Lately I am playing with LEDs, trying to build a pair of optical transceivers. The TX side will use some very bright 5 mm red LEDs made by OptoSupply. I chose those with 8° and 15° beamwidth. They are OS5RKA5102P and OS5RKA5111P respectively and they should emit 100'000 mcd each, which is quite impressive, also on your retina if you look straight into them.
For the records, one TX will have 8° LEDs, the second will use 15°.
Besides their weird leg shape that requires a custom footprint (I've done it for KiCad) the problem with these LEDs is that they look very similar and you can easily mix them. So, here is a closeup that helps distinguish which is which.
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| Left is the 8° OS5RKA5102P, right is the 15° OS5RKA5111P. |
Left is the 8° OS5RKA5102P, right is the 15° OS5RKA5111P. Physically the 8° has a narrower body, larger anode area and smaller tab on the anode leg.
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| LEDs and the bags they came in, to confirm part No.! |
While testing the 4x4 array I noticed that one LED was dimmer: a closer inspection confirmed that I had soldered a 15° LED amongst 8°. If they worked with the same current that wouldn't be a bit problem, but it is not the case with these two models.
