Academic literature on the topic 'Xenon headlight'

In this study, ageing effect for xenon through experiment has been studied. The study focuses on the modeling, ageing characteristics of xenon car headlight. The modeling of the lamp is based on spline interpolation algorithms. In this model, the voltage drop at the electrodes is considered as the aging factor. Ageing characteristics under the flicker condition for 4 types of xenon car headlight lamps have been measured. The flicker time is 4 seconds turn on and 2 seconds turn off, and the total testing time is 48 hours. The luminous, voltage and current of the lamp are measured. It is found that even a short period of flicker significantly affects the life time of the lamp.

Invention and improving the methods of ENT examination are closely connected with the technological inventions of the 19th and 20th centuries. The invention of the classical exam head mirror in 1861 and improvement of the manufacturing of compact and powerful sources of light (filament lamps) at the time caused the researchers to create new devices for ENT examination. In particular, a head-mounted electro-mirror was created, the principle of which later became the basis for the development of fiber-optic headlamps. The emergence of powerful halogen and xenon light sources in the mid-20th century and the use of fiber-optics technology led to the development of fundamentally new mirror less headlamps. The traditional head-mounted reflector has gradually disappeared from the practice of an otolaryngologist. For our part, we can see how fiber-optic headlamps have been progressively replaced by heavy-duty LED headlamps over the last nine years. In order to determine the effectiveness of each available headlamp type and to answer the question of whether there is a benefit in using and maintaining a reflector headlamp, and to determine which current head-lamps are effective, we conducted our own research. Summing up the results, we came to the conclusion that despite its historic role in the development of otorhinolaryngology, the headlamp reflector through its low, in comparison with modern illuminators, characteristics have lost its relevance and, apparently, nowadays can serve as a museum exhibit. The head-mounted LED illuminator, a 21st century device, is gaining in popularity and is gradually becoming the standard for use in primary ENT diagnosis and during otorhinolaryngological surgical interventions. Its features such as full autonomy, lightweight, ease of use – especially the alignment of the light beam with the surgeon's eye – long operating time without recharging the battery (7 to 30 days) – depending on the manufacturer and the workload of the device – is beyond competition with any other head-mounted device for ENT organ examination.

In collision reconstruction of nighttime accidents, the conspicuity of hazards from a driver's perspective is a critical factor. When the collision involves large commercial vehicles, the visibility of the reflective strips is essential in assessing avoidance. Reflective strips on commercial vehicles are generally consistent from vehicle to vehicle and are highly reflective between perpendicular and 45° viewing angles. However, at shallower viewing angles (closer to parallel viewing), which occurs when trailers begin turns, the reflective strips may not be effective. In this initial study, the effectiveness of reflective strips at shallow viewing angles (‘entrance angles’ of 45° to 90°) was examined under a variety of test conditions including high beams and viewing distances of up to 150 m. The results indicated that at entrance angles of less than 70°, reflective strips are highly effective warnings from a human factors perspective. At entrance angles of more than 75°, reflective strips are ineffective. From 70° to 75°, the results were sensitive to the test parameters. This study does not address the visibility of the tractor or other aspects of nighttime visibility. Further research is recommended to extend this study to greater viewing distances, xenon headlights, ‘dirty’ vs. ‘cleaned’ reflective strips, and wet roads, with particular attention to entrance angles of 70° to 75°.

This master’s thesis deals with the possibilities of illumination of motor vehicles. Thesis is divided into two sections, from which the first discusses precisely the possibilities of lighting of motor vehicles at the present time. What are the modern lighting techniques, that can be found on the market and what is their impact on safety enhancement in road traffic. Second section is about the practical measurement of low and high beam afterglow. This measurement is being compared between two types of headlamps, namely halogen headlights and xenon headlights. Part of the measurement is as well measurement of illumination intensity precisely for these headlights. The output of measurement is the creation of own illumination intensity diagrams and afterglow diagrams of particular headlights, in comparison to isolux diagrams provided by the headlights manufacturer. Consequently are solved the issues about utilization of the isolux diagrams in expert praxis.

碩士
國立彰化師範大學
電機工程學系
93
Abstract The goal of the thesis is to design and implement an electronic ballast for automotive xenon headlight lamps using DC 12V battery power source. Compared with electromagnetic ballasts, the electronic ballast used in this study utilizes the technology of switching converter and inverter to improve the efficiency, device size, lighting stability and lamp lifetime. Furthermore, the acoustic resonance problem can be solved by supplying square-waveform alternative current to the lamp. Typical electronic ballasts use a full bridge inverter to drive the xenon lamp, but this method increases the cost significantly. On the contrast, the traditional half bridge inverter has the advantage of lower cost but three intrinsic disadvantages: (1) unbalanced voltage output; (2) DC offset in transient period; (3) possible power failure at low operation frequencies. In order to solve these three problems, this study applies two DC power sources generated from a flyback converter for the half bridge inverter. The experimental results prove the feasibility of this method and show fine performance. In addition, several suggestions for advance research on the electronic ballast are presented in the thesis.

碩士
國立成功大學
電機工程學系碩博士班
95
This thesis presents a novel electronic ballast to drive dual Xenon headlight lamps. Two flyback converters are used to provide the lamp power from the warm-up period to the steady state. A common-leg bridge inverter is used to drive the two lamps with a low- frequency square-wave to eliminate the acoustic resonance from operation. The lamps are driven with negative lamp voltage to increase lamp life. Also, the electronic ballast is controlled by a micro control unit (MCU). The start-up sequences and constant lamp power control of the lamps are achieved by the digital signal processor (DSP). The transition state and steady state of a lamp are described in this thesis. Finally, a laboratory prototype of a 35W D1 automotive electronic ballast has been implemented to verify its feasibility.

碩士
國立雲林科技大學
電機工程系碩士班
93
This thesis carries on a deep discussion of operation principle and characteristic about high intensity discharge lamps for automotives, and develops an electronic ballast to achieve stable operation of the High Intensity Discharge Lamp (HID lamp). The circuit structure used in this thesis consists of three parts: (1) a flyback of boost converter, to supply the power for lamp; and (2) an igniting circuit, utilizing simple spark gap ignition circuit to offer the breaking voltage for high intensity discharge lamp; and (3) a full-bridge square wave inverter, offering a square wave of low frequency in order to suppress the acoustic resonance and improve light source stability. The system utilizes microcontroller ATmega 8535 of ATMAL for the system to control the time sequence when starting the lamp, and to scan the voltage and current when controlling the constant power for the lamp in steady state. Finally, an HID lamp of 35W for automotive is examined and analyzed.