LED applications in road and railway signals: is it possible to fit specifications?

Papalillo, Donato; Vecchio, Paolo del; Spagnolo, Giuseppe Schirripa

doi:10.1117/12.912384

Cited by 6 publications

(4 citation statements)

References 2 publications

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“…For different reasons. First of all, the LED technology is massively present in our everyday life: in general lighting, automotive headlamps, traffic signals, monitor and display technology [19][20][21][22][23][24][25][26], and also in the modern research in physics: for the development of LED, in 2014 Isamu Akasaki, Hiroshi Amano e Shuji Nakamura received the Nobel Prize in Physics [27,28].…”

Section: • I Hear and I Forget • I See And I Remember • I Do And I Un...mentioning

confidence: 99%

Simple equipment for teaching internal photoelectric effect

Spagnolo¹,

Postiglione²,

Angelis³

2020

Phys. Educ.

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In this paper, an educational tool is proposed to show the internal photoelectric effect in a simple and clear way for Undergraduate Physics courses or High Schools. Experimental evidence of the photoelectric effect is particularly important in the didactic experience. This effect is fundamental to introduce students to the world of quantum mechanics, and to the concept of quantized energy. However, it often requires uneconomical and not easy to use equipment. For this reason, here we describe the realization of a simple and low-cost system based on the LED to LED structure; LEDs can in fact act as light sources, but also as photodetectors, being sensitive to wavelengths equal to or shorter than the predominant wavelength they emit. Through the lightning of LEDs of different colors, we thus show that the verification of the photoelectric effect becomes easy.

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Section: • I Hear and I Forget • I See And I Remember • I Do And I Un...mentioning

confidence: 99%

Simple equipment for teaching internal photoelectric effect

Spagnolo¹,

Postiglione²,

Angelis³

2020

Phys. Educ.

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“…The positive ions create a potential well, as shown in the Figure 1, and the free electrons occupy the states of lowest energy. LED technology is widely present in our everyday life, like car headlights, TV and monitor technology, illumination systems for domestic and professional use [14][15][16][17][18]. In 2014 Isamu Akasaki, Hiroshi Amano e Shuji Nakamura received the Nobel Prize in Physics for the development of a blue light LED [19,20].…”

Section: Basic Properties Of the Photoelectric Effectmentioning

confidence: 99%

LED as Transmitter and Receiver of Light: A Simple Tool to Demonstration Photoelectric Effect

2019

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The experimental observations of the photoelectric effect show the properties of quantum mechanics of the electromagnetic field. For this reason, this important effect is commonly used as an introductory topic for the study of quantum physics. The “classical” demonstration of the photoelectric effect is very incisive; unfortunately, the experimental apparatus is not cheap and easy to realize. The typical use of LEDs is as light emitters, but they can be used even as photosensors and, in this case, they are sensitive to wavelengths equal to or shorter than the predominant wavelength it emits. Furthermore, a LED used as detector is sensitive to wavelengths equal to or shorter than the predominant wavelength it emits. This ability of LEDs offers the possibility of developing a simple tool able to demonstrate the photoelectric effect. This paper describes the realization of an economic, simple, easy and safe system to use for the experimental demonstration of the photoelectric effect, based on the LED to LED structure. The paper has educational purposes, oriented towards laboratory teaching activities.

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“…To use phosphor-free AlInGaP LEDs, several solutions have been implemented [12][13][14][15][16][17]. All of these systems work well.…”

Section: Introductionmentioning

confidence: 99%

LED Rail Signals: Full Hardware Realization of Apparatus with Independent Intensity by Temperature Changes

Spagnolo

Leccese

2021

Electronics

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Nowadays, signal lights are made using light-emitting diode arrays (LEDs). These devices are extremely energy efficient and have a very long lifetime. Unfortunately, especially for yellow/amber LEDs, the intensity of the light is closely related to the junction temperature. This makes it difficult to design signal lights to be used in naval, road, railway, and aeronautical sectors, capable of fully respecting national and international regulations. Furthermore, the limitations prescribed by the standards must be respected in a wide range of temperature variations. In other words, in the signaling apparatuses, a system that varies the light intensity emitted according to the operating temperature is useful/necessary. In this paper, we propose a simple and effective solution. In order to adjust the intensity of the light emitted by the LEDs, we use an LED identical to those used to emit light as a temperature sensor. The proposed system was created and tested in the laboratory. As the same device as the ones to be controlled is used as the temperature sensor, the system is very stable and easy to set up.

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LED applications in road and railway signals: is it possible to fit specifications?

Cited by 6 publications

References 2 publications

Simple equipment for teaching internal photoelectric effect

Simple equipment for teaching internal photoelectric effect

LED as Transmitter and Receiver of Light: A Simple Tool to Demonstration Photoelectric Effect

LED Rail Signals: Full Hardware Realization of Apparatus with Independent Intensity by Temperature Changes

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