Red LEDs with reverse polarity! (and ?)

Using Arduino LEDs and Multiplexing
1

I scrounged some red LEDs from bike lights I've found (when the snow melts they are all over the place).

LEDs are cheap, but I'm cheaper and I like to "recycle" components.

But some of these LEDs are a bit annoying.
They look like normal clear plastic LEDs, but the leg connected to "the smaller piece of metal" inside it is not the positive, but the negative leg!
It has a flat side that correctly denotes the negative leg, but they have fooled me a couple of times anyway.

Do any of you know more about these? Is there a good reason or is it just a production error that has been sold to the bike light factory?

2

Boffin1 purchased a batch of "reverse polarity" LEDs a while back. Maybe yours are part of that same batch :wink:

3

I always check the proper polarity of LEDs just before I solder them in with a multimeter, I just don't trust my memory or all manufactures. :wink:

Lefty

4

Peter_I:
It has a flat side that correctly denotes the negative leg, but they have fooled me a couple of times anyway.

The flat side is what you're supposed to use to identify LEDs, not the metal inside.

5

retrolefty:
I always check the proper polarity of LEDs just before I solder them in with a multimeter, I just don't trust my memory or all manufactures. :wink:

Good job soldering LED's with a Multimeter :slight_smile:

// Per.

6

Zapro:

retrolefty:
I always check the proper polarity of LEDs just before I solder them in with a multimeter, I just don't trust my memory or all manufactures. :wink:

Good job soldering LED's with a Multimeter :slight_smile:

// Per.

Yea, I did butcher that one a little, didn't I? :wink: