometrical nonlinearity on the motion of the tip mass. For a flexible unimorph cantilever, the errors caused by either of the inconsistent treatments of the geometrical nonlinearity were numerically analyzed, respectively, and the theoretical and experimental results showed that both of them have remarkable effects on the simulation accuracy under harmonic base excitations with the amplitudes of 1.5 g and 2.0 g (g = 9.81 m s−2). Under excitations of different levels, the voltage across a 500 kΩ resistor worked out from a published geometrically nonlinear model (GNM) and the proposed CGNM were compared with experiments. The CGNM is more accurate than the GNM in the prediction of the root mean square (RMS) voltage at the resonant frequency, especially under high-level excitations. Numerical simulations show that the optimum load resistance increases and the resonant frequency decreases when the excitation level increases due to the geometrical nonlinearity. The model may be used to predict the responses of cantilevered PEHs experiencing large amplitude vibrations.

A Wideband Rectenna Using High Gain Fractal Planar Monopole Antenna Array for RF Energy Scavenging

This paper introduces a wideband rectenna that can scavenge ambient wireless power to a range of frequency band from 0.91 GHz to 2.55 GHz efficiently. The proposed rectenna is based on a wideband 2 × 2 fractal monopole antenna array with omnidirectional radiation patterns and high gains of 5 to 8.3 dBi at the desired bands. An improved two-branch impedance matching technique is presented which is designed to enhance the rectifier circuit performance with a relatively low input power ranging from −25 dBm to 10 dBm. Also, a full-wave wideband rectifier that can suitably improve the RF-to-DC power conversion efficiency is designed for the rectenna. A peak efficiency of 76%, 71%, 61%, and 62% is obtained at 950, 1850, 2100, and 2450 MHz, respectively. Measurement results show that a conversion efficiency of 68% has been achieved over an optimal 4.7 kΩ resistor when the simultaneous four-band input power level is −10 dBm. Moreover, an output DC voltage of around 243 mV with voltage varying within 160–250 mV can be achieved by gathering the low ambient wireless power inside laboratory. This study proves that the proposed rectenna can be applied to a range of many low-power electronic applications.

Energy Harvesting Performance of Vertically Staggered Rectangle-Through-Holes Cantilever in Piezoelectric Vibration Energy Harvester

Abstract Piezoelectric vibration energy harvesting technology has attracted significant attention for its applications in integrated circuits, microelectronic devices, and wireless sensors due to high power density, easy integration, simple configuration, and other outstanding features. Among piezoelectric vibration energy harvesting structures, the cantilevered beam is one of the simplest and most commonly used structures. In this work, a vertically staggered rectangle-through-holes (VS-RTH) cantilevered model is proposed, which focuses on the multi-directional vibration collection. To verify the output performance of the device, this paper employs basic materials and fabrication methods with mathematical modeling. The simulations are conducted through finite element methods to discuss the properties of VS-RTH energy harvester on resonant frequency and output characteristics. Besides, an energy storage circuit is adopted as a collection system. It can achieve a maximum voltage of 4.5 V which is responded to the harmonic vibrating input of 1 N force and 1 m/s2 in a single vibrating direction. Moreover, the power density is 2.596 W/cm3 with a 100 kΩ resistor. It is almost four times better than the output of unidirectional cantilever beam with similar resonant frequency and volume. According to the more functionality in the applications, VS-RTH energy harvester can be used in general vibration acquisition of machines and vehicles. Except for electricity storage, the harvester can potentially employ as a sensor to monitor the diversified physical signals for smooth operation and emergence reports. Looking forward, the VS-RTH harvester renders an effective approach toward decomposing the vibration directions in the environment for further complicating vibration applications.

Voltage induced phase transition of polyethene glycol composite film filled with VO<sub>2</sub> nanoparticles

In this paper, the voltage induced metal-insulator phase transition (MIT) of polyethene glycol (PEG) composite film is investigated based on VO<sub>2</sub> nanoparticles prepared by the hydrothermal method and vacuum annealing process. High purity VO<sub>2</sub> (B) nanoparticles are obtained after being treated in a hydrothermal reactor at 180 ℃ for 12 h by using vanadium pentoxide (V<sub>2</sub>O<sub>5</sub>) and oxalic acid (H<sub>2</sub>C<sub>2</sub>O<sub>4</sub>·2H<sub>2</sub>O) as raw materials. The X-ray diffraction (XRD) pattern shows that the prepared nano-powders are free of impurities, and the scanning electron microscope (SEM) pictures confirm that the micro-morphology is of a band-shaped nano-structure. Next, these products are heated in a vacuum quartz tube at 500 ℃ for different times. The XRD and differential scanning calorimeter (DSC) curves of the annealed samples prove that the VO<sub>2</sub> (M) with MIT performance is successfully prepared. And the content of M phase in the sample increases with preparation time increasing. When the annealing time is longer than 60 min, all the samples are converted into materials with M phase. The SEM images show that the average length of the nano-powders decreases with the annealing time increasing from 10 min to 300 min. Then PEG coating containing VO<sub>2</sub> (M) nanoparticles is applied between two electrodes with a pitch of 1 mm on printed circuit board (PCB). The <i>V</i>-<i>I</i> test is carried out after a 20 kΩ resistor has been connected in the circuit. The results display repeatable non-linear <i>V</i>-<i>I</i> curves indicating that the composite film undergoes an MIT phase transition under voltage. After it is activated for the first test, the MIT voltage and non-linear coefficient increase exponentially as the length of VO<sub>2</sub> decreases. Besides, it is also found that the voltage across the material is maintained at around 10 V after the resistance has changed suddenly, which is similar to the behavior of diode clamping voltage. We believe that the phase transition voltage and non-linear coefficient of the VO<sub>2</sub> composite film are influenced by the intra-particle potential barrier and the inter-layer potential barrier. The longer the average length of the nanoparticles, the higher the potential barrier between the interfaces in the conductive channels is, and thus increasing the phase transition voltage and phase transition coefficient. The activation phenomenon of the thin film is caused by reducing the barrier between particles during the first test. Furthermore, the results can prove that the electric field is the determinant of the phase transition during the VO<sub>2</sub> composite film electrical field induced MIT of the VO<sub>2</sub> composite film. However, after the phase transition, Joule heat plays a significant role in maintaining the low resistance state.

A Compact Electromagnetic Vibration Energy Harvester with High Output Voltage

Non-resonant vibration energy harvesters (VEHs) attract much attention for the excellent performance in scavenging ambient low-frequency and broadband vibrations. In this paper, effects of the mild steel sheets, thicknesses of the magnets and coils, wire diameter of coils, and inner dimension of the coils on the outputs of a non-resonant electromagnetic vibration energy harvester (EMVEH) were simulated and the optimized geometries was obtained. Numerical simulations show that the mild steel sheets can enlarge the magnetic flux density about 25.0%, agreeing well with the experimental result that the output voltage increased about 29.3%. Under a base excitation of 0.3 g (where 1g = 9.8 m s−2) at 8.3 Hz, the RMS voltage across a 10.4 kΩ resistor of an EMVEH prototype, with the inner volume of 76.26 cm3, is about 15.53 V. The power density is about 304 µW cm−3, about 18.7% higher than the previous device.

Reference-Free Dynamic Voltage Scaler Based on Swapping Switched-Capacitors

This paper introduces a reference-free, scalable, and energy-efficient dynamic voltage scaler (DVS) that can be reconfigured for multiple outputs. The proposed DVS employs a novel swapping switched-capacitor (SSC) technique, which can generate target output voltages with higher resolution and smaller ripple voltages than the conventional voltage scalers based on switched-capacitors. The proposed DVS consists of a cascaded 2:1 converter based on swapping capacitors, which is essential to achieve both very small voltage ripple and fine-grain conversion ratios. One of the serious drawbacks of the conventional voltage scalers is the need for external reference voltages to maintain the target output voltage. The proposed SSC; however, eliminates the needs for any reference voltages. This significant benefit is achieved by the self-charging ability of the SSC, which can recharge all its capacitors to the configured voltage by simply swapping the two capacitors in each stage. The proposed SSC-DVS was designed with a resolution of 16 output levels and implemented using a 130 nm CMOS (Complementary Metal Oxide semiconductor) process. We conducted measured results and post-layout simulations with an input voltage of 1.5 V to produce an output voltage range of 0.085–1.4 V, which demonstrated a power efficiency of 85% for a load current of 550 µA with a voltage ripple of as low as 2.656 mV for a 2 KΩ resistor load.

A study of flexible piezoelectric generators by sputtering ZnO thin film on PET substrate

Flexible technology has recently received much attention in the field of flexible sensors, wearable electronic devices, flexible transparent displays, and energy harvesters. Zinc oxide (ZnO) thin film is the preferred material for use in flexible devices due to its environmental friendliness, high electrical performance and low synthesis temperature. In addition, ZnO possesses a non-centrosymmetric crystal structure, causing a piezoelectric effect in the material. This work presents the fabrication of flexible piezoelectric generators using the deposition of ZnO on a PET substrate using sputtering techniques. The fabricated flexible generators are capable of generating an output power of 14 µW through an optimal resistive load of 750 kΩ. An output voltage of 2.00 Vp and a current of 150 μA measured across a 750 kΩ resistor were subsequently obtained.

Energy harvesting using snap-through deformation in lattice structures

We demonstrated the feasibility of harvesting mechanical energy through the proper design and installation of a lattice structure which undergoes snap-through deformation under applied mechanical loading. First, the theoretical formulations for both symmetric and asymmetric modes of the snap-through deformation in a 2D lattice structure were derived. Then, experiments were conducted on the prototype to measure the energy harvesting ability at different frequencies and to investigate the capability of charging a capacitor connected to the lattice prototype. Finally, the effects of the defect in the lattice on energy harvesting were discussed. Our results showed that the average generated voltage across a 25 kΩ resistor increased by increasing the frequency of loading. However, energy stored in a capacitor was independent of loading frequency. For a defective structure with a fixed vertex, the generated voltage is lower yet increasing with the frequency of loading. The designed structure is robust and provides sustainable energy output under cyclic loading even with the presence of defects and imperfections.

Electrolyte-Gated Vertical Organic Transistor and Circuit

An electrolyte-gated vertical organic transistor (VOT) was reported with high transconductance (1.0 mS) and 104 ION/IOFF ratio. Under the gating potential, the filtrated ions through porous Ag electrode stabilized the electrochemically p-doped poly(3-hexylthiophene) (P3HT) to form ohmic contact with Ag electrodes for enhanced charge injection. The gate modulation involving mobile ions was reflected in their slow temporal responses and long retention time. The VOT circuit was demonstrated by loading VOT with a 10 KΩ resistor to exhibit the voltage gain of 7.4.

Performance Analysis of a Microbial Fuel Cell Using Different Substrate Materials for Different loads

This research paper analyses the current density and power density of a duel chamber microbial fuel cell using different substrate materials for different resistive loads. Sucrose, sugar and starch were treated as substrate and potassium ferricyanide was used as electron acceptor. The separation of the cathode and anode cell is provided by proton exchange membrane (PEM) in most of the microbial fuel cell (MFC). The most popular proton exchange membranes are nafion, hyflon, zirfon, ultrex CMI-7000 etc. But all of them are not available to use in this part of the world. As an alternate, salt bridge was used in this study as a PEM which is receptive to other ions & chemicals. Different organic materials like sucrose, glucose, starch can be used as substrate as those are available in organic wastage. As the container of bacteria, the sludge of drain of Dhaka was utilized. The voltage and current were measured across 9.81 kΩ and 5.91 kΩ resistors. 716.32 mV was measured as highest voltage across 9.81 kΩ resistor while 4.65 mA/m^2 and 3.09 mW/m^2 were recorded as maximum current density and power density respectively across 5.91 kΩ resistor for sucrose as substrate. The anode chamber was maintained in anaerobic condition. The temperature during these experiments was (22±2)o C.