Controlling the power flow in transmission systems has recently gained increased interest. The difficulties of building new lines and the pressure of having a high utilization of existing assets, makes the flexibility of grid systems increasingly important. This master thesis work investigates induction regulators as control devices for active power flow in a transmission system. A small change in angle of the rotor affects both the amplitude and the phase of the voltage. The magnetic coupling in the induction regulator can be controlled by changing the permeability of a thermo magnetic material such as gadolinium and can hence give a second independent controlling parameter. An analytical model and calculations in the FEM software AceTripleC together with Matlab, is used to simulate the influence of the regulators connected to a simple grid in case1, a 400 kV scenario and case 2, a 45 kV scenario. The analysis was carried out on a small transmission system consisting of two parallel transmission lines connected to source and load. The induction regulators are connected to one of the parallel transmission lines. The regulators modelled in case 1 must be able to control the active power flow in the regulated line to vary between 50 and 150 % of the original power flow through this line. This shall be done over a range of 0 to 800 MW transmitted power. The regulators modelled in case 2 must be able to control the active power flow in the regulated line to vary between 0 and 30 MW, if this does not cause the power flow in the parallel line to exceed 30 MW. This shall be done over a range of 0 to 50 MW transmitted power. The regulators are designed as small and inexpensive as possible while still fulfilling requirements regarding the active power flow controllability in the grid, current density in windings and maximum flux density in core and gap. The results indicate that the size of the 400 kV solution has to be reduced to become competitive whereas for the 45 kV solution the relative difference to existing solution is smaller. Advantages with the proposed design over a phase shifting transformer are mainly a simpler winding scheme and the absence of a tap changer.

This work describes the implementation of DC to DC converter for Smart Dust in 65 nm CMOS technology. The purpose of a DC to DC converter is to convert a battery voltage of 1 Vto a lower voltage of 0.5 V used by the processor. The topology used in this DC to DC converteris of Buck type which converts a higher voltage to lower voltage with the advantage of givinghigh efficiency about 75%. The system uses PWM (Pulse width modulation) technique. It usesnon-overlapping clock generation technique for reducing the power consumption. The systemprovides up to 5 mA load current and has power consumption of 2.5 mW.

Low drop out (LDO) voltage regulators are widely used for post regulating the switching ripples generated by the switched mode power supplies (SMPS). Due to demand for portable applications, industry is pushing for complete system on chip power management solutions. Hence, the switching frequencies of the SMPS are increasing to allow higher level of integration. Therefore, the subsequent post-regulator LDO must have good power supply rejection (PSR) up to switching frequencies of SMPS. Unfortunately, the conventional LDOs have poor PSR at high frequencies. The objective of this research is to develop novel LDO regulators that can achieve good high frequency PSR performance. In this thesis, two PSR improvement methods are presented. The first method proposes a novel power supply noise-cancelling scheme to improve the PSR of an external-capacitor LDO. The proposed power supply noise-cancelling scheme is designed using adaptive power consumption, thereby not degrading the power efficiency of the LDO. The second method proposes a feed forward ripple cancellation technique to improve the PSR of capacitor-less LDO; also a dynamically powered transient improvement scheme has been proposed. The feed forward ripple cancellation is designed by reusing the load transient improvement block, thus achieving the improvement in PSR with no additional power consumption. Both the projects have been designed in TSMC 0.18 μm technology. The first method achieves a PSR of 66 dB up to 1 MHz where as the second method achieves a 55 dB PSR up to 1 MHz.

Low Dropout Regulators (LDOs) are extensively used in portable applications like mobile phones, PDAs and notebooks. These portable applications demand high power efficiency and low output voltage ripple. In addition to these, the radio circuits in these applications demand high power supply rejection (PSR). The output voltage of a conventional DC/DC converter (generally switched mode) has considerable ripple which feeds as input to these LDOs. And the challenge is to suppress these ripples for wide range of frequencies (for radio units) to provide clean supply. Enhanced buffer based compensation is proposed for the fully on-chip CMOS LDO which stabilizes the loop for different load conditions as well as improve the power supply rejection (PSR) until frequencies closer to open loop‟s unity-gain frequency. The stability and PSR are totally valid even for load capacitor varying from 0 to 100 pF. The proposed capacitor-less LDO is fabricated in On-Semi 0.5 μm fully CMOS process. Experimental results confirm a PSR of -30 dB till 420 KHz for the maximum load current of 50mA. The load transients of the chip shows transient glitches less than 90 mV independent of output capacitance.

A new DC-DC up converter with high efficiency and low output ripple is proposed. We replace previous charge pump converters by switched-capacitor converters to improve the power efficiency and add a voltage regulator at the output to reduce the ripple voltage. The converter reduces the magnitude of output voltage ripples to 36% of the previous converter, and improves the power efficiency from 58% to 73%. The proposed converter is designed to obtain 1.6 mA driving capability with a output voltage around 5.3 ~ 5.4 V. A VCO is also added as the load to test the converter circuit. The VCO is insensititive to power supply noises. The proposed converter circuit is simulated in a TSMC 0.35-um Mixed-mode (2P4M) CMOS process.

Power management has had an ever increasing role in the present electronic industry. Battery powered and handheld applications require power management techniques to extend the life of the battery and consequently the operation life of the device. Most systems incorporate several voltage regulators which supply various subsystems and provide isolation among such subsystems. Low dropout (LDO) voltage regulators are generally used to supply low voltage, low noise analog circuitry. Each LDO regulator demands a large external capacitor, in the range of a few microfarads, to perform. These external capacitors occupy valuable board space, increase the IC pin count, and prohibit system-on-chip (SoC) solutions. The presented research provides a solution to the present bulky external capacitor LDO voltage regulators with a capacitor-less LDO architecture. The large external capacitor was completely removed and replaced with a reasonable 100pF internal output capacitor, allowing for greater power system integration for SoC applications. A new compensation scheme is presented that provides both a fast transient response and full range ac stability from a 0mA to 50mA load current. A 50mA, 2.8V, capacitor-less LDO voltage regulator was fabricated in a TSMC 0.35um CMOS technology, consuming only 65uA of ground current with a dropout voltage of 200mV. Experimental results show that the proposed capacitor-less LDO voltage regulator exceeds the current published works in both transient response and ac stability. The architecture is also less sensitive to process variation and loading conditions. Thus, the presented capacitor-less LDO voltage regulator is suitable for SoC solutions.

As the application of the consuming electronic products being used extensively, more and more functions can be worked on the same chip. Different function blocks may need different supply voltage. Considering of power consumption, circuit operated at low voltage and low current can achieve power reduction. Due to the energy crisis nowadays, plenty of products begin to focus on the green power. The main advantage of green power is saving power, which will not affect the efficiency. In addition, while the CMOS technology process evolves all the time, the stability of the operation voltage needs to be reduced by the advancement. Thus, the power management in a 3D graphic chip application is going to be introduced in this thesis. Utilizing the linear regulator to reduce the DC to 1.2, 1.1, 1.0, 0.9 and 0.8 V from 3.3V, and support a stable voltage for core circuits and I/O circuits. With the emphasis on the circuit efficiency is affected by power management, the level shifter to embed normal useful digital logic is also investigated. When using in the logic gates, it can reduce power consumption simultaneously. Therefore, it is important to adopt power IC in the future.

The idea to develop  a platform for a PID-controller came from the need to control the temperature in  an espresso machine in a more exact way than a thermostat could perform. In discussions with Syntronic AB the idea developed into PID-control for industrial use. Syntronic AB suggested that the platform should be based on a commercially available processor module to shorten the development time. The suggestion included the use of the microcomputer Raspberry Pi, which supports USB, HDMI, memory card and Ethernet. The work began with establishing a schedule for the 10 weeks of the projects duration, and after that a system specification listing all functions, implementation and limitations was made. When the foundation of the system specification was done, a preliminary system design took shape. Because of the Raspberry Pi´s lack of Analog-to-Digital converter, a circuit board containing Wheatstone bridges, differential amplifiers and a two channel Analog-to-Digital converter was fabricated. The choice of Operative System fell on Linux Raspbian Wheezy, a popular Linux distribution with good documentation. Embedded programming was made solely in C language, Nginx was used as server application making it possible to show real-time graph and receive parameter input from a webpage. The webpage was written in PHP and JavaScript for server and client side respectively. To evaluate the PID-controller it was mounted inside an espresso machine where it controlled the temperature of the boiler. Aiming for a short settling time, parameters for the PID-controller was produced by testing. / Idén till att utveckla en plattform för PID-reglering föddes ur tanken att kunna styra temperaturen i en espressomaskin på ett mer exakt sätt än vad en termostat förmår. Vid samtal med Syntronic AB utarbetades iden till att handla om PID-reglering för generella applikationer för industriellt bruk. Syntronic AB gav förslag om att basera reglersystemet på en kommersiellt tillgänglig processormodul för att minska utvecklingstiden. Förslaget innefattade mikrodatorn Raspberry Pi, som har stöd för USB, HDMI, minneskort och Ethernet.   Arbetet började med att upprätta en tidsplan för de tio veckor projektet pågick, sedan påbörjades en kravspecifikation som specificerar systemets alla funktioner, utförande och begränsningar. När grunderna i kravspecifikationen var klara togs en preliminär systemdesign fram. Eftersom nämnd mikrodator saknar en analog/digital-omvandlare konstruerades ett kretskort där kretsar för Wheatstone-bryggor, ADC, differentialförstärkare, ingångar och utgångar placerades. Val av operativsystem föll på Linux Raspbian Wheezy, då denna distribution var populär och hade en god dokumentation. All hårdvarunära programmering gjordes uteslutande i C-språk. Webbserver-applikationen Nginx installerades på mikrodatorn för att kunna visa grafer och kunna mata in parametrar via en hemsida över internet. Hemsidan skrevs i språken PHP och JavaScript för server- respektive klientsida. För att utvärdera PID-regulatorn, monterades den i en espressomaskin där den fick styra kokarens värmeelement. Parametrarna för PID-regulatorn testades fram för att om möjligt korta ner tiden tills dess att temperaturen blev stabil.

Serratia marcescens, a member of Enterobacteriaceae family, is a causative agent of nosocomial and opportunistic infections. Numerous reports show that the multidrug resistance among S. marcescens is growing. This organism has high-level intrinsic resistance to a variety of antimicrobial agents, which makes the treatment of infections caused by this bacterium very difficult. The major mechanism for antibiotic resistance, especially to fluoroquinolones, in Gram-negative organisms is the active efflux of the antibiotic molecule mediated by efflux pumps belonging to the Resistance-Nodulation-Cell Division (RND) family. It was previously shown that the SdeAB and SdeXY multidrug efflux pumps are important for conferring the intrinsic drug resistance in S.marcescens. In Escherichia coli, the up-regulation of transcriptional activators, such as MarA, SoxS and Rob, affect transcription of acrAB, tolC and micF. Over-expression of Rob results in increased expression of the E. coli AcrAB-TolC efflux pump and decreases outer membrane permeability through up-regulation of micF, resulting in multidrug, organic solvent and heavy metal resistance. In the present study, we report the identification of a rob gene in S. marcescens which has a 70% identity at the DNA level and 71% identity at the amino acid level to that of E. coli. Moreover, the S. marcescens rob demonstrated similar properties to the E. coli rob including having an effect on expression of outer membrane protein F (OmpF) and over-expression of SdeAB and SdeXY, conferring antibiotic resistance to divergent antibacterial agents and tolerance to organic solvents. We performed rob promoter evaluations using transcriptional fusions to the Green Fluorescence Protein (GFP) in the vector pGlow-TOPO and constructed a rob knock-out using the TargeTron Gene Knockout System. Promoter activity assessment, using the pGlow-TOPO reporter plasmid, showed that rob had higher promoter activity at 37°C than 30°C. In the presence of 2,2’-dipyridyl, rob promoter activity was observed to be slightly increased in the early and mid-log phase by 1.4 and 1.1 fold, respectively. We also showed that sodium decanoate and sodium salicylate can reduce the transcription of rob at 30°C and 37°C. This reduction was observed more potently when rob was exposed to sodium decanoate at 30°C. Minimum inhibitory concentration (MIC) for various antibiotics of the S. marcescens rob knock-out demonstrated a decrease in susceptibility to nalidixic acid, tetracycline, chloramphenicol, ciprofloxacin, norfloxacin, and ofloxacin. Over-expression of rob resulted in an increased resistance by 4, 2, and 2-fold to nalidixic acid, tetracycline and chloramphenicol, respectively. In addition, rob over-production displayed 8, 4, and 4-fold increase in resistance to ciprofloxacin, norfloxacin, ofloxacin, respectively. To discover the role of rob in the efflux mechanism, we performed ethidium bromide accumulation assays on over-expressing and knock-out strains. Organic solvent tolerance assays were carried out using n-hexane to determine if rob is involved in expression of efflux pumps. We found the rob null mutant to be sensitive to n-hexane while the over-expression of rob resulted in resistance to n-hexane. RT-PCR of the rob knock-out strain showed a decrease in expression of micF, ompC, sdeXY, sdeAB and tolC, respectively, and an increase in the expression of ompF. To conclude, we identified a rob homolog in S. marcescens which contributes to resistance to multiple antibiotics and tolerance to organic solvent.

To make a camera more user friendly or let it operate without an user the camera objective needs to be able to put thecamera lens in focus. This functionality requires a motor of some sort, due to its many benefits the ultrasonic motor is apreferred choice. The motor requires a driving circuit to produce the appropriate signals and this is what this thesis is about.Themain difficulty that needs to be considered is the fact that the ultrasonic motor is highly non-linear.This paper will give a brief walk through of how the ultrasonic motor works,its pros and cons and how to control it. How thedriving circuit is designed and what role the various components fills. The regulator is implemented in C-code and runs on amicro processor while the actual signal generation is done on a CPLD. The report ends with a few suggestions of how toimprove the system should the presented solution not perform at a satisfactory level.