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361 Uppsatser om Speech amplifier - Sida 1 av 25
Drivförstärkare : Bredbandig drivförstärkare med hög verkningsgrad
This report present the design and manufacturing of a wide-band driver amplifier placed in radar module for airborne applications. The major goals for the amplifier were a high efficiency and to deliver a predefined output power. To reach the second goal an additional preamplifier had to be constructed. The amplifiers were constructed in three steps: Design and Layout in the software Microwave Office, Mounting components and Verification. The driver amplifier was decided to be a push pull configuration consisting of two parallel transistors biased in class AB.
Design av slutsteg med digital PWM-teknik för gitarr
Softube has developed DSP-card and software for simulation of the sound of old tube amplifiers. The purpose with this thesis is to design a compact amplifier with high power to function together with the DSP-card and build a unit that can replace several other guitar amplifiers. The advantages with that kind of solution could be that it would be cheaper, easier to carry and easier to stor than the real amplifiers. The amplifier that has been designed is of class D type with digital PWM modulator. There is several types of amplifier modules on the market that use analog input signal, but if one of them would be used a D-A converter is needed on the DSP card.
PWM Effekt Audioförstärkare
The purpose with the report is to show that it is possible to design a class-D amplifier, using a programmable FPGA mounted on a developing card from Xess and a H-bridge. The FPGA was programmed in VHDL which is the language the software from Xilinx use to implement a logical function into the FPGA The logical function corresponds to a modeling of the music signal and the modeling can be described as a comparator which compare the music signal with a triangle wave and as a out signal produce a pulse width modulated (PWM) signal. The report is also a review and evaluating of two different modulating technologies, AD- modeling and BD-modeling. A detailed part about how the H-bridge was designed and how it works. The result of this project is a working audio amplifier to a significant lower price than the products in todays market..
Implementing a receiver in a fast data transfer system : A feasibility study
This report is an outcome of a master degree project at Linköpings University in co-operation with Micronic Laser Systems AB. The purpose with this master degree project was to investigate how to implement a receiver in a data transfer system. The system consists of several data channels, where every channel consists of three parts: driver, transmission lines and receiver. The driver send low amplitude differential signals via the transmission lines to the receiver that amplifies and converts it to a single-ended signal. The receiver has to be fast and be able to feed an output signal with high voltage swing.
Yttrandefrihetens gränser : En prövning utifrån tre fall och tre teoretiker
Freedom of speech has been a well discussed subject. Great philosophers and theoretics like Plato, Voltaire, Locke and Mill have again and again showed the importance of freedom of speech. Since the world have become bystanders to a series of events that can only classify as crimes aganst freedom of speech, it has become more important to study the phenomenon and analyse it. By finding cases where the freedom of speech has been compromised and analyse them in frames of three different theories, the argument of truth, the argument of democracy and the argument of tolerance, this paper makes the boundaries of freedom of speech a little clearer, and also makes a discussion about how reasonable the boundaries are possible. Everything according to the three theories.
Kan talspråk integreras inom kunskapsorganisation? Problematiken med talspråk som bibliografiskt språk
Writing has been the most important tool in knowledge organization KO. In our modern society we can use our speech as a technical tool to seek information. Can we apply speech as a tool to organize information? The aim of this masters thesis is to problemize speech aspects in the field of knowledge organization KO. The investigation has two main parts and I use a hermeneutic approach.
Perceptuell bedömning av tal före och efter svalglambåplastik hos patienter med velofarynxinsufficiens
Velopharyngeal insufficiency may affect resonance, articulation and thus how speech is perceived by other listeners. Velopharyngeal insufficiency is frequently found in the cleft palate population due to structural abnormalities of the palate. The pharyngeal flap is the most commonly used operation designed to improve velopharyngeal function. The aim of the present study was to compare speech before and after pharyngeal flap surgery by perceptual evaluation regarding nasality, articulation and deviant speech. The study includes preoperative and postoperative speech samples of 28 patients who underwent pharyngeal flap surgery at the University Hospital in Linköping between 2002 and 2007.
Unga vuxna med unilateral läpp-, käk- och gomspalt ? perceptuell bedömning och självskattning av tal och kommunikation
The purpose of this study was to investigate how young adults withunilateral cleft lip and palate assess their own speech and communication,and to let speech and language pathologists make a perceptual analysis ofthese individuals? speech at the age of 19 years. An additional aim was toexamine the relationship between these two different ways of evaluation.Data was collected through perceptual analysis from audio recordings and byusing a self-report questionnaire based on the ICF-structure (InternationalClassification of Function, disability and health). Altogether, 33 peopleparticipated. One third of the participants had no speech deficiencies.
Talresultat hos 16-åringar födda med unilateral läpp-, käk- och gomspalt samt jämförelse mellan erfarna och otränade lyssnares bedömningar
In this study the speech of adolescents with unilateral cleft lip andpalate (UCLP) and delayed closure of the hard palate was evaluated.Evaluations were made with experienced speech-language pathologists(SLP:s) and lay listeners. The SLP evaluation consisted of typical cleft palatespeech variables and some of them were adapted for lay listeners. Attitudestowards the speech of the adolescents were investigated by asking laylisteners if the speech constituted any hindrance to vocational performance.The SLP:s mainly found nasal escape and velopharyngeal impairment (VPI),although to a small degree and extent. The lay listeners mainly foundresonance deviations and indistinct speech. The latter was associated withhindrance to vocational performance.
Integrering av DSP i talförstärkaren MMT-4
Att ansluta en digital signalprocessor kräver ett omfattande arbete. Innehållet i denna rapport sammanfattar teoretiska metoder för att integrera den digitala signalprocessorn ADAU1701 i talförstärkaren MMT-4, utvecklad av företaget Xena Medical. Arbetet har till största delen bestått i att finna en lämplig DSP och studera dess datamanual för att anpassa den till talförstärkaren.Mycket av rapporten sammanfattar beräkningar av komponentvärden och anpassning av ADAU1701 för MMT-4:s behov. ADAU1701 beskrivs utifrån det så kallade selfboot-läget där processorn kan arbeta som fristående processor..
Automatiserad konstruktion av analoga förstärkare
The last few decades the development in the field of electronics has been huge. The components performance gets better at the same time as the manufacturing cost decreases. Many of the design moments that have to be done, are done automatically today, but it can get better. Especially for analog circuit design.At Electronic System in Linköpings universitet, research is in progress to develop a tool that can design analog circuits in reasonable time. It means that it has to size the components (transistors, resistances, capacitances etc), so that the circuit can fulfill the performance requirements.
Perceptuell bedömning av tal och röst hos vuxna med 22q11-deletionssyndrom
Speech anomalies have been described as characteristic symptoms forthe 22q11 deletion syndrome. However, research on speech and voice in adultswith the syndrome is still scarce. Previous research has indicated that speech andvoice anomalies seen in children with the syndrome might have neurologicalcauses. The aim of this study is to investigate speech and voice in a group ofadults diagnosed with the 22q11 deletion syndrome, with extra focus onanomalies with possible neurological cause. The researched group consisted of24 adults between the ages 19 to 38 with a verified 22q11-deletion, 16 womenand 8 men.
Trådlös energiöverföring via elektromagnetisk induktion
This paper describes a method for wireless energy transfer via near-field electromagnetic inductionthat is inexpensive, simple and can be applied to almost any type of system, regardless of size andenergy demands.The method uses a primary unit consisting of an oscillator, amplifier and inductive coil thattransfers energy to a secondary unit consisting of a coil, rectifier and voltage regulator. Two typesof oscillators and several amplifier designs were realized and evaluated together with a multitudeof flat coils of both monofilar and bifilar type.The results show that it is important to use an oscillator whose frequency is dependent on theinductance of the connected transmission coil, such as the Colpitts oscillator. This is preferable toan oscillator with a preset frequency, such as a Schmitt-trigger oscillator..
Utveckling av de enstaviga ordlistorna för talaudiometri - begreppsanalys och teoriutveckling
Audionomprogrammet.
Förväxlingar av ord i testet FB S/N +4
It is always more demanding and the risk for misunderstanding increases when communicating in noisy environments. The confusions and the mistakes that occur when speech is disturbed are very interesting and happens constantly. The purpose of this study was to examine speech recognition results from the test PB S/N +4 and find out which confusions that are made by the normal hearing and by the hearing impaired persons in the speech lists 3 and 4, and also analyse the mistakes from a phonetic perspective. Ten normal hearing and 50 persons with impaired hearing participated in the study. The people with impaired hearing were divided into two groups; DTMV 40 dB HL.The results were compared between the normal hearing and those with impaired hearing.