Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [light]

Light is a tag about anything generates photons in the visible spectrum

545 questions
17
votes
6 answers

Lumens specs when buying a flashlight/torch. Why maglite has only 680lm but cheap ones have 900,000?

I am working as a night delivery driver and when its dark and/or rainy it's almost impossible to read many of the house numbers/names I am looking for. I've heard of Maglite and in fact my friend has a large Maglite which is 680lm and very powerful…
Big T Larrity
  • 289
  • 2
  • 8
8
votes
5 answers

How do I manage a large array of "motion sensors" and lights?

I'm a web developer / system admin and I have a client project with a project that is just beyond me. In a nutshell, we need to the following capabilities: Track the status of hundreds of Passive Infrared Sensors Track the status of hundreds of…
Jake A. Smith
  • 181
  • 2
8
votes
2 answers

How to build disco lights?

When I was a teen, I joined an electronics club and built a disco board. I had 5 light bulbs, I painted them different colors. Then I built a board which was connected to these light bulbs. I'd connect my stereo to the board and the each light…
Angryhacker
  • 179
  • 1
  • 1
  • 4
7
votes
3 answers

What lamps are out there that don't flicker and give off warm light (like incandescent)?

In the past few years several countries stopped producing 100W incandescent lamps, and in a few years they may disappear to be succeeded by fluorescent lamps. I really don't like the flicker and the color most common fluorescent lamps produce. Are…
user1306322
  • 1,238
  • 3
  • 15
  • 26
7
votes
10 answers

Creating a new power source for light-string ornaments

I have a couple Hallmark Star Trek ornaments that plug into Christmas light strings. I'd like to convert the power supply to them from the light string plugged in the wall to a battery pack so I'm not anchored to a string of lights and to better…
Curtis
  • 173
  • 1
  • 1
  • 3
6
votes
6 answers

Why do my compact fluorescent lamps keep dying?

I know that this question may be off-topic here, but I'll ask it anyway since they do have electronics inside. I've noticed that my fluorescent lamps keep dying after only couple of months of use. When they die, they die in groups of 2-3 and as far…
AndrejaKo
  • 23,431
  • 27
  • 112
  • 189
3
votes
0 answers

Preamplifier that responds to 10 kHz

I am having a problem of designing pre-amplifier that responds to light pulses of 10 kHz. I have designed the one below but I don't understand the scenario in which the output voltage builds up to a very high level when the input pulses is about…
Francis Ignas
  • 39
  • 1
3
votes
2 answers

If I flick the light switch on and off will it damage the light?

Ive heard that when you flick the light switch on and off repeatedly it damages the bulb. I know this is certainly not true for LED bulbs, but Im wondering if and how it damages other kinds of bulbs. I know that light bulbs run off of ac current…
Rhezner
  • 145
  • 2
  • 11
3
votes
1 answer

Why are "flicker flame bulbs" always bulbs or how do flicker flame bulbs work?

In other words, I've never seen the type of filament (if filament is the correct term—if not, what is the correct term?) outside of a bulb—as seen in the video linked to below. Is there something about the way it works that makes them unsuitable…
derGral
  • 157
  • 1
  • 6
2
votes
1 answer

Is a pin fin heatsink with 4 fans enough for 2x 80W LEDs

I need advice: I plan to use a heat-sink for cooling 2x 80W white LEDs over my friend's tank. The heat-sink is a "pin fin" design, 6 inches by 6 inches which combined with active cooling should dissipate more heat than other fin designs. Here it…
alfred joseph
2
votes
1 answer

Star magnitude mini lights

I would like to display the big and little dippers on the outside back wall of my house using mini light bulbs of appropriate intensities. I converted those 14 star magnitudes to lumins. Unitizing there luminosity gives a range of 1 for the…
D Kahre
  • 21
  • 1
1
vote
2 answers

Have Pins light up after pushing a button/switch

I'm trying to create a "Push Pin" map for a friend as a gift. My friend has traveled through out the world and I'd like to organize the pins by year. So a different color pin for each year he has traveled to a specific location. I'd like to take it…
Christina Rule
  • 121
  • 1
  • 2
1
vote
1 answer

Why do fluorescent bulbs hum/buzz?

Why do fluorescent lamps buzz/hum? I have one above my desk right now and it is constantly humming/buzzing. Does the bulb need to be replaced? Do I have to take the light fixture apart and replace something in it?
Quaxton Hale
  • 129
  • 4
1
vote
4 answers

Easiest way to create electric light source from scratch

Is it possible to make lightbulbs or any other electric light source without using high tech equipment? Is there something that could be created in small workshop?
Bobi
  • 37
  • 6
1
vote
2 answers

What is going on inside this nightlight circuit?

I've got a small nightlight in my hallway that has a photocell on top so it only turns on when it's sufficiently dark out. Sometimes the light will be off and a shadow will cover the nightlight as someone walks by triggering the light to turn on.…
Nick
  • 113
  • 5
1
2