Abhijit Pathak - Academia.edu (original) (raw)
Papers by Abhijit Pathak
The capacitors used in these types of equipments are high voltage energy storage capacitors that ... more The capacitors used in these types of equipments are high voltage energy storage capacitors that need to be carefully charged by a specially designed “Capacitor-Charging Power Supply” CCPS. Fig (1) depicts charge and discharge cycle of the capacitor (or banks of capacitors in parallel, depending on the energy required), in which one can easily see the soft and slow charging cycle and the abrupt discharge. Notice also the trickle charge or refresh mode, which immediately follows the charge mode.
Power Electronics find numerous applications in a variety of HiRel fields, including space, aviat... more Power Electronics find numerous applications in a variety of HiRel fields, including space, aviation, automotive and other allied fields. To get desired MTBF and MTTR, many special design criteria, critical quality assurance and extensive testing are called for. Over time, these design criteria, quality standards, testing methodology have evolved, which, when properly implemented, result in long term reliability in harsh environment. To achieve high reliability of power electronics, recommended methods and considerations are mentioned and explained briefly. Space applications call for some additional considerations such as radiation hardness towards Total Ionization Dose (TID), Single Event Effects (SEE), ELDRS, Neutron effects; functional redundancy; heat dissipation through conduction and/or radiation due to vacuum; shock and vibrations and restrictions on weight and volume. Space applications also need unattended long term reliability for decades and remote operation through tele...
Procedia Computer Science
Abstract Now-a-days, the natural irrigation system is under pressure due to the growing water sho... more Abstract Now-a-days, the natural irrigation system is under pressure due to the growing water shortages, which are mainly caused by population growth and climate change. Therefore, the control of water resources to increase the allocation of retained water is very important. It has been observed in the last two decades, especially in the Indian sub-continent, the change of climate affects the agricultural crops production significantly. However, the prediction of good harvests before harvesting, enables the farmers as well as the government officials to take appropriate measures of marketing and storage of crops. Some strategies for predicting and modelling crop yields have been developed, although they do not take into account the characteristics of climate, and they are empirical in nature. In the proposed system, a Cuckoo Search Algorithm has been developed, allowing the allocation of water for farming under any conditions. The various parameters such as temperature, turbidity, pH., moisture have been collected by using Internet of Things (IoT) platform, equipped with related sensors and wireless communication systems. In this IoT platform the sensor data have been displayed in the cloud environment by using ThingSpeak. The data received in the ThingSpeak used in the proposed Cuckoo Search Algorithm, allowing the selection of appropriate crops for particular soil.
International Conference on Power Electronics and Drive Systems, 2003
Advances and breakthroughs continue in MOSFET and IGBT device technology and control strategies t... more Advances and breakthroughs continue in MOSFET and IGBT device technology and control strategies to accomplish goals of efficiency and compactness. It is imperative then to have matched MOSFET/ IGBT driver technology and techniques for reaping all the benefits. This paper describes three unique power management ICs: a 30 amp driver, a 45 MHz driver and a 6 amp high/low side
Additional Conferences (Device Packaging, HiTEC, HiTEN, & CICMT), 2015
Just about all downhole exploratory and operational tools employ a large number of analog and dig... more Just about all downhole exploratory and operational tools employ a large number of analog and digital electronics subsystems and different sensors, gauges etc.-all of which need stable and reliable D.C. power supplies. There exists a geothermal gradient of 25 to 30 0 C/km (40-48 0 C/mile) and at depth of 5 kms, temperature can be as high as 170 0 C and pressure up to 900 bars. But with increasing demand for oil and fast depleting crude oil reserves, almost all companies are now digging deeper and wider, with requirements for downhole tools to be rated at 200ºC. Its implications are that all electronics should not only survive but function at these higher temperatures and pressures. Leading companies, making oil exploration tools and equipment, in both "Logging while drilling" and "continuous logging" applications, need electronics for motion control, instrumentation, computation and telemetry and, to power them, require D.C. power supplies. In order to guarantee operations at 200ºC, manufacturers look for components rated about 10ºC-15 0 C higher or 215ºC to provide design margin. When oil exploration tools and equipment operate, the electronics contained therein also experience shock & vibrations. To ensure reliable operation, therefore, design efforts for all electronics subsystems and power supplies should take all these into account.
Many applications today require reliable and efficient switches that operate efficiently at high ... more Many applications today require reliable and efficient switches that operate efficiently at high voltages. It is rare to find MOSFETS above 1000 VDC and their high RDS(on) make their operation at high voltages unattractive. BiMOSFETs are devices, which have combined strengths of MOSFETs and IGBTs. Nonepitaxial construction and new fabrication processes involved in making BiMOSFETs are described. Many characteristics such as forward voltage drop, gate charge and switching times are shown with the help of curves. Taking into consideration their many advantages, some designs of power supplies for radar transmitters and pulse modulators using BiMOSFETs are presented here. Judicious selection of resonant mode ZVS/ZCS techniques, combined with current fed mode, yields power supplies with many attractive features and benefits for powering TWTs, klystrons and magnetrons. The same approach can be used for building high voltage power supplies for innumerable other applications.
Power Electronics find numerous applications in a variety of HiRel fields, including space, aviat... more Power Electronics find numerous applications in a variety of HiRel fields, including space, aviation, automotive and other allied fields. To get desired MTBF and MTTR, many special design criteria, critical quality assurance and extensive testing are called for. Over time, these design criteria, quality standards, testing methodology have evolved, which, when properly implemented, result in long term reliability in harsh environment. To achieve high reliability of power electronics, recommended methods and considerations are mentioned and explained briefly.
The capacitors used in these types of equipments are high voltage energy storage capacitors that ... more The capacitors used in these types of equipments are high voltage energy storage capacitors that need to be carefully charged by a specially designed “Capacitor-Charging Power Supply” CCPS. Fig (1) depicts charge and discharge cycle of the capacitor (or banks of capacitors in parallel, depending on the energy required), in which one can easily see the soft and slow charging cycle and the abrupt discharge. Notice also the trickle charge or refresh mode, which immediately follows the charge mode.
Power Electronics find numerous applications in a variety of HiRel fields, including space, aviat... more Power Electronics find numerous applications in a variety of HiRel fields, including space, aviation, automotive and other allied fields. To get desired MTBF and MTTR, many special design criteria, critical quality assurance and extensive testing are called for. Over time, these design criteria, quality standards, testing methodology have evolved, which, when properly implemented, result in long term reliability in harsh environment. To achieve high reliability of power electronics, recommended methods and considerations are mentioned and explained briefly. Space applications call for some additional considerations such as radiation hardness towards Total Ionization Dose (TID), Single Event Effects (SEE), ELDRS, Neutron effects; functional redundancy; heat dissipation through conduction and/or radiation due to vacuum; shock and vibrations and restrictions on weight and volume. Space applications also need unattended long term reliability for decades and remote operation through tele...
Procedia Computer Science
Abstract Now-a-days, the natural irrigation system is under pressure due to the growing water sho... more Abstract Now-a-days, the natural irrigation system is under pressure due to the growing water shortages, which are mainly caused by population growth and climate change. Therefore, the control of water resources to increase the allocation of retained water is very important. It has been observed in the last two decades, especially in the Indian sub-continent, the change of climate affects the agricultural crops production significantly. However, the prediction of good harvests before harvesting, enables the farmers as well as the government officials to take appropriate measures of marketing and storage of crops. Some strategies for predicting and modelling crop yields have been developed, although they do not take into account the characteristics of climate, and they are empirical in nature. In the proposed system, a Cuckoo Search Algorithm has been developed, allowing the allocation of water for farming under any conditions. The various parameters such as temperature, turbidity, pH., moisture have been collected by using Internet of Things (IoT) platform, equipped with related sensors and wireless communication systems. In this IoT platform the sensor data have been displayed in the cloud environment by using ThingSpeak. The data received in the ThingSpeak used in the proposed Cuckoo Search Algorithm, allowing the selection of appropriate crops for particular soil.
International Conference on Power Electronics and Drive Systems, 2003
Advances and breakthroughs continue in MOSFET and IGBT device technology and control strategies t... more Advances and breakthroughs continue in MOSFET and IGBT device technology and control strategies to accomplish goals of efficiency and compactness. It is imperative then to have matched MOSFET/ IGBT driver technology and techniques for reaping all the benefits. This paper describes three unique power management ICs: a 30 amp driver, a 45 MHz driver and a 6 amp high/low side
Additional Conferences (Device Packaging, HiTEC, HiTEN, & CICMT), 2015
Just about all downhole exploratory and operational tools employ a large number of analog and dig... more Just about all downhole exploratory and operational tools employ a large number of analog and digital electronics subsystems and different sensors, gauges etc.-all of which need stable and reliable D.C. power supplies. There exists a geothermal gradient of 25 to 30 0 C/km (40-48 0 C/mile) and at depth of 5 kms, temperature can be as high as 170 0 C and pressure up to 900 bars. But with increasing demand for oil and fast depleting crude oil reserves, almost all companies are now digging deeper and wider, with requirements for downhole tools to be rated at 200ºC. Its implications are that all electronics should not only survive but function at these higher temperatures and pressures. Leading companies, making oil exploration tools and equipment, in both "Logging while drilling" and "continuous logging" applications, need electronics for motion control, instrumentation, computation and telemetry and, to power them, require D.C. power supplies. In order to guarantee operations at 200ºC, manufacturers look for components rated about 10ºC-15 0 C higher or 215ºC to provide design margin. When oil exploration tools and equipment operate, the electronics contained therein also experience shock & vibrations. To ensure reliable operation, therefore, design efforts for all electronics subsystems and power supplies should take all these into account.
Many applications today require reliable and efficient switches that operate efficiently at high ... more Many applications today require reliable and efficient switches that operate efficiently at high voltages. It is rare to find MOSFETS above 1000 VDC and their high RDS(on) make their operation at high voltages unattractive. BiMOSFETs are devices, which have combined strengths of MOSFETs and IGBTs. Nonepitaxial construction and new fabrication processes involved in making BiMOSFETs are described. Many characteristics such as forward voltage drop, gate charge and switching times are shown with the help of curves. Taking into consideration their many advantages, some designs of power supplies for radar transmitters and pulse modulators using BiMOSFETs are presented here. Judicious selection of resonant mode ZVS/ZCS techniques, combined with current fed mode, yields power supplies with many attractive features and benefits for powering TWTs, klystrons and magnetrons. The same approach can be used for building high voltage power supplies for innumerable other applications.
Power Electronics find numerous applications in a variety of HiRel fields, including space, aviat... more Power Electronics find numerous applications in a variety of HiRel fields, including space, aviation, automotive and other allied fields. To get desired MTBF and MTTR, many special design criteria, critical quality assurance and extensive testing are called for. Over time, these design criteria, quality standards, testing methodology have evolved, which, when properly implemented, result in long term reliability in harsh environment. To achieve high reliability of power electronics, recommended methods and considerations are mentioned and explained briefly.