Instructables

Can you recommend an LED to me?

I'm looking for a white LED that is 5mm or smaller.  My problem is that there is such a great selection of LED's on the internet, I can't determine which of the many options are best!  Here's my criteria:

*5mm or smaller (cannot have a heatsink)
*white (preferably without a bluish tint; a pure white)
*wide viewing angle
*bright (high mcd)
† this is the order of priority for the criteria as well

I understand that there's a trade off between viewing angle and mcd; ideally I would like to find a happy medium.

Through the research I've done, I've heard names like Nichia GS, Cree 503D, and Jeled.  I'm not sure if these have a large enough viewing angle but regardless I wasn't able to find anywhere to buy these.  It would be great if you could include a link to a place to buy your suggested LED or at least insure that they are available for sale before posting a suggestion, after all it's not useful for me to know the name of a product I can't obtain.  As always, Thank you!

Picture of Can you recommend an LED to me?
I checked Digikey's catalog, and the closest thing I could find to your criteria was this:

http://www.digikey.com/product-detail/en/334-15%2FX1C5-1QSA/1080-1008-ND/2675499

That link should point to their part number "1080-1008-ND", which should be a white, round with domed top 5mm (T-1+3/4), through hole LED, with a clear lens, and a 50 degree viewing angle.

I've never really liked Digikey, mostly because their prices tend to be high, and their catalog is kind of confusing to use.  For example there's a check box for items "in stock", meaning that by default the search will include items they don't have.

I wish there was some way to save,and link too, one of those searches too.  I claim my search for your LED started here:
http://www.digikey.com/product-search/en/optoelectronics/leds-75ma-discrete/
and may have included these criteria:
Color:White
Mounting Type:Through Hole
Lens Style/Size: Round with Domed Top, 5mm T-1+3/4

Jameco also has a catalog that can be searched parametrically, sort of, and the closest match I found there was this:
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=2077061
I forgot to mention the surplusmongers, like:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G18709

And of course there's the Ebay, and the Hong Kong merchants.  They have good prices, but long shipping times to destinations in the Former U.S.
cdubnbird (author)  Jack A Lopez2 years ago
Is it possible for me to buy a high mcd LED with a small viewing angle and then file down the tip of the LED to hopefully increase the viewing angle?  Or does this simply lower the mcd proportionally? 

I found this: http://www.digikey.com/product-detail/en/VLHW4100/751-1502-ND/2403143 . I'm skeptical though, I was expecting to find that 5mm LED's would be able to handle more current -> higher mcd.

The LED on Digikey that you linked to is good but the one that I found has 5 degrees less of a viewing angle but 1775 more mcd.  My skepticism though is that the LED I link to in this comment is 3mm vs. the LED you found being 5mm.  I feel like the there should be a 5mm LED that will have higher specs. in both mcd and viewing angle than a 3mm on the basis that there is more room to incorporate components.

Thanks everyone for helping me out; I really appreciate it!
I think it is going to be tricky to file the round top off a LED, and have it remain optically clear.  I mean one might be able to achieve this by using successively finer grades of sandpaper, in effect polishing the plastic to make it clear again. 

However, the first cut, or sanding,  is going to be rough, and  I would expect that to just attenuate, or scatter, most of the light, an effect sort of like "frosted" glass.

In summary:  I dunno.  But it might be something fun to try though.
;-)
Kiteman2 years ago
Our resident LED expert is the member known as Phenoptix - you could ask him.
frollard2 years ago
Depends on what you're making...

What power supply do you have access to?
Do you want ridiculous bright? Using high power leds is often a better solution than many smaller leds as soon as you approach the >1 watt range. Most leds in that range are flat surface mounted and have a near 180 degree beam - you have to add a lens/reflector if you want it to tighten the beam. There are some higher power leds (>100-500mA) that don't require a heatsink explicitly, depending on how you mount them.

If you want a wide 5mm led - then search for 'straw hat' leds - they are the same 5mm as you have pictured, but they are significantly 'shorter' so the lense is closer to the diode element, giving a much wider beam.

You will find the colour of the white described as warm white (about 3k), cool white (anything over 6k) and pure white - usually in the middle. Warm is arguably quite 'yellow' and cool is arguably quite blue.

The less you pay, the less accurate the result will be compared to the specs promised on the sheets.

To reiterate, I love ebay sellers that ship directly from China. Most leds are manufactured in Asia, so buying 'local' isn't really buying local. The more you buy the cheaper they get, as with most things.

Lastly, power supply - leds are very efficient but they can be driven more or less efficiently depending on the circuit used, which again depends on your application.
+1, If you can stand the 2+ week lead time then from China through eBay is the only way to buy most electronic components (especially doodads for Arduino projects).