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Questions tagged [light]

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

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1answer
22 views

Magnetic ballast with g23 bulb with capacitor

I am trying to make a UV-b photo-therapy light and want to make sure I'm understanding the circuitry correctly-so i don't hastily burn a $50 bulb. Im using a Phillips PL-S 9W/01/2P (link here). It's ...
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1answer
48 views

Using an analog voltmeter to display the changes in out put made by a dimmer switch for a light

I'd like to preface by saying k know little to nothing about electrical engineer but would like help with making a lamp. I want to use a volt meter style gauge to display a different reading for a ...
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2answers
60 views

What kind of IC drives this safety LED night light?

This night light LEDs circuit has three 4 positions: off fast blinking slow blinking LEDs always on The big central component is a switch. I was wondering what IC drives the LEDs ? From what I can ...
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0answers
28 views

Problem with 5 meter LED strip light and 450W power supply [on hold]

I build LED strip lights using old florescent shop lights metal reflectors and used as the heat sink solution for the strip stick on LED light. Total of the LED strip was about 6.5 meters and I ...
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3answers
56 views

Non electrical background trying to make a cool little custom project - Help please?

Brief bit of background - I've built my own PC's, I've repaired phones, changed plugs, fit light fittings from diy stores, and have a basic (very basic) understanding of electronics, but have found ...
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0answers
18 views

Electrical workaround for wiring a smart switch [migrated]

There's the following setup in my bedroom: I need to wire the WiFi Switch in the setup above so I made the following workaround: Basically I dimissed Light Bulb 2 in order to get the power line to ...
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0answers
12 views

What is sthe difference between acoustic photon and acoustic phonon? [migrated]

In the book Biomedical Photonics Handbook, 3 Volume Set edited by Tuan Vo-Dinh, it is written : Brillouin Scattering is caused by the interaction of the photon with the acoustic phonon. As the result ...
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0answers
18 views

Making a bridge between VLC and LED's research literature and consumer datasheets

I'm working researching visible light communications (VLC) and I'm having some hard time trying to transpose what I see in consumer components datasheets to equations and theories from the field's ...
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2answers
120 views

How can I use an LED driver (QX5252) to light up 3 different color LEDs (Green, Yellow, Purple)?

I am trying to light up 6 LEDs with the common garden light circuit (2v Solar panel and 1.2V battery). The problem is that I want to light up 2 yellow LEDs, 2 green LEDs, and 2 purple LEDs ...
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2answers
482 views

Is the speed of electrical signals always constant within a CPU? [closed]

Microprocessors rely on assumptions about how long it takes for electrical signals to propagate through combinational logic circuits. As far as I understand from reading "Modern processor design", ...
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2answers
66 views

What is the response curve of a CMOS sensor cell to the amount of light?

Using my Nikon D5100, shooting RAW pictures and using Darktable to disable absolutely all contrast curves, white balancing, sharpening and even the debayering, I've measured the average value of the ...
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2answers
68 views

LED light bulbs in low atmospheric pressure

I have these (https://www.amazon.co.uk/gp/product/B01DBOKZVK/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1) LED lightbulbs. Can I use them in a pressure of ~30kPa (21" Hg vacuum)?
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2answers
70 views

Swap between two colors without an additional light?

A Quick Note I'm not sure of a more accurate name for this question. If you can think of a better name, feel free to edit and change the name. Also, I'm not the greatest with technical terminology so ...
2
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1answer
100 views

Normally On Circuit with Positive Trigger?

Pardon my lack of technical terms here; essentially I have an under glow kit on my car (along with some other lighting) that I want to expand the circuit on. I bought a pair of 5 pin relays to ...
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1answer
90 views

Is it possible to make a lightbulb light up by wetting your hands? [closed]

I was recently watching an Electroboom video on free energy devices, but my question is not about any of that stuff. Here's the video. At about 5:50 he claims and seemingly shows that he can light up ...
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2answers
111 views

Build my own light bulb

Before I start: I do not have a lot of experience in electrical engineering so I would appreciate clear statements and extensive explanations to be able to follow your ideas. I am currently trying to ...
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4answers
246 views

What is the RGB value of Edison Light Bulbs? [closed]

I've been doing a little electrical engineering (outside of my lane a bit). I'm trying to get the RGB values for Edison light bulbs. Can anyone provide me with those?
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4answers
4k views

Why does an LED have to be a diode?

I know LED stands for Light Emitting Diode; but why does this component need to be a diode to emit light? My question assumes that the "leds" we see everywhere (for lighting, screens, etc) are ...
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1answer
82 views

How to connect a LED G13 Tube directly to a power socket?

I am trying to build my own cheap lighting for my greenhouse. I have found a couple LED tubes that would be perfect for the task, only they are supposed to be mounted on a lamp of some sort. They have ...
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1answer
110 views

Light source that withstands extreme conditions [closed]

I am designing an aircraft obstruction light, and Federal Aviation Administration (FAA) requires crazy requirements for their standards. One standard goes as following (From FAA AC 150/5345-43H): 4....
2
votes
1answer
110 views

Can this 1000W ballast be wired for 240V and plugged to 120V to run a 400W MH Lamp?

I've a 1000W MH ballast. Is it okay to use the wiring for 240V the ballast and use it on 120V? Like does it reduce the ballast to 500W? I've attached a video for better understanding of how the bulb ...
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3answers
198 views

What makes same wattage led light bulb brighter than the other? [closed]

I noticed that one 10 W LED light bulb was 800 lumens and the other 1000. Both were warm white, 4000K, 80 CRI. What exactly makes one brighter than the other?
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2answers
170 views

Can you damage an LCD screen with a camera flash, high-powered flashgun/speedlight?

I'm curious as to what the limitations are in regards to uv radiation on LCD screens when subjecting them to high intensity light sources such as camera flashes (such as a nikon or canon speedlight). ...
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1answer
33 views

Infrared diodes illuminator scope

Can anyone tell me if there are certain specific criteria that states whether an infrared led can be used as an illuminator particularly the ones they use on hunting scopes. Would a tsal6100 for ...
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1answer
97 views

How to determine DC input voltage of a device without its charger? [closed]

Had a MotoMaster (Canadian Tire) 27/3 LED flashlight for 4 years now. Model was discontinued 2-3 years ago. Lost the charger at least 2 years ago and the light's battery FINALLY died today (!!) I ...
3
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1answer
102 views

Manufacturing of Translucent LED Indicating Symbols (e.g. router indicator lights) [closed]

I've been researching how manufacturers create custom LED-illuminated symbols such as those seen on the router in the image below: I haven't been able to find any information online from custom ...
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0answers
75 views

How to shield ambient light phototransistor from LED

My design requires a surface mount ambient light sensing phototransistor and a surface mount LED. The phototransistor's purpose is to sense the room's light level, and I don't want the LED light to be ...
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votes
1answer
34 views

Multiple lights dimming using single TRIAC zero detcetion module

We know well we can dim single lights using single TRIAC module with the help of PWM signals from controller. My question is, I want to control the lights which are placed on hall. Let us consider 15-...
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1answer
134 views

Which one is better to build lux meter, either LDR or photodiode?

I want to add the lux meter to my application. My controller works with 3.3V and ADC max reading voltage is 1.2Vref. I tried with LDR but I'm not able to get accurate values and the values also not ...
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2answers
373 views

Safety of “UV” LED

I am curious as to whether LEDs like these ones http://www.led4everything.com/catalog/product/view/id/410/s/st0028/ are harmful, they are advertised as UV. But are they just purple LEDs or actual UV? ...
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0answers
53 views

LCD panels used in projectors - What are their limitations?

It's important I point out immediately that I am an absolute novice at all this. I am trying to self-teach myself the basics by building things but it is a slow slow process. So please bear with me if ...
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0answers
68 views

concave conical lenses on 5050 SMD LEDs?

Is there any way to put plano-convex conical lenses, or something broadly equivalent, on 5050 SMD LEDs? The lenses I'm talking about are the type commonly built into cheap christmas-tree lights: As ...
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5answers
196 views

Rated vs. actual power usage of a linear fluorescent lamp

After having some power issues, I've decided to investigate the largest power drains in our company, and I've arrived at a realization that 128 lights adds up to a lot of power (and that's not even ...
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1answer
44 views

g23 socket and 11W UV-C bulb

because UV-C machines tend to be expensive, our lab working on biological/biochemical research has reverted to attempting to build a machine from scratch. Therefore, we recently purchased a G23 ...
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1answer
57 views

how to determine value of a power storage capacitor in an intermittent circuit [duplicate]

I made a post earlier about this but apparently there weren't enough details and i didn't explain it well enough so i will try this again: I have a circuit which runs on intervals of 0.75 seconds on/...
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2answers
88 views

Can kitchen salt break a LED lamp circuits/board? (weird problem) [closed]

Hello everyone I have a really weird situation. I had two Yongnuo YN-600 Air LED photo/video lights. On these lamps it says "DC, max input 8V, 5A". I was sold AC adapters to those lamps 12V 5A. They ...
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1answer
1k views

How can I reuse a crowdled bracelet?

I have been to an event last night, where I some wristbands produced by the Crowdled company (see links at the end). Material of one band: 3 colored leds (2 in total) and a button. Runs on battery. ...
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3answers
63 views

Making an automatic night light

I'm a total beginner so I'm sorry for stupid question(s). I want to design a circuit and I'm stuck. Here's the description: Photosensor outputs 0V until the ambient light decreases below certain ...
2
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1answer
36 views

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 ...
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2answers
58 views

220 VAC Control Transformer “voltage on” indicator light.

I would like to know where to place an indicator light (what voltage, as well) for the incoming 220VAC, after the 2 pole circuit breaker? The IEC Connector will provide 220VAC to the transformer, ...
0
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1answer
96 views

LED strip in series

I am planning to order LED strips, I need to connect 6 x 5m LED strips in parallel so that they can be controlled via single controller, but am not sure if the controller will be able to handle the ...
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4answers
133 views

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?
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1answer
41 views

Why do the brightness, luminous efficacy and power of this lightbulb not agree?

A particular LED lightbulb has luminous flux (brightness) \$\Phi_{\rm v}=820\ \rm lm\$, consumes electrical energy at a rate of \$P=9\ \rm W\$, and has a luminous efficacy of \$\eta=83\ \rm lm/W\$. ...
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2answers
55 views

How to measure body temprature and HBR with just one IR transmitter and receiver

I want to measure body temperature and heartbeat rate only with a IR receiver and transmitter. How could I do that? Is it an accurate method? Or I have to use IR temperature sensor for this.
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1answer
131 views

Designing custom LED bar as a replacement for standard headlight [closed]

I own an Opel/Vauxhall/Holden astra produced in 2000. Currently it is fitted with standard halogen headlights, however I am looking to improve the looks of the car by customizing the headlights. I am ...
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2answers
143 views

Connecting 220V mains switches (with on-indicator lights) to 12V COB LED lights in series

I wil be switching COB Led lights (each one rated at 12V, 200mA) individually with these switches. One end of each of the 60 COB LED lights is connected to 12V, the other end to 60 of these 220V ...
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2answers
617 views

How to calculate the energy output (in Joules) from an LED

I need to emit 20J over 5ms onto a target area of 962mm^2 from an LED source. The source as well as the target will reside in a completely encapsulated environment with reflective internal walls such ...
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1answer
50 views

What is the energy consumption of incandescent bulb as compared to LEDs and CFL bulbs? [closed]

I read this on website "The electricity used over the lifetime of a single incandescent bulb costs 5 to 10 times the original purchase price of the bulb itself" What does it mean? if the bulb is of ...
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1answer
50 views

Low power LED for autonomous project

I'm working on an autonomous project with a 3.3V powered Arduino and I need to add a led that power on when some actions happened (pressed button etc..). This LED needs to be seen during a sunny day ...
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1answer
126 views

current limiting filament bulb, revisited

I'm trying to size a bulb to limit DC booster pack current (harbor freight viking lithium) from overloading the 12V aux port (cigarette lighter) wiring which is fused at 15A. I'm ideally looking to ...