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With the advancement of technology, size, cost, and losses of the switched mode power supply (SMPS) have been decreasing. However, due to the high frequency switching, design of magnetic drives and isolation circuits are becoming a crucial factor in SMPS. This paper presents design criteria, procedure and implementation of AC-DC half bridge (HB) converter with lower cost, smaller size and lower voltage stress on the power switch.

The HB converter is designed in a symmetrical mode with a series coupling capacitor. Isolated power supplies are used for the converter and control circuit. Further, a transformer based isolated gate driver is used to drive both MOSFETs. The control IC works in voltage control mode to regulate voltage by controlling the duty cycle of the MOSFETs.

Control characteristics and performance of the HB converter is simulated using the MATLAB software and prototype of 170 W HB converter is built to validate the analytical results under variable load current and source voltage. The power quality and variation of load voltage at 2 A, 5 A, 7 A are reported.

This paper presents the design of a low-cost HB converter in a symmetrical mode which saves the additional cost of symmetric correction circuit normally required in asymmetrical mode design. This paper also focuses on the selection of primary and secondary side switch, series coupling capacitor, commuting diode, isolated drive and charge equalizer resistor.

Traditionally, industrial power supplies have been exclusively controlled through analog control to sustain high reliability with low cost. However, with the perpetual decrement in cost of digital controllers, the feasibility of a digitally controlled switch mode power supply has elevated significantly. This paper aims to outline the challenges related to the design of digital proportional-integral (PI) controlled synchronous rectifier (SR) buck converter by comparing controller performance in continuous and discrete time. The trapezoidal approximation-based digital PI control is designed for low voltage and high-frequency SR buck converter operating under continuous conduction mode.

The analog and digital controller are designed using a SISO tool of MATLAB. Here, zero-order hold transform is used to convert the transfer function from continuous to discrete time. Frequency and time domain analysis of continuous plant, discrete plant and close loop system is performed. The designed digital PI control is simulated in MATLAB Simulink. The simulated results is also verified on hardware designed around digital signal processing control.

The continuous and discrete control loops are validated with multiple tests in the time and frequency domain. The detailed steady state theoretical analysis and performance of the SR buck converter is presented and verified by simulation. It is found that the delay in digital control loop results in a low phase margin. This phase margin decreases with higher bandwidth. The hardware experiments with the digital control loop are carried out on a 10 W prototype. The chosen parameters for the SR buck converter are found to be optimum for steady and transient state response.

This paper compares the digital and analog control approach of compensator design. It focuses on the implications created at the time of transforming the control design from continuous to discrete time. Further, it also focuses on the selection of parameters such as phase margin, bandwidth and low pass filter.

The purpose of this paper is to study the properties of disc type negative temperature coefficient (NTC) thermistors based on the spinel system Mn‐Co‐Ni‐O with the doping of RuO₂ for the low‐resistance applications.

Emphasis was placed on the properties of ruthenium dioxide doped manganite spinel system for low‐resistance applications. The properties such as microstructure, X‐ray diffraction analysis and electrical properties are reported.

The prepared NTC thermistor compositions revealed the room temperature resistance and thermistor constant in the range of 28‐2,950 Ω and 1,539‐3,428 K, respectively. Hence, the prepared NTC thermistors with low resistance and moderate sensitivity are suitable from an industrial applications point of view.

The paper reports upon a synthesis procedure which is a straightforward preparation of highly densified ternary oxide (Mn‐Co‐No‐O) thermistors.

Aims to focus on temperature sensors.

Negative temperature co‐efficient thermistor powders of ternary Mn, Co, Ni oxide along with RuO₂ synthesized at relatively moderates temperature (1,000°C). Thick film thermistor paste compositions were formulated by mixing the semiconducting oxide powder, glass frit and organic vehicle. The physico‐chemical analysis, viz. X‐ray diffraction, scanning electron microscopy and thermogravimetry and IR spectroscopy were carried out for the synthesized powder and the resultant thick films. The X‐ray analysis of the powders showed the cubic spinel structure. The electrical properties like thermistor constant, sensitivity index and activation energy of the thick film NTC thermistor were determined.

The room temperature resistance is observed to range from 490 KΩ to 4.13 MΩ with thermistor constant ranging from 3,275 to 3,980 K, in the temperature range of 25‐300°C.

Describes research work on temperature sensors that are used for monitoring and control in many fields such as in home appliances, manufacturing industries, biomedical and automobile industries.

Sensing technology has been extensively researched and used due to its applications in industrial production and daily life. Due to inherent limitations of conventional silicon-based technology, researchers are now-a-days paying more attention to flexible electronics to design low-cost, high-sensitivity devices. This observational and analytical study aims to emphasis on carbon monoxide gas sensor. This review also focuses the challenges faced by flexible devices, offers the most recent research on paper-based gas sensors and pays special focus on various sensing materials and fabrication techniques.

To get the better insight into opportunities for future improvement, a number of research papers based on sensors were studied and realized the need to design carbon monoxide gas sensor. A number of parameters were then gone through to decide the flexibility parameter to be considered for design purposes. This review also focuses on the challenges faced by flexible devices and how they can be overcome.

It has been shown that carbon monoxide gas, being most contaminated gas, needs to be fabricated to sense low concentration at room temperature, considering flexibility as an important parameter. Regarding this parameter, some tests must be done to test whether the structure sustains or degrades after bending. The parameters required to perform bending are also described.

Due to inherent limitations of conventional silicon-based technology, now-a-days attention is paid towards flexible electronics to design low-cost, high-sensitivity devices. A number of research articles are provided in the literature concerning gas sensing for different applications using several sensing principles. This study aims to provide a comprehensive overview of recent developments in carbon monoxide gas sensors along with the design possibilities for flexible paper-based gas sensors. All the aspects have been taken into consideration for the fabrication, starting with paper characterization techniques, various sensing materials, manufacturing methodologies, challenges in the fabrication of flexible devices and effects of bending and humidity on the sensing performance.