Digital control of dual-load LCLC resonant converters

The paper proposes the analysis, design and realisation of dual-output resonant LCLC converters with independent output regulation, employing a single power stage and combined PWM and frequency control. Asymmetric switching of the power devices is used to facilitate independent control of the outputs to provide +5 V and +3.3 V from a 15 V-20 V input supply over a range of load condition

Rapid analysis & design methodologies of High-Frequency LCLC Resonant Inverter as Electrodeless Fluorescent Lamp Ballast

The papers presents methodologies for the analysis of 4th-order LCLC resonant power converters operating at 2.63 MHz as fluorescent lamp ballasts, where high frequency operation facilitates capacitive discharge into the tube, with near resonance operation at high load quality factor enabling high efficiency. State-variable dynamic descriptions of the converter are employed to rapidly determine the steady-state cyclic behaviour of the ballast during nominal operation. Simulation and experimental measurements from a prototype ballast circuit driving a 60 cm, 8W T5 fluorescent lamp are also included

Modelling and regulation of dual-output LCLC resonant converters

The analysis, design and control of 4th-order LCLC voltage-output series-parallel resonant converters (SPRCs) for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are employed and new analysis techniques are developed to establish operating mode boundaries with which to describe the internal behaviour of a dual-output resonant converter topology. The designer is guided through the most important criteria for realising a satisfactory converter, and the impact of parameter choices on performance is explored. Predictions from the resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control

Analysis and control of dual-output LCLC resonant converters, and the impact of leakage inductance

The analysis, design and control of 4th-order LCLC voltage-output series-parallel resonant converters (SPRCs) for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are developed to establish operating mode boundaries with which to describe the internal behaviour of dual-output resonant converters, and the impact of output leakage inductance. The resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control to verify the analysis, modeling and control predictions

Study of the Staebler-Wronski degradation effect in a-Si:H based p-i-n solar cell

Conversion of solar energy into electricity using environmentally safe and clean photovoltaic methods to supplement the ever increasing energy needs has been a cherished goal of many scientists and engineers around the world. Photovoltaic solar cells on the other hand, have been the power source for satellites ever since their introduction in the early sixties. For widespread terrestrial applications, however, the cost of photovoltaic systems must be reduced considerably. Much progress has been made in the recent past towards developing economically viable terrestrial systems, and the future looks highly promising. Thin film solar cells offer cost reductions mainly from their low processing cost, low material cost, and choice of low cost substrates. These are also very attractive for space applications because of their high power densities (power produced per kilogram of solar cell pay load) and high radiation resistance. Amorphous silicon based solar cells are amongst the top candidates for economically viable terrestrial and space based power generation. Despite very low federal funding during the eighties, amorphous silicon solar cell efficiencies have continually been improved - from a low 3 percent to over 13 percent now. Further improvements have been made by the use of multi-junction tandem solar cells. Efficiencies close to 15 percent have been achieved in several labs. In order to be competitive with fossil fuel generated electricity, it is believed that module efficiency of 15 percent or cell efficiency of 20 percent is required. Thus, further improvements in cell performance is imperative. One major problem that was discovered almost 15 years ago in amorphous silicon devices is the well known Staebler-Wronski Effect. Efficiency of amorphous silicon solar cells was found to degrade upon exposure to sunlight. Until now their is no consensus among the scientists on the mechanism for this degradation. Efficiency may degrade anywhere from 10 percent to almost 50 percent within the first few months of operation. In order to improve solar cell efficiencies, it is clear that the cause or causes of such degradation must be found and the processing conditions altered to minimize the loss in efficiency. This project was initiated in 1987 to investigate a possible link between metallic impurities, in particular, Ag, and this degradation. Such a link was established by one of the NASA scientists for the light induced degradation of n+/p crystalline silicon solar cells

Testing conditional factor models

Using nonparametric techniques, we develop a methodology for estimating and testing conditional alphas and betas and long-run alphas and betas, which are the averages of conditional alphas and betas, respectively, across time. The estimators and tests can be implemented for a single asset or jointly across portfolios. The traditional Gibbons, Ross, and Shanken (1989) test arises as a special case of no time variation in the alphas and factor loadings and homoskedasticity. As applications of the methodology, we estimate conditional CAPM and multifactor models on book-to-market and momentum decile portfolios. We reject the null that long-run alphas are equal to zero even though there is substantial variation in the conditional factor loadings of these portfolios

Tinjauan Yuridis terhadap Perluasan Alat Bukti Penyadapan dalam Tindak Pidana Korupsi

Pengaturan penyadapan di Indoneisa sendiri sudah di atur dalam beberapa undang-undang yakni undang-undang tindak pidana khusus dan juga dalam undang-undang tentang informasi dan transaksi elektronik, tetapi tidak di atur dalam undang-undang No. 8 tahun 1981 tentang KUHAP dan masih memiliki berbagai masalah mengenai pengaturan prosedur atau tata cara penyadapan sehingga terjadi ketidakseimbangan antara ketentuan yang satu dengan ketentuan yang lain, dan porses penyadapan harus sesuai dengan peraturan Perundang-undangan yang berlaku dan sesuai dengan apa yang disyaratkan antara lain penyadapan yang dilakukan harus benar-benar berdasarkan kepentingan hukum, proses penyadapan juga harus melalui persetujuan lembaga hukum terkait. Alat bukti penyadapan pada dasarnya tidak memiliki dasar hukum pada KUHAP, karena didalam KUHAP itu sendiri hanya mengatur lima alat bukti saja yaitu surat,keterangan ahli, keterangan saksi, petunjuk, dan keterangan terdakwa. Alat bukti penyadapan hanya di atur di tindak pidana khusus saja yaitu dalam UU 31 tahun 1999 jo undang-undang no 20 tahun 2001 pasal 26A tetang pemberantasan tindak pidana korupsi dan undang-undang 11 tahun 2008 tentang informasi dan transaksi elektronik. Perluasan alat bukti penyadapan dalam tindak pidana korupsi dapat dilihat dari Undang-undang Nomor 20 Tahun 2001 tentang Perubahan Atas Undang-undang Nomor 31 Tahun 1999 tentang Pemberantasan Tindak Pidana Korupsi yang memperluas alat bukti khususnya alat bukti petunjuk selain yang terdapat dalam KUHAP dimana bukti petunjuk bukan saja diperoleh dari keterangan saksi, surat dan keterangan tersangka tetapi sesuai Pasal 26A alat bukti petunjuk juga diperoleh dari alat bukti lain yang berupa informasi yang diucapkan, dikirim, diterima, atau disimpan secara elektronik dengan alat optik atau yang serupa dengan itu; dandokumen, yakni setiap rekaman data atau informasi yang dapat dilihat, dibaca, dan atau didengar yang dapat dikeluarkan dengan atau tanpa bantuan suatu sarana, baik yang tertuang di atas kertas, benda fisik apapun selain kertas, maupun yang terekam secara elektronik, yang berupa tulisan, suara, gambar, peta, rancangan, foto, huruf, tanda, angka, atau perforasi yang memiliki makna.Sehingga alasan untuk dilakukan perluasan alat bukti penyadapan karena ingin mencari bukti-bukti untuk mengungkap tindak pidana korupsi dan mencari kebenaran materil yang sangat sulit