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Yazdan Mehr, M. (author), Bahrami, A. (author), van Driel, W.D. (author), Fan, Xuejun (author), Davis, J.L. (author), Zhang, G.Q. (author)
In this paper, degradation mechanisms of optical materials, used in the light emitting diode (LED)-based products, are reviewed. The LED lighting is one of the fastest technology shifts in human history. Lighting accounts for almost 20% of the global electrical energy use, inferring that replacement of traditional lighting sources with LEDs...
journal article 2019
document
Yazdan Mehr, M. (author), van Driel, W.D. (author), De Buyl, Francois (author), Zhang, G.Q. (author)
Degradation mechanisms of silicone plates under harsh environment conditions are studied in this investigation. Environmental degradation of silicone free form, used as secondary optics in Light Emitting Diode LED lighting lamps and luminaires or any other applications requiring high quality optics being used, has negative implications for the...
journal article 2018
document
Sun, B (author), Fan, Xuejun (author), van Driel, W.D. (author), Cui, C (author), Zhang, G.Q. (author)
In this study, we present a general methodology that combines the reliability theory with physics of failure for reliability prediction of an LED driver. More specifically, an integrated LED lamp, which includes an LED light source with statistical distribution of luminous flux, and a driver with a few critical components, is considered. The...
journal article 2018
document
Middelburg, L.M. (author), el Mansouri, B. (author), Poelma, René H. (author), van Zeijl, H.W. (author), Wei, J. (author), Zhang, G.Q. (author), van Driel, W.D. (author)
The mechanical part of inertial sensors can be designed to have a large mechanical sensitivity, but also requires the transduction mechanism which translates this displacement. The overall system resolution in mechanical inertial sensors is dictated by the noise contribution of each stage and the magnitude of each sensitivity, see also Figure...
conference paper 2018
document
Sun, B. (author), Fan, Xuejun (author), Ye, H. (author), Fan, Jiajie (author), Qian, Cheng (author), van Driel, W.D. (author), Zhang, G.Q. (author)
In this paper, an integrated LED lamp with an electrolytic capacitor-free driver is considered to study the coupling effects of both LED and driver's degradations on lamp's lifetime. An electrolytic capacitor-less buck-boost driver is used. The physics of failure (PoF) based electronic thermal simulation is carried out to simulate the lamp's...
journal article 2017
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Sun, B. (author), Fan, Xuejun (author), Li, Lei (author), Ye, H. (author), van Driel, W.D. (author), Zhang, G.Q. (author)
This paper studies the interaction of catastrophic failure of the driver and LED luminous flux decay for an integrated LED lamp with an electrolytic capacitor-free LED driver. Electronic thermal simulations are utilized to obtain the lamp's dynamic history of temperature and current for two distinct operation modes: constant current mode (CCM...
journal article 2017
document
Yazdan Mehr, M. (author), Vollebregt, S. (author), van Driel, W.D. (author), Zhang, G.Q. (author)
A graphene monolayer has been successfully coated on one side of a bisphenol-A-polycarbonate (BPA-PC) plate, used as a substrate for remote phosphor applications in light-emitting diode (LED)-based products. Using a photoresist transferring method, graphene sheet has been coated on BPA-PC plates. The results show that this graphene monolayer...
journal article 2017
document
Yazdan Mehr, M. (author), van Driel, W.D. (author), Zhang, G.Q. (author)
A methodology, based on accelerated degradation testing, is developed to predict the lifetime of remote phosphor plates used in solid-state lighting (SSL) applications. Both thermal stress and light intensity are used to accelerate degradation reaction in remote phosphor plates. A reliability model, based on the Eyring relationship, is also...
journal article 2015
document
Yazdan Mehr, M. (author), van Driel, W.D. (author), Zhang, G.Q. (author)
In this paper, progresses of color maintenance, also known as color shift, in solid-state lighting (SSL) systems are thoroughly reviewed. First, color shift is introduced and a few examples are given from different real-life industrial conditions. Different degradation mechanisms in different parts of the system are also explained. Different...
review 2015
document
Dong, J. (author), van Driel, W.D. (author), Zhang, G.Q. (author)
This paper describes a new design concept of automatically diagnosing and compensating LED degradations in distributed solid state lighting (SSL) systems. A failed LED may significantly reduce the overall illumination level, and destroy the uniform illumination distribution achieved by a nominal system. To our knowledge, an automatic scheme to...
journal article 2011
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