- Calculating of the heat dissipation of a LED - Physics Forums
Welcome to PF At best, you can expect about 20% quantum efficiency from an LED The heat will therefore be greater than 80% of total power input You must run the LED cool for high efficiency, and for long life That suggests you should design for 100% heat generation Vf = 2 85 V If = 700 mA Maximum heat generation is 2 85 * 0 7 = 2 0 watt At best, that might be a 20% overestimate
- How many LEDs are in a typical LED monitor? - Physics Forums
A single pixel only puts out one color (red,gree or blue) groups of three or four pixels are used to give all the colors by varying amounts of these primary colors ps There are purely LED display screens used for large outdoors screen such as in stadiums - these do use groups of LEDs in each pixel to give either a red, green or blue light
- Why is the Anode of an LED Connected to Positive?
For an LED to work and emit light, one wants the current to come out of cathode, which is the pointy end in the figure View attachment 220324 To be more confusing, For a regular diode, the pointy end is labeled the positive terminal in a general circuit diagram, but if biased in such a manner, no current flows through the diode device
- Controling the wavelength of an LED through voltage?
An LED will drop a relative constant voltage (although not perfectly constant) regardless of the current through it Of course there is a usable range before damage occurs
- What is this electrical component CR - Physics Forums
What is this electrical component "CR"? Hey folks, Can anyone give me a hint to what the CR symbol in this wiring diagram might mean? I'm thinking it is some kind of switch The equipment is a solar cell tester Basically it traces I-V curves In the attached picture the pins
- Focusing UV light from a 275nm LED down to a small spot
Hello, I'm trying to focus a 275nm (with proper safety precautions) LED that looks to be a few mm in length and width (the light-emitting portion) to a smaller dot size The LED should probably be fairly close to the surface of the lens to collect more of the light The dot size would hopefully
- Diffraction grating with monochromatic light vs. white light?
(A) What kind of pattern of would you get if you shone monochromatic light on a diffraction grating? What pattern of light would you get if you shone white light on a diffraction grating? My answer: With monochromatic light, you would get a pattern of alternating light and dark bands With
- Window Detector Circuit Design: LED Activation for Voltage Thresholds
So as you can see I'm trying to make a window detector circuit that makes an LED turn on if the voltage is below or above a certain threshold In this case, I want the LED to turn on above 2V or below 1V
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