# Tag Info

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A few points that don't fit into a comment but could help you: Get a better laser source than a 4 \$laser diode. "Better" means a laser with higher beam quality. When you look at a laser's data sheet, it should specify a value$M^2\$ or "BPP" (beam parameter product). Both these numbers are related, the smaller they are, the better you ...

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On first inspection this looks to be done with diffuser placed above an LED light source. That will expand the cone of light generated by the LED to cover a larger area. As for the shape, it looks to be clear polycarbonate or acrylic that is painted on the inside with the image cutout. There are other ways to do this, but if you're working on something for ...

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By your metric, a electrically-heated black body radiator in vacuum would be very efficient. Incandescent bulbs are close, but run at high temperatures to make (at least some) visible light. However, the filament is not in vacuum, so incandescent bulbs have significant heat conduction losses. A typical bulb gets too hot to touch after running for a few ...

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This is a rather in-depth question but broadly speaking - The part of the LED which is affected by the liquid nitrogen is called the p-n junction. The two halves of the junction are a set distance apart, this is the "band-gap". Heating and cooling of the LED causes the crystal lattice of the p-n junction materials to either expand or retract. This causes ...

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In ground lighting is more expensive and requires the light source to be able to be run over by all vehicles that use the road, including very heavy vehicles. Such lighting only acts a point source of light that illuminates a small area on the ground as most of the light goes out into space. Care would be need to ensure the in ground lighting did not produce ...

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I would think because airports are really well maintained while regular road lights get covered in dirt, sand, mud, debris, and snow. Also, vandalism is more difficult when the lights are higher up than when they are at ground level. Functionally, it also makes sense for airport lights to point up since the planes are looking down. I don't think airport ...

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The lights are mounted within specifications for positioning as required by laws in countries where they are used/sold. Also, designers position them relating to the use the vehicle is likely to see, so if it is used through woods etc them the lights get mounted farther inboard so they get a bit more protection.

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You seem to face a few issues. First is to account for the potential to have patchiness in any one your sheets. Theoretical equations for light transmission through a system will be easiest when applied for isotropic materials, not for "patchy" systems. This problem has to be solved at the distributor end. Second is to account for the transmission (opacity)...

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Lightning often strikes at the highest point. So it's more likely to hit the trees (as they often do) than the bars. That's why lightning rods are build on high precipices, buildings, etc. Nevertheless; The safest strategy is to suspend All outdoor work in a lightning storm.

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After some more research, I found it: Scene-o-rama! These animated water motion signs from the 1950s and 1960s work by a plastic overlayer and roll film on the underside that constantly rotates in a loop. Scene-o-Rama was first widely used by Hamm's beer, but many other manufacturers adopted them as an advertising methodology. I remember seeing Michelob ...

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While an incandescent bulb can be a good visual indicator of the current and/or voltage in a circuit measuring its brightness and then converting that to numerical data is a very roundabout and error prone method. There is also a more fundamental problem that you are assuming a relationship between light level and wire thickness which you haven't proved ie ...

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You will need to use a light meter to measure luminous intensity. Because light is a form of radiation emitted by a source, it follows the inverse square law, where luminous intensity decreases with distance from the source of light. To ensure consistent and valid results for your experiment you will need to ensure the light meter sensor is placed at ...

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What you are asking for is called a spectrometer. There are two main ways spectrometers work: with a prism or a diffraction grating. Either way, different wavelenght of light end up getting spread out spacially. You then detect the amplitude at various points along this spread-out spectrum. Another crude way is with multiple filters, then detecting the ...

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The problem is probably that your frosted surface is too close to the LEDs. It needs to be far enough away, compared to the distance between the LEDs, that a point mid-way between two of them gets almost as much light as a point right in front of one. I would guess that it will start to look the way you want when the frosting-to-LED distance is about twice ...

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The biggest hurdle was the white light LEDs, which were first available commercially in 1996-1997, a few years after the blue light (1994) . The following image compares all types of lighting An 2018 article for Historical perspective on the physics of artificial lighting addresses many of your questions, and has the following image which summarises the ...

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You want to do a light spectrum analysis on the led. You can do this with a prism that will spread out the light into colors and then find where the peaks and valleys are in the spectrum. That or get a Optical spectrometer which will give better data than just a colored barcode.

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Autodesk 3D Studio used to do this when I was rendering with it around years 2000 to 2005. It is not free though. you could define one or many light sources and one or several cameras and then animate your model around a path and it would calculate the shadows and reflections and even you could define opacity, translucency, surface mesh any building ...

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The LED is a semiconductor that was designed for a certain voltage at a certain temperature. This certain voltage is called "band gap" and is set by properly doping it during manufacturing. The "band gap" is the voltage (think pressure) required for the electrons to hop the "gap". The larger the band gap, the higher the voltage to cross, the higher the ...

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Street lights are installed in order to provide a minimum lighting level along the roadway. Some municipalities or states or countries may have minimum lighting standards, but these often vary depending on the context (i.e. rural, urban, intersections). For certain situations, such as lighting for mid-block or pedestrian crossings, there may be additional ...

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U can use a mirror for feedback of the projected image and a SLR as in cameras (a piece of glass at an 45` angle to measure the difference between projected and image onthe screen and approp. adjust the focus.

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You want a polymer that is strong and easy to injection mold in thin sections (.7mm). Black nylon would be perfect.

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A foil coated plastic would be ideal as a metallic surface prevents light bleed and is easily manufactured. The higher the density of any material the less transparent they tend to be except in the case of transparent ones, obviously.

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A photo resistor or solar panel make for pretty easy/low cost light measuring solutions, but they are not super accurate and will be much more complicated than the primary project. Hook the solar panel directly to a volt meter. It will measure the amount of green light but will not be linear. For the photo resistor hook a battery in series with it and the ...

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I use leds with the chip ws2812 aka neopixel and are very easy to control with Arduino. With Raspberry Pi is a bit coplex due to timing requirements. With neopixel every led may be individually controlled with only one pin. Here you can find the led strip: https://www.adafruit.com/product/1376 I made a Christmas decoration with neopixel and Arduino Yun ...

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The answer is YES for monochromatic LEDs and "not really" for Phosphor-converted LEDs. Monochromatic LEDs can change a lot in color depending on the operating temperature, with probably the worst ones being the Amber LEDs (590~600nm) that shift from amber-yellow to red when heated. Since you are talking about "white" LEDs, you are talking ...

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To add to Carl Witthoft's answer: In diode-based lasers (similar concept to LEDs) temperature control is important for maintaining a precise, stable wavelength. This is related to the band edge moving slightly with temperature. However, as Carl Witthoft said, this is a small effect on the scale of "colors" -- my recollection is a degree Celsius ...

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There is no such single LED. White is produced either with a mixing of color LEDs or by embedding an LED, typically UV, inside a "bulb" with a phosphor coating such that the coating absorbs the photons and re-emits a wide spectrum of light. That said, if you are mixing tricolor LEDs and their power outputs change at different gains with temperature, ...

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I don't think your metric is particularly useful. You even elude to the flaw yourself, incandescent bulbs should be more efficient than LEDS in your system, because they create more heat than light. You are thinking of efficiency wrong in this case. It isn't just the ratio of energy out to energy in. It's the ratio of useful energy out to energy in. ...

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Your major gotcha in this is probably thermal rating which is not going to be exactly wonderful with a PLA part. Also, a lamp does not connect between ground a phase (except in weird circumstances), it connects between phase and neutral both of which are viewed as live current carrying conductors. There is a reason most electrical accessories are made ...

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