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Questions tagged [color]

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Is brightness for WS2812B LED voltage dependent?

I understand that this would be true for any other regular LED. The doc states that it accepts +3.5~+5.3 V. I was wondering if it is somehow internally converted to operate at the same level as long ...
somerandomusername's user avatar
0 votes
0 answers
50 views

Dealing with IEC and NEC wiring color code in the same equipment

I am dealing with IEC and NEC standards for wiring color codes. For the first time, I have to integrate european (and UL certified) COTS products - power supplies - into a system for the US market. ...
vionyst's user avatar
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-2 votes
1 answer
77 views

Why can't I divide the total number of bytes of a .BMP file by the color depth? [closed]

I have a .BMP file resize.bmp. The total number of bytes that encode pixels in this file is 320 bytes. The color depth in this file is 3 bytes. 0x176 total number of bytes including Header 0x140 ...
stm's user avatar
  • 89
0 votes
1 answer
72 views

What are LCD subpixels made of?

Just curious. I don't really need to know this level of granular detail for my job (AV technician) but in courses/articles about color LCD displays they explain everything... except what the red, ...
itsagift's user avatar
5 votes
1 answer
145 views

Why are Lunar White LEDs not a standard part, or what am I missing?

TL;DR: Lunar White is a widely-used standard color in signaling work (like, every pedestrian signal that conforms to ITE specifications uses it, as far as I can tell), so why can't you buy Lunar White ...
ThreePhaseEel's user avatar
3 votes
1 answer
89 views

LTspice Color Palette

In order to make my graphs printer friendly, I have made a color palette in LTspice that looks something like this: How do I make this permanent? It keeps restoring to its default settings... How do ...
courageouslywin's user avatar
8 votes
1 answer
801 views

What does a gold band in the third position on a resistor with 5th band being white mean?

Any idea how I am supposed to interpret this component? I would not have expected a gold in third position for a resistor with 5 colors. Edit: this other thread gives explanation as to how to ...
SkiNoU's user avatar
  • 83
1 vote
1 answer
281 views

Odd discoloration on wall outlet [closed]

Just noticed a very odd brown looking discoloration (see image) on the top plug of a wall outlet. The items outlet has been in use without issue for awhile. Should I be concerned about the ...
JohnBuilder's user avatar
0 votes
1 answer
99 views

LED : Multiplexing : Color-mixing (RGB)

With a single RGB (red-green-blue) LED, if: Enabling the colors non-simultaneously (via multiplexing or a similar form of PWM), At a frequency which is sufficiently-high to make flicker indiscernible,...
kando's user avatar
  • 437
1 vote
0 answers
287 views

Photodiode circuit to compensate for LED temperature drift

I'm trying to create a stable light source using 5000K white LEDs. In researching this I've discovered that LEDs drift with temperature by a non-negligible amount. Further research leads me to believe ...
JesseBuesking's user avatar
0 votes
3 answers
180 views

Creating an even, color mixed field from an array of RGB LEDs

I'm working on a lighting application which requires a very even, well mixed field of light. I'm using an array of RGB LEDs to generate the light, and then using a piece of opaque plastic to diffuse ...
flimsy's user avatar
  • 362
1 vote
2 answers
335 views

How to produce a perfect color wheel using an RGB LED?

I am trying to produce a perfect color wheel using a bunch of WS2812 RGB LEDs. My current attempt is to convert HSL (H = angle in color wheel, S = 100%, L = 50%) to RGB and send the RGB to the LEDs. ...
Daniel's user avatar
  • 111
2 votes
3 answers
155 views

How to estimate LED color before buying?

Manufacturers of LEDs mention color as a wavelength in nanometers. Is there any method or tool for estimating differences between colors? For example, how to check if a LED is dark or light green? In ...
Misaz's user avatar
  • 385
1 vote
4 answers
2k views

What do bi/tri color LEDs look like when switched at high speed?

So, if I have (say) a red/green bicolor LED and switch between the two colors faster than the eye can see (eg 250 Hz), what colors are perceived? Can I use a RGB tricolor LED to mix any color output?
Dirk Bruere's user avatar
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1 vote
1 answer
88 views

What is this standard for phone wire colors, found in Lithuania?

I have found disused phone wiring in the walls of a house in Lithuania. The cable was probably installed around 2014 and has the following wire colors: white yellow orange green gray red White/...
user149408's user avatar
0 votes
0 answers
369 views

RGB LED Color Calibration to D65

I am trying to determine resistor values to set the forward current per color of an RGB LED. I would like to achieve approximate D65 (daylight white) when all LED channels are driven at maximum ...
usman510's user avatar
0 votes
2 answers
201 views

Why does pixel binning remove colors and provide monochrome image only with CMOS color cameras?

Some industrial cameras (astrophotography or microscopy) offer a hardware digital "binning" feature. Indeed, sending uncompressed 10 megapixels x 3 RGB bytes per pixel x 30 frames per second ...
Basj's user avatar
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0 votes
1 answer
679 views

Convert RGB to the composite video / S-video (math)

I used to do it in circuits with CXA1645 or AD725. But this question is not about soldering, it is about math and digital processing. Imagine I am designing the entry-level graphics processor using ...
Anonymous's user avatar
  • 7,120
2 votes
3 answers
923 views

How do bicolor LEDs switch colors?

I recently purchased a decorative light with two different bicolor LEDs connected in alternating series fashion. It has red/green and red/blue LEDs connected in alternating series On the driver side ...
VIREN RAMCHANDANI's user avatar
8 votes
7 answers
5k views

RGB spectrum of an RGB LED [closed]

What colors is an RGB LED actually able to emit? Obviously, it's not able to represent the whole spectrum of RGB (it will not be black, or brown). I'm referring to a LED like this: I found the ...
mnj's user avatar
  • 207
2 votes
4 answers
576 views

Is the luminous efficiency of a 5000 K incandescent greater than that of a 3000 K bulb?

The color temperature represents the color of light emitting from an ideal black body, when heated to said temperature in kelvin, and how an incandescent bulb emits light is close to a black body. ...
AlienBoy's user avatar
9 votes
3 answers
4k views

My DIY RGB LED panel powered by 9V battery works but certain colors like blue, white, and purple don't work

I am able to power on my LED unit here with a 9V battery. I'm using a recharble lithium 9V as well. I can't figure out why I can't get blue, purple, and white. The only colors I get are red, orange, ...
Destructo's user avatar
  • 107
0 votes
1 answer
535 views

Wire color standards for a reversible DC motor [closed]

I'm working on a project with a DC motor that runs in both directions. If the motor ran only in one direction, I'd use red/black for positive and ground, but as they reverse, there isn't a consistent ...
BillThePlatypus's user avatar
1 vote
0 answers
67 views

Color Sensor Range

From what I've seen in spec sheets for modern color sensors (as of late 2020), the optimum sensing range is generally on the scale of centimeters. I am curious about the physics that can explain this ...
John's user avatar
  • 11
2 votes
1 answer
1k views

Why does color of addressable RGB LED strip change when dimming?

TL;DR I have an addressable LED strip with TM1814 IC's. (So it's actually a RGBW strip. Download datasheet here.) When set to orange at full brightness, it's orange. But when set to orange at 10%, it ...
empewoow's user avatar
2 votes
1 answer
1k views

Analog video chrominance decoding - PAL/NTSC

I'm implementing an analog video decoder on FPGA. I find some difficulties during chrominance decoding. I appreciate if you can help me. These are the steps as I'm doing: I generate an NTSC ColorBar ...
tgharbi's user avatar
  • 21
0 votes
0 answers
61 views

Headphone Jack wire coding is different

I recently opened my headphone jack because one side of headphones wasn't working There are 6 wires basically Dark green, dark blue, yellow, red and two copper wires Please help which wire should I ...
Mikul Rai's user avatar
0 votes
0 answers
60 views

Consistency Concerns Between Series RGB LEDs in a String

My concern/question: If one has a string of series RGB LEDs (w/ independent elements) and was to light green to 100% and red to approximately 75% -- in an effort to illuminate the Amber color -- how ...
cguenther0929's user avatar
2 votes
1 answer
640 views

Calculate RGB color ratio for a color space given a white point?

I am new to the field of displays and color science. I am trying to calculate RGB color ratio for NTSC color space using D65 white point. Can anyone point me to a good reference on it or how I can do ...
QContinuum's user avatar
1 vote
1 answer
426 views

HP C8941 Photosensor wire colors

I removed a photosensor from an OLD hp Inkject Printer. The photosensor is called "C8941-80018". I can't find any datasheet online. Does anyone know what wire color is what?
Smoking Diesel GR's user avatar
11 votes
2 answers
1k views

Image position and size controls vs beam alignment in a color CRT

If you look at a the shadow mask of a color CRT, you can have a pattern like this: Most TVs were purely analog and had knobs to move the picture horizontally and vertically. How does the green gun ...
Thomas's user avatar
  • 1,069