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# How to calculate distance of LED light

Posts: 4
Hello
How to calculate LED light distance what is the procedure
in oval led

## Comments

• 7 Comments sorted by Date Added Votes
• Posts: 722
d=C/t where C is the speed of light.
Turn on led, start timer, sense led light, stop timer, calculate.
What do you mean by "...in oval led"?
Florida, between St. Petersburg and the Gulf of Mexico

Do not look directly into laser with remaining good eye...
• Posts: 570
IMHO, I almost can bet YRTYRT is simply trying to calculate, from a geometric standpoint, the distance an oval led is projecting its light, by measuring the two diameters of the ligh glow (oval-shaped, not elliptic) and knowing the involved viewing angles.

In the absence of an exact representation of led die placement inside its package, some assumptions should be made (e.g.; led die longitudinally centered inside package body).

Easy peasy trigonometry, home work!
• Posts: 4
In the absence of an exact representation of led die placement inside its package, some assumptions should be made (e.g.; led die longitudinally centered inside package body).

Easy peasy trigonometry, home work!

Hello
What is Die of led mean what is it geometry and trigonometry
• Posts: 570
YRTYRT wrote: »
What is Die of led mean what is it geometry and trigonometry

Hi YRTYRT, welcome to the forums.

To simplify things, I believe we should start from a commom knowledge base, so the terms we're about to use, during information exchange, doesn't appear strange to anyone.

Whenever possible, I'll resort to linking some web content. The intention here is to point some topics for you to study, without bloating the thread and also to avoid any concerns about infringement of copyrighted material.

As for your questions, in the order you've posted them:

Led die (scuse me by using some jargon) or led chip is the tiny piece of silicon where a LED (Light Emmiting Diode) is constructed.

eagerlearning.org/electronics/introduction/light-emitting-diodes/

https://commons.wikimedia.org/wiki/File:LED_Device.jpg

The led chip is mounted onto a metallic fixture, formed at one of the tips of its terminals, and then encapsulated with crystal-clear or colored, light transmissive epoxy.

The shape of the transversal section of the mold will define it as being a circle, oval, square, rectangle, whichever...

The lenses that focuses the light beam emmited by the led chip are also formed during the encapsulation stage.

There are also leds with flat-shaped epoxy surfaces, but I believe, in your case, you are meant to use dome-shaped ones.

As an example/shape of an oval led: (Click at the [PDF] link, almost at the center of the page, to download/open it)

https://broadcom.com/products/leds-and-displays/high-brightness/oval-through-hole-lamps/hlmp-lm3v-24pdd

Then, the next link will refer to ovals and their geometry.

https://quatr.us/math/area-oval-geometry.htm

The two diameters I was refering in my earlier post, are the height and widht of the light glow an oval led is intended to project, for example, when pointed to a sheet of white paper or carton, or even to a white painted wall.

Normally, when taking measurements of a color-biased light glow, I use to point the beam to a white obstacle, in order to better see the contour it defines.

As for geometry and trigonometry, Wikipedia (google the terms) has good references about them.

Hope the above could guide your study.
• Posts: 3,944
edited September 17
Not on topic, but very fun...

Whit+

"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
• Posts: 1,992
Our great Rear Admiral Grace Hopper,

she did not really invented COBOL but she made it happen. What a smart and strong women she was...

Enjoy

Mike
I am just another Code Monkey.
A determined coder can write COBOL programs in any language. -- Author unknown.
Press any key to continue, any other key to quit

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this post are to be interpreted as described in RFC 2119.
• Posts: 4
Hello
Can any one send me oval led here in india
i want to know it how it work
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