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

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5 views

Has this light earthed itself?

After accidentally earthing the live wire going to the outside light whilst putting a faceplate back on (patched up now), the light has stopped working. I've just been out with a multimeter to see if ...
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0answers
37 views

What makes a certain fixture burn through bulbs? [migrated]

I have one outdoor fixture that inn which the bulbs burn within two or three months of being installed. This happens with both cfl and incandescent bulbs. Any ideas why this is happening?
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26 views

RGB LED BCP wire [on hold]

Ok so I know how rgb light strips like this one work but I am not sure how the ones like this work because there so close together. What bcp would i need? How would i even start making this?
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0answers
54 views

Light powered by rocking kinetic device

I want to know if i can power a lower power light by simply rocking it. The light only needs to be on while its moving so should only require a small amount of power. I have included a picture that ...
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4answers
234 views

Which type of LEDs is a good source of light and can replace the sun

There is often no sun were I live so I need some advice for building a LED matrix that can replace the sun light and possibly avoid bad wavelength. UV produces vitamin D but upon reading ...
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3answers
269 views

LED bulb still emits light when turned off

I have recently purchased an IKEA LED bulb with G9 fittings, to replace a halogen one. This one. The bulb is installed in a lamp with 3 other halogen G9s in a 3 + 1 configuration with a 3-state ...
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4answers
152 views

Flashing leds from bicycle tail light [closed]

I'm not sure if this is the right place but I'm a bit puzzled by this (cheap chinese) bicycle tile light. I opened it up, but I don't seem to get it working again. It has three components: the ...
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0answers
50 views

What AWG wire should I use to connect RGB Signal Amps to LED Strip?

I am wiring in some 5050 RGB LED strip lights in my basement. There is a small utility room adjoining and I'm keen to keep the transformers and signal amplifiers in there in order that they can be ...
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24 views

plane electromagnetic waves

In free space with no charge, both the curl and divergence of electric field is zero. Plane electromagnetic field exists in such region. Besides plane electromagnetic fields, does any other solution ...
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1answer
55 views

How do I tell if a lightbulb is LED?

I have this bulb, that I didn't buy myself, and I don't have the packaging, nor do I know the price or anything. The writing says: ...
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3answers
172 views

Bike light blink speed adjustment

I am trying to construct a circuit to control an LED in a bike light kind of circuit. This circuit must be designed so that a button press can change the current setting of the light. So for instance ...
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1answer
72 views

Sequential Taillight Modification

I am interested in almost duplicating the functionality of the new Mustangs. When the rear tail lights are activated (there are 3 in a row on each side), I'd like the first one, then the second one, ...
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1answer
55 views

How light strike works?

I am new here and I don't know if I have chosen right stackexchange but anyway. I am making a little toy, just for educational purpose. I would like to understand how light strike works. It is a gun ...
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1answer
2k views

Do “blown” fluorescent lights still use electricity?

When a fluorescent light fixture goes out, it often flickers and then after a while stops shining altogether. When this happens and when it finally dies is the circuit broken and does it still use ...
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0answers
66 views

Light whose brightness varies with position

As a disclaimer, this is a complete beginner question as I know absolutely nothing about this field. I'd like to have an LED whose brightness is a function of its position in a room. For example, if ...
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0answers
77 views

Simple Circuit To Light Up OLED

I'm a ICT student and need to make a circuit to light up an OLED. we have developed an OLED but have some trouble with the power supply. We need to have an arduino so we can send an PWM-signal to the ...
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5answers
5k views

Can I turn Radio waves into light?

Wikipedia says that the frequency of light is 300 THz. I've made a radio waves transmitter that transmits about 100 MHz. If I increase the frequency of the transmitter to 300 THz, will the antenna ...
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0answers
37 views

Light sensitive resistor

I have a CdSe light sensitive resistor which goes from 0.1k to 30k light->dark . It works fine outside the circuit. When I pass +/- 1V 400Hz AC across it, it seems to always have a low resistance. Is ...
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3answers
67 views

Magnetic reed switch current ratings

I wish to use some 12 V, 5 W xenon light bulbs under separate shelves of a cabinet. I'd like them to power-on using a magnetic reed switch attached to the cabinet door. The magnetic reed switch I ...
2
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3answers
244 views

How do Wi-Fi controlled light switches feed themselves?

There are smart light switches in the market that are Wi-Fi controlled like Plumlife (formerly ube) and Belkin WeMo. I wonder how they control the electricity that they operate on. When I unplug my ...
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1answer
128 views

Adding a switch to an existing light

I've read about 3-way and 4-way switches but I don't understand something. I am aiming to create a bluetooth controlled home network. One of the modules would include a light switch. How would I go ...
2
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2answers
135 views

Run 12v Incandescent Bulbs off Fluorescent Ballast

Can I use a 120v AC to 12v AC electronic transformer to power 12v bulbs? I have a 150 watt transformer that I tried connecting to a single 10w incandescent bulb, but the bulb just flickers at a low ...
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3answers
81 views

Lumens vs Watts

What of this words define the intensity of the light of a bulb? Lumens or watts? I don't know if I am right. Lumens means intensity of the light and watts the consumption of the bulb
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1answer
51 views

how to turn backlight on for BC1202A LCD

Hopefully this question isn't too novicelike: I have an LCD (BC1202A) that I want to drive from a parallax propeller board. Spec data:link1 and link2 After hours of mucking around (mis-wiring, ...
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2answers
378 views

Two relays for DRL on a car

I am trying to make a circuit for my newly installed DRL (Day running lights), what I am trying to do is have the DRL run all the time, turn off when using high beam, dimmed when headlights are on. I ...
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4answers
312 views

Which circuit to use to automatically turn off the backlight of a GLCD after 30s?

Have you ever seen smart phones automatically turn their screens off after a short time to save the power? I want to do it on the back light of my GLCD (ks108sed). Descriptions: Back light will ...
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4answers
253 views

Cool White LED bulbs: Are they “full-spectrum”?

I don't have much knowledge on LED lights and find the technology quite fascinating (yes, I know, it is not that knew!) I have read that in order to create "white" light, LEDs actually need to emit ...
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0answers
63 views

WeMo Wireless Light Switch US convert to be used in UK?

I am in love with this thing and just cannot believe that it runs 120V 15A. Step down transformer would be too big since this thing should fit into the wall. http://www.belkin.com/us/p/P-F7C030/ ...
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1answer
69 views

How to make a dimmer for a 11W CFL?

I have a desk lamp, that uses 11W/827 CFLs (current one is an Osram Dulux S) The lamp uses a power supply ("Type BL1"), but it seems the transformer acts more like an AC/AC power converter, as it ...
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1answer
71 views

Using 6x58W fluorescent lamps instead of 6x55W, what could possibly go wrong? [closed]

I'm planning to buy a fluorescent photography lighting head, but the manufacturer specified it uses 6x55W lamps, but I want to use Philips Graphica 58W lamps. 3 watts more per lamp, doesn't look like ...
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5answers
185 views

How to generate Red light from a Blue-Dominated Spectrum

I have a white LED light source, the spectrum of which looks as follows --- want to filter out red light from this white LED source. But as you can see the spectrum dwindles in the red zone. And ...
2
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1answer
51 views

Taking power from two different feeds

Probably a silly question I know but I'm not all that good when it comes to wiring but at the same time don't want to blow myself, or my car up! I have a set of sidelights/ daytime lights that take a ...
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2answers
73 views

Do parabolic reflectors in globes increase the brightness of the filament's light, or just 'spread' the light?

If you compare a traditional 60W incandescent globe with the same filament specification as one with with a parabolic reflector built into the globe, does the (usually) aluminium reflector actually ...
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1answer
78 views

Digital light organ

I am trying to make a circuit that takes an audio signal from an MP3 player and converts the signal into digital signals based on frequency. Audio In is the is the signal from the audio jack of an ...
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2answers
115 views

Is it possible to run 230V LED - or flourecent “spiral-tube” - lightbulb with a 9V battery?

I would like to power a 230V LED lightbulb with a 9V battery. I assume I'll have to dissect it... Surely there must be some sort of power-converter and rectifier from 230V-AC to something a lot ...
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1answer
757 views

How to build a blinking 12V indicator LED light

I attempt to build a blinking circuit using 12V truck light ( like this one: http://www.princessauto.com/pal/en/Tail-Lights/4-in-LED-Stop-Turn-Tail-Light/8126047.p). I have try to build a single LED ...
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3answers
517 views

What makes an incandescent light bulb run out?

What is or are, the most likely and common ways - the weak links in the chain (including I assume poor electricity wiring / configured housing) - that cause a traditional incandescent light bulb to ...
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1answer
172 views

MCU Electronic Power Switch

How would I wire a light-emitting device (not necessarily an LED) in the following schematic to indicate the input (High to run) is high? Would it be in parallel with R4? Before or after R3? ...
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1answer
99 views

Connect two-function brake light to three-function car circuit

I need to replace my 12VDC (bulb based) brake lights but I am unable to find a three-function light (Running/Brake/Off) with the same specs. I did however find a two-function light LED fixture ...
3
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1answer
333 views

Most efficient way to power both 12V and 5V off a battery

I'm building a lighting project for Burning Man and I have both 12V inputs and 5V inputs that need to be powered off of batteries. Here are the max loads: ATmega328p - 25mA at 5V Addressable LEDs - ...
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1answer
188 views

How hot does a florescent light filament get?

I understand that a florescent light bulb radiates light as a result of exciting mercury in the bulb with electrons and those electrons are emitted by a filament. What is the highest temperature that ...
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1answer
95 views

Rigging an MRI machine with club speakers and lights

I'm using a magnetic resonance imaging (MRI) machine to fMRI trial subjects while they experience club-like conditions. This means I need loud, high-fidelity speakers, flashing multicolored lights ...
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2answers
318 views

Why don't solar cells produce visible light when supplied with electricity?

... A cursory Google search didn't reveal an answer... Is the energy conversion a one-way process?
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1answer
63 views

CFLs and Incandescent Lightbulbs in household light fixture

I have a few light fixtures around the house where there are multiple sockets per fixture - 4 sockets/fixture in the kitchen, dining room, bathroom ceiling light fixtures. I began the process of ...
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1answer
130 views

SMD LED Perimeter Lighting with PWM for Dimming on each colour

simulate this circuit – Schematic created using CircuitLab So from the start what Im trying to achieve is drive way lighting in which each colour is separately dimmable with a pulse width ...
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1answer
67 views

LED light muliplexing

Is it possible to multiplex multiple power LED strings from a single driver unit to reduce heat generated? For example I have two 20 Watt (100V @ 200mA) LED lamps. If I include an electronic switch ...
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2answers
128 views

Transmitting data over light with USB

I'm working on a project that uses light as a medium for data transmission. I would like to achieve about 2-3 MB/s. It suppose to virtually behave like any LAN cable. I would want to know if it is ...
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1answer
51 views

Avalanche Photodiode Current Gain

I'm designing a readout circuit for an APD manifactured by Hamamatsu Photonics (datasheet). However, I've found myself lacking some information about exactly how would the device behave in my ...
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1answer
1k views

Is an 120V LED light bulb compatible with a 220V mains? [closed]

Would an excellent LED light bulb like the Cree 60 Watt Replacement TW Series (designed for the US market) work in European countries? On the packaging it says "Use only on 120 volt AC circuits." and ...
4
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2answers
237 views

Are photoresistors reliable for light sensing applications?

I've used photoresistors for hobby projects before, such as this one: http://www.foxytronics.com/learn/electronics/kit-guides/starter-electronics-kit-guide/making-an-led-light-sensor However, now ...