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Questions tagged [lighting]

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10
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4answers
4k views

Are LEDs in modern streetlights usually pulsed? If so, roughly what frequency?

I can think of some reasons why modern LED streetlights would likely be pulsed; Efficient voltage conversion starting from line voltage would likely include an AC or switching step higher than 60 Hz....
6
votes
2answers
308 views

Philips 9 W luminaire quotes 7 A for 300 ms inrush!

In his answer to Will repeatedly turning a light bulb on and off damage it? @Bradicul stated, An example of inrush current is an LED downlight fitting with 9 W (0.0375 A at 240 V) will have any ...
5
votes
2answers
2k views

What is the theoretical limit of lumen/watt for lighting systems?

Nowadays we see LEDs with 300 lumen per watt luminous efficacy. They still waste a lot of power as heat. Now what is the limit of electricity to light conversion? Say we build an LED with 100% ...
5
votes
2answers
776 views

Precision mini winch (with position feedback) for kinetic lighting?

I am trying to create a kinetic lighting installation for my home, above the dining table (see example here https://www.youtube.com/watch?v=-DZ18DNbjTQ ). Obviously I will use max around 20 lights. ...
4
votes
2answers
822 views

Why is one lightbulb in a string illuminated? [closed]

I noticed that in various strings of lights only one was illuminated. It seems implausible that all but one out of several hundred blew. What caused this and why did this particular light turn on?
4
votes
2answers
1k views

Rewiring USB LED lights to directly use a 5V DC-DC Converter

I'm currently helping a friend who is renovating a VW camper to fit some LED lighting as she has no electrical experience. She has a 10 metre set of LED fairy lights that are powered via USB (bigclive ...
3
votes
3answers
2k views

Is 12V or 240V more efficient for a domestic solar powered lighting circuit?

I'm about to buy a house with an existing solar system, with 12V batteries and a 240V inverter driving the mains and lighting. I will be installing new smart lights throughout. My question is, should ...
3
votes
3answers
2k views

How Is Intensity of Blue Light Measured?

As a hobby project and to help solve issues getting up early in the morning (specially given that it's winter and the sun isn't up until long after I am) I'm trying to find a bright blue light that I ...
3
votes
1answer
86 views

Choosing the right transformer to replace batteries?

I have an idea for a hack I'd like to build, but I need some help figuring out the right transformer. Let me know if there's a better place to post this sort of request. I have some exterior LED path ...
3
votes
2answers
168 views

Multiple lights with button that turns one on at a time [closed]

I am an artist trying to make an installation but I'm not too familiar with electrical work. I want to have multiple light bulbs wired to one button. Each time the button is pushed one light bulb ...
2
votes
3answers
5k views

Wiring a bunch of micro LED fairy lights to a single power source in parallel

I want to create a cascade effect using the wire fairy lights, like in this photo . What would I need to accomplish this? I can find the coils of lights for cheap online that use battery packs, but ...
2
votes
1answer
239 views

How can we power Christmas LED lights without mains supply

I have read the other thread 'Best way to power Christmas lights without nearby outlet' and my question does differ. We have a Christmas Tree which sits in the middle of our Village Green every year. ...
2
votes
2answers
460 views

Strange light bulb phenomenon

Let me explain. My son has a small typical night light that occasionally will go out, even if the bulb isn't dead. Usually I'll tap on it repetitively or shake it to get it to work again. When I ...
2
votes
3answers
308 views

Can I use ethernet instead of DMX for DIY led lighting?

I've read that while most pro-lighting is uses dmx, some intelligent lighting rigs use ethernet. I'm interested in building some MCU controlled L.E.D. footlights for my stage show, and currently know ...
2
votes
2answers
182 views

LED lighting that lasts longer than me [closed]

My research has indicated that failure in LED lighting (incandescent replacements) results from failure in the support components rather than the actual LEDS themselves. How can I build and/or modify ...
2
votes
2answers
108 views

Why a CFL lights up when I touch it?

When there is a very low voltage (AC), even for a compact fluorescent lamp (CFL), it glows very dim (orangish in color) at the beginning of the glass but when I hold the glass just for a second, it ...
2
votes
1answer
46 views

LED selection for my application

I need to select LED/LEDs for a light source in my project. The requirement is that the light source should approximately be able to project light beam of 1.5m diameter on a surface, from a distance ...
1
vote
1answer
1k views

How can you make a light source brighter?

I am about to begin to work on an electronics project that involves the output of red light. After playing around with a bunch of LED’s, I realize that red and yellow are the weakest as far as “...
1
vote
3answers
4k views

Understanding 3 phase 480V lighting circuit

I understand that you would use 480V light fixtures as opposed to 277V because the 480V have a lower current draw, resulting in a more efficient system. What I don't understand is how this circuit ...
1
vote
1answer
744 views

Best Lamp Dimming Circuit? [closed]

What's the best way to dim a lamp, and why? Also, which method is typically used in most typical residential dimmers? I originally thought it was as simple as wiring a potentiometer between the source ...
1
vote
2answers
19k views

Best way to power Christmas lights without nearby outlet

I want to power Christmas lights (without a nearby power outlet) for at least 2 hours and was wondering how to go about it. The lights run on 120V AC and draw .34A per strip (about 40 watts) and I ...
1
vote
2answers
74 views

compact fluorescent lamp noise on digital signals

The answers to this question about CFLs (compact fluorescent lights) in an electronics lab indicate there is some concern about the presence of electronic ballasts and CFLs in connection to radio and ...
1
vote
1answer
71 views

Determining the number of lighting fixtures

This may be more of a common sense question but I would like to expand my horizons on the subject. My research tells me that lumens = surface area x foot-candles. So if I am lighting up a 50' x 50' ...
1
vote
1answer
197 views

Big picture: Ceiling LED control [closed]

I have been looking at ceiling LEDs for a while; I am owner-building a house ATM, and "wondered" how I can control the ceiling LEDs -- most 9-12W, probably 30-ish of them; in 3-4 different zones. ...
1
vote
2answers
1k views

Car interior light with multiple “triggers” - 12V DC power

trying to add some lighting in the foot wells and under the seats in my car so that when someone drops something down there in the dark, it's not something that (at least not every time) requires ...
1
vote
1answer
64 views

Lightning protection for Antenna Connector

I want to add lightning and ESD protection for the antenna used with my PCB (Wireless Gateway). The antennas that will be used with my PCB are Pole Mount Antenna. There are three different types of ...
1
vote
2answers
76 views

Relay switching a light causes a spike, making a raspberry pi halt

The problem in short: I worry that switching lights is causing a spike. Occasionally a Raspberry Pi halts completely after a relay is switched. The setup: A Raspberry Pi 3 is connected to an ...
1
vote
5answers
5k views

LED lights wired in Series will not light

I have a pack of simple LED lights that I planned on wiring in my boat for cabin lights. I installed and wired them all in a simple series circuit. Power supply connected to switch, switch connected ...
1
vote
1answer
95 views

Street Lighting Circuit Analysis

1- How does a typical street lighting circuit look like? (for 230V/50Hz, with details) 2- Without having the network plans or knowing anything about the topology of the circuit, is it possible to map ...
1
vote
1answer
98 views

What are typical track lighting track profiles used in Europe?

In the U.S., the typical track lighting track profiles are known as "H", "J" and "L". Their cross-sections can be easily found by googling them. Are these same cross-sections used in Europe? If not, ...
1
vote
1answer
37 views

Powering same LED strip from 2 drivers - diode?

So I'm looking at adding some LED mood lighting to our bedroom. End game is to have a single LED strip controlled by 2 different switches Currently, I have 2 switched 240V AC outlets, one either side ...
1
vote
3answers
130 views

Off grid LED solar lighting without batteries

I have 2 COB LEDs (12-14V DC, 50W, I think with 3,75 A in data sheet). I need to run them with a solar panel, it should only run when there is sunlight no batteries needed. Using a 270W panel (open ...
1
vote
1answer
102 views

Basic electric/wiring questions resources

I have a 12V DC motor that I want to power alongside a 40 Watt incandescent bulb (I might find an LED bulb that works aesthetically).  I need to run a single cord to power both.  Preferably with a ...
1
vote
0answers
98 views

Commercial 1.5m / 5' LED light fitting parallel LED arrangement

I am reviewing LED light fittings for an industrial premises refit. As with most of the experienced users on this site I like to understand what I'm purchasing and have opened up a sample fitting to ...
0
votes
3answers
15k views

Full Spectrum LED(400nm~840nm) vs Grow Light LED (RED+BLUE)

I'm planning to buy lights for my planted aquarium tank. After a small research I found that regular lights are not suited for growing plants. Beacuse they need BLUE for Leaf Growth and RED for Stem ...
0
votes
1answer
112 views

Two lights, two switches… one problem!

I'm looking to set up an AC 240-volt lighting circuit consisting of two lights (let's call them L1 and L2), a standard switch (SW1) and a PIR. The goal is to have SW1 turn on only L1, but if the PIR ...
0
votes
2answers
97 views

1-wire fairy lights

I have here some fairly lights. It's a string of coloured LEDs with a transformer and control box at one end. The control box lets you select a bazillion different lighting patterns. (Presumably the ...
0
votes
2answers
75 views

DC ring mains for lighting, revisited

Traditionally ring mains for lighting have been (relatively) low current AC mains typically at 110/230VAC. It makes sense these days to replace that with lower power, lower voltage wiring to more ...
0
votes
2answers
325 views

Does color rendering index increase with brightness?

I've been reading about LED strips and thinking about switching to those from my serial incandescent lamp setup, and I can't figure out if CRI (color rendering index) is tied to a certain standard ...
0
votes
2answers
283 views

Making a 5v 12v and -12v PSU [closed]

I'm trying to make a PSU for a Zero88 Juggler lighting desk (as ours has been misplaced and a new one is £70) and am struggling to find a transformer to be able to power it. The pin out on the back of ...
0
votes
2answers
83 views

Soft Touch Lamp Turning on by Itself [closed]

This has been driving me crazy for several years now -- my soft touch lamp has been turning itself on most mornings. Some details: It is definitely tied to sunrise/dawn, as the time each day varies ...
0
votes
2answers
82 views

Dimmer buzzing, lights flickering [closed]

Got an issue with my lights and a dimmer. I got a room with 4 lights in it (6W LED panel lights) and a 60-600W dimmer. Somewhy, the lights from time to time flicker and the dimmer is buzzing all the ...
0
votes
3answers
957 views

DALI Communication: Is DALI protocol a byte transfer mechanism or packet layer mechanism?

As per the DALI light-control standard protocol, DALI bus communication uses Asynchronous half-duplex(two-wire) serial communication. It uses Manchester coding at 1200 bits per second(baud). A DALI ...
0
votes
2answers
214 views

Power Distribution to Greenhouse LED Lighting

I'm working on designing a custom LED lighting control system for an agricultural research project. This involves supplying significant amperage to high power LEDs distributed over a wide area (e.g. ...
0
votes
1answer
49 views

Uneven LED Lighting Wired in Series

I’m struggling with six 11.5-watt LED cans wired in series. With a 75-watt incandescent at the end, the other five seem to function properly, though the incandescent is dull. With an LED in its place, ...
0
votes
1answer
55 views

Wiring 2 separate PIR’s to an LED Floodlight

If possible can someone please confirm that this would work? I want to place a waterproof box on the front of the house, next to this I will put an LED floodlight (without PIR), I then want to put 1 ...
0
votes
2answers
187 views

Strange behavior of the DALI controlled luminaires

I faced a strange behavior of a DALI controlled LED luminaires circuit. I have 48 LED luimianires with a MeanWell ELG150-C700-DA drivers connaected according to the scheme below: I commissioned the ...
0
votes
1answer
31 views

HID Lamp Ballast Using TI UCC2305

I am trying to control an OSRAM XENARC 66140 35W HID (High-intensity discharge) Lamp with a circuit which contains Texas Instruments UCC2305. I have obtained 4 original lamps from OSRAM and tried on ...
0
votes
2answers
960 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 ...
0
votes
1answer
251 views

PWM dimmed led floor lamp: can it cause eye strain? [closed]

I have a floor lamp (standing lamp which spreads light via the ceiling). It uses LEDs and it's dimmable. When I capture the light with a camera I can clearly see oscillations. It is known that PWM-...