Questions tagged [light]
Light is a tag about anything generates photons in the visible spectrum
418
questions
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1answer
46 views
Am I thinking about this correctly regarding 12V, 24V and 120V LED lighting?
Most of the LED light strips I see are either 12V or 24V, which require a driver to step down the power from 120v at the wall (thus the little black transformers that come with them).
However... I ...
0
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2answers
63 views
Connecting a light to a battery
my son and I are working through this book called The Thomas Edison Book of Easy and Incredible Experiments.
We are stuck on the first experiment where you make a switch to connect a battery to a ...
0
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1answer
28 views
Dim a 110 Light using 5v PWM with no ZC
I was wondering if anyone has any ideas of a way I could Dim a 110v Halogen light with the use of 5V PWM, or with 0-24v control.
My controller, has the basic (designed) 0-24v control. It also has ...
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2answers
82 views
Is this neon light display real or fake? how does it work? [closed]
Is this neon light display real or fake? if real, then how does it work?
https://www.youtube.com/watch?v=xlcywgEMuGI
3
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1answer
69 views
Can I modify this LED Light Circuit board to not strobe and just stay lit? [closed]
I'm looking for anyone who might know if I can modify this small LED light circuit board to not strobe?
I want to use it for my van as indicator lights, I've only managed to find these that will fit ...
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1answer
43 views
Understanding CFLs in Electrical Circuits
I wish to have a better understanding of how CFLs work in a electrical circuit like a home.
A CFL broke a little towards the top when I touched it.
I noticed it light up at the bottom and then made ...
0
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1answer
69 views
What is this IC “30=70H”?
I'm hoping to identify the IC on this Philips Hue lightstrip controller in order to replace it.
The IC blew after a barrel connector head used had it's polarity reversed, so 24V went in the wrong way ...
0
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1answer
40 views
Issues encountered when adding DC adapter to light powered by battery
I have an LED light bar powered by 6 AA batteries connected in series. There is also an RF control unit to turn the light on/off. The light eats through the batteries rather quickly thus I decided to ...
0
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1answer
41 views
Fairy lights dimming over time
I have had this cheap set of fairy lights for a few years. Powered by 3xAA batteries.
Recently when they are turned on they start bright as they always were then proceed to get dimmer and dimmer ...
1
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1answer
29 views
How to use a power meter to measure irradiance?
I have got a Zes Zimmer LMG95 power meter and an RS-ID-5 Fraunhofer ISE WPVS reference cell.
The LMG95 has got simultaneous voltage and current measurement and can do custom calculations. The WPVS ...
1
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2answers
92 views
Logic Implementation
I need to implement a circuit but Im having some trouble since Im novice on electronics.
I have 4 inputs. A being ON/OFF switch. B is an Inibitor. C is an Emergency and D is not an adequate ocasion.
...
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1answer
70 views
Electrical induction at a distance through coils for an LED night light
I have 3 decorative candle based night lights, and as an enthusiast project I decided to use LEDs instead of candles to modernize them and make them cooler.
I don't want to use batteries, and I want ...
0
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1answer
66 views
Best sensor to measure light intensity in open room
I am working on a project to understand how robot localization is effected by light levels. I am wanting to build a circuit which can be mounted on a small robot near the camera and can determine lux ...
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1answer
39 views
Do I need a wire connected to the negative terminal for led light bars and if so can I use the negative terminal as ground for the relay
I'm not sure if this will work can someone help me out
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0answers
358 views
Motorcycle hazard light circuit design
My motorcycle has turn signals (2 on each side, front and back) with a switch to signal a left/right turn. I would like to add a hazard light switch to blink all four signals. I am here to ask whether ...
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6answers
6k views
Lumens specs when buying a flashlight/torch. Why maglite has only 680lm but cheap ones have 900,000? [closed]
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 ...
0
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2answers
148 views
NVG compatibility LED Lights
For an avionics application I need to make a keypanel which has NVG compatible LED lights behind its keys. I am trying to understand how does the NVG compatibility (Night vision Goggles) relates to ...
0
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1answer
49 views
Standard time for LED light testing [closed]
What is the exact timing for testing(continuity, electrical parameter, optical parameter, thermal parameter) of LED lamp after manufacturing?
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1answer
392 views
Bypassing a multi function Christmas light string controller
I'm getting annoyed with my light string, it turns on to a random effect out of 8 and all I want is an always on.
I managed to find this great website showcasing different controllers and how to ...
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0answers
89 views
Ordinary LED response to nanosecond pulses
Can anybody explain to me the output waveform generated on pins of an ordinary LED when it is exposed to very short light pulses?
I can clearly see that there is a precise difference in the length of ...
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2answers
91 views
Is there a way to measure or infer the color of a material from a distance (~2m), without using visible light?
I've recently started working on a graphics/SLAM project. We've encountered a problem that requires us to measure or infer the color / spectral reflectance (and ideally albedo) of points on objects in ...
0
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1answer
27 views
Create circuit with triggered light and simultaneous output to computer [closed]
I'm doing an experiment and will be collecting voltage data (from strain gauges) which will be inputted to a computer through a conditioning system.
I would also like to collect video footage of the ...
0
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0answers
25 views
LCD for SLA 3D Printer Resin Curing
I'm doing some research on what types of LCD displays can be used to filter and pass UV light for resin curing - specifically in the context of building a DIY 3D SLA printer.
The community commonly ...
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5answers
4k views
Omnidirectional LED, is it possible? [closed]
I have a project in mind that involves lights from a small LED (SMD would be nice) and i've come across this big problem but apparently there's no solution for it on Internet. I need that LED to be ...
0
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3answers
138 views
How to monitor switch state?
Background
I am building a simple web application using raspberry as a server. I am using this raspberry also to control an arduino. A user can send commands through the browser to the raspberry, and ...
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1answer
61 views
Circuit topology name and function for PNP transistor in light barrier circuit
I have seen this rather simple circuit for end position detection of a DC motor drive mechanism. An infrared LED (V402) and a phototransistor (V401) are used as a light barrier.
Can someone give me a ...
1
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1answer
86 views
Help with wiring OEM LED turn signals that has 2 voltage inputs
The term AFS is used in the 2nd diagram to help differentiate between the
bulb type turn signals vs the led type.
I'm trying to swap my headlights(without-AFS) to a higher trim version(AFS) on my ...
0
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1answer
81 views
Building Led light which work on 230V supply
I have a couple of 9W LED bulbs(1) at home with blown drivers. I got some replacement boards(3) with driver circuit and LEDs on the board itself. Now that the old LEDs(2) along with the aluminum PCBs ...
0
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1answer
86 views
LPC1768 - Green LED when LDR sees light, Red LED when LDR is covered
I have been trying to achieve a task I am working on and I believe I am almost there. It successfully changes colors whenever I cover it but when it does, the red LED keeps blinking instead of it ...
0
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0answers
219 views
Irradiance sensor circuit
Im trying to measure the irradiance from the sun using the following TIA circuit:
I'm using a BPW34 photodiode due to the good spectral range and for being cheap.
Also the datasheet provides a ...
10
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2answers
199 views
Which part of some LED TV screens acts as two gratings crossed at non-straight angle?
Some modern LED TVs display the following diffraction pattern (photos taken from this question):
In my answer to another question about the origin of this pattern I explained that this should be due ...
0
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1answer
99 views
How to filter out certain wavelengths of light [closed]
I am trying to filter out certain wavelengths of light and I was wondering if there is a way that you can filter them out. I am using Silicon Photomultipliers (Linked below) and I only want to detect ...
0
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0answers
74 views
Photodiode to detect light
For a university purpose I am preparing a project, actually I am thinking of using a photodiode in reverse bias in order to measure intensity of light.
I divided this project in some phases:
1) ...
2
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2answers
96 views
Light sensors sensitive enough to detect for PWM from CF and LEDs?
I have an extreme sensitivity to PWM light sources such as computer screens and light bulbs. This can make it very challenging to make a purchase as I end up having to do lots of guesswork with ...
2
votes
1answer
55 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 ...
0
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0answers
40 views
Light illumination method for video camera and CV detection
My control application implements human face detection and recognition with using of CV library. My device uses usual VGA USB video camera.
Problem:
Good and uniform light illumination allows ...
0
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1answer
35 views
Directly Using a Smart Charger with An Old Vector Hunting Spotlight? [closed]
I have an old hunting spotlight (http://documents.dewalt.com/documents/English/Instruction%20Manual/Vector/VEC184POB.pdf) which has a small 12V sealed lead-acid battery.
The chargers that come with ...
0
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0answers
89 views
LED Light changes color on being turned on/off simultaneously
What type of circuitry/driver is present in the lights that change color on being turned on/off ?
I have a LED tube light which cycles through 3 modes (i.e. color 1, color 2, both color). Its circuit ...
1
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1answer
56 views
Is Power Factor only relevant at rated load in Light Equipment?
As you might know, LED lamps over 25W require a minimum 0.9 power factor in Europe.
I have designed a PSU for a specific LED lamp which is rated about 50W. There is a PFC-stage (crm) in order to ...
0
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3answers
90 views
dc voltage control for LED lights?
I'm looking for a little bit of help on a project I'm working on.
I need to find some way to make led light bars (18w and 120w) to automatically start out dim and gradually brighten to full ...
14
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6answers
4k views
Can antennas be viewed as light sources?
Clearly antennas are nothing but a device to radiate the electrical energy through electromagnetic waves.
Since visible light is also simply a certain range of frequencies, isn't it more easier to ...
0
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0answers
93 views
Bare LED light flickering on constant voltage pover supply
I have this LED light which started blinking under some use. So, I desoldered the SMD LED component and hooked it up to a variable power supply. When I apply 6V, the LED starts to emit a little bit of ...
0
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1answer
75 views
Light bulb LED equivalent of a CFL (Compact Fluorescent Lamp)
If I have a CFL light bulb of 100W what would be (how many watts ) its equivalent in LED.
In the place where I live LEDs have taken over and CFLs are no longer available, but I need stron bright ...
0
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1answer
70 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 ...
1
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1answer
65 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 ...
0
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2answers
79 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 ...
0
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3answers
63 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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2answers
1k 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
522 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
160 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 ...
