Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [lighting]

37 questions
7
votes
3 answers

LED Lumen Calculations

I am using an LED as a point source for a school project. I have two questions in regards to the LED(s). I know that light follows the inverse square law when measuring perceived brightness, but all sources I can find show examples of a round bulb…
Klyer Norman
  • 71
  • 1
4
votes
1 answer

Alternatives to laser line?

I'm trying to project a very thin line at a low angle over some surface defects (peaks and troughs). The scale is ~20mm square, but the defects can be sub-mm (0.2 - 1.0mm). I am currently using a line generated by a laser pointer. The $4 laser…
John
  • 165
  • 5
4
votes
2 answers

What plastic material blocks the most amount of light?

If I have a grid array of LED's surrounded by roughly 0.7mm thickness plastic walls. What material at this thickness would prevent light bleed side to side so that individual LED's can light up but not light up their neighbor?
Davbog
  • 383
  • 4
  • 11
3
votes
1 answer

Street Light Arrangement Method

Hello I am a high school student and I am curious about how street light is arranged along the road. Is there government laws to install street light on the road or is the arangement of the street light that is the most efficient to its road? If it…
JSChang
  • 31
  • 1
3
votes
4 answers

How do I measure the brightness of a light bulb?

I am working on a science fair project. My question is if electricity moves better through a thin wire or a thicker wire. I need to collect data and make charts, and the thing I want to measure is the brightness. The only problem is that I'm not…
hpenney2
  • 29
  • 2
2
votes
1 answer

Where to acquire / create LED optics

I'm working on a few projects that require lenses to focus LED light flashes, similar to those lenses used by police lights (TIR lens) and other strobe traffic lighting utilizing Fresnel lenses. I've scoured the internet and cannot find anyone…
Zero
  • 121
  • 4
2
votes
3 answers

How can I achieve good diffusion from an LED light source?

I have a light fixture which is designed as three rows of LED light strips. The problem is that the LEDs appear as brilliant points of light. In the fixture I want to diffuse this light so that it appears pure and continuous. The fixture points…
Wallace Park
  • 1,635
  • 1
  • 15
  • 21
2
votes
2 answers

How to predict shadows of a house (3D modeling + sunlight)?

Imagine a house/building, seen from outside, at sunrise. As the the sun moves in the horizon, a) the shadow of the house is displaced/deformed, and b) some faces of the house have more/less sunlight in the afternoon than in the morning. I need to…
terauser
  • 27
  • 2
2
votes
2 answers

LED color change in extreme cold

Which part of the LED is affected when it is exposed to liquid nitrogen? I have seen experiments showing LED's brightness increasing and color shifting, when the LED is submerged in liquid nitrogen. I have also seen one where the color went DOWN in…
bobiscool
  • 31
  • 1
  • 4
2
votes
3 answers

Animated light box signs

In the old days there was a type of sign/light you would find in bars and restaurants which was animated. It would be a lit scene usually of water, like a lake with a waterfall, and by some means it would animate and look like the water was…
Wallace Park
  • 1,635
  • 1
  • 15
  • 21
1
vote
2 answers

Sun exposure in room as a function of day and time?

Background (may be safely ignored): I am buying (most of) a rowhouse from the 1930s. I am now working with an architect to improve its energy efficiency. Let us focus on the main room, which can be said to be a long box pointing East-northeast, with…
H A Helfgott
  • 121
  • 5
1
vote
1 answer

Flood light pole components

I saw this flood light pole. It has two LED bulbs, but I do not know what the box in the middle is (it was not an LED), could you guys help me understand what this could be? This flood light is located in a plaza parking lot called Churchill square,…
RSM
  • 271
  • 1
  • 6
1
vote
0 answers

How to calculate the 'Daylight Factor' of a room?

I am a faculty in a public school. Our school has to submit an infrastructure report to the funding agency. One of the questions asked is to calculate the 'Daylight Factor' in each classroom. I have done some research online and I have come up with…
Miz
  • 111
  • 2
1
vote
1 answer

Which optical filter to use for flat black non-glare aerospace indicator?

I am currently designing a LED light indicator for use in an aircraft cockpit replica. I’m asking for expert advice on the type of lenses to use in order to get a result similar to shown pictures. When illuminated, the indicators display a really…
GunMan
  • 11
  • 1
1
vote
1 answer

Passive Infrared Sensors (PIR) spectrum and reflections

I have a common PIR occupancy sensor (Lutron MS-OPS5M-WH). I am trying to get the sensor to cover an irregular-shaped room. I could expand the field-of-view of the sensor to cover the whole room by installing a mirror so that the PIR sensor could…
BetterSense
  • 181
  • 4
1
2 3